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Does deletion of cohesin change gene expression? | The conditional deletion of cohesin from noncycling thymocytes preserved enhancer position, H3K27ac, H4K4me1, and enhancer transcription, but weakened interactions between enhancers. Interestingly, ~ 50% of deregulated genes reside in the vicinity of enhancer elements, suggesting that cohesin regulates gene expression through spatial clustering of enhancer elements. | |
Do MAIT cells have a role in multiple myeloma? | Yes, MAIT cells may represent new immunotherapeutic targets for treatment of Multiple Myeloma and other malignancies | Author information:
(1)Department of Microbiology and Immunology, Peter Doherty Institute for
Infection and Immunity, University of Melbourne, Parkville, Victoria, 3010,
Australia.
(2)Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne,
Victoria, 3000, Australia.
(3)ARC Centre of Excellence in Advanced Molecular Imaging, University of
Melbourne, Parkville, Victoria, 3010, Australia.
(4)Sir Peter MacCallum Department of Oncology, The University of Melbourne,
Parkville, 3010, Australia.
(5)The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria,
3050, Australia.
(6)Clinical Haematology and Bone Marrow Transplant Service, Royal Melbourne
Hospital, Parkville, Victoria, 3002, Australia.
(7)Department of Medicine, University of Melbourne, Parkville, Victoria, 3010,
Australia.
(8)Division of Chemistry & Structural Biology, Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
(9)ARC Centre of Excellence in Advanced Molecular Imaging, University of
Queensland, Queensland, 4072, Australia.
(10)Department of Microbiology and Immunology, Peter Doherty Institute for
Infection and Immunity, University of Melbourne, Parkville, Victoria, 3010,
Australia. [email protected].
(11)ARC Centre of Excellence in Advanced Molecular Imaging, University of
Melbourne, Parkville, Victoria, 3010, Australia. [email protected]. Multiple myeloma (MM) is a progressive monoclonal B cell maligcy, for which
survival and progression largely relies on the crosstalk of tumor cells with the
bone marrow (BM) microenvironment, inducing immune escape, angiogenesis, bone
destruction and drug resistance. Despite great therapeutic advances, most of the
MM patients still relapse and remain incurable. Over the past years,
immunotherapy has emerged as a new field in cancer therapy. Here, the immune
cells of the patients themselves are activated to target the tumor cells. In MM,
several effector cells of the immune system are present in the BM
microenvironment; unfortunately, they are mostly all functionally impaired. In
this review, we focus on the role of innate-like T cells in MM, particularly
CD1d- and MR1- restricted T cells such as respectively invariant natural killer
T (iNKT) cells and mucosal associated invariant T (MAIT) cells. These cells have
the capacity upon activation to rapidly release copious amounts of cytokines
affecting a wide range of innate and adaptive immune responses, and could
therefore play a key protective role in anti-tumor immunity. We describe recent
observations with regard to functional exhaustion of iNKT and MAIT cells in MM
pathology and discuss the potential application of checkpoint inhibition as an
attractive target for prolonged activation of these immunomodulatory T cells in
the treatment of MM. |
What is ProSavin? | ProSavin, a lentiviral vector based gene therapy aimed at restoring local and continuous dopamine production in patients with advanced Parkinson's disease. It has been shown to be well tolerated in a Phase I/II first-in-human study, with significant improvements in motor behavior from baseline at 1 year. Moderate improvements in motor behavior over baseline continued to be reported in the majority of patients who could still be evaluated up to 5 years of follow-up. | BACKGROUND: Parkinson's disease is typically treated with oral dopamine
replacement therapies; however, long-term treatment leads to motor complications
and, occasionally, impulse control disorders caused by intermittent stimulation
of dopamine receptors and off-target effects, respectively. We aimed to assess
the safety, tolerability, and efficacy of bilateral, intrastriatal delivery of
ProSavin, a lentiviral vector-based gene therapy aimed at restoring local and
continuous dopamine production in patients with advanced Parkinson's disease.
METHODS: We undertook a phase 1/2 open-label trial with 12-month follow-up at
two study sites (France and UK) to assess the safety and efficacy of ProSavin
after bilateral injection into the putamen of patients with Parkinson's disease.
All patients were then enrolled in a separate open-label follow-up study of
long-term safety. Three doses were assessed in separate cohorts: low dose
(1·9×10(7) transducing units [TU]); mid dose (4·0×10(7) TU); and high dose
(1×10(8) TU). Inclusion criteria were age 48-65 years, disease duration 5 years
or longer, motor fluctuations, and 50% or higher motor response to oral
dopaminergic therapy. The primary endpoints of the phase 1/2 study were the
number and severity of adverse events associated with ProSavin and motor
responses as assessed with Unified Parkinson's Disease Rating Scale (UPDRS) part
III (off medication) scores, at 6 months after vector administration. Both
trials are registered at ClinicalTrials.gov, NCT00627588 and NCT01856439.
FINDINGS: 15 patients received ProSavin and were followed up (three at low dose,
six mid dose, six high dose). During the first 12 months of follow-up, 54
drug-related adverse events were reported (51 mild, three moderate). Most common
were increased on-medication dyskinesias (20 events, 11 patients) and on-off
phenomena (12 events, nine patients). No serious adverse events related to the
study drug or surgical procedure were reported. A significant improvement in
mean UPDRS part III motor scores off medication was recorded in all patients at
6 months (mean score 38 [SD 9] vs 26 [8], n=15, p=0·0001) and 12 months (38 vs
27 [8]; n=15, p=0·0001) compared with baseline.
INTERPRETATION: ProSavin was safe and well tolerated in patients with advanced
Parkinson's disease. Improvement in motor behaviour was observed in all
patients.
FUNDING: Oxford BioMedica. Parkinson's disease is typically treated with oral dopamine replacement
therapies. However, long-term use is complicated by motor fluctuations from
intermittent stimulation of dopamine receptors and off-target effects. ProSavin,
a lentiviral vector based gene therapy that delivers local and continuous
dopamine, was previously shown to be well tolerated in a Phase I/II
first-in-human study, with significant improvements in motor behavior from
baseline at 1 year. Here, patients with Parkinson's disease from the open-label
trial were followed up in the long term to assess the safety and efficacy of
ProSavin after bilateral injection into the putamen. Fifteen patients who were
previously treated with ProSavin have been followed for up to 5 years, with some
having been seen for 8 years. Eight patients received deep brain stimulation at
different time points, and their subsequent assessments continued to assess
safety. Ninety-six drug-related adverse events were reported (87 mild, 6
moderate, 3 severe) of which more than half occurred in the first year. The most
common drug-related events were dyskinesias (33 events, 11 patients) and on-off
phenomena (22 events, 11 patients). A significant improvement in the defined
"off" Unified Parkinson's Disease Rating Scale part III motor scores, compared
to baseline, was seen at 2 years (mean score 29 · 2 vs. 38 · 4, n = 14,
p < 0.05) and at 4 years in 8/15 patients. ProSavin continued to be safe and
well tolerated in patients with Parkinson's disease. Moderate improvements in
motor behavior over baseline continued to be reported in the majority of
patients who could still be evaluated up to 5 years of follow-up. |
Are stretch enhancers transcribed more than super-enhancers? | No. Super-enhancers are transcriptionally more active and cell type-specific than stretch enhancers. | Super-enhancers and stretch enhancers represent classes of transcriptional
enhancers that have been shown to control the expression of cell identity genes
and carry disease- and trait-associated variants. Specifically, super-enhancers
are clusters of enhancers defined based on the binding occupancy of master
transcription factors, chromatin regulators, or chromatin marks, while stretch
enhancers are large chromatin-defined regulatory regions of at least 3,000 base
pairs. Several studies have characterized these regulatory regions in numerous
cell types and tissues to decipher their functional importance. However, the
differences and similarities between these regulatory regions have not been
fully assessed. We integrated genomic, epigenomic, and transcriptomic data from
ten human cell types to perform a comparative analysis of super and stretch
enhancers with respect to their chromatin profiles, cell type-specificity, and
ability to control gene expression. We found that stretch enhancers are more
abundant, more distal to transcription start sites, cover twice as much the
genome, and are significantly less conserved than super-enhancers. In contrast,
super-enhancers are significantly more enriched for active chromatin marks and
cohesin complex, and more transcriptionally active than stretch enhancers.
Importantly, a vast majority of super-enhancers (85%) overlap with only a small
subset of stretch enhancers (13%), which are enriched for cell type-specific
biological functions, and control cell identity genes. These results suggest
that super-enhancers are transcriptionally more active and cell type-specific
than stretch enhancers, and importantly, most of the stretch enhancers that are
distinct from super-enhancers do not show an association with cell identity
genes, are less active, and more likely to be poised enhancers. |
What is Q-SYMBIO? | Q-SYMBIO is a randomised, double-blind, multicentre trial with focus on SYMptoms, BIomarker status [Brain-Natriuretic Peptide (BNP)], and long-term Outcome [hospitalisations/mortality] that assessed coenzyme Q10 as adjunctive treatment of chronic heart failure. METHOD: Patients with moderate to severe HF were randomly assigned in a 2-year prospective trial to either CoQ10 100 mg 3 times daily or placebo, in addition to standard therapy. The primary short-term endpoints at 16 weeks were changes in New York Heart Association (NYHA) functional classification, 6-min walk test, and levels of N-terminal pro-B type natriuretic peptide. The primary long-term endpoint at 2 years was composite major adverse cardiovascular events as determined by a time to first event analysis. CONCLUSION: Long-term CoQ10 treatment of patients with chronic HF is safe, improves symptoms, and reduces major adverse cardiovascular events. | |
What is the function of the NIPBL factor in genome conformation? | The NIPBL protein stimulates cohesin's ABC-like ATPase and is essential for loading cohesin onto chromosomes.. NIPBL recruits histone deacetylases to mediate local chromatin modifications. | Cohesin regulates sister chromatid cohesion during the mitotic cell cycle with
Nipped-B-Like (NIPBL) facilitating its loading and unloading. In addition to
this canonical role, cohesin has also been demonstrated to play a critical role
in regulation of gene expression in nondividing cells. Heterozygous mutations in
the cohesin regulator NIPBL or cohesin structural components SMC1A and SMC3
result in the multisystem developmental disorder Cornelia de Lange Syndrome
(CdLS). Genome-wide assessment of transcription in 16 mutant cell lines from
severely affected CdLS probands has identified a unique profile of dysregulated
gene expression that was validated in an additional 101 samples and correlates
with phenotypic severity. This profile could serve as a diagnostic and
classification tool. Cohesin binding analysis demonstrates a preference for
intergenic regions suggesting a cis-regulatory function mimicking that of a
boundary/insulator interacting protein. However, the binding sites are enriched
within the promoter regions of the dysregulated genes and are significantly
decreased in CdLS proband, indicating an alternative role of cohesin as a
transcription factor. Cornelia de Lange syndrome (CdLS) is a developmental disorder caused by
mutations in NIPBL, a protein which has functionally been associated with the
cohesin complex. Mutations in core cohesin complex components have also been
reported in individuals with CdLS-like phenotypes. In addition to its role in
sister chromatid cohesion, cohesin is thought to play a role in regulating gene
expression during development. The mechanism of this gene regulation remains
unclear, but NIPBL and cohesin have been reported to affect long-range
chromosomal interactions, both independently and through interactions with CTCF.
We used fluorescence in situ hybridization to investigate whether the disruption
of NIPBL affects chromosome architecture. We show that cells from CdLS patients
exhibit visible chromatin decompaction, that is most pronounced across gene-rich
regions of the genome. Cells carrying mutations predicted to have a more severe
effect on NIPBL function show more extensive chromatin decompaction than those
carrying milder mutations. This cellular phenotype was reproduced in normal
cells depleted for NIPBL with siRNA, but was not seen following the knockdown of
either the cohesin component SMC3, or CTCF. We conclude that NIPBL has a
function in modulating chromatin architecture, particularly for gene-rich areas
of the chromosome, that is not dependent on SMC3/cohesin or CTCF, raising the
possibility that the aetiology of disorders associated with the mutation of core
cohesin components is distinct from that associated with the disruption of NIPBL
itself in classical CdLS. The cohesin complex is crucial for chromosome segregation during mitosis and has
recently also been implicated in transcriptional regulation and chromatin
architecture. The NIPBL protein is required for the loading of cohesin onto
chromatin, but how and where cohesin is loaded in vertebrate cells is unclear.
Heterozygous mutations of NIPBL were found in 50% of the cases of Cornelia de
Lange Syndrome (CdLS), a human developmental syndrome with a complex phenotype.
However, no defects in the mitotic function of cohesin have been observed so far
and the links between NIPBL mutations and the observed developmental defects are
unclear. We show that NIPBL binds to chromatin in somatic cells with a different
timing than cohesin. Further, we observe that high-affinity NIPBL binding sites
localize to different regions than cohesin and almost exclusively to the
promoters of active genes. NIPBL or cohesin knockdown reduce transcription of
these genes differently, suggesting a cohesin-independent role of NIPBL for
transcription. Motif analysis and comparison to published data show that NIPBL
co-localizes with a specific set of other transcription factors. In cells
derived from CdLS patients NIPBL binding levels are reduced and several of the
NIPBL-bound genes have previously been observed to be mis-expressed in CdLS. In
summary, our observations indicate that NIPBL mutations might cause
developmental defects in different ways. First, defects of NIPBL might lead to
cohesin-loading defects and thereby alter gene expression and second, NIPBL
deficiency might affect genes directly via its role at the respective promoters. Haploinsufficiency for Nipbl, a cohesin loading protein, causes Cornelia de
Lange Syndrome (CdLS), the most common "cohesinopathy". It has been proposed
that the effects of Nipbl-haploinsufficiency result from disruption of
long-range communication between DNA elements. Here we use zebrafish and mouse
models of CdLS to examine how transcriptional changes caused by Nipbl deficiency
give rise to limb defects, a common condition in individuals with CdLS. In the
zebrafish pectoral fin (forelimb), knockdown of Nipbl expression led to size
reductions and patterning defects that were preceded by dysregulated expression
of key early limb development genes, including fgfs, shha, hand2 and multiple
hox genes. In limb buds of Nipbl-haploinsufficient mice, transcriptome analysis
revealed many similar gene expression changes, as well as altered expression of
additional classes of genes that play roles in limb development. In both
species, the pattern of dysregulation of hox-gene expression depended on genomic
location within the Hox clusters. In view of studies suggesting that Nipbl
colocalizes with the mediator complex, which facilitates enhancer-promoter
communication, we also examined zebrafish deficient for the Med12 Mediator
subunit, and found they resembled Nipbl-deficient fish in both morphology and
gene expression. Moreover, combined partial reduction of both Nipbl and Med12
had a strongly synergistic effect, consistent with both molecules acting in a
common pathway. In addition, three-dimensional fluorescent in situ hybridization
revealed that Nipbl and Med12 are required to bring regions containing
long-range enhancers into close proximity with the zebrafish hoxda cluster.
These data demonstrate a crucial role for Nipbl in limb development, and support
the view that its actions on multiple gene pathways result from its influence,
together with Mediator, on regulation of long-range chromosomal interactions. BACKGROUND: Cornelia de Lange syndrome (CdLS) is a multisystem developmental
disorder frequently associated with heterozygous loss-of-function mutations of
Nipped-B-like (NIPBL), the human homolog of Drosophila Nipped-B. NIPBL loads
cohesin onto chromatin. Cohesin mediates sister chromatid cohesion important for
mitosis but is also increasingly recognized as a regulator of gene expression.
In CdLS patient cells and animal models, expression changes of multiple genes
with little or no sister chromatid cohesion defect suggests that disruption of
gene regulation underlies this disorder. However, the effect of NIPBL
haploinsufficiency on cohesin binding, and how this relates to the clinical
presentation of CdLS, has not been fully investigated. Nipbl haploinsufficiency
causes CdLS-like phenotype in mice. We examined genome-wide cohesin binding and
its relationship to gene expression using mouse embryonic fibroblasts (MEFs)
from Nipbl+/- mice that recapitulate the CdLS phenotype.
RESULTS: We found a global decrease in cohesin binding, including at
CCCTC-binding factor (CTCF) binding sites and repeat regions. Cohesin-bound
genes were found to be enriched for histone H3 lysine 4 trimethylation (H3K4me3)
at their promoters; were disproportionately downregulated in Nipbl mutant MEFs;
and displayed evidence of reduced promoter-enhancer interaction. The results
suggest that gene activation is the primary cohesin function sensitive to Nipbl
reduction. Over 50% of significantly dysregulated transcripts in mutant MEFs
come from cohesin target genes, including genes involved in adipogenesis that
have been implicated in contributing to the CdLS phenotype.
CONCLUSIONS: Decreased cohesin binding at the gene regions is directly linked to
disease-specific expression changes. Taken together, our Nipbl
haploinsufficiency model allows us to analyze the dosage effect of cohesin
loading on CdLS development. The cohesin complex mediates DNA-DNA interactions both between (sister chromatid
cohesion) and within chromosomes (DNA looping). It has been suggested that
intra-chromosome loops are generated by extrusion of DNAs through the lumen of
cohesin's ring. Scc2 (Nipbl) stimulates cohesin's ABC-like ATPase and is
essential for loading cohesin onto chromosomes. However, it is possible that the
stimulation of cohesin's ATPase by Scc2 also has a post-loading function, for
example driving loop extrusion. Using fluorescence recovery after photobleaching
(FRAP) and single-molecule tracking in human cells, we show that Scc2 binds
dynamically to chromatin, principally through an association with cohesin.
Scc2's movement within chromatin is consistent with a 'stop-and-go' or 'hopping'
motion. We suggest that a low diffusion coefficient, a low stoichiometry
relative to cohesin, and a high affinity for chromosomal cohesin enables Scc2 to
move rapidly from one chromosomal cohesin complex to another, performing a
function distinct from loading. A cohesin-loading factor (NIPBL) is one of important regulatory factors in the
maintece of 3D genome organization and function, by interacting with a large
number of factors, e.g. cohesion, CCCTC-binding factor (CTCF) or cohesin complex
component. The present article overviews the critical and regulatory roles of
NIBPL in cohesion loading on chromotin and in gene expression and
transcriptional signaling. We explore molecular mechanisms by which NIPBL
recruits endogenous histone deacetylase (HDAC) to induce histone deacetylation
and influence multi-dimensions of genome, through which NIPBL "hop" movement in
chromatin regulates gene expression and alters genome folding. NIPBL regulates
the process of CTCF and cohesion into chromatin loops and topologically
associated domains, binding of cohesion and H3K4mes3 through interaction among
promoters and enhancers. HP1 recruits NIPBL to DNA damage site through
RNF8/RNF168 ubiquitylation pathway. NIPBL contributes to regulation of
genome-controlled gene expression through the influence of cohesin in chromosome
structure. NIPBL interacts with cohesin and then increases transcriptional
activities of REC8 promoter, leading to up-regulation of gene expression. NIPBL
movement among chromosomal loops regulates gene expression through dynamic
alterations of genome organization. Thus, we expect a new and deep insight to
understand dynamics of chromosome and explore potential strategies of therapiesc
on basis of NIPBL. |
Is mesothelioma caused by asbestos exposure? | Yes, mesothelioma is caused by asbestos exposure. | OBJECTIVE: Maligt pleural mesothelioma in rural Turkey frequently results
from environmental exposure to tremolite asbestos or fibrous zeolite (erionite).
The aim of this study was to determine the CT features of maligt pleural
mesothelioma in patients exposed to asbestos or erionite.
MATERIALS AND METHODS: The CT scans of 84 patients with proved maligt pleural
mesothelioma were retrospectively evaluated. Twenty patients (24%) had been
exposed to erionite and 64 patients (76%) had been exposed to asbestos. The CT
scans were interpreted by seven observers who did not know the clinical or
pathologic findings.
RESULTS: CT scans showed either unilateral pleural thickening or pleural
nodules/masses in all patients. Pleural nodules were present in 25 patients
(30%) and pleural masses in 44 patients (52%). Pleural effusion was found in 61
patients (73%), mediastinal pleural involvement in 78 (93%), pleural
calcifications in 52 (62%), involvement of the interlobar fissures in 64 (76%),
and volume contraction in 61 (73%). Reduced size of the hemithorax was
significantly correlated with chest wall involvement. On the basis of CT
findings, the preassigned staging was changed in 21 patients (25%), including
44% of the patients with disease that had been classified as stage I. CT
findings were not significantly different between the patients exposed to
erionite and those exposed to asbestos.
CONCLUSION: The most common CT findings in cases of maligt pleural
mesothelioma were unilateral pleural thickening or pleural nodules/masses with
or without effusion. CT provided valuable information on the extent of the
disease, which was important for staging. Although the CT features are not
pathognomonic, they provide valuable clues to the diagnosis in patients who have
been exposed to mineral fibers. Asbestos exposure causes asbestosis and maligt mesothelioma, disorders which
remain difficult to cure. We focused on alveolar macrophages (AM) and natural
killer (NK) cells in asbestosis and mesothelioma, respectively, and examined
their functions upon exposure to asbestos or in patients with mesothelioma.
Exposure to asbestos caused rat AM to exhibit high production of transforming
growth factor-beta (TGF-β) with prolonged survival in the absence of other
cells, not simultaneously with the apoptosis caused by asbestos. The NK cell
line showed impaired cytotoxicity with altered expression of activating
receptors upon exposure to asbestos, and primary NK cells in culture with
asbestos and peripheral blood NK cells in mesothelioma shared a decrease in
expression of NKp46, a representative activating receptor. The AM finding
indicates that AM contribute to asbestosis by playing a direct role in the
fibrogenic response, as well as the inflammatory response. The response of NK
cells indicates that exposure to asbestos has an immune-suppressive effect, as
well as a tumorigenic effect. Our studies therefore reveal novel effects of
asbestos exposure on AM and tumor immunity, which may represent valuable
information for construction of a strategy for prevention and cure of asbestosis
and maligt mesothelioma. Asbestos-related diseases persist, because millions of workers have had prior
exposure and many industrializing countries continue to use asbestos. Globally,
an estimated 107,000 people die annually from lung cancer, maligt
mesothelioma, and asbestosis due to occupational asbestos exposure. Maligt
mesothelioma and lung cancer are caused by all major types of asbestos. Asbestos
causes more lung cancer deaths than maligt mesothelioma of the pleura; most
cases of the latter are due to asbestos exposure. The cancer risk increases with
cumulative asbestos exposure, with increased risk even at low levels of exposure
to asbestos. Based on empirical studies, an estimated cumulative occupational
exposure to asbestos of 1 fiber/mL-year substantially raises maligt
mesothelioma risk. No safe threshold for asbestos exposure has been established
for lung cancer and mesothelioma. The validity of fiber-type risk assessments
depends critically on the quality of exposure assessments, which vary
considerably, leading to a high degree of uncertainty. Asbestos exposure without
asbestosis and smoking increases the risk of lung cancer. The joint effect of
asbestos and smoking is supra-additive, which may depend in part on the presence
of asbestosis. Asbestos workers who cease smoking experience a dramatic drop in
lung cancer risk, which approaches that of nonsmokers after 30 years. Studies to
date show that longer, thinner fibers have a stronger association with lung
cancer than shorter, less thin fibers, but the latter nonetheless also show an
association with lung cancer and mesothelioma. Low-dose chest computed
tomographic scanning offers an unprecedented opportunity to detect early-stage
lung cancers in asbestos-exposed workers. Maligt mesothelioma is caused by exposure to asbestos, which is known to have
carcinogenic effects. However, the development of mesothelioma takes a long
period and results from a low or intermediate dose of exposure. These findings
have motivated us to investigate the immunological effects of asbestos exposure
and analyze immune functions of patients with mesothelioma and pleural plaque, a
sign of exposure to asbestos. Here, we review our knowledge concerning natural
killer (NK) cells and cytotoxic T lymphocytes (CTL). NK cells showed impaired
cytotoxicity with altered expression of activating receptors upon exposure to
asbestos, while induction of granzyme(+) cells in CD8(+) lymphocytes was
suppressed by asbestos exposure. It is interesting that a decrease in NKp46, a
representative activating receptor, is common between NK cells in PBMC culture
with asbestos and those of mesothelioma patients. Moreover, it was observed that
CD8(+) lymphocytes may be stimulated by some kind of "nonself" cells in
plaque-positive individuals and in mesothelioma patients, whereas CTL in
mesothelioma is impaired by poststimulation maintece of cytotoxicity. These
findings suggest that analysis of immunological parameters might contribute to
the evaluation of health conditions of asbestos-exposed individuals and to a
greater understanding of the pathology of maligt mesothelioma. OBJECTIVES/HYPOTHESIS: Occupational exposure to asbestos occurs in many
workplaces and is well known to cause asbestosis, lung cancer, and mesothelioma.
However, the link between asbestos exposure and other maligcies was not
confirmed. The aim of the current meta-analysis was to provide a summary measure
of risk for laryngeal cancer associated with occupational asbestos exposure.
STUDY DESIGN: Systematic review and meta-analysis.
METHODS: Electronic databases were searched for studies characterizing the
association between asbestos and laryngeal cancer. Standardized mortality rate
(SMR) with its 95% confidence interval (CI) of each study was combined using a
fixed or random effect model.
RESULTS: Significantly increased SMR for laryngeal cancer was observed when
subjects were exposed to asbestos (SMR = 1.69, 95% CI = 1.45-1.97, P < .001),
with little evidence of heterogeneity among studies (Q = 15.39, P = .803, I(2) =
0.0%). Effect estimates were larger for cohorts controlling for male subjects,
Europe and Oceania, mining and textile industries, exposure to crocidolite, long
study follow-up (>25 years), and SMR for lung cancer > 2.0. Publication bias was
not detect by Begg test (P = .910) and Egger test (P = .340).
CONCLUSIONS: Our study supports the association of exposure to asbestos with an
increased risk of laryngeal cancer mortality among male workers.
LEVEL OF EVIDENCE: NA Laryngoscope, 126:1169-1174, 2016. BACKGROUND: Maligt mesothelioma caused by asbestos exposure has a long
latency period. A ban on asbestos use may not be apparent in decreased incidence
in the population until after several decades. The aim was to evaluate changes
in the incidence of maligt mesothelioma, and the possible impact of the
asbestos ban implemented in Iceland in 1983.
METHODS: This is a population study on aggregate level; the source of data was
the Icelandic Cancer Registry, the National Cause-of-Death Registry, and the
National Register. Volume of asbestos import was obtained from Customs Tariff.
The import figures reflect fairly accurately the amount used, as there are no
mines in the country.
RESULTS: Asbestos import peaked in 1980 at 15.0 kg/capita/year, diminishing to
0.3 kg/capita/year ten years after the ban in 1983, and to zero in the most
recent years. Seventy-nine per cent of the cases of maligt mesothelioma were
men, and 72 % were of pleural origin. Mesothelioma incidence increased steadily
from 1965 to 2014, when it reached 21.4 per million among men, and 5.6 among
women. Mortality in 2014 was 22.2 per million among men, and 4.8 among women.
CONCLUSION: Maligt mesothelioma incidence and mortality increased in the
population during the period, despite the ban on asbestos use from 1983. This is
in agreement with the long latency time for maligt mesothelioma. In line with
the previously high per capita volume of asbestos import, many buildings,
equipment, and structures contain asbestos, so there is an on-going risk of
asbestos exposure during maintece, renovations and replacements. It is thus
difficult to predict when the incidence of maligt mesothelioma will decrease
in the future. During the last ten-year period, the incidence in Iceland was
higher than the recently reported incidence in neighbouring countries. Mesothelioma, a rare tumor, is highly correlated with asbestos exposure.
Mesothelioma, similar to all asbestos-related diseases, is dose/intensity
dependent to some degree, and studies showed the risk of mesothelioma rises with
cumulative exposures. Multiple processes occur in an individual before
mesothelioma occurs. The impact of mesothelioma in the United States has been
continuous over the last half century, claiming between 2,000 and 3,000 lives
each year. Mesothelioma is a preventable tumor that is more frequently reported
as associated with asbestos exposure among men than women. However, the rate of
asbestos-associated mesothelioma is on the rise among women due to better
investigation into their histories of asbestos exposure. It is of interest that
investigators detected asbestos-associated cases of mesothelioma in women from
nonoccupational sources-that is, bystander, incidental, or take-home exposures.
It is postulated that asbestos-associated mesotheliomas, in both men and women,
are likely underreported. However, with the implementation of the most recent
ICD-10 coding system, the correlation of mesothelioma with asbestos exposure is
expected to rise to approximately 80% in the United States. This study examined
the demographic and etiological nature of asbestos-related mesothelioma. IMPORTANCE: Maligt peritoneal mesothelioma is a rare, aggressive tumor
arising from the peritoneal lining, induced by asbestos, therapeutic radiation,
or germline mutations. Nevertheless, the molecular features remain largely
unknown.
OBJECTIVE: To investigate anaplastic lymphoma kinase (ALK) rearrangements in a
large series of peritoneal mesothelioma and characterize the mutational
landscape of these tumors.
DESIGN, SETTING, AND PARTICIPANTS: We studied 88 consecutive patients (39 men,
49 women; median age 61, range 17-84 years) with peritoneal mesotheliomas
diagnosed at a single institution between 2005 and 2015. We identified
ALK-positive mesotheliomas by immunohistochemistry and confirmed ALK
rearrangement by fluorescence in situ hybridization (FISH). In ALK-rearranged
cases, we characterized the fusion partners using targeted next-generation
sequencing of both tumor DNA and RNA. In select cases, we quantified asbestos
fibers by combined scanning electron microscopy and x-ray spectroscopy. We also
explored ALK rearrangement in a separate series of 205 patients with pleural
mesothelioma.
MAIN OUTCOMES AND MEASURES: Identification and characterization of novel ALK
rearrangements and correlations with clinicopathologic characteristics.
RESULTS: Anaplastic lymphoma kinase was positive by immunohistochemistry in 11
(13%) peritoneal mesotheliomas (focal weak in 8, diffuse strong in 3). In focal
weak ALK-positive cases, no ALK rearrangement was detected by FISH or
next-generation sequencing. In strong diffuse ALK-positive cases, FISH confirmed
ALK rearrangements, and next-generation sequencing identified novel fusion
partners ATG16L1, STRN, and TPM1. Patients with ALK-rearranged peritoneal
mesotheliomas were women and younger than patients without ALK rearrangement
(median age 36 vs 62; Mann-Whitney test, P = .02), but all other
clinicopathologic characteristics (size of tumor nodules, histology, treatment,
and survival) were not different. No asbestos fibers were detected in
ALK-rearranged cases. Furthermore, loss of chromosomal region 9p or 22q or
genetic alterations in BAP1, SETD2, or NF2 typically present in peritoneal
mesothelioma were absent in the ALK-rearranged cases. All pleural mesotheliomas
were ALK-negative by immunohistochemistry.
CONCLUSIONS AND RELEVANCE: We identified unique ALK rearrangements in a subset
of patients with peritoneal mesothelioma, each lacking asbestos fibers,
therapeutic radiation, and cytogenetic and molecular alterations typically found
in these tumors. Identification of clinically actionable ALK rearrangements may
represent a novel pathogenetic mechanism of maligt peritoneal mesothelioma
with promise for targeted therapy. Maligt mesothelioma is a rare and aggressive pleural or peritoneal tumour
almost always caused by exposure to asbestos fibres. Exposure to asbestos can
cause maligt mesothelioma 30-40 years after exposure. A description of
sources of exposure is important for prevention and possible ficial
compensation. Three women with cases of histologically confirmed maligt
mesothelioma diagnosed from non-occupational asbestos exposure are described.
Patients were contacted for an interview to assess their exposure history to
asbestos. All three cases had mixed exposure histories related to secondary,
environmental contamination, and domestic exposure. This case series highlight
how ubiquitous asbestos is in the environment and how diverse the exposures may
be. It is anticipated that a significant number of cases of non-occupational
mesothelioma will be seen in many countries for several decades given the extent
of asbestos containing materials. Occupational asbestos exposure occurs in many workplaces and is a well-known
cause of mesothelioma and lung cancer. However, the association between
nonoccupational asbestos exposure and those diseases is not clearly described.
The aim of this study was to investigate cause-specific mortality among the
residents of Amagasaki, a city in Japan with many asbestos factories, and
evaluate the potential excess mortality due to established and suspected
asbestos-related diseases. The study population consisted of 143 929 residents
in Amagasaki City before 1975 until 2002, aged 40 years or older on January 1,
2002. Follow-up was carried out from 2002 to 2015. Standardized mortality ratio
(SMR) with its 95% confidence interval (CI) was calculated by sex, using the
mortality rate of the Japanese population as reference. A total of 38 546 deaths
(including 303 from mesothelioma and 2683 from lung cancer) were observed. The
SMRs in the long-term residents' cohort were as follows: death due to all
causes, 1.12 (95% CI, 1.10-1.13) in men and 1.07 (95% CI, 1.06-1.09) in women;
lung cancer, 1.28 (95% CI, 1.23-1.34) in men and 1.23 (95% CI, 1.14-1.32) in
women; and mesothelioma, 6.75 (95% CI, 5.83-7.78) in men and 14.99 (95% CI,
12.34-18.06) in women. These SMRs were significantly higher than expected. The
increased SMR of mesothelioma suggests the impact of occupational asbestos
exposure among men and nonoccupational asbestos exposure among women in the
long-term residents' cohort. In addition, the high level of excess mortality
from mesothelioma has persisted, despite the mixture of crocidolite and
chrysotile no longer being used for three or four decades. |
Which diagnostic test is approved for coronavirus infection screening? | Real-time reverse transcription-PCR (rRT-PCR) is mostly used as the lab test for screening coronaviral infection. | BACKGROUND: An outbreak of severe acute respiratory syndrome (SARS) began in
Canada in February 2003. The initial diagnosis of SARS was based on clinical and
epidemiological criteria. During the outbreak, molecular and serologic tests for
the SARS-associated coronavirus (SARS-CoV) became available. However, without a
"gold standard," it was impossible to determine the usefulness of these tests.
We describe how these tests were used during the first phase of the SARS
outbreak in Toronto and offer some recommendations that may be useful if SARS
returns.
METHODS: We examined the results of all diagnostic laboratory tests used in 117
patients admitted to hospitals in Toronto who met the Health Canada criteria for
suspect or probable SARS. Focusing on tests for SARS-CoV, we attempted to
determine the optimal specimen types and timing of specimen collection.
RESULTS: Diagnostic test results for SARS-CoV were available for 110 of the 117
patients. SARS-CoV was detected by means of reverse-transcriptase polymerase
chain reaction (RT-PCR) in at least one specimen in 59 (54.1%) of 109 patients.
Serologic test results of convalescent samples were positive in 50 (96.2%) of 52
patients for whom paired serum samples were collected during the acute and
convalescent phases of the illness. Of the 110 patients, 78 (70.9%) had
specimens that tested positive by means of RT-PCR, serologic testing or both
methods. The proportion of RT-PCR test results that were positive was similar
between patients who met the criteria for suspect SARS (50.8%, 95% confidence
interval [CI] 38.4%-63.2%) and those who met the criteria for probable SARS
(58.0%, 95% CI 44.2%-70.7%). SARS-CoV was detected in nasopharyngeal swabs in 33
(32.4%) of 102 patients, in stool specimens in 19 (63.3%) of 30 patients, and in
specimens from the lower respiratory tract in 10 (58.8%) of 17 patients.
INTERPRETATION: These findings suggest that the rapid diagnostic tests in use at
the time of the initial outbreak lack sufficient sensitivity to be used
clinically to rule out SARS. As tests for SARS-CoV continue to be optimized,
evaluation of the clinical presentation and elucidation of a contact history
must remain the cornerstone of SARS diagnosis. In patients with SARS, specimens
taken from the lower respiratory tract and stool samples test positive by means
of RT-PCR more often than do samples taken from other areas. A new human coronavirus (CoV), subsequently named Middle East respiratory
syndrome (MERS)-CoV, was first reported in Saudi Arabia in September 2012. In
response, we developed two real-time reverse transcription-PCR (rRT-PCR) assays
targeting the MERS-CoV nucleocapsid (N) gene and evaluated these assays as a
panel with a previously published assay targeting the region upstream of the
MERS-CoV envelope gene (upE) for the detection and confirmation of MERS-CoV
infection. All assays detected ≤10 copies/reaction of quantified RNA
transcripts, with a linear dynamic range of 8 log units and 1.3 × 10(-3) 50%
tissue culture infective doses (TCID50)/ml of cultured MERS-CoV per reaction.
All assays performed comparably with respiratory, serum, and stool specimens
spiked with cultured virus. No false-positive amplifications were obtained with
other human coronaviruses or common respiratory viral pathogens or with 336
diverse clinical specimens from non-MERS-CoV cases; specimens from two confirmed
MERS-CoV cases were positive with all assay signatures. In June 2012, the U.S.
Food and Drug Administration authorized emergency use of the rRT-PCR assay panel
as an in vitro diagnostic test for MERS-CoV. A kit consisting of the three assay
signatures and a positive control was assembled and distributed to public health
laboratories in the United States and internationally to support MERS-CoV
surveillance and public health responses. BACKGROUND: Coronaviruses (CoVs) are large ribonucleic acid (RNA) viruses
causing primarily respiratory disease in humans. A novel human coronavirus,
subsequently named middle east respiratory syndrome coronavirus (MERS-CoV), was
first reported in Saudi Arabia in September of 2012. With increasing numbers of
infections and deaths from MERS-CoV, development of a rapid and reliable kit was
crucial to prevent further spread of MERS-CoV.
OBJECTIVES: In this study, we present two real-time reverse-transcription
polymerase chain reaction (rRT-PCR) assays for in-house rapid and sensitive
diagnostic testing of MERS-CoV, detecting the regions upstream of the envelope
gene (upE) and open reading frame (ORF) 1b, respectively, for initial screening
and final confirmation of MERS-CoV infection, as recommended by the world health
organization (WHO).
MATERIALS AND METHODS: In this experimental study, acquiring patient samples was
difficult; thus, according to WHO recommendations and standard protocols, we
synthesized RNA sequences of upE and ORF1b genes as the template signatures and
TaqMan based-diagnostic rRT-PCR assays were carried out using these synthetic
genes for detection of MERS-CoV. In this research, we also inaugurated a
cell-free system to transcribe these RNA sequences using the DNA templates
synthesized.
RESULTS: The upE and ORF1b based one-step rRT-PCR assays were optimized by
testing several times via different synthetic RNAs, and validation results were
highly successful. The sensitivity obtained for upE was fewer than ten copies of
RNA template per reaction and for ORF1b was 50 or fewer copies per reaction.
CONCLUSIONS: This study showed that the developed rRT-PCR assays are rapid,
reliable, reproducible, specific, sensitive, and simple tools for detection of
MERS-CoV. Finally, a kit consisting of two assay signatures and controls was
assembled, which can be distributed to public health laboratories in Iran to
support international MERS-CoV surveillance and public health response. |
What is Xanamem? | UE2343 was identified as a potent, orally bioavailable, brain-penetrant 11b-HSD1 inhibitor and selected for clinical studies. Reducing glucocorticoid exposure in the brain via intracellular inhibition of the cortisol-regenerating enzyme 11b-hydroxysteroid dehydrogenase type 1 (11b-HSD1) has emerged as a therapeutic strategy to treat cognitive impairment in early Alzheimer's disease (AD). UE2343 is safe, well tolerated and reaches the brain at concentrations predicted to inhibit 11b-HSD1. UE2343 is therefore a suitable candidate to test the hypothesis that 11b-HSD1 inhibition in brain improves memory in patients with AD. | |
Can nrf2 activation lead to resistance to radiotherapy? | Resistance to chemoradiotherapy is a major obstacle to successful treatment of glioblastoma. Recently, the role of NF-E2-related factor 2 (Nrf2) in enhancing chemoradiation sensitivity has been reported in several types of cancers. Blocking Nrf2 activation may be a promising method enhancing chemoradiation sensitivity of glioblastoma cells. | Cancer stem cells (CSCs) express high levels of drug efflux transporters and
antioxidant genes, and are therefore believed to be responsible for cancer
recurrence following chemo/radiotherapy intervention. In this study, we
investigated the role of NF-E2-related factor 2 (NRF2), a master regulator of
antioxidant gene expression, in the growth and stress resistance of CSC-enriched
mammosphere. The MCF7 mammospheres expressed significantly higher levels of the
NRF2 protein and target gene expression compared to the monolayer. As underlying
mechanisms, we observed that proteolytic activity and expression of the
proteasome catalytic subunits were decreased in the mammospheres. Additionally,
mammospheres retained a high level of p62 and the silencing of p62 was observed
to attenuate NRF2 activation. NRF2 increase was confirmed in sphere-cultures of
the colon and ovarian cancer cells. The functional implication of NRF2 was
demonstrated in NRF2-knockdown mammospheres. NRF2-silenced mammospheres
demonstrated increased cell death and retarded sphere growth as a result of
target gene repression. Moreover, unlike the control mammospheres,
NRF2-knockdown mammospheres did not develop anticancer drug resistance.
Collectively, these results indicated that altered proteasome function and p62
expression caused NRF2 activation in CSC-enriched mammospheres. In addition,
NRF2 appeared to play a role in CSC survival and anticancer drug resistance. Exploiting oxidative stress has recently emerged as a plausible strategy for
treatment of human cancer, and antioxidant defenses are implicated in resistance
to chemotherapy and radiotherapy. Targeted suppression of antioxidant defenses
could thus broadly improve therapeutic outcomes. Here, we identify the
AMPK-related kinase NUAK1 as a key component of the antioxidant stress response
pathway and reveal a specific requirement for this role of NUAK1 in colorectal
cancer. We show that NUAK1 is activated by oxidative stress and that this
activation is required to facilitate nuclear import of the antioxidant master
regulator NRF2: Activation of NUAK1 coordinates PP1β inhibition with AKT
activation in order to suppress GSK3β-dependent inhibition of NRF2 nuclear
import. Deletion of NUAK1 suppresses formation of colorectal tumors, whereas
acute depletion of NUAK1 induces regression of preexisting autochthonous tumors.
Importantly, elevated expression of NUAK1 in human colorectal cancer is
associated with more aggressive disease and reduced overall
survival.Significance: This work identifies NUAK1 as a key facilitator of the
adaptive antioxidant response that is associated with aggressive disease and
worse outcome in human colorectal cancer. Our data suggest that transient NUAK1
inhibition may provide a safe and effective means for treatment of human
colorectal cancer via disruption of intrinsic antioxidant defenses. Cancer
Discov; 8(5); 632-47. ©2018 AACR.This article is highlighted in the In This
Issue feature, p. 517. |
Are there interactions between short and long noncoding RNAs? | Yes. Short RNAs and long noncoding RNAs (lncRNAs) interact with each other with reciprocal consequences for their fates and functions. | |
Which molecule is inhibited by encorafenib? | Encorafenib is a BRAF inhibitor. It is a promising therapy for metastatic or inoperable melanoma with a BRAF mutation. | PURPOSE: To test second-line personalized medicine combination therapies, based
on genomic and proteomic data, in patient-derived xenograft (PDX) models.
EXPERIMENTAL DESIGN: We established 12 PDXs from BRAF inhibitor-progressed
melanoma patients. Following expansion, PDXs were analyzed using targeted
sequencing and reverse-phase protein arrays. By using multi-arm preclinical
trial designs, we identified efficacious precision medicine approaches.
RESULTS: We identified alterations previously described as drivers of
resistance: NRAS mutations in 3 PDXs, MAP2K1 (MEK1) mutations in 2, BRAF
amplification in 4, and aberrant PTEN in 7. At the protein level, re-activation
of phospho-MAPK predominated, with parallel activation of PI3K in a subset.
Second-line efficacy of the pan-PI3K inhibitor BKM120 with either BRAF
(encorafenib)/MEK (binimetinib) inhibitor combination or the ERK inhibitor
VX-11e was confirmed in vivo Amplification of MET was observed in 3 PDX models,
a higher frequency than expected and a possible novel mechanism of resistance.
Importantly, MET amplification alone did not predict sensitivity to the MET
inhibitor capmatinib. In contrast, capmatinib as single agent resulted in
significant but transient tumor regression in a PDX with resistance to BRAF/MEK
combination therapy and high pMET. The triple combination
capmatinib/encorafenib/binimetinib resulted in complete and sustained tumor
regression in all animals.
CONCLUSIONS: Genomic and proteomic data integration identifies dual-core pathway
inhibition as well as MET as combinatorial targets. These studies provide
evidence for biomarker development to appropriately select personalized
therapies of patients and avoid treatment failures. See related commentary by
Hartsough and Aplin, p. 1550. Purpose: Encorafenib, a selective BRAF inhibitor (BRAFi), has a pharmacologic
profile that is distinct from that of other clinically active BRAFis. We
evaluated encorafenib in a phase I study in patients with BRAFi treatment-naïve
and pretreated BRAF-mutant melanoma.Experimental Design: The pharmacologic
activity of encorafenib was first characterized preclinically. Encorafenib
monotherapy was then tested across a range of once-daily (50-700 mg) or
twice-daily (75-150 mg) regimens in a phase I, open-label, dose-escalation and
-expansion study in adult patients with histologically confirmed
advanced/metastatic BRAF-mutant melanoma. Study objectives were to determine the
maximum tolerated dose (MTD) and/or recommended phase II dose (RP2D),
characterize the safety and tolerability and pharmacokinetic profile, and assess
the preliminary antitumor activity of encorafenib.Results: Preclinical data
demonstrated that encorafenib inhibited BRAF V600E kinase activity with a
prolonged off-rate and suppressed proliferation and tumor growth of BRAF
V600E-mutant melanoma models. In the dose-escalation phase, 54 patients (29
BRAFi-pretreated and 25 BRAFi-naïve) were enrolled. Seven patients in the
dose-determining set experienced dose-limiting toxicities. Encorafenib at a dose
of 300 mg once daily was declared the RP2D. In the expansion phase, the most
common all-cause adverse events were nausea (66%), myalgia (63%), and
palmar-plantar erythrodysesthesia (54%). In BRAFi-naïve patients, the overall
response rate (ORR) and median progression-free survival (mPFS) were 60% and
12.4 months [95% confidence interval (CI), 7.4-not reached (NR)]. In
BRAFi-pretreated patients, the ORR and mPFS were 22% and 1.9 months (95% CI,
0.9-3.7).Conclusions: Once-daily dosing of single-agent encorafenib had a
distinct tolerability profile and showed varying antitumor activity across
BRAFi-pretreated and BRAFi-naïve patients with advanced/metastatic melanoma.
Clin Cancer Res; 23(18); 5339-48. ©2017 AACR. RATIONALE: BRAF and MEK inhibitors have significantly improved the prognosis of
metastatic melanoma, by inhibiting both the mitogen-activated protein kinase
(MAP-kinase) pathway. They are associated with infrequent adverse kidney events.
Most of these are related to the use of BRAF inhibitors and involve interstitial
nephritis with acute tubular necrosis.
PATIENT CONCERNS: We report a unique case of glomerulonephritis with renal
granulomatous vasculitis in a patient diagnosed with metastatic melanoma treated
with BRAF and MEK inhibitors. The patient was a 55-year old woman, who presented
a melanoma of the right thigh with pulmonary metastasis. Treatment started in
November 2015, with Encorafenib and Binimetinib, new BRAF and MEK inhibitors,
respectively. Two months after the beginning of the treatment, there was a
worsening of her renal function with significant proteinuria.
DIAGNOSES: Kidney biopsy showed extracapillary proliferation in the glomeruli
with a granulomatous reaction.
INTERVENTIONS AND OUTCOMES: Renal function recovered completely after withdrawal
of the chemotherapy.
LESSONS: All the reported kidney adverse events secondary to BRAF and MEK
inhibitors in the literature are related to the use of BRAF inhibitors. Some
previous reported mechanistic investigations also provide insight between BRAF
inhibitors and podocytes injuries. Therefore, encorafenib most likely is the
main responsible of the disease. However, evidence has emerged that inhibition
of the MAP kinase pathway could also enhance autoimmunity. Thus, binimetinib may
also have played a role and the combination of BRAF and MEK inhibitors may have
facilitated this autoimmune kidney disease. Encorafenib (LGX818) is a promising BRAFV600E inhibitor that has efficacy
against metastatic melanoma. To better understand its pharmacokinetics, we
studied its interactions with the multidrug efflux transporters ABCB1 and ABCG2
and the multidrug metabolizing enzyme CYP3A. In polarized MDCK-II cells,
encorafenib was efficiently transported by canine and human ABCB1 and ABCG2 and
by mouse Abcg2. Upon oral administration to wild-type, Abcb1a/1b-/-, Abcg2-/-,
and Abcb1a/1b;Abcg2-/- mice, encorafenib was absorbed very quickly and to very
high plasma levels, but without clear changes in oral availability between the
strains. Upon oral or intravenous administration, encorafenib brain accumulation
was markedly increased in Abcb1a/1b;Abcg2-/- mice and to a lesser extent in
Abcb1a/1b-/- mice. However, absolute brain concentrations and brain-to-plasma
ratios remained very low in all strains, indicating intrinsically poor brain
penetration of encorafenib. Upon intravenous administration, Abcb1a/1b;Abcg2-/-
mice showed somewhat reduced plasma elimination of encorafenib compared to
wild-type mice, and lower accumulation of the drug in the intestinal tract,
suggesting a limited role for these transporters in intestinal elimination of
the drug. In Cyp3a-/- mice plasma levels of encorafenib were not markedly
increased, suggesting a limited impact of Cyp3a on encorafenib oral
availability. The low brain penetration of encorafenib might limit its efficacy
against maligcies positioned behind a functional blood-brain barrier, but its
oral bioavailability and distribution to other tested organs (liver, kidney,
spleen, testis) was high. Acquired resistance of metastatic melanoma (MM) tumors to BRAF V600E inhibitors
(BRAFi's) is commonplace in the clinic. Habitual relapse of patients contributes
to <20% 5-year survival rates in MM. We previously identified serine synthesis
as a critical detrmit of late-stage cancer cell resistance to BRAFi's.
Pre-treatment with DNA damaging agent gemcitabine (a nucleoside analog)
re-sensitized drug-resistant cancer cells to BRAFi's dabrafenib and vemurafenib.
Importantly, the combination treatments were effective against BRAF wild type
cancer cells potentially expanding the clinical reach of BRAFi's. In this study,
we identify the antifolate methotrexate (MTX) as a sensitizer of acquired- and
intrinsically-resistant MM cells to BRAFi's dabrafenib and encorafenib. We
identify a novel, positive correlation between dabrafenib treatments and repair
delay of MTX induced single-strand DNA (ssDNA) breaks. Cells arrest in G1 phase
following simultaneous MTX + dabrafenib treatments and eventually die via
apoptosis. Importantly, we identify RAS codon 12 activating mutations as
prognostic markers for MTX + BRAFi treatment efficacy. We describe a method of
killing drug-resistant MM cells that if translated has the potential to improve
MM patient survival. BACKGROUND: Combined BRAF-MEK inhibitor therapy is the standard of care for
BRAFV600-mutant advanced melanoma. We investigated encorafenib, a BRAF inhibitor
with unique target-binding properties, alone or in combination with the MEK
inhibitor binimetinib, versus vemurafenib in patients with advanced
BRAFV600-mutant melanoma.
METHODS: COLUMBUS was conducted as a two-part, randomised, open-label phase 3
study at 162 hospitals in 28 countries. Eligible patients were aged 18 years or
older and had histologically confirmed locally advanced (American Joint
Committee on Cancer [AJCC] stage IIIB, IIIC, or IV), unresectable or metastatic
cutaneous melanoma, or unknown primary melanoma; a BRAFV600E or BRAFV600K
mutation; an Eastern Cooperative Oncology Group (ECOG) performance status of 0
or 1; and were treatment naive or had progressed on or after previous first-line
immunotherapy. In part 1 of the study, patients were randomly assigned (1:1:1)
via interactive response technology to receive either oral encorafenib 450 mg
once daily plus oral binimetinib 45 mg twice daily (encorafenib plus binimetinib
group), oral encorafenib 300 mg once daily (encorafenib group), or oral
vemurafenib 960 mg twice daily (vemurafenib group). The primary endpoint was
progression-free survival by blinded independent central review for encorafenib
plus binimetinib versus vemurafenib. Efficacy analyses were by
intention-to-treat. Safety was analysed in patients who received at least one
dose of study drug and one postbaseline safety assessment. The results of part 2
will be published separately. This study is registered with ClinicalTrials.gov,
number NCT01909453, and EudraCT, number 2013-001176-38.
FINDINGS: Between Dec 30, 2013, and April 10, 2015, 577 of 1345 screened
patients were randomly assigned to either the encorafenib plus binimetinib group
(n=192), the encorafenib group (n=194), or the vemurafenib group (n=191). With a
median follow-up of 16·6 months (95% CI 14·8-16·9), median progression-free
survival was 14·9 months (95% CI 11·0-18·5) in the encorafenib plus binimetinib
group and 7·3 months (5·6-8·2) in the vemurafenib group (hazard ratio [HR] 0·54,
95% CI 0·41-0·71; two-sided p<0·0001). The most common grade 3-4 adverse events
seen in more than 5% of patients in the encorafenib plus binimetinib group were
increased γ-glutamyltransferase (18 [9%] of 192 patients), increased creatine
phosphokinase (13 [7%]), and hypertension (11 [6%]); in the encorafenib group
they were palmoplantar erythrodysaesthesia syndrome (26 [14%] of 192 patients),
myalgia (19 [10%]), and arthralgia (18 [9%]); and in the vemurafenib group it
was arthralgia (11 [6%] of 186 patients). There were no treatment-related deaths
except for one death in the combination group, which was considered possibly
related to treatment by the investigator.
INTERPRETATION: Encorafenib plus binimetinib and encorafenib monotherapy showed
favourable efficacy compared with vemurafenib. Overall, encorafenib plus
binimetinib appears to have an improved tolerability profile compared with
encorafenib or vemurafenib. Encorafenib plus binimetinib could represent a new
treatment option for patients with BRAF-mutant melanoma.
FUNDING: Array BioPharma, Novartis. PURPOSE: Dual MAPK pathway inhibition (dMAPKi) with BRAF and MEK inhibitors
improves survival in BRAF V600E/K mutant melanoma, but the efficacy of dMAPKi in
non-V600 BRAF mutant tumors is poorly understood. We sought to characterize the
responsiveness of class II (enhanced kinase activity, dimerization dependent)
BRAF mutant melanoma to dMAPKi.
EXPERIMENTAL DESIGN: Tumors from patients with BRAF wild-type (WT), V600E (class
I), and L597S (class II) metastatic melanoma were used to generate
patient-derived xenografts (PDX). We assembled a panel of melanoma cell lines
with class IIa (activation segment) or IIb (p-loop) mutations and compared these
with WT or V600E/K BRAF mutant cells. Cell lines and PDXs were treated with
BRAFi (vemurafenib, dabrafenib, encorafenib, and LY3009120), MEKi (cobimetinib,
trametinib, and binimetinib), or the combination. We identified 2 patients with
BRAF L597S metastatic melanoma who were treated with dMAPKi.
RESULTS: BRAFi impaired MAPK signaling and cell growth in class I and II BRAF
mutant cells. dMAPKi was more effective than either single MAPKi at inhibiting
cell growth in all class II BRAF mutant cells tested. dMAPKi caused tumor
regression in two melanoma PDXs with class II BRAF mutations and prolonged
survival of mice with class II BRAF mutant melanoma brain metastases. Two
patients with BRAF L597S mutant melanoma clinically responded to dMAPKi.
CONCLUSIONS: Class II BRAF mutant melanoma is growth inhibited by dMAPKi.
Responses to dMAPKi have been observed in 2 patients with class II BRAF mutant
melanoma. These data provide rationale for clinical investigation of dMAPKi in
patients with class II BRAF mutant metastatic melanoma.See related commentary by
Johnson and Dahlman, p. 6107. The FDA approved the BRAF/MEK inhibitor combination encorafenib/binimetinib for
patients with metastatic or inoperable melanoma with a BRAF V600E or V600K
mutation. The approval was based on results of a phase III trial in which
patients treated with the combination had a median progression-free survival of
14.9 months, compared with 7.3 months in a control group that received
vemurafenib alone. Encorafenib, a new-generation BRAF inhibitor, has been approved by FDA for the
treatment of melanoma in combination with binimetinib. However, the mechanism of
the drug works in colorectal cancer (CRC) is still unclear. In this study, the
suppression of growth of CRC cells by encorafenib was investigated. The effects
of treatment of encorafenib on pathways linked to cancer were studied, and the
effective inhibition of cell proliferation was documented. Our findings showed
that cell migration was inhibited by encorafenib through a likely involvement of
MPP and TIMP modulation. Furthermore, encorafenib treatment also induced cell
cycle arrest. In addition, induction of apoptosis in CRC cells by elevating
levels of PUMA. These observations indicate the potential therapeutic efficacy
of encorafenib on CRC. |
What is the basis of the capture Hi-C experimental protocol? | Capture Hi-C (CHi-C) allows high-resolution analysis of targeted regions of the genome by incorporating a sequence capture step into a Hi-C protocol. Capture Hi-C (CHi-C) enriches standard Hi-C libraries for regions of biological interest, for example by specifically targeting gene promoters, aiding identification of biologically significant chromatin interactions compared to conventional Hi-C, for an equivalent number of sequence reads | Genome-wide association studies have identified more than 70 common variants
that are associated with breast cancer risk. Most of these variants map to
non-protein-coding regions and several map to gene deserts, regions of several
hundred kilobases lacking protein-coding genes. We hypothesized that gene
deserts harbor long-range regulatory elements that can physically interact with
target genes to influence their expression. To test this, we developed Capture
Hi-C (CHi-C), which, by incorporating a sequence capture step into a Hi-C
protocol, allows high-resolution analysis of targeted regions of the genome. We
used CHi-C to investigate long-range interactions at three breast cancer gene
deserts mapping to 2q35, 8q24.21, and 9q31.2. We identified interaction peaks
between putative regulatory elements ("bait fragments") within the captured
regions and "targets" that included both protein-coding genes and long noncoding
(lnc) RNAs over distances of 6.6 kb to 2.6 Mb. Target protein-coding genes were
IGFBP5, KLF4, NSMCE2, and MYC; and target lncRNAs included DIRC3, PVT1, and
CCDC26. For one gene desert, we were able to define two SNPs (rs12613955 and
rs4442975) that were highly correlated with the published risk variant and that
mapped within the bait end of an interaction peak. In vivo ChIP-qPCR data show
that one of these, rs4442975, affects the binding of FOXA1 and implicate this
SNP as a putative functional variant. Multiple regulatory elements distant from their targets on the linear genome can
influence the expression of a single gene through chromatin looping. Chromosome
conformation capture implemented in Hi-C allows for genome-wide agnostic
characterization of chromatin contacts. However, detection of functional
enhancer-promoter interactions is precluded by its effective resolution that is
determined by both restriction fragmentation and sensitivity of the experiment.
Here we develop a capture Hi-C (cHi-C) approach to allow an agnostic
characterization of these physical interactions on a genome-wide scale.
Single-nucleotide polymorphisms associated with complex diseases often reside
within regulatory elements and exert effects through long-range regulation of
gene expression. Applying this cHi-C approach to 14 colorectal cancer risk loci
allows us to identify key long-range chromatin interactions in cis and trans
involving these loci. Genome-wide association studies have been tremendously successful in identifying
genetic variants associated with complex diseases. The majority of association
signals are intergenic and evidence is accumulating that a high proportion of
signals lie in enhancer regions. We use Capture Hi-C to investigate, for the
first time, the interactions between associated variants for four autoimmune
diseases and their functional targets in B- and T-cell lines. Here we report
numerous looping interactions and provide evidence that only a minority of
interactions are common to both B- and T-cell lines, suggesting interactions may
be highly cell-type specific; some disease-associated SNPs do not interact with
the nearest gene but with more compelling candidate genes (for example, FOXO1,
AZI2) often situated several megabases away; and finally, regions associated
with different autoimmune diseases interact with each other and the same
promoter suggesting common autoimmune gene targets (for example, PTPRC, DEXI and
ZFP36L1). Genome-wide association studies (GWAS) have identified approximately 100 breast
cancer risk loci. Translating these findings into a greater understanding of the
mechanisms that influence disease risk requires identification of the genes or
non-coding RNAs that mediate these associations. Here, we use Capture Hi-C
(CHi-C) to annotate 63 loci; we identify 110 putative target genes at 33 loci.
To assess the support for these target genes in other data sources we test for
associations between levels of expression and SNP genotype (eQTLs),
disease-specific survival (DSS), and compare them with somatically mutated
cancer genes. 22 putative target genes are eQTLs, 32 are associated with DSS and
14 are somatically mutated in breast, or other, cancers. Identifying the target
genes at GWAS risk loci will lead to a greater understanding of the mechanisms
that influence breast cancer risk and prognosis. Efforts are being directed to systematically analyze the non-coding regions of
the genome for cancer-driving mutations1-6. cis-regulatory elements (CREs)
represent a highly enriched subset of the non-coding regions of the genome in
which to search for such mutations. Here we use high-throughput chromosome
conformation capture techniques (Hi-C) for 19,023 promoter fragments to catalog
the regulatory landscape of colorectal cancer in cell lines, mapping CREs and
integrating these with whole-genome sequence and expression data from The Cancer
Genome Atlas7,8. We identify a recurrently mutated CRE interacting with the ETV1
promoter affecting gene expression. ETV1 expression influences cell viability
and is associated with patient survival. We further refine our understanding of
the regulatory effects of copy-number variations, showing that RASL11A is
targeted by a previously identified enhancer amplification1. This study reveals
new insights into the complex genetic alterations driving tumor development,
providing a paradigm for employing chromosome conformation capture to decipher
non-coding CREs relevant to cancer biology. |
What is the role of Scc2/Nipbl? | Scc2 (Nipbl) stimulates cohesin's ABC-like ATPase and is essential for loading cohesin onto chromosomes. Scc2 also binds dynamically to chromatin, principally through an association with cohesin. Scc2's movement within chromatin is consistent with a 'stop-and-go' or 'hopping' motion. A low diffusion coefficient, a low stoichiometry relative to cohesin, and a high affinity for chromosomal cohesin enables Scc2 to move rapidly from one chromosomal cohesin complex to another, performing a function distinct from loading. | The cohesin complex mediates DNA-DNA interactions both between (sister chromatid
cohesion) and within chromosomes (DNA looping). It has been suggested that
intra-chromosome loops are generated by extrusion of DNAs through the lumen of
cohesin's ring. Scc2 (Nipbl) stimulates cohesin's ABC-like ATPase and is
essential for loading cohesin onto chromosomes. However, it is possible that the
stimulation of cohesin's ATPase by Scc2 also has a post-loading function, for
example driving loop extrusion. Using fluorescence recovery after photobleaching
(FRAP) and single-molecule tracking in human cells, we show that Scc2 binds
dynamically to chromatin, principally through an association with cohesin.
Scc2's movement within chromatin is consistent with a 'stop-and-go' or 'hopping'
motion. We suggest that a low diffusion coefficient, a low stoichiometry
relative to cohesin, and a high affinity for chromosomal cohesin enables Scc2 to
move rapidly from one chromosomal cohesin complex to another, performing a
function distinct from loading. |
What is the chromosomal location of the LDL receptor gene associated with autosomal dominant Familial Hypercholesterolemia? | Familial hypercholesterolemia (FH) is an autosomal dominant inherited metabolic disorder resulting in advanced vascular atherosclerosis and premature death, primarily from coronary artery disease. The primary defect is a mutation in the gene encoding for the plasma LDL receptor located on the short arm of chromosome 19 | Clinical familial hypercholesterolemia has been shown to result from mutations
in 2 genes, the low density lipoprotein (LDL) receptor on chromosome 19 and
apolipoprotein B on chromosome 2. However, we have recently described a Utah
pedigree in which linkage to both genes was clearly excluded. A multipoint
linkage analysis of 583 markers genotyped on 31 (18 affected) members of this
pedigree was undertaken to localize a genetic region that may harbor a third
gene that could result in clinical familial hypercholesterolemia. A multipoint
log of the odds score of 6.8 was obtained for markers on 1p32. Haplotype
carriers and affected status are completely concordant (18/18 persons). The
phenotype is also expressed in young children (ages 4 and 9). Specific
recombit individuals in the pedigree restrict the region of linkage to an
approximately 17 cM interval between polymorphic markers D1S2130 and D1S1596.
This region appears to overlap the region found linked to severe
hypercholesterolemia in French and Spanish families. The identification of the
gene in this region may provide important pathophysiological insights into new
mechanisms that may lead to highly elevated LDL cholesterol and other associated
dyslipidemic phenotypes. |
Can brain derived exosomes carry APP molecules? | Yes,
small lipid vesicles called exosomes, secreted in the extracellular milieu by cortical neurons, carry endogenous APP | Alzheimer's disease (AD) is the most common form of dementia and is associated
with the deposition of the 39- to 43-amino acid beta-amyloid peptide (Abeta) in
the brain. C-terminal fragments (CTFs) of amyloid precursor protein (APP) can
accumulate in endosomally derived multivesicular bodies (MVBs). These
intracellular structures contain intraluminal vesicles that are released from
the cell as exosomes when the MVB fuses with the plasma membrane. Here we have
investigated the role of exosomes in the processing of APP and show that these
vesicles contain APP-CTFs, as well as Abeta. In addition, inhibition of
gamma-secretase results in a significant increase in the amount of alpha- and
beta-secretase cleavage, further increasing the amount of APP-CTFs contained
within these exosomes. We identify several key members of the secretase family
of proteases (BACE, PS1, PS2, and ADAM10) to be localized in exosomes,
suggesting they may be a previously unidentified site of APP cleavage. These
results provide further evidence for a novel pathway in which APP fragments are
released from cells and have implications for the analysis of APP processing and
diagnostics for Alzheimer's disease. Exosomes are small vesicles secreted by most cell types including neurons that
function in intercellular communication through transfer of their cargo or
encapsulate and eliminate unnecessary cellular components and therefore have a
broad impact on nerve development, activation and regeneration. In addition,
exosomes have been observed to be involved in spreading pathological misfolded
proteins, thereby leading to the onset and propagation of disease. Alzheimer
disease (AD) is the most common form of dementia and characterized by two types
of lesions: amyloid plaques and neurofibrillary tangles. Accumulating evidence
has demonstrated that exosomes are associated with amyloid precursor (APP) and
Tau proteins and play a controversial role in Alzheimer's disease process. In
this review, we will discuss the role of exosomes in the metabolism and
secretion of APP and Tau proteins and their subsequent impact on AD
pathogenesis. Amyloid precursor protein (APP) processing is central in Alzheimer's disease
(AD) pathogenesis. The healthy unaffected neurons suffer the transmission of
amyloid protein from pathologically affected neurons, which may play an
important role in the anatomical spread of the disease. Exosomes are appropriate
candidates for transmission of amyloid species, because of their potential role
as "intercellular transportation". To address a role of secreted exosomes in
neuronal homeostasis in AD, we harvested exosomes from the conditioned medium of
HEK293-APP Swe/Ind cells. We have demonstrated that these exosomes contained APP
and were capable of efficiently transferring APP to normal primary neurons.
Moreover, these exosomes had dose-dependent detrimental effect on cultured
neurons. Our results suggest a key mechanism underlying the spread of amyloid
protein in the brain and the acceleration of pathology in AD; exosomes secretion
serves to amplify and propagate Alzheimer's disease related pathology. |
List the most common cancers after a radiation exposure? | well-known increase in leukaemia, increases in solid cancer such as cancers of the lung, breast, stomach and thyroid have also been demonstrated. | Within months of Roentgen's discovery of X rays, severe adverse effects were
reported, but not well publicized. As a result, over the next two decades,
fluoroscope operators suffered lethal skin carcinomas. Later, case reports
appeared concerning leukemia in radiation workers, and infants born with severe
mental retardation after their mothers had been given pelvic radiotherapy early
in pregcy. Fluoroscopy and radiotherapy for benign disorders continued to be
used with abandon until authoritative reports were published on the adverse
effects of ionizing radiation by the U.S. NAS-NRC and the UK MRC in 1956.
Meanwhile, exposure to the atomic bombs in Japan had occurred and epidemics of
delayed effects began to be recognized among the survivors: cataracts (1949),
leukemia (1952) and severe mental retardation among newborn infants after
intrauterine exposure (1952). No statistically significant excess of germ-cell
genetic effects was detected by six clinical measurements (1956), the F1
mortality (1981), cytogenetic studies (1987) or biochemical genetic studies
(1988). Somatic cell effects were revealed by long-lasting chromosomal
aberrations in peripheral lymphocytes (1968), and somatic cell mutations were
found at the glycophorin A locus in erythrocytes (1992). Molecular biology is a
likely focus of new studies based on the function of the gene for ataxia
telangiectasia (1995), a disorder in which children have severe, even lethal
acute radiation reactions when given conventional doses of radiotherapy for
lymphoma, to which they are prone. Also, obligate heterozygote female relatives
can be studied for increased susceptibility to radiation-induced breast cancer,
as suggested by clinical studies. The tumor registries in Hiroshima and Nagasaki
now provide incidence data that show the extent of increases in eight common
cancers and no increase in eight others (1994). The possibility of very late
effects of A-bomb exposure is suggested by recent reports of increased
frequencies of hyperparathyroidism, parathyroid cancers and certain causes of
death other than cancer. BACKGROUND: Because survival rates among childhood cancer patients are
increasing, assessing the risk of second and subsequent maligt neoplasms
(SMNs) is ever more important. Using the Childhood Cancer Survivor Study cohort,
we identified the risk of SMNS:
METHODS: A retrospective cohort of 13 581 children diagnosed with common cancers
before age 21 years and surviving at least 5 years was constructed with the use
of data from patients treated at 25 U.S. and Canadian institutions. SMNs were
ascertained through self-administered questionnaires and verified by pathology
reports. Information on therapeutic exposures was abstracted from medical
records. The risk of SMN was evaluated by standardized incidence ratios (SIRs)
and excess absolute risk. Poisson multiple regression models were used to assess
the impact of host and therapy factors on the risk of developing SMNS: All
statistical tests were two-sided.
RESULTS: In 298 individuals, 314 SMNs were identified (SIR = 6.38; 95%
confidence interval [CI] = 5.69 to 7.13). The largest observed excess SMNs were
bone and breast cancers (SIR = 19.14 [95% CI = 12.72 to 27.67] and SIR = 16.18
[95% CI = 12.35 to 20.83], respectively). A statistically significant excess of
SMNs followed all childhood cancers. In multivariate regression models adjusted
for therapeutic radiation exposure, SMNs of any type were independently
associated with female sex (P<.001), childhood cancer at a younger age (P for
trend <.001), childhood Hodgkin's disease or soft-tissue sarcoma (P<.001 and P
=.01, respectively), and exposure to alkylating agents (P for trend =.02).
Twenty years after the childhood cancer diagnosis, the cumulative estimated SMN
incidence was 3.2%. However, only 1.88 excess maligcies occurred per 1000
years of patient follow-up.
CONCLUSIONS: Success in treating children with cancer should not be overshadowed
by the incidence of SMNS: However, patients and health-care providers must be
aware of risk factors for SMNs so that surveillance is focused and early
prevention strategies are implemented. Susceptibility to most common cancers is likely to involve interaction between
multiple low risk genetic variants. Although there has been great progress in
identifying such variants, their effect on phenotype and the mechanisms by which
they contribute to disease remain largely unknown. We have developed a mouse
melanoma model harboring two mutant oncogenes implicated in human melanoma,
CDK4(R24C) and NRAS(Q61K). In these mice, tumors arise from benign precursor
lesions that are a recognized strong risk factor for this neoplasm in humans. To
define molecular events involved in the pathway to melanoma, we have for the
first time applied the Collaborative Cross (CC) to cancer research. The CC is a
powerful resource designed to expedite discovery of genes for complex traits. We
characterized melanoma genesis in more than 50 CC strains and observed
tremendous variation in all traits, including nevus and melanoma age of onset
and multiplicity, anatomical site predilection, time for conversion of nevi to
melanoma and metastases. Intriguingly, neonatal ultraviolet radiation exposure
exacerbated nevus and melanoma formation in most, but not all CC strain
backgrounds, suggesting that genetic variation within the CC will help explain
individual sensitivity to sun exposure, the major environmental skin carcinogen.
As genetic variation brings about dramatic phenotypic diversity in a single
mouse model, melanoma-related endophenotype comparisons provide us with
information about mechanisms of carcinogenesis, such as whether melanoma
incidence is dependent upon the density of pre-existing nevus cells. Mouse
models have been used to examine the functional role of gene mutations in
tumorigenesis. This work represents their next phase of development to study how
biological variation greatly influences lesion onset and aggressiveness even in
the setting of known somatic driver mutations. |
Which are the main G1/S transcription factors in yeast? | MBF/SBF is the major transcriptional repressor of G1/S genes in Saccharomyces cerevisiae. | We previously isolated the SKN7 gene in a screen designed to isolate new
components of the G1-S cell cycle transcription machinery in budding yeast. We
have now found that Skn7 associates with Mbp1, the DNA-binding component of the
G1-S transcription factor DSC1/MBF. SKN7 and MBP1 show several genetic
interactions. Skn7 overexpression is lethal and is suppressed by a mutation in
MBP1. Similarly, high overexpression of Mbp1 is lethal and can be suppressed by
skn7 mutations. SKN7 is also required for MBP1 function in a mutant compromised
for G1-specific transcription. Gel-retardation assays indicate that Skn7 is not
an integral part of MBF. However, a physical interaction between Skn7 and Mbp1
was detected using two-hybrid assays and GST pulldowns. Thus, Skn7 and Mbp1 seem
to form a transcription factor independent of MBF. Genetic data suggest that
this new transcription factor could be involved in the bud-emergence process. The G(1)/S transition is a critical control point for cell proliferation and
involves essential transcription complexes termed SBF and MBF in Saccharomyces
cerevisiae or MBF in Schizosaccharomyces pombe. In the fungal pathogen Candida
albicans, G(1)/S regulation is not clear. To gain more insight into the G(1)/S
circuitry, we characterized Swi6p, Swi4p and Mbp1p, the closest orthologues of
SBF (Swi6p and Swi4p) and MBF (Swi6p and Mbp1p) components in S. cerevisiae. The
mbp1Δ/Δ cells showed minor growth defects, whereas swi4Δ/Δ and swi6Δ/Δ yeast
cells dramatically increased in size, suggesting a G(1) phase delay. Gene set
enrichment analysis (GSEA) of transcription profiles revealed that genes
associated with G(1)/S phase were significantly enriched in cells lacking Swi4p
and Swi6p. These expression patterns suggested that Swi4p and Swi6p have
repressing as well as activating activity. Intriguingly, swi4Δ/Δ swi6Δ/Δ and
swi4Δ/Δ mbp1Δ/Δ strains were viable, in contrast to the situation in S.
cerevisiae, and showed pleiotropic phenotypes that included multibudded yeast,
pseudohyphae, and intriguingly, true hyphae. Consistently, GSEA identified
strong enrichment of genes that are normally modulated during C. albicans-host
cell interactions. Since Swi4p and Swi6p influence G(1) phase progression and
SBF binding sites are lacking in the C. albicans genome, these factors may
contribute to MBF activity. Overall, the data suggest that the putative G(1)/S
regulatory machinery of C. albicans contains novel features and underscore the
existence of a relationship between G(1) phase and morphogenetic switching,
including hyphal development, in the pathogen. In Saccharomyces cerevisiae, G1/S transcription factors MBF and SBF regulate a
large family of genes important for entry to the cell cycle and DNA replication
and repair. Their regulation is crucial for cell viability, and it is conserved
throughout evolution. MBF and SBF consist of a common component, Swi6, and a
DNA-specific binding protein, Mbp1 and Swi4, respectively. Transcriptional
repressors bind to and regulate the activity of both transcription factors. Whi5
binds to SBF and represses its activity at the beginning of the G1 phase to
prevent early activation. Nrm1 binds to MBF to repress transcription as cells
progress through S phase. Here, we describe a protein motif, the GTB motif (for
G1/S transcription factor binding), in Nrm1 and Whi5 that is required to bind to
the transcription factors. We also identify a region of the carboxy terminus of
Swi6 that is required for Nrm1 and Whi5 binding to their target transcription
factors and show that mutation of this region overrides the repression of MBF-
and SBF-regulated genes by Nrm1 and Whi5. Finally, we show that the GTB motif is
the core of a functional module that is necessary and sufficient for targeting
of the transcription factors by their cognate repressors. Transcriptional regulatory networks play a central role in optimizing cell
survival. How DNA binding domains and cis-regulatory DNA binding sequences have
co-evolved to allow the expansion of transcriptional networks and how this
contributes to cellular fitness remains unclear. Here we experimentally explore
how the complex G1/S transcriptional network evolved in the budding yeast
Saccharomyces cerevisiae by examining different chimeric transcription factor
(TF) complexes. Over 200 G1/S genes are regulated by either one of the two TF
complexes, SBF and MBF, which bind to specific DNA binding sequences, SCB and
MCB, respectively. The difference in size and complexity of the G1/S
transcriptional network across yeast species makes it well suited to investigate
how TF paralogs (SBF and MBF) and DNA binding sequences (SCB and MCB) co-evolved
after gene duplication to rewire and expand the network of G1/S target genes.
Our data suggests that whilst SBF is the likely ancestral regulatory complex,
the ancestral DNA binding element is more MCB-like. G1/S network expansion took
place by both cis- and trans- co-evolutionary changes in closely related but
distinct regulatory sequences. Replacement of the endogenous SBF DNA-binding
domain (DBD) with that from more distantly related fungi leads to a contraction
of the SBF-regulated G1/S network in budding yeast, which also correlates with
increased defects in cell growth, cell size, and proliferation. To understand how commitment to cell division in late G1 phase (Start) is
controlled by growth and nutrients in budding yeast, we determined the absolute
concentrations of the G1/S transcription factors SBF (composed of Swi4 and Swi6)
and MBF (composed of Mbp1 and Swi6), the transcriptional repressor Whi5, and the
G1 cyclins, Cln1 and Cln2, in single live yeast cells using scanning number and
brightness (sN&B) microscopy. In rich medium, Whi5, Mbp1, and Swi6
concentrations were independent of cell size, whereas Swi4 concentration doubled
in G1 phase, leading to a size-dependent decrease in the Whi5/Swi4 ratio. In
small cells, SBF and MBF copy numbers were insufficient to saturate target G1/S
promoters, but this restriction diminished as cells grew in size. In poor
medium, SBF and MBF subunits, as well as Cln1, were elevated, consistent with a
smaller cell size at Start. A mathematical model constrained by sN&B data
suggested that size- and nutrient-dependent occupancy of G1/S promoters by
SBF/MBF helps set the cell size threshold for Start activation. |
What is Hemochromatosis? | Hereditary hemochromatosis (HH) is a group of genetic iron overload disorders that manifest with various symptoms, including hepatic dysfunction, diabetes, and cardiomyopathy. | Hemochromatosis is a common disorder characterized by excess iron absorption and
accumulation of iron in tissues. Usually hemochromatosis is inherited in an
autosomal recessive pattern and is caused by mutations in the HFE gene. Less
common non-HFE-related forms of hemochromatosis have been reported and are
caused by mutations in the transferrin receptor 2 gene and in a gene localized
to chromosome 1q. Autosomal domit forms of hemochromatosis have also been
described. Recently, 2 mutations in the ferroportin1 gene, which encodes the
iron transport protein ferroportin1, have been implicated in families with
autosomal domit hemochromatosis from the Netherlands and Italy. We report the
finding of a novel mutation (V162del) in ferroportin1 in an Australian family
with autosomal domit hemochromatosis. We propose that this mutation disrupts
the function of the ferroportin1 protein, leading to impaired iron homeostasis
and iron overload. Hereditary hemochromatosis is an inherited disorder of iron metabolism in the
Caucasian population with an autosomal recessive inheritance and a prevalence
between 1 in 200 and 1 in 500. Until the discovery of HFE gene the diagnosis of
hemochromatosis required documentation of iron overload or family linkage using
HLA testing. The discovery of HFE gene has established the foundation for a
better understanding of iron homeostasis and has changed hemochromatosis
management: liver biopsy, gold standard diagnostic, was replaced by genetic test
and it was suggested that population screening using genetic testing might be
ideal for HFE related hemochromatosis. Considered for long time a unitary
disease, a monogenic disorder characterized by excess tissue deposits of iron
and subsequently organ damage, hemochromatosis is in fact a polygenic disease
with many faces. The Online Mendelian Inheritance in Man database has lists four
types of hereditary hemochromatosis, each of them caused by a different gene
mutation (hepcidine, hemojuvelin, transferring receptor 2, ferroportin). The
basic features shared by iron overload disorders associated with mutation in
HFE, hepcidine, hemojuvelin, transferring receptor 2, ferroportin gene indicate
that they are genetic variation of the same syndrome. Hereditary hemochromatosis
must be distinguished from the other syndrome of iron overload and the classic
term hereditary hemochromatosis should be reserved only for HFE related
hemochromatosis. Hereditary hemochromatosis is an iron overload disorder that can lead to the
impairment of multiple organs and is caused by mutations in one or more
different genes. Type 1 hemochromatosis is the most common form of the disease
and results from mutations in the HFE gene. Juvenile hemochromatosis (JH) is the
most severe form, usually caused by mutations in hemojuvelin (HJV) or hepcidin
(HAMP). The autosomal domit form of the disease, type 4, is due to mutations
in the SLC40A1 gene, which encodes for ferroportin (FPN). Hereditary
hemochromatosis is commonly found in populations of European origin. By
contrast, hemochromatosis in Asia is rare and less well understood and can be
masked by the presence of iron deficiency and secondary iron overload from
thalassemia. Here, we provide a comprehensive report of hemochromatosis in a
group of patients of Asian origin. We have identified novel mutations in HJV,
HAMP, and SLC40A1 in countries not normally associated with hereditary
hemochromatosis (Pakistan, Bangladesh, Sri Lanka, and Thailand). Our family
studies show a high degree of consanguinity, highlighting the increased risk of
iron overload in many countries of the developing world and in countries in
which there are large immigrant populations from these regions. OBJECTIVE: Hemochromatosis is an inherited disease with iron overload and joint
involvement resembling osteoarthritis. To determine the rate of joint
replacement surgery in patients with hemochromatosis, we performed a
cross-sectional cohort study.
METHODS: A total of 199 individuals with hereditary hemochromatosis were
included. The prevalence of joint replacement surgery in hip, knee, and ankle
joints because of secondary osteoarthritis was assessed. Data were compared with
917 healthy subjects from the population-based Bruneck study.
RESULTS: A total of 32 of 199 individuals with hemochromatosis received joint
replacement surgery with a total number of 52 joints replaced. Compared with
expected rates in healthy individuals, patients with hemochromatosis had a
significantly higher risk for joint replacement surgery (odds ratio 9.0;
confidence interval, 4.6-17.4). Joint replacement occurred significantly earlier
in life in patients with hemochromatosis; 21.9% of the patients with
hemochromatosis and 1.7% of healthy individuals required joint replacement
before the age of 50 years (P=.0027). Moreover, patients with hemochromatosis
were more likely to require multiple joint replacements (8.5%) than the control
group (expected rate 0.3%; P=.0001).
CONCLUSION: Hemochromatosis is a risk factor for joint replacement surgery
because of severe secondary osteoarthritis. Hereditary hemochromatosis type 1, also known as hereditary hemochromatosis
classical (HHC), is an iron overload disorder associated, in most cases, with
mutations of the hemochromatosis (HFE) gene. Although suggested algorithms for
diagnosing iron overload are available, there are still questions about options
for genetic and biochemical screening for hemochromatosis and duration of
treatment. This article provides a summary of an expert workgroup meeting
convened on September 24-25, 2009, entitled "Iron Overload: What is the Role of
Public Health?" The purpose of the meeting was to enable subject matter experts
to share their most recent clinical and scientific iron overload information and
to facilitate the discussion of future endeavors, with special emphasis on the
role of public health in this field. The two main topics were the research
priorities of the field, including clinical, genetic, and public health issues,
and the concerns about the validity of current screening recommendations for the
condition. Hereditary hemochromatosis is an autosomal recessive disorder that disrupts the
body's regulation of iron. It is the most common genetic disease in whites. Men
have a 24-fold increased rate of iron-overload disease compared with women.
Persons who are homozygous for the HFE gene mutation C282Y comprise 85 to 90
percent of phenotypically affected persons. End-organ damage or clinical
manifestations of hereditary hemochromatosis occur in approximately 10 percent
of persons homozygous for C282Y. Symptoms of hereditary hemochromatosis are
nonspecific and typically absent in the early stages. If present, symptoms may
include weakness, lethargy, arthralgias, and impotence. Later manifestations
include arthralgias, osteoporosis, cirrhosis, hepatocellular cancer,
cardiomyopathy, dysrhythmia, diabetes mellitus, and hypogonadism. Diagnosis
requires confirmation of increased serum ferritin levels and transferrin
saturation, with or without symptoms. Subtyping is based on genotypic
expression. Serum ferritin measurement is the most useful prognostic indicator
of disease severity. Liver biopsy is performed to stage the degree of fibrosis
with severe ferritin elevation or transaminitis, or to diagnose nonclassical
hereditary hemochromatosis in patients with other genetic defects. Treatment of
hereditary hemochromatosis requires phlebotomy, and the frequency is guided by
serial measurements of serum ferritin levels and transferrin saturation. Iron
avidity can result from overtreatment. If iron avidity is not suspected, it may
mimic undertreatment with persistently elevated transferrin saturation. Dietary
modification is generally unnecessary. Universal screening for hereditary
hemochromatosis is not recommended, but testing should be performed in
first-degree relatives of patients with classical HFE-related hemochromatosis,
those with evidence of active liver disease, and patients with abnormal iron
study results. Screening for hepatocellular carcinoma is reserved for those with
hereditary hemochromatosis and cirrhosis. BACKGROUND: Hereditary hemochromatosis is a disorder that can cause iron
overload and organ damage. Hereditary hemochromatosis is characterized by
mutations in the HFE gene. HFE C282Y homozygotes and compound heterozygotes
(C282Y/H63D) are at risk of developing manifestations of hemochromatosis.
Abnormal iron study results also occur in many liver and hematologic diseases.
The aim of this study was to evaluate the accuracy of diagnosis of hereditary
hemochromatosis.
METHODS: Pertinent clinical and laboratory data, including HFE genotype, were
tabulated from the electronic medical records of patients with the International
Classification of Diseases 9th Revision code 275, "disorders of iron
metabolism," who were seen at a tertiary referral center between January 2002
and May 2012.
RESULTS: HFE genotyping was obtained in only 373 of 601 patients (62%); 200 were
C282Y homozygotes or compound heterozygotes. Of the 173 patients with
nonhereditary hemochromatosis genotypes, 53% were misdiagnosed with hereditary
hemochromatosis and 38% underwent phlebotomy. In two thirds of these cases, the
misdiagnosis was made by a nonspecialist. In the remaining 228 patients who were
not genotyped, 80 were diagnosed with hereditary hemochromatosis and 64 were
phlebotomized. Of patients misdiagnosed with hemochromatosis, 68% had known
liver disease and 5% had a hematologic cause of abnormal iron study results.
CONCLUSIONS: Abnormal iron study results in patients with nonhereditary
hemochromatosis genotypes commonly lead to a misdiagnosis of hereditary
hemochromatosis and inappropriate treatment with phlebotomy. This error often is
seen in the setting of elevated iron study results secondary to chronic liver
diseases. Furthermore, hereditary hemochromatosis is commonly diagnosed and
treated without HFE genotyping. We suggest that phlebotomy centers require a
documented HFE genotype before initiating phlebotomy. Hemochromatosis (iron storage disease) has been reported in diverse mammals
including bottlenose dolphins (Tursiops truncatus). The primary cause of
excessive iron storage in humans is hereditary hemochromatosis. Most human
hereditary hemochromatosis cases (up to 90%) are caused by a point mutation in
the hfe gene, resulting in a C282Y substitution leading to iron accumulation. To
evaluate the possibility of a hereditary hemochromatosis-like genetic
predisposition in dolphins, we sequenced the bottlenose dolphin hfe gene, using
reverse transcriptase-PCR and hfe primers designed from the dolphin genome, from
liver of affected and healthy control dolphins. Sample size included two case
animals and five control animals. Although isotype diversity was evident, no
coding differences were identified in the hfe gene between any of the animals
examined. Because our sample size was small, we cannot exclude the possibility
that hemochromatosis in dolphins is due to a coding mutation in the hfe gene.
Other potential causes of hemochromatosis, including mutations in different
genes, diet, primary liver disease, and insulin resistance, should be evaluated. Hereditary hemochromatosis (HH) is a genetic disorder of iron metabolism that
may lead to iron overload. Clinical penetrance is low, however those afflicted
may develop cirrhosis, hepatocellular carcinoma, diabetes mellitus, and
cardiomyopathy. Treatment of HH involves regular phlebotomy to reduce the
systemic iron burden. In many countries-including the United States-numerous
blood centers do not accept donated blood obtained from HH patients during
therapeutic phlebotomy and there are inconsistent positions regarding this
globally. This refusal of blood is borne out of a few concerns. First, there is
a theoretical increase in the infectious risk of these blood products,
particularly by siderophilic organisms such as Yersinia enterocolitica. Second,
given the increased incidence of hepatitis C infection from nonvoluntary donors
in the 1970s, there is a concern that blood units from HH donors may harbor
additional risk given the nonvoluntary nature of their presentation. In this
review, we examine the existing biological and clinical data concerning
infectious risk and summarize clinical experience from centers allowing HH
donors, and demonstrate that blood from HH patients is safe and should be
allowed into the donor pool. We conclude that there is no convincing evidence to
exclude this population from serving as blood donors. (Hepatology
2018;67:1150-1157). Hereditary hemochromatosis (HH) is a group of genetic iron overload disorders
that manifest with various symptoms, including hepatic dysfunction, diabetes,
and cardiomyopathy. Classic HH type 1, which is common in Caucasians, is caused
by bi-allelic mutations of HFE. Severe types of HH are caused by either
bi-allelic mutations of HFE2 that encodes hemojuvelin (type 2A) or HAMP that
encodes hepcidin (type 2B). HH type 3, which is of intermediate severity, is
caused by bi-allelic mutations of TFR2 that encodes transferrin receptor 2.
Mutations of SLC40A1 that encodes ferroportin, the only cellular iron exporter,
causes either HH type 4A (loss-of-function mutations) or HH type 4B
(gain-of-function mutations). Studies on these gene products uncovered a part of
the mechanisms of the systemic iron regulation; HFE, hemojuvelin, and TFR2 are
involved in iron sensing and stimulating hepcidin expression, and hepcidin
downregulates the expression of ferroportin of the target cells. Phlebotomy is
the standard treatment for HH, and early initiation of the treatment is
essential for preventing irreversible organ damage. However, because of the
rarity and difficulty in making the genetic diagnosis, a large proportion of
patients with non-HFE HH might have been undiagnosed; therefore, awareness of
this disorder is important. Mutations of SLC40A1 encoding ferroportin (Fpn), the unique cellular iron
exporter, severely affect iron homeostasis causing type 4 hereditary
hemochromatosis, an autosomal domit iron overload condition with variable
phenotypic manifestations. This disease can be classified as type 4A, better
known as "ferroportin disease", which is due to "loss of function" mutations
that lead to decreased iron export from cells, or as type 4B hemochromatosis,
which is caused by "gain of function" mutations, conferring partial or complete
resistance to hepcidin-mediated Fpn degradation. In this work, we discuss
clinical and molecular findings on a group of patients in whom a SLC40A1 single
copy missense variant was identified. Three novel variants, p.D181N, p.G204R and
p.R296Q were functionally characterized. Fpn D181N and R296Q mutants can be
classified as full or partial loss of function, respectively. Replacement of
G204 with arginine appears to cause a more complex defect with impact both on
iron export function and hepcidin sensitivity. This finding confirms the
difficulty of predicting the effect of a mutation on the molecular properties of
Fpn in order to provide an exhaustive explanation to the wide variability of the
phenotype in type 4 hereditary hemochromatosis. Hereditary hemochromatosis (HH) is one of the most common genetically
transmitted conditions in individuals of Northern European ancestry. The disease
is characterized by excessive intestinal absorption of dietary iron, resulting
in pathologically high iron storage in tissues and organs. If left untreated, HH
can damage joints and organs, and eventually lead to death. There are four main
classes of HH, as well as five individual molecular subtypes, caused by
mutations in five genes, and the approaches implemented in the discovery of each
HH type have specific histories and unique aspects. In this chapter, we review
the genetics of the different HH types, including the strategies used to detect
the causal variants in each case and the manner in which genetic variants were
found to affect iron metabolism. |
What molecules are the multidrug transporter MDR3 targeting? | Multidrug-resistant P-glycoprotein 3 (MDR3) is a phospholipid translocator. | The ATP-binding cassette transporter ABCB4/MDR3 is critical for biliary
phosphatidylcholine (PC) excretion at the canalicular membrane of hepatocytes.
Defective ABCB4 gene expression and protein function result in various
cholestatic liver and bile duct injuries. Thyroid hormone receptor (THR) is a
major regulator of hepatic lipid metabolism; we explored its potential role in
ABCB4 regulation. Thyroid hormone T3 stimulation to human hepatocyte models
showed direct transcriptional activation of ABCB4 in a dose- and time-dependent
manner. To determine whether THRβ1 (the main THR isoform of the liver) is
involved in regulation, we tested THRβ1-specific agonists (e.g., GC-1, KB-141);
these agonists resulted in greater stimulation than the native hormone. KB-141
activated hepatic ABCB44 expression in mice, which enhanced biliary PC secretion
in vivo. We also identified THR response elements 6 kb upstream of the ABCB4
locus that were conserved in humans and mice. Thus, T3-via THRβ1 as a novel
transcriptional activator regulates ABCB4 to increase ABCB4 protein levels at
the canalicular membrane and promote PC secretion into bile. These findings may
have important implications for understanding thyroid hormone function as a
potential modifier of bile duct homeostasis and provide pharmacologic
opportunities to improve liver function in hepatobiliary diseases caused by low
ABCB4 expression. The multiple drug resistance 3 (MDR3) protein is a canalicular phospholipid
translocator involved in the bile secretion and encoded by the ABCB4 gene. Its
deficiency is related to a large spectrum of liver diseases. Taking into account
the increased evidence about the involvement of synonymous variants in inherited
diseases, this study aims to explore the putative effects of silent genetic
variants on the ABCB4 expression. We performed an exhaustive computational
approach using ESE finder, RegRNA 2.0, MFOLD, SNPfold, and %MinMax software
added to the measurement of the Relative Synonymous Codon Usage. This analysis
included 216 synonymous variants distributed throughout the ABCB4 gene. Results
have shown that 11 synonymous coding SNPs decrease the ESE activity, while 8 of
them change the codon frequency. Besides, the c.24C>T variation, located 21
nucleotides downstream the start A (Adenine) U (Uracil) G (Glutamine) AUG causes
an increase in the local stability. Moreover, the computational analysis of the
3'UTR region showed that six of the eight variants located in this region
affected the Wild Type (WT) pattern of the miRNA targets sites and/or their
proper display. The 26 sSNPs retained as putatively functional possessed a very
low allele frequency, supporting their pathogenicity. In conclusion, the
obtained results suggest that some synonymous SNPs in the ABCB4 gene, considered
up to now as neutral, may be involved in the MDR3 deficiency. Multidrug-resistant P-glycoprotein 3 (MDR3) is a phospholipid translocator
encoded by the ABCB4 gene located on chromosome 7. MDR3 mediates the
translocation of phosphatidylcholine across the canalicular membrane of the
hepatocyte into bile. Severe MDR3 deficiency typically occurs during childhood
with progressive cholestasis evolving to cirrhosis and liver failure, requiring
liver transplantation. In this article, we report 2 pediatric cases of severe
MDR3 deficiency with paucity of interlobular bile ducts. Both underwent living
donor liver transplantation at our center for decompensated liver disease and
portal hypertension. We diagnosed severe MDR3 deficiency in both the cases with
negative MDR3 immunostaining in the explanted liver. Genetic studies revealed
homozygous deletion single base pair deletion in exon 24 of the ABCB4 gene in
the second child. The patients are on regular follow-up after liver transplant
and are doing well. Our report highlights that cholangiopathy in MDR3 deficiency
can lead to ductopenia in pediatric livers. |
What is the role of the Hof1-Cyk3 interaction in yeast? | In Saccharomyces cerevisiae, it is well established that Hof1, Cyk3, and Inn1 contribute to septum formation and cytokinesis. There is also evidence that they interact physically. | |
List features of the SAM syndrome. | SAM syndrome is characterized by severe dermatitis, multiple allergies and metabolic wasting. It is caused by mutations in the desmoglein 1 gene (DSG1). | Monoallelic desmoglein 1 mutations have been known for many years to cause
striate palmoplantar keratoderma, but only recently, biallelic loss-of-function
mutations were associated with a new disorder, designated as SAM syndrome
(comprising severe dermatitis, multiple allergies and metabolic wasting) in two
consanguineous families. We report on a new case from a third independent family
with the homozygous nonsense mutation, c.2659C>T, p.R887* in exon 15 of DSG1
(desmoglein 1 gene). This mutation led to mRNA decay and loss of expression of
desmoglein 1. The clinical phenotype consisted of severe palmoplantar
keratoderma, dermatitis and multiple allergies. In contrast to the previous
cases, malabsorption, hypoalbuminaemia, developmental delay, hypotrichosis or
severe recurrent infections were not observed. Recently, homozygous mutations in the desmoglein-1 (DSG1) gene and heterozygous
mutation in the desmoplakin (DSP) gene have been demonstrated to be associated
with severe dermatitis, multiple allergies and metabolic wasting (SAM) syndrome
(Mendelian Inheritance in Man no. 615508). We aim to identify the molecular
basis for a Chinese pedigree of SAM syndrome. A Chinese pedigree of SAM syndrome
was subjected to mutation detection in the DSG1 gene. Sequence analysis of the
DSG1 gene and quantitative reverse transcriptase polymerase chain reaction
analysis for gene expression of DSG1 using cDNA derived from the epidermis of
patients and controls were both performed. Skin biopsies were also taken from
patients for pathological study and transmission electron microscopy
observation. Novel homozygous splicing mutation c.1892-1delG in the exon-intron
border of the DSG1 gene has been demonstrated to be associated with SAM
syndrome. We report a new family of SAM syndrome of Asian decent and expand the
spectrum of mutations in the DSG1 gene. Severe dermatitis, multiple allergies and metabolic wasting (SAM) syndrome is a
recently recognized syndrome caused by mutations in the desmoglein 1 (DSG1) and
desmoplakin (DSP) genes. Only two cases of SAM-DSP have been reported. We report
on a 2-year-old girl presenting with pustular lakes within areas of erythema and
large accumulations of intraepidermal neutrophils, which initially led to our
misdiagnosis of generalized pustular psoriasis. No mutation was found in either
the IL36RN or CARD14 genes by Sanger sequencing. The distinctive manifestations
of erythroderma with severe itching, hypotrichosis, enamel defects,
onychodystrophy, palmoplantar keratoderma and the crucial result of de novo
missense mutation in exon 14 of the DSP gene (c.1828T>C, p.S610P) discovered by
next-generation sequencing finally confirmed the diagnosis of SAM syndrome. The
eruptions significantly improved after a 4-week treatment with oral acitretin
and topical pimecrolimus. Oral gabapentin was prescribed simultaneously for
4 months, relieving her skin pruritus and suggesting that early treatment with
pimecrolimus, acitretin and gabapentin for SAM-DSP syndrome is effective. It may
even inhibit multiple allergies induced by skin barrier injury. In this work we
also review the clinical features, differential diagnoses and pathological
manifestations of SAM-DSP syndrome. |
What does the Smith–Waterman algorithm do? | The Smith-Waterman algorithm performs local sequence alignments. | The Smith-Waterman algorithm for local sequence alignment is one of the most
important techniques in computational molecular biology. This ingenious dynamic
programming approach was designed to reveal the highly conserved fragments by
discarding poorly conserved initial and terminal segments. However, the existing
notion of local similarity has a serious flaw: it does not discard poorly
conserved intermediate segments. The Smith-Waterman algorithm finds the local
alignment with maximal score but it is unable to find local alignment with
maximum degree of similarity (e.g. maximal percent of matches). Moreover, there
is still no efficient algorithm that answers the following natural question: do
two sequences share a (sufficiently long) fragment with more than 70% of
similarity? As a result, the local alignment sometimes produces a mosaic of
well-conserved fragments artificially connected by poorly-conserved or even
unrelated fragments. This may lead to problems in comparison of long genomic
sequences and comparative gene prediction as recently pointed out by Zhang et
al. (Bioinformatics, 15, 1012-1019, 1999). In this paper we propose a new
sequence comparison algorithm (normalized local alignment ) that reports the
regions with maximum degree of similarity. The algorithm is based on fractional
programming and its running time is O(n2log n). In practice, normalized local
alignment is only 3-5 times slower than the standard Smith-Waterman algorithm. |
Is SATB1 positioned close to AT-rich sequences? | Yes, SATB1 is preferentially located at the start of an AT-rich sequence and is associated with other, more diffuse AT- rich sequences in the genome. | A cis-acting DNA regulatory element 3' to the A gamma-globin gene contains eight
distinct regions of DNA-protein interaction distributed over 750 bp of DNA. The
sequences of two foot-printed regions (sites I and IV) are A-T rich and generate
a highly retarded complex on gel shift analysis with nuclear extract from human
erythroleukemia (K562) cells. We have purified a 98-kD protein that reproduces
this gel shift. Tryptic cleavage and peptide sequence analysis demonstrated that
the 98-kD protein is identical to a recently cloned protein, special A-T-rich
binding protein 1 (SATB1), that binds selectively to nuclear
matrix/scaffold-associated regions of DNA (MARs/SARs). We have shown by
functional analysis that the 3' A gamma regulatory element associates with the
nuclear matrix. SATB1 mRNA was identified in K562 cells, and reverse
transcriptase-polymerase chain reaction (RT-PCR) demonstrated its transcript in
several other hematopoietic lines. Antisera to SATB1 caused ablation of the gel
shift complex generated by both the crude nuclear extract and the purified 98-kD
protein with the site I oligonucleotide. Furthermore, oligonucleotides that bind
SATB1 inhibited formation of the site I gel shift complex when added as excess
unlabeled competitor. An immunoblot analysis of the site I gel shift complex
documented the presence of SATB1. Binding of SATB1 to two sites within the 3' A
gamma regulatory element and its MAR/SAR activity suggests that this element may
influence gene expression through interaction with the nuclear matrix. The t(14,18) chromosomal translocation that occurs in human follicular lymphoma
constitutively activates the BCL2 gene and disrupts control of apoptosis.
Interestingly, 70% of the t(14,18) translocations are confined to three 15-bp
clusters positioned within a 150-bp region (major breakpoint region or [MBR]) in
the untranslated portion of terminal exon 3. We analyzed DNA-protein
interactions in the MBR, as these may play some role in targeting the
translocation to this region. An 87-bp segment (87MBR) immediately 3' to
breakpoint cluster 3 was essential for DNA-protein interaction monitored with
mobility shift assays. We further delineated a core binding region within 87MBR:
a 33-bp, very AT-rich sequence highly conserved between the human and mouse BCL2
gene (37MBR). We have purified and identified one of the core factors as the
matrix attachment region (MAR) binding protein, SATB1, which is known to bind to
AT-rich sequences with a high propensity to unwind. Additional factors in
nuclear extracts, which we have not yet characterized further, increased SATB1
affinity for the 37MBR target four- to fivefold. Specific binding activity
within 37MBR displayed cell cycle regulation in Jurkat T cells, while levels of
SATB1 remained constant throughout the cell cycle. Finally, we demonstrated in
vivo binding of SATB1 to the MBR, strongly suggesting the BCL2 major breakpoint
region is a MAR. We discuss the potential consequences of our observations for
both MBR fragility and regulatory function. SATB1 (special AT-rich sequence-binding protein-1) provides a key link between
DNA loop organization, chromatin modification/remodeling, and association of
transcription factors at matrix attachment regions (MARs). To investigate the
role of SATB1 in cellular events, we performed a yeast two-hybrid screen that
identified SUMO-1, Ubc9, and protein inhibitor of activated STAT (PIAS) family
members as SATB1 interaction partners. These proteins, working in concert,
enhanced SUMO conjugation to lysine-744 of SATB1. Overexpression of SUMO or PIAS
in Jurkat cells, which express high levels of endogenous SATB1, exhibited
enhanced caspase cleavage of this MAR-associating protein. Sumoylation-deficient
SATB1 (SATB1(K744R)) failed to display the characteristic caspase cleavage
pattern; however, fusion of SUMO in-frame to SATB1(K744R) restored cleavage. A
SUMO-independent interaction of inactive caspase-6 and SATB1 was noted. A subset
of total cellular SATB1 localized into promyelocytic leukemia nuclear bodies
where enhanced SATB1 cleavage was detected subsequent to caspase activation.
These results reveal a novel sumoylation-directed caspase cleavage of this key
regulatory molecule. The role of regulated proteolysis of SATB1 may be to
control transcription in immune cells during normal cell functions or to assist
in efficient and rapid clearance of nonfunctional or potentially damaging immune
cells. BACKGROUND: Special AT rich sequence binding protein 1 (SATB1) plays a crucial
role in the biology of various types of human cancer. However, the role of SATB1
in human nasopharyngeal carcinoma (NPC) remains unknown. In the present study,
we sought to investigate the contribution of aberrant SATB1 expression in the
progression of NPC and its association with the Epstein Barr virus (EBV)-encoded
latent membrane protein 1 (LMP-1).
METHODS: Immunohistochemical analysis was performed to detect SATB1 and LMP-1
protein in clinical samples, and the association of SATB1 protein expression
with patient clinicopathological characteristics and LMP-1 expression were
analyzed. SATB1 expression profiles were evaluated in well-differentiated NPC
cell line CNE1, poorly-differentiated CNE2Z, undifferentiated C666-1 and
immortalized nasopharyngeal epithelia NP-69 cells using quantitative RT-PCR,
western blotting and fluorescent staining. After inhibition the SATB1 expression
by using SATB1 specific small interfering RNA in these cell lines, the change of
cell proliferation was investigated by western blotting analysis of PCNA
(proliferating cell nuclear antigen) expression and CCK-8 assay, and the cell
migration was assessed by Transwell migration assay. Finally, the expressions of
SATB1 and PCNA were examined in CNE1 cells that forced LMP-1 expression by
fluorescent staining and RT-PCR.
RESULTS: Immunohistochemical analysis revealed that SATB1 protein expression was
elevated in NPC tissues compared to benign nasopharyngeal tissues (P = 0.005).
Moreover, high levels of SATB1 protein expression were positively correlated
with clinical stage (P = 0.025), the status of lymph node metastasis (N
classification) (P = 0.018), distant metastasis (M classification) (P = 0.041)
and LMP-1 expression status (r = 2.35, P < 0.01) in NPC patients. In vitro
experiments demonstrated that an inverse relationship between SATB1 expression
and NPC differentiation status, with SATB1 weakly expressed in NP-69 cells and
CNE1 cells, and significant increasingly expressed in CNE-2Z and C666-1 cells.
Targeted knockdown of SATB1 expression obviously attenuated the proliferation
and migration of highly SATB1-expressing CNE2Z and C666-1 cells, but not NP-69
and CNE1 cells. Interestingly, forced LMP-1 expression in CNE1 cells led to a
surprisingly increasing SATB1 expression and nuclear location, companying with
an up-regulated PCNA expression.
CONCLUSIONS: Our results reveal that EBV LMP-1-mediated over-expression of SATB1
is associated with NPC progression, suggesting SATB1 may represent a promising
biomarker and therapeutic target for NPC. AIM: Special AT-rich sequence-binding protein 1 (SATB1) is a cell type-specific
matrix attachment region binding protein, functioning as a global genome
organizer. This study aims to investigate the expression pattern and the
prognostic value of SATB1 in colorectal cancer.
METHODS AND RESULTS: Prospectively collected data were obtained and tissue
microarrays were constructed from a cohort of 352 patients. SATB1 protein
expression was evaluated by immunohistochemistry and scored by two independent
investigators. SATB1 expression was predomitly nuclear in both normal and
cancer tissues. Loss of SATB1 nuclear expression was seen in 22% of colorectal
cancers compared to 1.5% of adjacent normal colorectal tissue, and was
associated with worse overall survival (P = 0.02) independent of age and stage
of disease (HR 2.48 with 95% CI 1.31-4.70). Loss of SATB1 expression was more
evident in younger patients (P = 0.03), tumours with mucinous or signet ring
histology (P = 0.0001) and poor differentiation (P = 0.005). SATB1 expression
was associated with a survival advantage in patients with Dukes C tumours who
received adjuvant chemotherapy.
CONCLUSION: Loss of SATB1 nuclear expression correlates with poor survival and a
less favourable response to adjuvant chemotherapy in colorectal cancer. The
value of SATB1 in individualized colorectal cancer therapy warrants further
evaluation. SATB1 (special AT-rich binding protein 1) is a global chromatin organizer
regulating the expression of a large number of genes. Overexpression has been
found in various solid tumors and positively correlated with prognostic and
clinicopathological properties. In colorectal cancer (CRC), SATB1 overexpression
and its correlation with poor differentiation, invasive depth, TNM (tumor,
nodes, metastases) stage and prognosis have been demonstrated. However, more
detailed studies on the SATB1 functions in CRC are warranted. In this article,
we comprehensively analyze the cellular and molecular role of SATB1 in CRC cell
lines with different SATB1 expression levels by using RNAi-mediated knockdown.
Using siRNAs with different knockdown efficacies, we demonstrate
antiproliferative, cell cycle-inhibitory and proapoptotic effects of SATB1
knockdown in a SATB1 gene dose-dependent manner. Tumor growth inhibition is
confirmed in vivo in a subcutaneous tumor xenograft mouse model using stable
knockdown cells. The in-depth analysis of cellular effects reveals increased
activities of caspases-3, -7, -8, -9 and other mediators of apoptotic pathways.
Similarly, the analysis of E- and N-cadherin, slug, twist, β-catenin and MMP7
indicates SATB1 effects on epithelial-mesenchymal transition (EMT) and matrix
breakdown. Our results also establish SATB1 effects on receptor tyrosine kinases
and (proto-)oncogenes such as HER receptors and Pim-1. Taken together, this
suggests a more complex molecular interplay between tumor-promoting and possible
inhibitory effects in CRC by affecting multiple pathways and molecules involved
in proliferation, cell cycle, EMT, invasion and cell survival. Base excision repair is initiated by DNA glycosylases that recognize specific
altered bases. DNA glycosylases for oxidized bases carry both a glycosylase
activity that removes the faulty base and an apyrimidinic/apurinic lyase
activity that introduces a single-strand DNA incision. In particular, the CUT
domains within the CUX1 and CUX2 proteins were recently shown to interact with
the 8-oxoguanine (8-oxoG) DNA glycosylase and stimulate its enzymatic
activities. SATB1, which contains two CUT domains, was originally characterized
as a T cell-specific genome organizer whose aberrant overexpression in breast
cancer can promote tumor progression. Here we investigated the involvement of
SATB1 in DNA repair. SATB1 knockdown caused a delay in DNA repair following
exposure to H2O2, an increase in OGG1-sensitive oxidized bases within genomic
DNA, and a decrease in 8-oxoG cleavage activity in cell extracts. In parallel,
we observed an increase in phospho-CHK1 and γ-H2AX levels and a decrease in DNA
synthesis. Conversely, ectopic expression of SATB1 accelerated DNA repair and
reduced the levels of oxidized bases in genomic DNA. Moreover, an enhanced
GFP-SATB1 fusion protein was rapidly recruited to laser microirradiation-induced
DNA damage. Using purified proteins, we showed that SATB1 interacts directly
with OGG1, increases its binding to 8-oxoG-containing DNA, promotes Schiff base
formation, and stimulates its glycosylase and apyrimidinic/apurinic lyase
enzymatic activities. Structure/function analysis demonstrated that CUT domains,
but not the homeodomain, are responsible for the stimulation of OGG1. Together,
these results identify another CUT domain protein that functions both as a
transcription factor and an accessory factor in base excision repair. The Special AT-rich Sequence Binding Protein 1 (SATB1) exerts multiple
functions, by influencing the structural organization of chromatin and
interacting with several co-activators and co-repressors of transcription. Thus,
SATB1 affects the expression of various genes by multiple mechanisms of action,
involving three-dimensional chromatin architecture. More recently, SATB1 has
been connected with solid tumors, tumorigenesis, tumor progression and tumor
immunity. On the diagnostic side, SATB1 levels were found to correlate with
clinicopathological features like increased TNM stage, reduced tumor
differentiation, and a shorter overall survival. SATB1 expression was also
identified as an independent prognostic marker in various cancers. Moreover,
different gene knockdown or ectopic overexpression strategies in cancer cells
have identified SATB1 to affect proliferation, cell cycle, apoptosis, cell
morphology / cell polarity, EMT and multidrug-resistance as well as tumor
formation, growth, invasion and metastasis in vivo. These processes are mediated
through a great multitude of SATB1 target genes, including many (proto-)
oncogenes. Functional and molecular studies on SATB1 in various cancers are
comprehensively summarized, and the prospects and caveats of SATB1 as tumor
marker and as putative target molecule are discussed. |
Describe the Java Adverse Drug Event (JADE) tool | The Java Adverse Drug event (Jade) is a tool for medical researchers to explore adverse drug events using health insurance plans and drug-drug interactions. | BACKGROUND: The Joint Asia Diabetes Evaluation (JADE) Program is a web-based
program incorporating a comprehensive risk engine, care protocols, and clinical
decision support to improve ambulatory diabetes care.
METHODS: The JADE Program uses information technology to facilitate healthcare
professionals to create a diabetes registry and to deliver an evidence-based
care and education protocol tailored to patients' risk profiles. With written
informed consent from participating patients and care providers, all data are
anonymized and stored in a databank to establish an Asian Diabetes Database for
research and publication purpose.
RESULTS: The JADE electronic portal (e-portal: http://www.jade-adf.org) is
implemented as a Java application using the Apache web server, the mySQL
database and the Cocoon framework. The JADE e-portal comprises a risk engine
which predicts 5-year probability of major clinical events based on parameters
collected during an annual comprehensive assessment. Based on this risk
stratification, the JADE e-portal recommends a care protocol tailored to these
risk levels with decision support triggered by various risk factors. Apart from
establishing a registry for quality assurance and data tracking, the JADE
e-portal also displays trends of risk factor control at each visit to promote
doctor-patient dialogues and to empower both parties to make informed decisions.
CONCLUSIONS: The JADE Program is a prototype using information technology to
facilitate implementation of a comprehensive care model, as recommended by the
International Diabetes Federation. It also enables health care teams to record,
manage, track and analyze the clinical course and outcomes of people with
diabetes. OBJECTIVE: The objective of our project was to create a tool for physicians to
explore health claims data with regard to adverse drug reactions. The Java
Adverse Drug Event (JADE) tool should enable the analysis of prescribed drugs in
connection with diagnoses from hospital stays.
METHODS: We calculated the number of days drugs were taken by using the defined
daily doses and estimated possible interactions between dispensed drugs using
the Austria Codex, a database including drug-drug interactions. The JADE tool
was implemented using Java, R and a PostgreSQL database.
RESULTS: Beside an overview of the study cohort which includes selection of
gender and age groups, selected statistical methods like association rule
learning, logistic regression model and the number needed to harm have been
implemented.
CONCLUSION: The JADE tool can support physicians during their planning of
clinical trials by showing the occurrences of adverse drug events with
population based information. |
Which drugs were tested in the CheckMate 227 clinical trial? | CheckMate-227 clinical trial tested ipilimumab plus nivolumab for the treatment of non-small cell lung cancer. | The monoclonal antibodies ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1)
have shown remarkable antitumor activity in an increasing number of cancers.
When combined, ipilimumab and nivolumab have demonstrated superior activity in
patients with metastatic melanoma (CHECKMATE-067). Here we describe the
preclinical development strategy that predicted these clinical results.
Synergistic antitumor activity in mouse MC38 and CT26 colorectal tumor models
was observed with concurrent, but not sequential CTLA-4 and PD-1 blockade.
Significant antitumor activity was maintained using a fixed dose of anti-CTLA-4
antibody with decreasing doses of anti-PD-1 antibody in the MC38 model.
Immunohistochemical and flow cytometric analyses confirmed that CD3+ T cells
accumulated at the tumor margin and infiltrated the tumor mass in response to
the combination therapy, resulting in favorable effector and regulatory T-cell
ratios, increased pro-inflammatory cytokine secretion, and activation of
tumor-specific T cells. Similarly, in vitro studies with combined ipilimumab and
nivolumab showed enhanced cytokine secretion in superantigen stimulation of
human peripheral blood lymphocytes and in mixed lymphocyte response assays. In a
cynomolgus macaque toxicology study, dose-dependent immune-related
gastrointestinal inflammation was observed with the combination therapy; this
response had not been observed in previous single agent cynomolgus studies.
Together, these in vitro assays and in vivo models comprise a preclinical
strategy for the identification and development of highly effective antitumor
combination immunotherapies. BACKGROUND: Nivolumab plus ipilimumab showed promising efficacy for the
treatment of non-small-cell lung cancer (NSCLC) in a phase 1 trial, and tumor
mutational burden has emerged as a potential biomarker of benefit. In this part
of an open-label, multipart, phase 3 trial, we examined progression-free
survival with nivolumab plus ipilimumab versus chemotherapy among patients with
a high tumor mutational burden (≥10 mutations per megabase).
METHODS: We enrolled patients with stage IV or recurrent NSCLC that was not
previously treated with chemotherapy. Those with a level of tumor programmed
death ligand 1 (PD-L1) expression of at least 1% were randomly assigned, in a
1:1:1 ratio, to receive nivolumab plus ipilimumab, nivolumab monotherapy, or
chemotherapy; those with a tumor PD-L1 expression level of less than 1% were
randomly assigned, in a 1:1:1 ratio, to receive nivolumab plus ipilimumab,
nivolumab plus chemotherapy, or chemotherapy. Tumor mutational burden was
determined by the FoundationOne CDx assay.
RESULTS: Progression-free survival among patients with a high tumor mutational
burden was significantly longer with nivolumab plus ipilimumab than with
chemotherapy. The 1-year progression-free survival rate was 42.6% with nivolumab
plus ipilimumab versus 13.2% with chemotherapy, and the median progression-free
survival was 7.2 months (95% confidence interval [CI], 5.5 to 13.2) versus 5.5
months (95% CI, 4.4 to 5.8) (hazard ratio for disease progression or death,
0.58; 97.5% CI, 0.41 to 0.81; P<0.001). The objective response rate was 45.3%
with nivolumab plus ipilimumab and 26.9% with chemotherapy. The benefit of
nivolumab plus ipilimumab over chemotherapy was broadly consistent within
subgroups, including patients with a PD-L1 expression level of at least 1% and
those with a level of less than 1%. The rate of grade 3 or 4 treatment-related
adverse events was 31.2% with nivolumab plus ipilimumab and 36.1% with
chemotherapy. ical; CheckMate 227 ClinicalTrials.gov number, NCT02477826 .).
CONCLUSIONS: Progression-free survival was significantly longer with first-line
nivolumab plus ipilimumab than with chemotherapy among patients with NSCLC and a
high tumor mutational burden, irrespective of PD-L1 expression level. The
results validate the benefit of nivolumab plus ipilimumab in NSCLC and the role
of tumor mutational burden as a biomarker for patient selection. (Funded by
Bristol-Myers Squibb and Ono Pharmaceut The first data from the phase III CheckMate-227 trial of ipilimumab plus
nivolumab for the treatment of non-small cell lung cancer suggests that the two
drugs boost progression-free survival in patients with a high tumor mutation
burden. After 1 year, progression-free survival was 43% for patients treated
with the checkpoint inhibitor combination, compared with 13% for patients
treated with chemotherapy. Nivolumab and ipilimumab, two therapeutic immune checkpoint inhibitor antibodies
that block PD-1 and CTLA-4, respectively, have indications in cancer as single
agents and in combination. In this Review, we examine the potential role of dual
immune checkpoint inhibition with nivolumab plus ipilimumab in the management of
patients with previously untreated advanced non-small-cell lung cancer, based on
results from the Phase III CheckMate 227 study. Immunotherapies with indications
in the first-line treatment of non-small-cell lung cancer include pembrolizumab
alone and combined with chemotherapy, and atezolizumab combined with bevacizumab
and chemotherapy. CheckMate 227 is the first Phase III study evaluating
first-line chemotherapy-sparing combination immunotherapy and including tumor
mutational burden as a biomarker for patient selection. Author information:
(1)LungenClinic Grosshansdorf, Airway Research Center North (ARCN), German
Center for Lung Research (DZL), Wöhrendamm 80, 22927 Grosshansdorf, Germany.
Electronic address: [email protected].
(2)Centrul de Oncologie Sf Nectarie, 23A Caracal St, Craiova, 200347, Romania.
Electronic address: [email protected].
(3)Chungbuk National University Hospital, 776, 1 Sunhwan-ro, Seowon-gu,
Cheongju-si, Chungcheonbuk-do, 28644, South Korea. Electronic address:
[email protected].
(4)Universidad Autónoma de Madrid, Instituto de Investigación Puerta de Hierro,
Hospital Puerta de Hierro de Majadahonda, C / Manuel de Falla 1, Madrid,
Majadahonda, 28222, Spain. Electronic address: [email protected].
(5)The Cancer Institute Hospital of Japanese Foundation for Cancer Research,
3-8-31 Ariake, Tokyo, Koto-ku, 135-8550, Japan. Electronic address:
[email protected].
(6)Oddzial Onkologii Radioterapii Szpital/Gdansk Medical University, UI.
Powstania Styczniowego 1, Gdynia, 81-519, Poland. Electronic address:
[email protected].
(7)Cross Cancer Institute, 11560 University Ave, Edmonton, Alberta, T6G 1Z2,
Canada. Electronic address: [email protected].
(8)University Hospitals of Leicester NHS Trust, Department of Infection,
Leicester, Leicestershire, LE1 5WW, UK. Electronic address:
[email protected].
(9)Institut de Cancérologie de l'Ouest, Centre Rene Gauducheau, Boulevard
Jacques Monod, 44805 Nantes-Saint Herblain Cedex, France. Electronic address:
[email protected].
(10)Notre Dame University and Edith Cowan University, 100 Murdoch Drive,
Murdoch, Perth, Western Australia, 6150, Australia. Electronic address:
[email protected].
(11)CHU de Rennes, 2 Rue Henri le Guilloux, Rennes, 35033, France. Electronic
address: [email protected].
(12)CACON, Hospital de Caridade de Ijuí, Av David Jose Martins, Centro, Ijuí,
Rio Grande do Sul, 98700-000, Brazil. Electronic address: [email protected].
(13)IONC - Universidad Católica de Córdoba, Parana 560. 2 Piso, Cordoba, 5000,
Argentina. Electronic address: [email protected].
(14)Bristol-Myers Squibb, 3401 Princeton Pike, Lawrenceville, NJ, 08648, USA.
Electronic address: [email protected].
(15)Bristol-Myers Squibb, 3401 Princeton Pike, Lawrenceville, NJ, 08648, USA.
Electronic address: [email protected].
(16)Bristol-Myers Squibb, 3401 Princeton Pike, Lawrenceville, NJ, 08648, USA.
Electronic address: [email protected].
(17)Bristol-Myers Squibb, 3401 Princeton Pike, Lawrenceville, NJ, 08648, USA.
Electronic address: [email protected].
(18)Adelphi Values, 290 Congress Street 7th Floor, Boston, MA, 02210, USA.
Electronic address: [email protected].
(19)Adelphi Values, 290 Congress Street 7th Floor, Boston, MA, 02210, USA.
Electronic address: [email protected].
(20)Adelphi Values, Adelphi Mill, Grimshaw Ln, Bollington, Cheshire, SK10 5JB,
UK. Electronic address: [email protected].
(21)Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 1650 Orleans St,
CRB1-G94, Baltimore, MD, 21287, USA. Electronic address: [email protected]. |
What is known about PAI-1 in longevity in humans? | Plasminogen activator inhibitor-1 (PAI-1) has been shown to be a key component of the senescence-related secretome and a direct mediator of cellular senescence. In murine models of accelerated aging, genetic deficiency and targeted inhibition of PAI-1 protect against aging-like pathology and prolong life span. However, the role of PAI-1 in human longevity remains unclear.
, in centenarians there was a significantly higher frequency of the 4G allele and of the homozygous 4G4G genotype associated with high PAI-1 levels. Since high PAI-1 is considered a predictor of recurrent myocardial infarction in young men, it is intriguing that the corresponding genetic marker is more frequent in centenarians who have escaped major age-related atherothrombotic disease and reached the extreme limits of human life. Homozygosity for the 4G allele, despite its association with impaired fibrinolysis, is compatible with successful aging. | Gene polymorphisms associated with the plasma levels of fibrinogen, factor VII,
and plasminogen activator inhibitor 1 (PAI-1)-hemostasis proteins that help to
predict the risk of atherothrombotic disease-were compared in 124 healthy
individuals > or = 100 years old and 130 young, healthy individuals to identify
genetic influences on extreme longevity. We investigated the restriction
fragment length polymorphism G/A-455 located in the promoter of the
beta-fibrinogen gene, the guanine insertion/deletion polymorphism 4G/5G in the
promoter of the PAI-1 gene, and the R353Q substitution polymorphism in exon 8 of
the factor VII gene. Alleles and genotypes associated with elevated plasma
levels of fibrinogen and factor VII were found with similar frequencies in
centenarians and in the comparison group. However, in centenarians there was a
significantly higher frequency of the 4G allele and of the homozygous 4G4G
genotype associated with high PAI-1 levels. Since high PAI-1 is considered a
predictor of recurrent myocardial infarction in young men, it is intriguing that
the corresponding genetic marker is more frequent in centenarians who have
escaped major age-related atherothrombotic disease and reached the extreme
limits of human life. Homozygosity for the 4G allele, despite its association
with impaired fibrinolysis, is compatible with successful aging. Inflammatory response genes may influence life span or quality at advanced ages.
Using data from the population-based cardiovascular health study (CHS) cohort,
we examined the associations between promoter polymorphisms of several
inflammation and thrombosis genes with longevity. We ascertained genotypes for
interleukin (IL)-6 -174 G/C, beta-fibrinogen -455 G/A, plasminogen activator
inhibitor (PAI)-1 -675 4G/5G, and thrombin-activatable fibrinolysis inhibitor
(TAFI) -438 G/A in 2224 men and women > or = 65 years old at baseline. During 10
years of follow-up, men with the TAFI -438 A/A genotype had decreased mortality
due to all causes, and lived, on average, 0.9 more years of life, or 1.1 more
years of healthy life, than men with the -438 G allele. The effects of TAFI -438
G/A in women were smaller and not statistically significant. PAI-1 4G/4G
genotype appeared to be associated with lower non-cardiovascular mortality in
men, but with greater cardiovascular mortality in women. In exploratory
analyses, we observed a possible interaction among anti-inflammatory drugs,
interleukin-6 -174 C/C genotype, and longevity. These findings suggest that
modulators of fibrinolytic activity may have a generalized influence on aging,
and merit further investigation in studies of genetic determits of human
longevity. Plasminogen activator inhibitor-1 (PAI-1) has been shown to be a key component
of the senescence-related secretome and a direct mediator of cellular
senescence. In murine models of accelerated aging, genetic deficiency and
targeted inhibition of PAI-1 protect against aging-like pathology and prolong
life span. However, the role of PAI-1 in human longevity remains unclear. We
hypothesized that a rare loss-of-function mutation in SERPINE1 (c.699_700dupTA),
which encodes PAI-1, could play a role in longevity and metabolism in humans. We
studied 177 members of the Berne Amish community, which included 43 carriers of
the null SERPINE1 mutation. Heterozygosity was associated with significantly
longer leukocyte telomere length, lower fasting insulin levels, and lower
prevalence of diabetes mellitus. In the extended Amish kindred, carriers of the
null SERPINE1 allele had a longer life span. Our study indicates a causal effect
of PAI-1 on human longevity, which may be mediated by alterations in metabolism.
Our findings demonstrate the utility of studying loss-of-function mutations in
populations with geographic and genetic isolation and shed light on a novel
therapeutic target for aging. |
Does metformin alleviate atherosclerosis? | Yes. Metformin has been shown to decrease frequency of atherosclerosis-associated adverse effects in statin-intolerant patients and to slow the pathogenesis of type 2 diabetes mellitus. | BACKGROUND: Metformin and rosiglitazone both improve glycemic control in type 2
diabetes mellitus, however may possess different anti-inflammatory and
anti-atherosclerotic properties. We investigated the effects of these
medications on high-sensitivity C-reactive protein (hsCRP) and carotid artery
intima-media thickness (CIMT) to determine their relative potential to reduce
cardiovascular risk independent of their antihyperglycemic actions.
METHODS: Ninety-two subjects with suboptimally controlled diabetes mellitus
(hemoglobin A1c [HbA1c] >7.0%) were assigned to therapy with either
rosiglitazone 4 mg once daily or metformin 850 mg twice daily for 24 weeks. The
primary end point was the change in hsCRP after 24 weeks. The change in CIMT was
prespecified as a secondary end point.
RESULTS: Metformin and rosiglitazone treatment led to similar significant
improvements in glycemic control (HbA1c -1.08% in the rosiglitazone group and
-1.18% in the metformin group, P = nonsignificant). High-sensitivity C-reactive
protein levels decreased by an average of 68% in the rosiglitazone group (5.99
+/- 0.88 to 1.91 +/- 0.28 mg/L, P < .001), compared with a nonsignificant 4%
reduction in hsCRP with metformin (5.69 +/- 0.83 to 5.46 +/- 0.92 mg/L; P =
nonsignificant). Maximal CIMT progressed in the metformin group (+0.084 +/-
0.038 mm), whereas regression of maximal CIMT was observed in the rosiglitazone
group (-0.037 +/- 0.031 mm; P = .02 for the between group comparison). Similar
changes were observed for mean CIMT. The change in hsCRP and maximal CIMT were
related in a multivariable model controlling for changes in HbA1c and lipid
parameters (r = .31; P = .01).
CONCLUSIONS: Rosiglitazone, compared to metformin, induced a prompt and profound
reduction in hsCRP levels independent of its effect on glycemia. This change was
associated with regression of CIMT after 24 weeks. Metformin is a widely used antidiabetic drug that exerts cardiovascular
protective effects in patients with diabetes. How metformin protects against
diabetes-related cardiovascular diseases remains poorly understood. Here, we
show that metformin abated the progression of diabetes-accelerated
atherosclerosis by inhibiting mitochondrial fission in endothelial cells.
Metformin treatments markedly reduced mitochondrial fragmentation, mitigated
mitochondrial-derived superoxide release, improved endothelial-dependent
vasodilation, inhibited vascular inflammation, and suppressed atherosclerotic
lesions in streptozotocin (STZ)-induced diabetic ApoE-/- mice. In high
glucose-exposed endothelial cells, metformin treatment and adenoviral
overexpression of constitutively active AMPK downregulated mitochondrial
superoxide, lowered levels of dynamin-related protein (Drp1) and its
translocation into mitochondria, and prevented mitochondrial fragmentation. In
contrast, AMPK-α2 deficiency abolished the effects of metformin on Drp1
expression, oxidative stress, and atherosclerosis in diabetic ApoE-/-/AMPK-α2-/-
mice, indicating that metformin exerts an antiatherosclerotic action in vivo via
the AMPK-mediated blockage of Drp1-mediated mitochondrial fission. Consistently,
mitochondrial division inhibitor 1, a potent and selective Drp1 inhibitor,
reduced mitochondrial fragmentation, attenuated oxidative stress, ameliorated
endothelial dysfunction, inhibited inflammation, and suppressed atherosclerosis
in diabetic mice. These findings show that metformin attenuated the development
of atherosclerosis by reducing Drp1-mediated mitochondrial fission in an
AMPK-dependent manner. Suppression of mitochondrial fission may be a therapeutic
approach for treating macrovascular complications in patients with diabetes. Statins are widely used to reduce cardiovascular risk. Unfortunately, some
patients still experience cardiovascular events though prescribed with
high-intensity statins. Metformin, an anti-diabetic drug, was reported to
possess anti-atherosclerotic effects. Therefore, the experiments were designed
to evaluate whether combined use of metformin and atorvastatin can achieve
additional benefits. In rabbits fed a high-cholesterol diet, we evaluated the
effects of the combination therapy on atherosclerotic plaques, lipid profiles,
blood glucose levels, liver and kidney functions. Effects of combination therapy
on cholesterol efflux and the expression of related transporters were studied in
vitro. Our results showed that the combination therapy induced a more
significant decrease in atherosclerotic lesion area than atorvastatin without
additional lipid-lowering effect. The combination therapy significantly
increased the percentage of large high-density lipoprotein subfraction. The
intravenous glucose tolerance test showed that atorvastatin-treated rabbits had
an increased area under the curve for time-dependent glucose levels after a
bolus injection of glucose, which was completely reversed by metformin
treatment. In cultured macrophages, co-treatment with metformin and atorvastatin
promoted cholesterol efflux and up-regulated expression of ATP-binding cassette
transporters A1 and G1. Taken together, our results suggest that
atorvastatin/metformin combination therapy may achieve additional
anti-atherosclerotic benefits likely through increasing cholesterol efflux in
macrophages. Lipids are responsible for the atheromatous plaque formation during
atherosclerosis by their deposition in the subendothelial intima of the aorta,
leading to infarction. Sterol regulatory element-binding protein 2 (SREBP2),
regulating cholesterol homeostasis, is suggested to play a pivotal role during
the early incidence of atherosclerosis through dysregulation of lipid
homeostasis. Here we demonstrate that oxidative stress stimulates
SREBP2-mediated cholesterol uptake via low density lipoprotein receptor (LDLR),
rather than cholesterol synthesis, in mouse vascular aortic smooth muscle cells
(MOVAS) and THP-1 monocytes. The enhancement of mature form of SREBP2 (SREBP2-M)
during oxidative stress was associated with the inhibition of AMP-activated
protein kinase (AMPK) activation. In contrast, inhibition of either SREBP2 by
fatostatin or LDLR by siLDLR resulted in decreased cholesterol levels during
oxidative stress. Thereby confirming the role of SREBP2 in cholesterol
regulation via LDLR. Metformin-mediated activation of AMPK was able to
significantly abrogate cholesterol uptake by inhibiting SREBP2-M. Interestingly,
although metformin administration attenuated angiotensin (Ang)-II-impaired lipid
homeostasis in both aorta and liver tissues of ApoE-/- mice, the results
indicate that SREBP2 through LDLR regulates lipid homeostasis in aorta but not
in liver tissue. Taken together, AMPK activation inhibits oxidative
stress-mediated SREBP2-dependent cholesterol uptake, and moreover,
metformin-induced prevention of atheromatic events are in part due to its
ability to regulate the SREBP2-LDLR axis. |
List side effects of radiation therapy? | radiation-induced tumors
radiation necrosis
microangiopathy
progressive leukencephalopathy
pneumonitis
disturbance of the blood-brain barrier
radionecrosis of brain tissue
radiogenic liver damage
mucositis
colitis
osteitis
osteoradionecrosis
myositis
Radiation-induced fibrosis
Acute skin reactions | BACKGROUND: Radiation-induced fibrosis (RIF) is one of the severe long-term side
effects of radiation therapy (RT) with a crucial impact on the development of
postoperative wound healing disorders (WHD). The grades of fibrosis vary between
mild to severe depending on individual radiosensitivity. In this study, we have
investigated the molecular pathways that influence RIF and have correlated data
from immunohistochemistry (IHC) for von -Willebrand Factor (vWF) and from
Real-Time Polymerase Chain Reaction (RT-PCR) concerning markers such as
Transforming Growth Factor (TGF)-β 1, and vWF, with clinical data concerning the
occurrence of WHD during follow-up.
METHODS: Expression profiles of the genes encoding TGF-β 1, vWF, and
α-procollagen (PC) were analyzed, by RT-PCR, in specimens from patients with
(n = 20; 25.6 %) and without (n = 58; 74.4 %) a history of previous RT to the
head and neck. Moreover, IHC against vWF was performed. Clinical data on the
occurrence of cervical WHDs were analyzed and correlated.
RESULTS: A statistically significant increase in the expression profiles of α-PC
and TGF-β 1 was observed in previously irradiated skin samples (occurrence of RT
>91 days preoperatively). vWF showed a statistically significant increase in
non-irradiated tissue. Moreover, analysis of expression profiles in patients
with and without WHDs during follow-up was performed. IHC showed a reduced
amount of vessels and structural changes in epidermal tissue post-RT.
CONCLUSIONS: The expression of markers of fibrosis and angiogenesis was analyzed
in order to gain insight into molecular pathways that account for structural
changes in irradiated skin and that eventually lead to WHDs. The results are
congruent with reports from the literature and are a possible starting point for
further research, as anti-TGF-β 1 treatment, for example, could represent new
therapeutic opportunities in the management of previously irradiated patients. BACKGROUND: Peritumoral normal tissue is inevitably also irradiated during
radiotherapy, depending on the location and size of the target volume as well as
the cumulative dose. Depending on the temporal course after irradiation acute,
subacute, and chronic alterations are described in co-irradiated normal tissue
that can be detected by imaging. Radiation damage can be transient or
persistent.
OBJECTIVE: This article gives an overview of the most important signs of
radiation-induced radiogenic alterations to tissue in various organ systems.
FINDINGS: Frequent radiation-induced tissue alterations found by imaging are
pneumonitis, disturbance of the blood-brain barrier, radionecrosis of brain
tissue, radiogenic liver damage, mucositis, colitis, osteitis,
osteoradionecrosis and myositis. The combination with systemic chemotherapy or
immunotherapy can increase the severity of radiogenic reactions of normal
tissue.
RECOMMENDATIONS FOR AFTERCARE: The most important differential diagnosis for
radiogenic alterations to normal tissue is post-therapeutic tumor recurrence.
Besides typical latency periods, location and matching with the radiation field
are important differentiation criteria, depending on the tumor biology and the
radiation technique. The follow-up schedule should follow the current guidelines
and the clinical condition of the patient should be additionally considered. The
radiologist needs to be familiar with the typical imaging morphology of
radiogenic tissue changes to avoid false interpretation during follow-up
investigations. Radiation therapy has been a cornerstone of cancer management for many decades
and is an integral part of the multi-modality care of patients with brain
tumors. The known serious side effects of radiation therapy on the head or
central nervous system are uncommon and include radiation necrosis,
microangiopathy, and progressive leukencephalopathy. In addition, there have
been descriptions of radiation-induced tumors including sarcomas, gliomas,
lymphomas, and carcinomas of the thyroid. Patients who have received radiation
therapy of the head or face may rarely develop radiation-induced tumors, a
majority of which are meningiomas, followed by radiation-induced gliomas (RIGs)
and sarcomas. The increased risk of RIGs is well described in both the pediatric
and adult populations and after the use of both therapeutic and diagnostic
radiations. The incidence of RIGs is estimated at approximately 0.5-2.7% at a
latent period of approximately 15 years. The risk appears to be dependent on
patient age at treatment, as well as radiation dose and treatment volume
considerations. The scope of this review focuses on the etiology, clinical
features, and management of RIGs as they relate to previous radiation therapy. |
Are CD8+ (cytotoxic) T cells and CD4+ Helper T cells generated in the thyroid and express the T-cell receptor? | Through positive selection, double-positive cells in the thymus differentiate into CD4(+) or CD8(+) T single-positive cells that subsequently develop into different types of effective T cells, such as T-helper and cytotoxic T lymphocyte cells, These two cell types are derived from common precursors in the thymus. | Mature T cells express either CD4 or CD8 on their surface. Most helper T cells
express CD4, which binds to class II major histocompatibility complex (MHC)
proteins, and most cytotoxic T cells express CD8, which binds to class I MHC
proteins. In the thymus, mature CD4+CD8- and CD4-CD8+ T cells expressing alpha
beta T-cell antigen receptors (TCR) develop from immature thymocytes through
CD4+CD8+ alpha beta TCR+ intermediates. Experiments using mice transgenic for
alpha beta TCR suggest that the specificity of the TCR determines the CD4/CD8
phenotype of mature T cells. These results, however, do not indicate how a T
cell differentiates into the CD4 or CD8 lineage. Here we show that the CD4
transmembrane region and/or cytoplasmic tail mediates the delivery of a specific
signal that directs differentiation of T cells to a CD4 lineage. We generated
transgenic mice expressing a hybrid molecule composed of the CD8 alpha
extracellular domains linked to the CD4 transmembrane region and cytoplasmic
tail. We predicted that this hybrid molecule would bind to class I MHC proteins
through the extracellular domains but deliver the intracellular signals
characteristic of CD4. By crossing our transgenic mice with mice expressing a
transgenic alpha beta TCR specific for a particular antigen plus class I MHC
protein, we were able to express the hybrid molecule in developing thymocytes
expressing the class I MHC-restricted TCR. Our results show that the signal
transduced by the hybrid molecule results in the differentiation of immature
thymocytes expressing a class I-restricted TCR into mature T cells expressing
CD4. Individual T cell populations are characterized by specific surface proteins,
namely by the T cell receptor complex (TCR) and by two accessory molecules, CD8
(Lyt2) and CD4 (L3T4). CD8 and CD4 are required for T cell interactions with
class I or class II major histocompatibility complex molecules. In the thymus,
immature CD8(-4)-TCR- cells differentiate, possibly via a short stage of CD8+4-
thymocytes, into CD8+4+ TCR+ T cells and mature further into the main T cell
populations, the CD8+4- TCR+ cytotoxic T lymphocytes and the CD4+8- TCR+ T
helper cells. In order to analyse the differentiation steps involving CD8, we
generated transgenic mice expressing mu heavy chain genes from an anti-Lyt2.2
hybridoma. Transgenic lines expressing either the complete (mu sm) or only the
secreted mu protein (mu s) suffer from a severe depletion of their CD8+4+
thymocytes affecting also the mature CD8+4- and CD4+8- populations. The
depletion is correlated to the expression of transgenic mu-chain proteins within
thymocytes. This intrathymocyte expression of the mu chain prevents CD8-4-
thymocytes from further differentiation, most probably via intracellular
interactions between mu heavy chain and CD8 proteins. These results show that
CD8 plays an important role during thymocyte maturation. The mechanism by which an initially uncommitted cell chooses between alternative
fates is a central issue in developmental biology. In the mammalian thymus, CD4
helper T cells and CD8 cytotoxic T cells arise from a common precursor that
expresses both CD4 and CD8. The choice between the CD4 and CD8 lineage is linked
to the specificity of the T-cell antigen receptor expressed by a thymocyte, but
whether lineage commitment is stochastic or instructed has not been definitively
resolved. We present evidence that expression of a constitutive CD8 transgene
during thymic selection permits development of mature CD4 cells bearing the
class I-restricted F5 T-cell antigen receptor. These results suggest that there
is a stochastic component to the development of class I major histocompatibility
complex-restricted T cells. Signals elicited by binding of the T-cell antigen receptor and the CD4/CD8
co-receptor to major histocompatibility complex (MHC) molecules control the
generation of CD4+ (helper) or CD8+ (cytotoxic) T cells from thymic precursors
that initially express both co-receptor proteins. These precursors have unique,
clonally distributed T-cell receptors with unpredictable specificity for the
self-MHC molecules involved in this differentiation process. However, the mature
T cells that emerge express only the CD4 (MHC class II-binding) or CD8 (MHC
class I-binding) co-receptor that complements the MHC class-specificity of the
T-cell receptor. How this matching of co-receptor-defined lineage and
T-cell-receptor specificity is achieved remains unknown, as does whether
signalling by the T-cell receptors, co-receptors and/or general cell-fate
regulators such as Notch-1 contributes to initial lineage choice, to subsequent
differentiation processes or to both. Here we show that the CD4 versus CD8
lineage fate of immature thymocytes is controlled by the co-receptor-influenced
duration of initial T-cell receptor-dependent signalling. Notch-1 does not
appear to be essential for this fate determination, but it is selectively
required for CD8+ T-cell maturation after commitment directed by T-cell
receptors. This indicates that the signals constraining CD4 versus CD8 lineage
decisions are distinct from those that support subsequent differentiation events
such as silencing of co-receptor loci. CD4(+) T cells are generally specialized to function as helper cells and CD8(+)
T cells are generally specialized to function as cytotoxic effector cells. To
explain how such concordance is achieved between co-receptor expression and
immune function, we considered two possibilities. In one case, immature
CD4(+)CD8(+) thymocyte precursors might first down-regulate expression of one
co-receptor molecule, with the remaining co-receptor molecule subsequently
activating the appropriate helper or cytotoxic functional program.
Alternatively, we considered that the same intrathymic signals that selectively
extinguished expression of one or the other co-receptor molecule might
simultaneously initiate the appropriate helper or cytotoxic functional program.
In the present study, we attempted to distinguish between these alternatives by
examining thymocyte precursors of CD8(+) T cells for expression of Cathepsin C
and Cathepsin W, molecules important for cytotoxic effector function. We report
in developing thymocytes that Cathepsin C and Cathepsin W are expressed
coordinately with extinction of CD4 co-receptor expression. We conclude that CD4
extinction and initiation of the cytotoxic functional program occurs
simultaneously during differentiation of CD8(+) T cells in the thymus. During blood cell development, hematopoietic stem cells generate diverse mature
populations via several rounds of binary fate decisions. At each bifurcation,
precursors adopt one fate and inactivate the alternative fate either
stochastically or in response to extrinsic stimuli and stably maintain the
selected fates. Studying of these processes would contribute to better
understanding of etiology of immunodeficiency and leukemia, which are caused by
abnormal gene regulation during the development of hematopoietic cells. The
CD4(+) helper versus CD8(+) cytotoxic T-cell fate decision serves as an
excellent model to study binary fate decision processes. These two cell types
are derived from common precursors in the thymus. Positive selection of their
TCRs by self-peptide presented on either MHC class I or class II triggers their
fate decisions along with mutually exclusive retention and silencing of two
coreceptors, CD4 and CD8. In the past few decades, extensive effort has been
made to understand the T-cell fate decision processes by studying regulation of
genes encoding the coreceptors and selection processes. These studies have
identified several key transcription factors and gene regulatory networks. In
this chapter, I will discuss recent advances in our understanding of the binary
cell fate decision processes of T cells. Through positive selection, double-positive cells in the thymus differentiate
into CD4(+) or CD8(+) T single-positive cells that subsequently develop into
different types of effective T cells, such as T-helper and cytotoxic T
lymphocyte cells, that play distinctive roles in the immune system. Development,
differentiation, and function of thymocytes and CD4(+) and CD8(+) T cells are
controlled by a multitude of secreted and intracellular factors, ranging from
cytokine signaling modules to transcription factors and epigenetic modifiers.
Members of the E26 transformation specific (Ets) family of transcription
factors, in particular, are potent regulators of these CD4(+) or CD8(+) T-cell
processes. In this review, we summarize and discuss the functions and underlying
mechanisms of the Ets family members that have been characterized as involved in
these processes. Ongoing research of these factors is expected to identify
practical applications for the Ets family members as novel therapeutic targets
for inflammation-related diseases. The adaptive immune system is dependent on functionally distinct lineages of T
cell antigen receptor αβ-expressing T cells that differentiate from a common
progenitor in the thymus. CD4+CD8+ progenitor thymocytes undergo selection
following interaction with MHC class I and class II molecules bearing peptide
self-antigens, giving rise to CD8+ cytotoxic and CD4+ helper or regulatory T
cell lineages, respectively. The strict correspondence of CD4 and CD8 expression
with distinct cellular phenotypes has made their genes useful surrogates for
investigating molecular mechanisms of lineage commitment. Studies of Cd4 and Cd8
transcriptional regulation have uncovered cis-regulatory elements that are
critical for mediating epigenetic modifications at distinct stages of
development to establish heritable transcriptional programs. In this review, we
examine the epigenetic mechanisms involved in Cd4 and Cd8 gene regulation during
T cell lineage specification and highlight the features that make this an
attractive system for uncovering molecular mechanisms of heritability. A fundamental question in developmental immunology is how bipotential thymocyte
precursors generate both CD4+ helper and CD8+ cytotoxic T cell lineages. The MHC
specificity of αβ T cell receptors (TCRs) on precursors is closely correlated
with cell fate-determining processes, prompting studies to characterize how
variations in TCR signaling are linked with genetic programs establishing
lineage-specific gene expression signatures, such as exclusive CD4 or CD8
expression. The key transcription factors ThPOK and Runx3 have been identified
as mediating development of helper and cytotoxic T cell lineages, respectively.
Together with increasing knowledge of epigenetic regulators, these findings have
advanced our understanding of the transcription factor network regulating the
CD4/CD8 dichotomy. It has also become apparent that CD4+ T cells retain
developmental plasticity, allowing them to acquire cytotoxic activity in the
periphery. Despite such advances, further studies are necessary to identify the
molecular links between TCR signaling and the nuclear machinery regulating
expression of ThPOK and Runx3. |
What bacteria is associated with Gastric cancer and peptic ulcers? | Helicobacter pylori (H. pylori), a gram-negative microaerophilic bacterial pathogen that colonizes the stomachs of more than half of all humans, is linked to chronic gastritis, peptic ulcers and gastric cancer. | The human pathogen Helicobacter pylori is associated with gastritis, peptic
ulcer disease, and gastric cancer. The pathogenesis of H. pylori infection in
vivo was studied by adapting fresh clinical isolates of bacteria to colonize the
stomachs of mice. A gastric pathology resembling human disease was observed in
infections with cytotoxin-producing strains but not with noncytotoxic strains.
Oral immunization with purified H. pylori antigens protected mice from bacterial
infection. This mouse model will allow the development of therapeutic agents and
vaccines against H. pylori infection in humans. Helicobacter pylori is the major causal factor in chronic gastritis. Its
acquisition leads to a chronic, usually lifelong, inflammation of the gastric
mucosa, which may gradually progress to atrophy (with intestinal metaplasia) in
a significant proportion of infected individuals. This progression is probably
multifactorial, being influenced by genetic or environmental factors in addition
to H. pylori infection. The pathogenesis of peptic ulcer and gastric cancer is
closely associated with H. pylori gastritis and its subsequent atrophic sequelae
(atrophic gastritis). H. pylori-induced gastritis is an important risk factor in
the multifactorial aetiology of these diseases. It causes a cascade of reactions
that damage the gastric mucosa and epithelium in various ways. The specific
mechanisms involved are largely unknown. Some are probably bacterium-related
reactions, which are influenced by various virulence factors, and others are
consequences of the mucosal inflammation and atrophy. The risk of peptic ulcer
and gastric cancer in patients with H. pylori gastritis can be summarized as
follows: i) the risk of both peptic ulcer and gastric cancer is low in
individuals with a normal stomach; ii) the risk of peptic ulcer is approximately
ten times higher and the risk of gastric cancer approximately twice as high in
patients with non-atrophic H. pylori-positive gastritis as in those with a
normal stomach; iii) these risks are further increased (twofold to threefold)
when there is antral atrophy; whereas iv) in the presence of corpus atrophy the
risk of gastric cancer remains high, but that of peptic ulcer decreases
gradually to zero with increasing severity of corpus atrophy. BACKGROUND: Helicobacter pylori has been linked to chronic gastritis, peptic
ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Invasive
tests are less sensitive than noninvasive tests in diagnosing H. pylori
infection in patients with bleeding peptic ulcers. The H. pylori stool antigen
test has been useful in diagnosing H. pylori in patients with peptic ulcers
before and after eradication of H. pylori. The aim of this study was to evaluate
the H. pylori stool antigen test in patients with bleeding peptic ulcers.
METHODS: Patients with bleeding and nonbleeding peptic ulcers underwent a rapid
urease test, histology, bacterial culture and H. pylori stool antigen test.
Positive H. pylori infection was defined as a positive culture or both a
positive histology and a positive rapid urease test. Helicobacter pylori stool
antigen was assessed with a commercial kit (Diagnostec H. pylori antigen EIA
Kit, Hong Kong).
RESULTS: Between October 2000 and April 2002, 93 patients with bleeding peptic
ulcers (men/women: 78/15, gastric ulcer/duodenal ulcer: 58/35) and 59 patients
with nonbleeding peptic ulcers (men/women: 47/12, gastric ulcer/duodenal ulcer:
30/29) were enrolled in this study. Forty-seven (50.5%) patients with bleeding
peptic ulcers and 30 (50.8%) patients with nonbleeding peptic ulcers, were found
to be infected with H. pylori (p > .1). Helicobacter pylori stool antigen tests
were positive in 54 (58.1%) and 30 (50.8%) patients with bleeding peptic ulcers
and nonbleeding peptic ulcers, respectively (p > .1). The sensitivity (82% vs.
93%), specificity (68% vs. 93%), positive predictive value (74% vs. 93%),
negative predictive value (77% vs. 93%) and diagnostic accuracy (75% vs. 93%)
were all lower in patients with bleeding vs. nonbleeding peptic ulcers. The
specificity, positive predictive value, and diagnostic accuracy of the H. pylori
stool antigen test in patients with bleeding peptic ulcers were significantly
lower than those in patients with nonbleeding peptic ulcers (p = .01, p = .02
and p = .003, respectively).
CONCLUSION: The H. pylori stool antigen test is not reliable for diagnosing H.
pylori infection in patients with bleeding peptic ulcers. The concentrations of free D- and L-amino acids were determined in the gastric
juice from four groups: patients suffering from early gastric carcinoma with or
without Helicobacter pylori infection, and patients without carcinoma but with
peptic ulcers, duodenal ulcers or chronic gastritis with or without H. pylori
infection. H. pylori is a bacterium associated with gastric inflammation and
peptic ulcers and is a risk factor for stomach cancer. The highest D-amino acid
ratios (free D-amino acid concentration to the total corresponding free D- and
L-amino acid concentration) were 29%, 26%, 18%, 4% and 1% for proline, alanine,
serine, aspartate and glutamate, respectively. The gastric juice levels of
L-alanine, L-serine, L-proline, L-glutamate and D-alanine in the samples
obtained from subjects bearing early gastric carcinoma and H. pylori were
significantly higher than in the samples from the other three groups. Except for
D-alanine, there was no correlation between the D-amino acid concentrations and
presence of carcinoma or H. pylori. Helicobacter Pylori (H. pylori) is a gram-negative bacteria infecting numerous
people all over the world. It has been established that H. pylori play an
important role in pathogenesis of gastritis, peptic ulcer and gastric cancer.
Pathogenic features of this bacterium are mainly attributes to the existence of
pathogenic islands (PAI) genes. The most known genes in these islands are
cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene (VacA). Most
studies demonstrated various frequency of CagA and VacA in patient with peptic
ulcer or gastritis in different countries. This variation in CagA and VacA
frequency may be due to the capability of this bacterium to be genetically
versatile and can alter the expression of these genes with geographic diversity.
Although H. pylori infection is not usually associated with any clinical
symptoms, but sometimes leads to inflammation in gastrointestinal system and
resulted in peptic ulcer and gastric cancer. In this regard, this review will
illustrate the importance of Helicobacter pylori in pathogenesis of
gastrointestinal disorders with focusing on CagA and VacA virulence factors. Helicobacter pylori (H. pylori), a gram-negative microaerophilic bacterial
pathogen that colonizes the stomachs of more than half of all humans, is linked
to chronic gastritis, peptic ulcers and gastric cancer. Spiral-shaped H. pylori
undergo morphologic conversion to a viable but not culturable coccoid form when
they transit from the microaerobic stomach into the anaerobic intestinal tract.
However, little is known about the morphological and pathogenic characteristics
of H. pylori under prolonged anaerobic conditions. In this study, scanning
electron microscopy was used to document anaerobiosis-induced morphological
changes of H. pylori, from helical to coccoid to a newly defined fragmented
form. Western blot analysis indicated that all three forms express certain
pathogenic proteins, including the bacterial cytotoxin-associated gene A (CagA),
components of the cag-Type IV secretion system (TFSS), the blood group
antigen-binding adhesin BabA, and UreA (an apoenzyme of urease), almost equally.
Similar urease activities were also detected in all three forms of H. pylori.
However, in contrast to the helical form, bacterial motility and TFSS activity
were found to have been abrogated in the anaerobiosis-induced coccoid and
fragmented forms of H. pylori. Notably, it was demonstrated that some of the
anaerobiosis-induced fragmented state cells could be converted to
proliferation-competent helical bacteria in vitro. These results indicate that
prolonged exposure to the anaerobic intestine may not eliminate the potential
for H. pylori to revert to the helical pathogenic state. Strains of Helicobacter pylori that cause ulcer or gastric cancer typically
express a type IV secretion system (T4SS) encoded by the cag pathogenicity
island (cagPAI). CagY is an ortholog of VirB10 that, unlike other VirB10
orthologs, has a large middle repeat region (MRR) with extensive repetitive
sequence motifs, which undergo CD4+ T cell-dependent recombination during
infection of mice. Recombination in the CagY MRR reduces T4SS function,
diminishes the host inflammatory response, and enables the bacteria to colonize
at a higher density. Since CagY is known to bind human α5β1 integrin, we tested
the hypothesis that recombination in the CagY MRR regulates T4SS function by
modulating binding to α5β1 integrin. Using a cell-free microfluidic assay, we
found that H. pylori binding to α5β1 integrin under shear flow is dependent on
the CagY MRR, but independent of the presence of the T4SS pili, which are only
formed when H. pylori is in contact with host cells. Similarly, expression of
CagY in the absence of other T4SS genes was necessary and sufficient for whole
bacterial cell binding to α5β1 integrin. Bacteria with variant cagY alleles that
reduced T4SS function showed comparable reduction in binding to α5β1 integrin,
although CagY was still expressed on the bacterial surface. We speculate that
cagY-dependent modulation of H. pylori T4SS function is mediated by alterations
in binding to α5β1 integrin, which in turn regulates the host inflammatory
response so as to maximize persistent infection.IMPORTANCE Infection with
H. pylori can cause peptic ulcers and is the most important risk factor for
gastric cancer, the third most common cause of cancer death worldwide. The major
H. pylori virulence factor that determines whether infection causes disease or
asymptomatic colonization is the type IV secretion system (T4SS), a sort of
molecular syringe that injects bacterial products into gastric epithelial cells
and alters host cell physiology. We previously showed that recombination in
CagY, an essential T4SS component, modulates the function of the T4SS. Here we
found that these recombination events produce parallel changes in specific
binding to α5β1 integrin, a host cell receptor that is essential for
T4SS-dependent translocation of bacterial effectors. We propose that
CagY-dependent binding to α5β1 integrin acts like a molecular rheostat that
alters T4SS function and modulates the host immune response to promote
persistent infection. |
Is Huntington's disease is caused by expansion of a CTG repeat in the HTT gene on Chromosome 4? | No, Huntington's disease is caused by expansion of a CAG repeat (not CTG) in the HTT gene on Chromosome 4. | Huntington's disease (HD) is an autosomal domit neurodegenerative disease
caused by the expansion of a CAG trinucleotide repeat in exon 1 of the
huntingtin (htt) gene. Emergence and progression of HD depend on continuous
expression of mutant Huntingtin protein (Htt). Therefore, blocking expression of
mutant Htt might be a promising therapeutic strategy. We generated a
high-capacity adenoviral (HC-Ad) vector expressing a short hairpin RNA (shRNA)
targeted to exon 1 of the htt gene. In vitro, this vector efficiently inhibited
Htt expression in neuronal and nonneuronal cell lines. In addition, the number
of Htt-immunoreactive (IR) aggregates, a hallmark of HD pathology, was
significantly reduced after gene transfer with this vector. Importantly, the
attenuation of aggregate formation by shRNA was observed in vivo after
stereotaxic injection into the striatum of mouse models of HD. The vector was
tested in two models: the R6/2 transgenic mouse model and a mouse model based on
the local injection of an adenoviral vector expressing a truncated version of
mutant Htt. In both models an efficient reduction in mutant Htt aggregate load
measured by decreased Htt-IR aggregate formation was observed. Our results
support the further development of shRNA for HD therapy. Huntington's disease (HD) is a neurodegenerative disease caused by the expansion
of a CAG trinucleotide repeat in exon 1 of the huntingtin (HTT) gene. Here, we
report that the transcript of the peroxisome proliferator-activated receptor-γ
(PPARγ), a transcription factor that is critical for energy homeostasis, was
markedly downregulated in multiple tissues of a mouse model (R6/2) of HD and in
lymphocytes of HD patients. Therefore, downregulation of PPARγ seems to be a
pathomechanism of HD. Chronic treatment of R6/2 mice with an agonist of PPARγ
(thiazolidinedione, TZD) rescued progressive weight loss, motor deterioration,
formation of mutant Htt aggregates, jeopardized global ubiquitination profiles,
reduced expression of two neuroprotective proteins (brain-derived neurotrophic
factor and Bcl-2) and shortened life span exhibited by these mice. By reducing
HTT aggregates and, thus, ameliorating the recruitment of PPARγ into HTT
aggregates, chronic TZD treatment also elevated the availability of the PPARγ
protein and subsequently normalized the expression of two of its downstream
genes (the glucose transporter type 4 and PPARγ coactivator-1 alpha genes). The
protective effects described above appear to have been exerted, at least
partially, via direct activation of PPARγ in the brain, as TZD was detected in
the brains of mice treated with TZD and because a PPARγ agonist (rosiglitazone)
protected striatal cells from mHTT-evoked energy deficiency and toxicity. We
demonstrated that the systematic downregulation of PPARγ seems to play a
critical role in the dysregulation of energy homeostasis observed in HD, and
that PPARγ is a potential therapeutic target for this disease. Huntington's disease (HD), caused by a CAG repeat expansion in the huntingtin
(HTT) gene, is characterized by abnormal protein aggregates and motor and
cognitive dysfunction. Htt protein is ubiquitously expressed, but the striatal
medium spiny neuron (MSN) is most susceptible to dysfunction and death. Abnormal
gene expression represents a core pathogenic feature of HD, but the relative
roles of cell-autonomous and non-cell-autonomous effects on transcription remain
unclear. To determine the extent of cell-autonomous dysregulation in the
striatum in vivo, we examined genome-wide RNA expression in symptomatic
D9-N171-98Q (a.k.a. DE5) transgenic mice in which the forebrain expression of
the first 171 amino acids of human Htt with a 98Q repeat expansion is limited to
MSNs. Microarray data generated from these mice were compared with those
generated on the identical array platform from a pan-neuronal HD mouse model,
R6/2, carrying two different CAG repeat lengths, and a relatively high degree of
overlap of changes in gene expression was revealed. We further focused on known
canonical pathways associated with excitotoxicity, oxidative stress,
mitochondrial dysfunction, dopamine signaling and trophic support. While genes
related to excitotoxicity, dopamine signaling and trophic support were altered
in both DE5 and R6/2 mice, which may be either cell autonomous or non-cell
autonomous, genes related to mitochondrial dysfunction, oxidative stress and the
peroxisome proliferator-activated receptor are primarily affected in DE5
transgenic mice, indicating cell-autonomous mechanisms. Overall, HD-induced
dysregulation of the striatal transcriptome can be largely attributed to
intrinsic effects of mutant Htt, in the absence of expression in cortical
neurons. Huntington's disease (HD) is an autosomal disease caused by a CAG repeat
expansion in the huntingtin (HTT) gene. The resultant mutant HTT protein (mHTT)
forms aggregates in various types of cells, including neurons and glial cells
and preferentially affects brain function. We found that two HD mouse models
(Hdh(150Q) and R6/2) were more susceptible than wild-type (WT) mice to
lipopolysaccharide-evoked systemic inflammation and produced more
proinflammatory cytokines in the brain. Such an enhanced inflammatory response
in the brain was not observed in N171- 82Q mice that express mHTT only in
neurons, but not in glial cells. Thus, HD glia might play an important role in
chronic inflammation that accelerates disease progression in HD mice.
Intriguingly, enhanced activation of nuclear factor (NF)-κB-p65 (p65), a
transcriptional mediator of inflammatory responses, was observed in astrocytes
of patients and mice with HD. Results obtained using primary R6/2 astrocytes
suggest that these cells exhibited higher IκB kinase (IKK) activity that caused
prolongation of NF-κB activation, thus upregulating proinflammatory factors
during inflammation. R6/2 astrocytes also produced a more-damaging effect on
primary R6/2 neurons than did WT astrocytes during inflammation. Blockage of IKK
reduced the neuronal toxicity caused by R6/2 astrocytes and ameliorated several
HD symptoms of R6/2 mice (e.g. decreased neuronal density, impaired motor
coordination and poor cognitive function). Collectively, our results indicate
that enhancement of the p65-mediated inflammatory response in astrocytes
contributes to HD pathogenesis. Therapeutic interventions aimed at preventing
neuronal inflammation may be an important strategy for treating HD. Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG
trinucleotide repeat expansion in the huntingtin (HTT) gene. Disease
pathogenesis derives, at least in part, from the long polyglutamine tract
encoded by mutant HTT. Therefore, considerable effort has been dedicated to the
development of therapeutic strategies that significantly reduce the expression
of the mutant HTT protein. Antisense oligonucleotides (ASOs) targeted to the CAG
repeat region of HTT transcripts have been of particular interest due to their
potential capacity to discriminate between normal and mutant HTT transcripts.
Here, we focus on phosphorodiamidate morpholino oligomers (PMOs), ASOs that are
especially stable, highly soluble and non-toxic. We designed three PMOs to
selectively target expanded CAG repeat tracts (CTG22, CTG25 and CTG28), and two
PMOs to selectively target sequences flanking the HTT CAG repeat (HTTex1a and
HTTex1b). In HD patient-derived fibroblasts with expanded alleles containing 44,
77 or 109 CAG repeats, HTTex1a and HTTex1b were effective in suppressing the
expression of mutant and non-mutant transcripts. CTGn PMOs also suppressed HTT
expression, with the extent of suppression and the specificity for mutant
transcripts dependent on the length of the targeted CAG repeat and on the CTG
repeat length and concentration of the PMO. PMO CTG25 reduced HTT-induced
cytotoxicity in vitro and suppressed mutant HTT expression in vivo in the
N171-82Q transgenic mouse model. Finally, CTG28 reduced mutant HTT expression
and improved the phenotype of Hdh(Q7/Q150) knock-in HD mice. These data
demonstrate the potential of PMOs as an approach to suppressing the expression
of mutant HTT. Author information:
(1)Department of Pediatrics, University of California San Diego, La Jolla,
California, USA.
(2)Department of Laboratory Medicine, University of Washington, Seattle,
Washington, USA.
(3)Department of Cellular and Molecular Medicine, University of California San
Diego, La Jolla, California, USA.
(4)Institute for Genomic Medicine, University of California San Diego, La Jolla,
California, USA.
(5)Sanford Consortium for Regenerative Medicine, University of California San
Diego, La Jolla, California, USA.
(6)Division of Neurobiology, Department of Psychiatry, Johns Hopkins University
School of Medicine, Baltimore, Maryland, USA.
(7)Scripps Institute for Oceanography, University of California San Diego, La
Jolla, California, USA.
(8)Department of Medicine, University of North Carolina, Chapel Hill, North
Carolina, USA.
(9)Department of Neurology, Johns Hopkins University School of Medicine,
Baltimore, Maryland, USA.
(10)Department of Pharmacology, Johns Hopkins University School of Medicine,
Baltimore, Maryland, USA.
(11)Department of Neuroscience, Johns Hopkins University School of Medicine,
Baltimore, Maryland, USA.
(12)Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California,
USA.
(13)Department of Pathology, University of California San Diego, La Jolla,
California, USA.
(14)Department of Neurosciences, University of California San Diego, La Jolla,
California, USA.
(15)Division of Biological Sciences, University of California San Diego, La
Jolla, California, USA.
(16)Rady Children's Hospital, San Diego, California, USA. Author information:
(1)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Genetics, Paris, France2Assistance Publique-Hôpitaux de Paris,
Pitié-Salpêtrière University Hospital, Department of Neurology, Paris, France.
(2)Institut du Cerveau et de la Moelle Epinière, Paris, France4Institut National
de la Santé et de la Récherche Médicale Unité 1127, Centre National de la
Recherche Scientifique Unité Mixte de Recherche 7225, Sorbonne Universités,
Université Pierre et Marie Curie University Paris 06 Unité Mixte de Recherche
S1127, Paris, France5Ecole Pratique des Hautes Etudes, Paris, France.
(3)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Genetics, Paris, France.
(4)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Neurology, Paris, France6Assistance Publique-Hôpitaux de Paris,
Unité de Neurologie de la Mémoire et du Langage, Centre Hospitalier Saint-Anne,
Paris, France.
(5)Assistance Publique-Hôpitaux de Paris, Reference Centre for Huntington's
Disease, Unité Fonctionnelle de Neurologie Cognitive, Henri Mondor University
Hospital, Créteil, France8Institut National de la Santé et de la Récherche
Médicale Unité 955 Team 1, Institut Mondor de Recherche Biomédicale, Faculté de
Médecine de Créteil, Créteil, France9Institut d'Etude de la Cognition, Ecole
Normale Supérieure, Paris, France.
(6)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Neurology, Paris, France10Department of Neurology, McGovern
Medical School, UTHealth, Houston, Texas.
(7)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Neurology, Paris, France3Institut du Cerveau et de la Moelle
Epinière, Paris, France.
(8)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Neurology, Paris, France3Institut du Cerveau et de la Moelle
Epinière, Paris, France4Institut National de la Santé et de la Récherche
Médicale Unité 1127, Centre National de la Recherche Scientifique Unité Mixte de
Recherche 7225, Sorbonne Universités, Université Pierre et Marie Curie
University Paris 06 Unité Mixte de Recherche S1127, Paris, France.
(9)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University Hospital,
Department of Genetics, Paris, France3Institut du Cerveau et de la Moelle
Epinière, Paris, France4Institut National de la Santé et de la Récherche
Médicale Unité 1127, Centre National de la Recherche Scientifique Unité Mixte de
Recherche 7225, Sorbonne Universités, Université Pierre et Marie Curie
University Paris 06 Unité Mixte de Recherche S1127, Paris, France.
(10)Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière University
Hospital, Department of Genetics, Paris, France3Institut du Cerveau et de la
Moelle Epinière, Paris, France4Institut National de la Santé et de la Récherche
Médicale Unité 1127, Centre National de la Recherche Scientifique Unité Mixte de
Recherche 7225, Sorbonne Universités, Université Pierre et Marie Curie
University Paris 06 Unité Mixte de Recherche S1127, Paris, France5Ecole Pratique
des Hautes Etudes, Paris, France. Huntington's disease (HD) is a polyglutamine disorder caused by a CAG expansion
in the Huntingtin (HTT) gene exon 1. This expansion encodes a mutant protein
whose abnormal function is traditionally associated with HD pathogenesis;
however, recent evidence has also linked HD pathogenesis to RNA stable hairpins
formed by the mutant HTT expansion. Here, we have shown that a locked nucleic
acid-modified antisense oligonucleotide complementary to the CAG repeat
(LNA-CTG) preferentially binds to mutant HTT without affecting HTT mRNA or
protein levels. LNA-CTGs produced rapid and sustained improvement of motor
deficits in an R6/2 mouse HD model that was paralleled by persistent binding of
LNA-CTG to the expanded HTT exon 1 transgene. Motor improvement was accompanied
by a pronounced recovery in the levels of several striatal neuronal markers
severely impaired in R6/2 mice. Furthermore, in R6/2 mice, LNA-CTG blocked
several pathogenic mechanisms caused by expanded CAG RNA, including small RNA
toxicity and decreased Rn45s expression levels. These results suggest that
LNA-CTGs promote neuroprotection by blocking the detrimental activity of CAG
repeats within HTT mRNA. The present data emphasize the relevance of expanded
CAG RNA to HD pathogenesis, indicate that inhibition of HTT expression is not
required to reverse motor deficits, and further suggest a therapeutic potential
for LNA-CTG in polyglutamine disorders. Huntington's disease (HD) is a fatal, neurodegenerative disorder in which
patients suffer from mobility, psychological and cognitive impairments. Existing
therapeutics are only symptomatic and do not significantly alter the disease
progression or increase life expectancy. HD is caused by expansion of the CAG
trinucleotide repeat region in exon 1 of the Huntingtin gene (HTT), leading to
the formation of mutant HTT transcripts (muHTT). The toxic gain-of-function of
muHTT protein is a major cause of the disease. In addition, it has been
suggested that the muHTT transcript contributes to the toxicity. Thus, reduction
of both muHTT mRNA and protein levels would ideally be the most useful
therapeutic option. We herein present a novel strategy for HD treatment using
oligonucleotides (ONs) directly targeting the HTT trinucleotide repeat DNA. A
partial, but significant and potentially long-term, HTT knock-down of both mRNA
and protein was successfully achieved. Diminished phosphorylation of HTT
gene-associated RNA-polymerase II is demonstrated, suggestive of reduced
transcription downstream the ON-targeted repeat. Different backbone chemistries
were found to have a strong impact on the ON efficiency. We also successfully
use different delivery vehicles as well as naked uptake of the ONs,
demonstrating versatility and possibly providing insights for in vivo
applications. Huntington disease (HD) is a domitly inherited disorder caused by a CAG
expansion mutation in the huntingtin (HTT) gene, which results in the HTT
protein that contains an expanded polyglutamine tract. The adult form of HD
exhibits a late onset of the fully symptomatic phase. However, there is also a
long presymptomatic phase, which has been increasingly investigated and
recognized as important for the disease development. Moreover, the juvenile form
of HD, evoked by a higher number of CAG repeats, resembles a neurodevelopmental
disorder and has recently been the focus of additional interest. Multiple lines
of data, such as the developmental necessity of HTT, its role in the cell cycle
and neurogenesis, and findings from pluripotent stem cells, suggest the
existence of a neurodevelopmental component in HD pathogenesis. Therefore, we
discuss the early molecular pathogenesis of HD in pluripotent and neural stem
cells, with respect to the neurodevelopmental aspects of HD. Collaborators: Coleman A, Santos RD, Decolongon J, Sturrock A, Bardinet E, Ret
CJ, Justo D, Lehericy S, Marelli C, Nigaud K, Valabrègue R, van den Bogaard S,
Dumas EM, van der Grond J, t'Hart EP, Jurgens C, Witjes-Ane MN, Arran N,
Callaghan J, Stopford C, Frost C, Jones R, Hobbs N, Lahiri N, Ordidge R, Owen G,
Pepple T, Read J, Say M, Wild E, Patel A, Fox NC, Gibbard C, Malone I, Crawford
H, Whitehead D, Kee S, Cash DM, Berna C, Bechtel N, Bohlen S, Man AH, Kraus
P, Axelson E, Wang C, Acharya T, Lee S, Monaco W, Campbell C, Queller S,
Whitlock K, Campbell C, Campbell M, Frajman E, Milchman C, O'Regan A,
Labuschagne I, Stout J, Landwehrmeyer B, Craufurd D, Scahill R, Hicks S, Kennard
C, Johnson H, Tobin A, Rosas HD, Reilmann R, Borowsky B, Pourchot C, Andrews SC,
Bachoud-Lévi AC, Bentivoglio AR, Biunno I, Bonelli R, Burgunder JM, Dunnett S,
Ferreira J, Handley O, Heiberg A, Illmann T, Landwehrmeyer GB, Levey J,
Ramos-Arroyo MA, Nielsen J, Koivisto SP, Päivärinta M, Roos RAC, Sebastián AR,
Tabrizi S, Vandenberghe W, Verellen-Dumoulin C, Uhrova T, Wahlström J, Zaremba
J, Baake V, Barth K, Garde MB, Betz S, Bos R, Callaghan J, Come A, Guedes LC,
Ecker D, Finisterra AM, Fullam R, Gilling M, Gustafsson L, Handley OJ, Hvalstedt
C, Held C, Koppers K, Lamanna C, Laurà M, Descals AM, Martinez-Horta S, Mestre
T, Minster S, Monza D, Mütze L, Oehmen M, Orth M, Padieu H, Paterski L, Peppa N,
Koivisto SP, Di Renzo M, Rialland A, Røren N, Šašinková P, Timewell E, Townhill
J, Cubillo PT, da Silva WV, van Walsem MR, Whalstedt C, Witjes-Ané MN, Witkowski
G, Wright A, Zielonka D, Zielonka E, Zinzi P, Bonelli RM, Lilek S, Hecht K,
Herranhof B, Holl A, Kapfhammer HP, Koppitz M, Magnet M, Müller N, Otti D,
Painold A, Reisinger K, Scheibl M, Schöggl H, Ullah J, Braunwarth EM, Brugger F,
Buratti L, Hametner EM, Hepperger C, Holas C, Hotter A, Hussl A, Müller C, Poewe
W, Seppi K, Sprenger F, Wenning G, Boogaerts A, Calmeyn G, Delvaux I, Liessens
D, Somers N, Dupuit M, Minet C, van Paemel D, Ribaï P, Verellen-Dumoulin C,
Boogaerts A, Vandenberghe W, van Reijen D, Klempír J, Majerová V, Roth J,
Stárková I, Hjermind LE, Jacobsen O, Nielsen JE, Larsen IU, Vinther-Jensen T,
Hiivola H, Hyppönen H, Martikainen K, Tuuha K, Allain P, Bonneau D, Bost M,
Gohier B, Guérid MA, Olivier A, Prundean A, Scherer-Gagou C, Verny C, Babiloni
B, Debruxelles S, Duché C, Goizet C, Jameau L, Lafoucrière D, Spampinato U,
Barthélémy R, De Bruycker C, Carette MCA, Defebvre EDL, Delliaux M, Delval A,
Destee A, Dujardin K, Lemaire MH, Manouvrier S, Peter M, Plomhouse L,
Sablonnière B, Simonin C, Thibault-Tanchou S, Vuillaume I, Bellonet M,
Berrissoul H, Blin S, Courtin F, Duru C, Fasquel V, Godefroy O, Krystkowiak P,
Mantaux B, Roussel M, Wannepain S, Azulay JP, Delfini M, Eusebio A, Fluchere F,
Mundler L, Anheim M, Julié C, Boukbiza OL, Longato N, Rudolf G, Tranchant C,
Zimmermann MA, Kosinski CM, Milkereit E, Probst D, Reetz K, Sass C, Schiefer J,
Schlangen C, Werner CJ, Gelderblom H, Priller J, Prüß H, Spruth EJ, Ellrichmann
G, Herrmann L, Hoffmann R, Kaminski B, Kotz P, Prehn C, Saft C, Lange H, Maiwald
R, Löhle M, Maass A, Schmidt S, Bosredon C, Storch A, Wolz A, Wolz M, Capetian
P, Lambeck J, Zucker B, Boelmans K, Ganos C, Heinicke W, Hidding U, Lewerenz J,
Münchau A, Orth M, Schmalfeld J, Stubbe L, Zittel S, Diercks G, Dressler D,
Gorzolla H, Schrader C, Tacik P, Ribbat M, Longinus B, Bürk K, Möller JC,
Rissling I, Mühlau M, Peinemann A, Städtler M, Weindl A, Winkelmann J, Ziegler
C, Bechtel N, Beckmann H, Bohlen S, Hölzner E, Lange H, Reilmann R, Rohm S,
Rumpf S, Schepers S, Weber N, Dose M, Leythäuser G, Marquard R, Raab T,
Wiedemann A, Barth K, Buck A, Connemann J, Ecker D, Geitner C, Held C, Kesse A,
Landwehrmeyer B, Lang C, Lewerenz J, Lezius F, Nepper S, Niess A, Orth M,
Schneider A, Schwenk D, Süßmuth S, Trautmann S, Weydt P, Cormio C, Sciruicchio
V, Serpino C, de Tommaso M, Capellari S, Cortelli P, Galassi R, Rizzo G, Poda R,
Scaglione C, Bertini E, Ghelli E, Ginestroni A, Massaro F, Mechi C, Paganini M,
Piacentini S, Pradella S, Romoli AM, Sorbi S, Abbruzzese G, di Poggio MB,
Ferrandes G, Mandich P, Marchese R, Albanese A, Di Bella D, Castaldo A, Di
Donato S, Gellera C, Genitrini S, Mariotti C, Monza D, Nanetti L, Paridi D,
Soliveri P, Tomasello C, De Michele G, Di Maio L, Massarelli M, Peluso S, Roca
A, Russo CV, Salvatore E, Sorrentino P, Amico E, Favellato M, Griguoli A,
Mazzante I, Petrollini M, Squitieri F, D'Alessio B, Esposito C, Bentivoglio R,
Frontali M, Guidubaldi A, Ialongo T, Jacopini G, Piano C, Romano S, Soleti F,
Spadaro M, Zinzi P, van Hout MSE, Verhoeven ME, van Vugt JPP, de Weert AM,
Bolwijn JJW, Dekker M, Kremer B, Leenders KL, van Oostrom JCH, van den Bogaard
SJA, Bos R, Dumas EM, 't Hart EP, Roos RAC, Kremer B, Verstappen CCP, Aaserud O,
C JF, Heiberg A, van Walsem MR, Wehus R, Bjørgo K, Fannemel M, Gørvell PF,
Lorentzen E, Koivisto SP, Retterstøl L, Stokke B, Bjørnevoll I, Sando SB,
Dziadkiewicz A, Nowak M, Robowski P, Sitek E, Slawek J, Soltan W, Szinwelski M,
Blaszcyk M, Boczarska-Jedynak M, Ciach-Wysocka E, Gorzkowska A, Jasinska-Myga B,
Klodowska-Duda G, Opala G, Stompel D, Banaszkiewicz K, Bocwinska D,
Bojakowska-Jaremek K, Dec M, Krawczyk M, Rudzinska M, Szczygiel E, Szczudlik A,
Wasielewska A, Wójcik M, Bryl A, Ciesielska A, Klimberg A, Marcinkowski J,
Samara H, Sempolowicz J, Zielonka D, Gogol A, Janik P, Kwiecinski H, Jamrozik Z,
Antczak J, Jachinska K, Krysa W, Rakowicz M, Richter P, Rola R, Ryglewicz D,
Sienkiewicz-Jarosz H, Stepniak I, Sulek A, Witkowski G, Zaremba J, Zdzienicka E,
Zieora-Jakutowicz K, Ferreira JJ, Coelho M, Guedes LC, Mendes T, Mestre T,
Valadas A, Andrade C, Gago M, Garrett C, Guerra MR, Herrera CD, Garcia PM,
Barbera MA, Guia DB, Herz LC, Catena JL, Ferrer PQ, Sebastián AR, Carruesco
GT, Bas J, Busquets N, Calopa M, Robert MF, Viladrich CM, Idiago JMR, Riballo
AV, Cubo E, Polo CG, Mariscal N, Rivadeneyra PJ, Barrero F, Morales B, Fenollar
M, García RG, Ortega P, Villanueva C, Alegre J, Bascuñana M, Caldentey JG,
Ventura MF, Ribas GG, de Yébenes JG, Moreno JLL, Cubillo PT, Alegre J, Frech FA,
de Yébenes JG, Ruíz PJG, Martínez-Descals A, Guerrero R, Artiga MJS, Sánchez V,
Perea MFN, Fortuna L, Manzanares S, Reite G, Torres MMA, Moreau LV, González
González S, Guisasola LM, Salvador C, Martín ESS, Ramirez IL, Gorospe A, Lopera
MR, Arques PN, Rodríguez MJT, Pastor BV, Gaston I, Martinez-Jaurrieta MD,
Ramos-Arroyo MA, Moreno JMG, Lucena CM, Damas F, Cortegana HEP, Peña JC, Redondo
L, Carrillo F, Teresa Cáceres M, Mir P, Suarez MJL, Vargas-González L, Bosca ME,
Brugada FC, Burguera JA, Campos A, Vilaplana GCP, Berglund P, Constantinescu R,
Fredlund G, Høsterey-Ugander U, Linnsand P, Neleborn-Lingefjärd L, Wahlström J,
Wentzel M, Loutfi G, Olofsson C, Stattin EL, Westman L, Wikström B, Burgunder
JM, Stebler Y, Kaelin A, Romero I, Schüpbach M, Weber Zaugg S, Hauer M,
Gonzenbach R, Jung HH, Mihaylova V, Petersen J, Jack R, Matheson K,
Miedzybrodzka Z, Rae D, Simpson SA, Summers F, Ure A, Vaughan V, Akhtar S,
Crooks J, Curtis A, de Souza J, Piedad J, Rickards H, Wright J, Coulthard E,
Gethin L, Hayward B, Sieradzan K, Wright A, Armstrong M, Barker RA, O'Keefe D,
Di Pietro A, Fisher K, Goodman A, Hill S, Kershaw A, Mason S, Paterson N,
Raymond L, Swain R, Guzman NV, Busse M, Butcher C, Callaghan J, Dunnett S,
Clenaghan C, Fullam R, Handley O, Hunt S, Jones L, Jones U, Khalil H, Minster S,
Owen M, Price K, Rosser A, Townhill J, Edwards M, Ho C, Hughes T, McGill M,
Pearson P, Porteous M, Smith P, Brockie P, Foster J, Johns N, McKenzie S,
Rothery J, Thomas G, Yates S, Burrows L, Chu C, Fletcher A, Gallantrae D, Hamer
S, Harding A, Klöppel S, Kraus A, Laver F, Lewis M, Longthorpe M, Markova I,
Raman A, Robertson N, Silva M, Thomson A, Wild S, Yardumian P, Chu C, Evans C,
Gallentrae D, Hamer S, Kraus A, Markova I, Raman A, Chu C, Hamer S, Hobson E,
Jamieson S, Kraus A, Markova I, Raman A, Musgrave H, Rowett L, Toscano J, Wild
S, Yardumian P, Bourne C, Clapton J, Clayton C, Dipple H, Freire-Patino D, Grant
J, Gross D, Hallam C, Middleton J, Murch A, Thompson C, Alusi S, Davies R, Foy
K, Gerrans E, Pate L, Andrews T, Dougherty A, Golding C, Kavalier F, Laing H,
Lashwood A, Robertson D, Ruddy D, Santhouse A, Whaite A, Andrews T, Bruno S,
Doherty K, Golding C, Haider S, Hensman D, Lahiri N, Lewis M, Novak M, Patel A,
Robertson N, Rosser E, Tabrizi S, Taylor R, Warner T, Wild E, Arran N, Bek J,
Callaghan J, Craufurd D, Fullam R, Hare M, Howard L, Huson S, Johnson L, Jones
M, Murphy H, Oughton E, Partington-Jones L, Rogers D, Sollom A, Snowden J,
Stopford C, Thompson J, Trender-Gerhard I, Verstraelen N, Westmoreland L,
Armstrong R, Dixon K, Nemeth AH, Siuda G, Valentine R, Harrison D, Hughes M,
Parkinson A, Soltysiak B, Bandmann O, Bradbury A, Gill P, Fairtlough H,
Fillingham K, Foustanos I, Kazoka M, O'Donovan K, Peppa N, Taylor C, Tidswell K,
Quarrell O, Burgunder JM, Lau PN, Pica E, Tan L. Huntington's disease (HD) is caused by a CAG repeat expansion that encodes a
polyglutamine (polyQ) expansion in the HD disease protein, huntingtin (HTT).
PolyQ expansion promotes misfolding and aggregation of mutant HTT (mHTT) within
neurons. The cellular pathways, including ubiquitin-dependent processes, by
which mHTT is regulated remain incompletely understood. Ube2W is the only
ubiquitin conjugating enzyme (E2) known to ubiquitinate substrates at their
amino (N)-termini, likely favoring substrates with disordered N-termini. By
virtue of its N-terminal polyQ domain, HTT has an intrinsically disordered amino
terminus. In studies employing immortalized cells, primary neurons and a
knock-in (KI) mouse model of HD, we tested the effect of Ube2W deficiency on
mHTT levels, aggregation and neurotoxicity. In cultured cells, deficiency of
Ube2W activity markedly decreases mHTT aggregate formation and increases the
level of soluble monomers, while reducing mHTT-induced cytotoxicity. Consistent
with this result, the absence of Ube2W in HdhQ200 KI mice significantly
increases levels of soluble monomeric mHTT while reducing insoluble oligomeric
species. This study sheds light on the potential function of the non-canonical
ubiquitin-conjugating enzyme, Ube2W, in this polyQ neurodegenerative disease. Huntington's disease (HD), a domitly inherited neurodegenerative disease, is
defined by its genetic cause, a CAG-repeat expansion in the HTT gene, its motor
and psychiatric symptomology and primary loss of striatal medium spiny neurons
(MSNs). However, the molecular mechanisms from genetic lesion to disease
phenotype remain largely unclear. Mouse models of HD have been created that
exhibit phenotypes partially recapitulating those in the patient, and
specifically, cortico-striatal disconnectivity appears to be a shared pathogenic
event shared by HD mouse models and patients. Molecular studies have begun to
unveil converging molecular and cellular pathogenic mechanisms that may account
for cortico-striatal miscommunication in various HD mouse models. Systems
biological approaches help to illuminate synaptic molecular networks as a nexus
for HD cortio-striatal pathogenesis, and may offer new candidate targets to
modify the disease. In Huntington's disease (HD), expansion of CAG codons in the huntingtin gene
(HTT) leads to the aberrant formation of protein aggregates and the differential
degeneration of striatal medium spiny neurons (MSNs). Modeling HD using
patient-specific MSNs has been challenging, as neurons differentiated from
induced pluripotent stem cells are free of aggregates and lack an overt cell
death phenotype. Here we generated MSNs from HD patient fibroblasts through
microRNA-based direct neuronal conversion, bypassing the induction of
pluripotency and retaining age signatures of the original fibroblasts. We found
that patient MSNs consistently exhibited mutant HTT (mHTT) aggregates,
mHTT-dependent DNA damage, mitochondrial dysfunction and spontaneous
degeneration in culture over time. We further provide evidence that erasure of
age stored in starting fibroblasts or neuronal conversion of presymptomatic HD
patient fibroblasts results in differential manifestation of cellular phenotypes
associated with HD, highlighting the importance of age in modeling late-onset
neurological disorders. Huntington's disease (HD) is an inherited neurodegenerative disease caused by an
expanded CAG repeat in the huntingtin (HTT) gene. CAG repeat length explains
around half of the variation in age at onset (AAO) but genetic variation
elsewhere in the genome accounts for a significant proportion of the remainder.
Genome-wide association studies have identified a bidirectional signal on
chromosome 15, likely underlain by FANCD2- and FANCI-associated nuclease 1
(FAN1), a nuclease involved in DNA interstrand cross link repair. Here we show
that increased FAN1 expression is significantly associated with delayed AAO and
slower progression of HD, suggesting FAN1 is protective in the context of an
expanded HTT CAG repeat. FAN1 overexpression in human cells reduces CAG repeat
expansion in exogenously expressed mutant HTT exon 1, and in patient-derived
stem cells and differentiated medium spiny neurons, FAN1 knockdown increases CAG
repeat expansion. The stabilizing effects are FAN1 concentration and CAG repeat
length-dependent. We show that FAN1 binds to the expanded HTT CAG repeat DNA and
its nuclease activity is not required for protection against CAG repeat
expansion. These data shed new mechanistic insights into how the genetic
modifiers of HD act to alter disease progression and show that FAN1 affects
somatic expansion of the CAG repeat through a nuclease-independent mechanism.
This provides new avenues for therapeutic interventions in HD and potentially
other triplet repeat disorders. Huntington's disease (HD) is an autosomal progressive neurodegenerative disorder
caused by the expansion of CAG repeats in the HTT gene. Intermediate alleles
(IAs) are in the range of 27-35 repeats and have been associated to a normal
phenotype. The aim of this work was to analyze the association between
intermediate huntingtin CAG-repeat alleles (IAs) and neurodegenerative diseases,
other than HD. We screened the HTT CAG repeats in patients with Alzheimer's
disease (AD) (n = 1126), Parkinson's disease (PD) (n = 610), and frontotemporal
lobar degeneration (FTLD) (n = 225). We also studied 509 healthy controls (HCs).
The relative frequency of IAs for each group was 6.03% in AD, 5.3% in FTLD, 3.5%
in PD, and 2.9% in HCs. The frequency of IA was significantly higher among
patients with AD when compared to HCs (p = 0.011, OR = 2.11, 95% CI =
1.19-3.74); no significant difference was observed in FTLD (p = 0.17; OR = 1.88,
95% CI = 0.85-4.03) and PD (p = 0.69; OR = 1.21; 95% CI (0.61-2.37) versus HCs.
No atypical symptoms or clinical features distinctive of HD were found among
carriers of IAs. We found 3 cases with CAG expansions within the pathological
range, one diagnosed with AD, one with PD, and one with FTD. Results suggest
that IAs might have a role in the pathogenesis of AD. In addition, HD patients
might be misdiagnosed with other neurodegenerative diseases, particularly when
CAG repeats are in the lower pathological range. Huntington's disease (HD) is an autosomal domit disorder caused by an
expansion in the trinucleotide CAG repeat in exon-1 in the huntingtin gene,
located on chromosome 4. When the number of trinucleotide CAG exceeds 40
repeats, disease invariably is manifested, characterized by motor, cognitive,
and psychiatric symptoms. The huntingtin (Htt) protein and its mutant form
(mutant huntingtin, mHtt) are ubiquitously expressed but although multiple brain
regions are affected, the most vulnerable brain region is the striatum. Striatal
medium-sized spiny neurons (MSNs) preferentially degenerate, followed by the
cortical pyramidal neurons located in layers V and VI. Proposed HD pathogenic
mechanisms include, but are not restricted to, excitotoxicity, neurotrophic
support deficits, collapse of the protein degradation mechanisms, mitochondrial
dysfunction, transcriptional alterations, and disorders of myelin. Studies
performed in cell type-specific and regionally selective HD mouse models
implicate both MSN cell-autonomous properties and cell-cell interactions,
particularly corticostriatal but also with non-neuronal cell types. Here, we
review the intrinsic properties of MSNs that contribute to their selective
vulnerability and in addition, we discuss how astrocytes, microglia, and
oligodendrocytes, together with aberrant corticostriatal connectivity,
contribute to HD pathophysiology. In addition, mHtt causes cell-autonomous
dysfunction in cell types other than MSNs. These findings have implications in
terms of therapeutic strategies aimed at preventing neuronal dysfunction and
degeneration. |
What is the purpose of the 123 dihydrorhodamine assay? | detection of inheritance pattern in thirty-three mexican males with chronic granulomatous disease | OBJECTIVE: Wegener's granulomatosis (WG) is strongly associated with
antineutrophil cytoplasmic autoantibodies (ANCAs) directed against proteinase 3
(PR3). Recent studies have shown that membrane-bound PR3 (mPR3) is
differentially expressed and colocalizes with CD177/NB1 on circulating
neutrophils. We undertook this study to assess the differential expression of
CD177 on neutrophils from patients with ANCA-associated systemic vasculitis
(ASV) in comparison with patients with systemic lupus erythematosus (SLE),
patients with rheumatoid arthritis (RA), and healthy individuals, and to
investigate whether colocalization of mPR3 and CD177 affects anti-PR3-mediated
neutrophil activation.
METHODS: Expression of CD177 and mPR3 was analyzed by flow cytometry on isolated
neutrophils from patients with ASV (n=53), those with SLE (n=30), those with RA
(n=26), and healthy controls (n=31). Neutrophil activation mediated by anti-PR3
antibodies was assessed by measuring the oxidative burst with a dihydrorhodamine
assay.
RESULTS: Percentages of CD177-expressing neutrophils were significantly higher
in patients with ASV and those with SLE than in healthy controls. In 3 healthy
donors, CD177 expression was not detected. After priming with tumor necrosis
factor alpha, neutrophils remained negative for CD177 while mPR3 expression was
induced. Neutrophils from CD177-negative donors or CD177- neutrophils sorted
from donors with bimodal expression were susceptible to anti-PR3-mediated
oxidative burst. Variation in the extent of anti-PR3-mediated neutrophil
activation among different donors occurred independent of the percentage of
CD177-expressing neutrophils.
CONCLUSION: Membrane expression of CD177 on circulating neutrophils is increased
in patients with ASV and in those with SLE, but not in RA patients. However,
primed neutrophils from CD177-negative individuals also express mPR3 and are
susceptible to anti-PR3-mediated oxidative burst, suggesting that recruitment of
CD177-independent mPR3 is involved in anti-PR3-induced neutrophil activation. BACKGROUND: Chronic granulomatous disease (CGD) is an uncommon congenital
phagocyte disorder characterized by recurrent life-threatening infections. CGD
generally present with recurrent suppurative infections, however, intracranial
fungal abscess complicating CGD may cause a diagnostic problem to anyone
unfamiliar with its clinical and radiological features.
HISTORY: We report the case of a 16-year-old boy who was consulted with a
differential diagnosis of an intracranial tumor. The clues of his medical
history and physical examination made us consider the diagnosis of CGD.
Cytometric dihydrorhodamine assay and genotyping confirmed an autosomal
recessive CGD. He was successfully treated without any complication or sequel
for 18 months follow-up period with surgery and interferon-gamma, in addition
with, liposomal amphotericin B and voriconazole that were found to be sensitive
to the Aspergillus fumigates, which had been grown from the culture of the
abscess cavity.
DISCUSSION: We discuss the pathogenesis, radiological techniques, and management
of cerebral Aspergillus abscess in a patient with CGD.
CONCLUSION: Presentation of CGD with a cerebral Aspergillus abscess, mimicking a
brain tumor is extremely rare in children; clinicians and neurosurgeons must be
aware. The best management modality for cerebral Aspergillus abscess is to be
vigilant about the disease, whereas adjuvant surgical and medical therapy with a
close follow-up must be warranted for all cases. Tight junction has a crucial role in regulating paracellular transports (as a
barrier) and in separating apical from basolateral compartments to maintain cell
polarity (as a fence). Tight junction can be disrupted by various stimuli,
including oxidative stress, pathogens and proinflammatory cytokines. However,
association of defective tight junction with kidney stone pathogenesis remains
unknown. We therefore examined whether calcium oxalate monohydrate (COM)
crystals, which are the major crystalline composition in kidney stones, have any
effects on expression and function of tight junction of polarized renal tubular
epithelial cells. Western blot analysis revealed marked decrease in levels of
occludin and zonula occludens-1 (ZO-1) in COM-treated polarized Madin-Darby
canine kidney (MDCK) cells. Immunofluorescence staining revealed not only the
decline of these tight junction proteins but also their redistribution and
dissociation in COM-treated cells. Additionally, transepithelial resistance was
significantly decreased, indicating impaired tight junction barrier and
increased paracellular permeability in COM-treated cells. Subcellular
fractionation followed by western blot analysis of Na(+)/K(+)-ATPase-α1 revealed
that this basolateral membrane marker was also detectable in apical membrane
fraction of COM-treated cells, but not in apical membrane fraction of control
cells. Immunofluorescence study confirmed the translocation of
Na(+)/K(+)-ATPase-α1 (from basolateral to apical membranes) in COM-treated
cells, indicating impaired fence function of the tight junction. Moreover,
dihydrorhodamine assay using flow cytometry revealed the significantly higher
level of hydrogen peroxide in the COM-treated cells. These data provide the
first evidence to demonstrate decreased expression and defective barrier and
fence functions of the tight junction of renal tubular epithelial cells exposed
to COM crystals that may be fundamental for subsequent renal tubulointerstitial
injury, which in turn enhances the stone pathogenesis. |
What is the mode of action of filgotinib? | Filgotinib is an oral selective Janus kinase 1 (JAK1) inhibitor. It has been tested in patients with rheumatoid arthritis and Chroni's disease, and has been shown to be effective. | OBJECTIVE: The selective Janus kinase 1 inhibitor filgotinib (GLPG0634), which
is currently in clinical development for the treatment of rheumatoid arthritis
(RA) and Crohn's disease, demonstrated encouraging safety and efficacy profiles
in RA patients after 4 weeks of daily dosing. As RA patients might be treated
with multiple medications simultaneously, possible drug-drug interactions of
filgotinib with cytochrome P450 enzymes and with key drug transporters were
evaluated in vitro and in clinical studies.
METHODS: The enzymes involved in filgotinib's metabolism and the potential
interactions of the parent and its active major metabolite with
drug-metabolizing enzymes and drug transporters, were identified using
recombit enzymes, human microsomes, and cell systems. Furthermore,
filgotinib's interaction potential with CYP3A4 was examined in an open-label
study in healthy volunteers, which evaluated the impact of filgotinib
co-administration on the CYP3A4-sensitive substrate midazolam. The potential
interaction with the common RA drug methotrexate was investigated in a clinical
study in RA patients.
RESULTS: In vitro, filgotinib and its active metabolite at clinically relevant
concentrations did not interact with cytochrome P450 enzymes and uridine
5'-diphospho-glucuronosyltransferases, and did not inhibit key drug
transporters. In the clinic, a lack of relevant pharmacokinetic drug
interactions by filgotinib and its active metabolite with substrates of CYP3A4,
as well as with organic anion transporters involved in methotrexate elimination
were found.
CONCLUSION: the collective in vivo and in vitro data on drug-metabolizing
enzymes and on key drug transporters, support co-administration of filgotinib
with commonly used RA drugs to patients without the need for dose adjustments. BACKGROUND: Filgotinib (GLPG0634, GS-6034) is a once-daily, orally administered,
Janus kinase 1 (JAK1)-selective inhibitor. The FITZROY study examined the
efficacy and safety of filgotinib for the treatment of moderate-to-severe
Crohn's disease.
METHODS: We did a randomised, double-blind, placebo-controlled phase 2 study,
which recruited patients from 52 centres in nine European countries. We enrolled
eligible patients aged 18-75 years with a documented history of ileal, colonic,
or ileocolonic Crohn's disease for 3 months or more before screening, as
assessed by colonoscopy and supported by histology, and a Crohn's Disease
Activity Index (CDAI) score during screening between 220 and 450 inclusive.
Patients were randomly assigned (3:1) to receive filgotinib 200 mg once a day or
placebo for 10 weeks. Patients were stratified according to previous anti-tumour
necrosis factor alpha exposure, C-reactive protein concentration at screening
(≤10 mg/L or >10 mg/L), and oral corticosteroid use at baseline, using an
interactive web-based response system. The primary endpoint was clinical
remission, defined as CDAI less than 150 at week 10. After week 10, patients
were assigned based on responder status to filgotinib 100 mg once a day,
filgotinib 200 mg once a day, or placebo for an observational period lasting a
further 10 weeks. The filgotinib and placebo treatment groups were compared
using ANCOVA models and logistic regression models containing baseline values
and randomisation stratification factors as fixed effects. Analyses were done on
the intention-to-treat non-responder imputation set. The trial was registered at
ClinicalTrials.gov, number NCT02048618.
FINDINGS: Between Feb 3, 2014, and July 10, 2015, we enrolled 174 patients with
active Crohn's disease confirmed by centrally read endoscopy (130 in the
filgotinib 200 mg group and 44 in the placebo group). In the intention-to-treat
population, 60 (47%) of 128 patients treated with filgotinib 200 mg achieved
clinical remission at week 10 versus ten (23%) of 44 patients treated with
placebo (difference 24 percentage points [95% CI 9-39], p=0·0077). In a pooled
analysis of all periods of filgotinib and placebo exposure over 20 weeks,
serious treatment-emergent adverse effects were reported in 14 (9%) of 152
patients treated with filgotinib and three (4%) of 67 patients treated with
placebo.
INTERPRETATION: Filgotinib induced clinical remission in significantly more
patients with active Crohn's disease compared with placebo, and had an
acceptable safety profile.
FUNDING: Galapagos. OBJECTIVES: To evaluate the efficacy and safety of different doses of
filgotinib, an oral Janus kinase 1 inhibitor, as monotherapy in patients with
active rheumatoid arthritis (RA) and previous inadequate response to
methotrexate (MTX).
METHODS: In this 24-week phase IIb study, patients with moderately to severely
active RA were randomised (1:1:1:1) to receive 50, 100 or 200 mg filgotinib once
daily, or placebo, after a ≥4-week washout from MTX. The primary end point was
the percentage of patients achieving an American College of Rheumatology (ACR)20
response at week 12.
RESULTS: Overall, 283 patients were randomised and treated. At week 12,
significantly more patients receiving filgotinib at any dose achieved ACR20
responses versus placebo (≥65% vs 29%, p<0.001). For other key end points at
week 12 (ACR50, ACR70, ACR-N, Disease Activity Score based on 28 joints and C
reactive protein, Clinical Disease Activity Index, Simplified Disease Activity
Index and Health Assessment Questionnaire-Disability Index) significant
differences from baseline in favour of filgotinib 100 and 200 mg versus placebo
were seen; responses were maintained or improved through week 24. Rapid onset of
action was observed for most efficacy end points. Dose-dependent increases in
haemoglobin were observed. The percentage of patients with treatment-emergent
adverse events (TEAE) was similar in the placebo and filgotinib groups (∼40%).
Eight patients on filgotinib and one on placebo had a serious TEAE, and four
patients, all of whom received filgotinib, experienced a serious infection. No
tuberculosis or opportunistic infections were reported.
CONCLUSIONS: Over 24 weeks, filgotinib as monotherapy was efficacious in
treating the signs and symptoms of active RA, with a rapid onset of action.
Filgotinib was generally well tolerated.
TRIAL REGISTRATION NUMBER: NCT01894516. OBJECTIVES: To evaluate the efficacy and safety of different doses and regimens
of filgotinib, an oral Janus kinase 1 inhibitor, as add-on treatment to
methotrexate (MTX) in patients with active rheumatoid arthritis (RA) and
inadequate response to MTX.
METHODS: In this 24-week phase IIb study, patients with moderate-to-severe
active RA receiving a stable dose of MTX were randomised (1:1:1:1:1:1:1) to
receive placebo or 50, 100 or 200 mg filgotinib, administered once daily or
twice daily. Primary end point was the percentage of patients achieving a week
12 American College of Rheumatology (ACR)20 response.
RESULTS: Overall, 594 patients were randomised and treated. At week 12,
significantly more patients receiving filgotinib 100 mg once daily or 200 mg
daily (both regimens) achieved an ACR20 response versus placebo. For other key
end points at week 12 (ACR50, ACR-N, Disease Activity Score based on 28 joints
and C reactive protein value, Clinical Disease Activity Index, Simplified
Disease Activity Index and Health Assessment Questionnaire-Disability Index),
differences in favour of 100 or 200 mg filgotinib daily were seen versus
placebo; responses were maintained or improved through to week 24. Rapid onset
of action and dose-dependent responses were observed for most efficacy end
points and were associated with an increased haemoglobin concentration. No
significant differences between once-daily and twice-daily regimens were seen.
Treatment-emergent adverse event rates were similar in placebo and filgotinib
groups. Serious infections occurred in one and five patients in the placebo and
filgotinib groups, respectively. No tuberculosis or opportunistic infections
were reported.
CONCLUSIONS: Filgotinib as add-on to MTX improved the signs and symptoms of
active RA over 24 weeks and was associated with a rapid onset of action.
Filgotinib was generally well tolerated.
TRIAL REGISTRATION NUMBER: NCT01888874. OBJECTIVE: JAK inhibitors have shown efficacy in rheumatoid arthritis (RA). We
undertook this study to test our hypothesis that selective inhibition of JAK-1
would combine good efficacy with a better safety profile compared with less
selective JAK inhibitors.
METHODS: In two 4-week exploratory, double-blind, placebo-controlled phase IIa
trials, 127 RA patients with an insufficient response to methotrexate (MTX)
received filgotinib (GLPG0634, GS-6034) oral capsules (100 mg twice daily or 30,
75, 150, 200, or 300 mg once daily) or placebo, added onto a stable regimen of
MTX, to evaluate safety, efficacy, pharmacokinetics (PK), and pharmacodynamics
(PD) of filgotinib. The primary efficacy end point was the number and percentage
of patients in each treatment group meeting the American College of Rheumatology
20% improvement criteria (achieving an ACR20 response) at week 4.
RESULTS: Treatment with filgotinib at 75-300 mg met the primary end point and
showed early onset of efficacy. ACR20 response rates progressively increased to
week 4, and the Disease Activity Score in 28 joints using the C-reactive protein
(CRP) level decreased. Marked and sustained improvements were observed in serum
CRP level and other PD markers. The PK of filgotinib and its major metabolite
was dose proportional over the 30-300 mg range. Early side effects seen with
other less selective JAK inhibitors were not observed (e.g., there was no
worsening of anemia [JAK-2 inhibition related], no effects on liver
transaminases, and no increase in low-density lipoprotein or total cholesterol).
A limited decrease in neutrophils without neutropenia was consistent with
immunomodulatory effects through JAK-1 inhibition. There were no infections.
Overall, filgotinib was well tolerated. Events related to study drug were mild
or moderate and transient during therapy, and the most common such event was
nausea.
CONCLUSION: Selective inhibition of JAK-1 with filgotinib shows initial efficacy
in RA with an encouraging safety profile in these exploratory studies. Biologics were the first targeted therapies for rheumatoid arthritis (RA),
having in common high clinical efficacy. Being proteins, they are administered
parenterally. The first oral targeted small molecules approved for RA are
competitive inhibitors of the Janus kinase (JAK) enzyme family which mediate
signalling for a cytokine subset important in RA pathogenesis. Areas covered:
Several JAK inhibitors have been developed with differing selectivity for the
four JAK enzymes with a view to generating oral, multi-cytokine inhibitors. Here
we review the pharmacology and clinical trial data for efficacy and safety of
filgotinib, an investigational selective JAK1 inhibitor. We contextualise the
contemporary approach to RA management and substantial unmet needs that remain.
Expert opinion: The selectivity of filgotinib for JAK1 may have theoretical
advantages in terms of limiting toxicity. However, establishing whether this is
so before larger numbers of patients are exposed in phase III and beyond in the
real word setting, will be difficult. Filgotinib clinical trial data to date has
been encouraging with rapid, sustained efficacy with promising safety and
tolerability. We are likely to see an expanding choice of approved JAK
inhibitors in the clinic but it may not be straightforward to distinguish safety
and efficacy differences. BACKGROUND: The aim was to assess patient-reported outcomes (PROs) in patients
with rheumatoid arthritis (RA) treated with filgotinib during two phase 2b,
24-week, randomized, placebo-controlled studies.
METHODS: Patients with moderate-to-severe active RA and an inadequate response
to methotrexate (MTX) were randomized to daily placebo or filgotinib 50 mg, 100
mg, or 200 mg as add-on therapy to MTX (NCT01888874) or as monotherapy
(NCT01894516). At week 12, nonresponders receiving filgotinib 50 mg in both
studies or placebo in the add-on study, and all patients receiving placebo as
monotherapy, were re-assigned to filgotinib 100 mg. PROs were measured using the
Health Assessment Questionnaire - Disability Index (HAQ-DI) including Patient
Pain assessed by visual analog scale, and the Patient Global Assessment of
Disease Activity (Patient Global), the Functional Assessment of Chronic Illness
Therapy (FACIT)-Fatigue Scale (Version 4), and the 36-Item Short Form Health
Survey (SF-36).
RESULTS: At week 12, improvements in all PROs, apart from the SF-36 mental
component in the add-on study, were statistically better with filgotinib than
placebo; some improvements were noted as early as the first assessment time
point (week 1 or week 4). Filgotinib improved HAQ-DI by 0.58-0.84 points,
FACIT-Fatigue by 6.9-11.4 points, Patient Global by 25.2-35.6 mm, and Pain by
24.2-37.9 mm; scores were maintained or improved to week 24. Across all PROs,
more patients achieved minimal clinically important differences and normative
values with filgotinib 200 mg than placebo. Patients re-assigned to filgotinib
100 mg at week 12 experienced improvements in PROs between weeks 12 to 24.
CONCLUSIONS: Filgotinib as MTX add-on therapy or as monotherapy demonstrated
rapid and sustained (to 24 weeks) improvements in health-related quality of life
and functional status in patients with active RA.
TRIAL REGISTRATION: MTX add-on study: ClinicalTrials.gov , NCT01888874 .
Registered on 28 June 2013. Monotherapy study: ClinicalTrials.gov , NCT01894516
. Registered on 10 July 2013. AIMS: Filgotinib (GS-6034, formerly GLPG0634) is an oral, selective Janus kinase
1 (JAK1) inhibitor that showed early response and sustained efficacy in patients
with rheumatoid arthritis and with Crohn's disease. The aim of the present study
was to investigate the impact of age and renal impairment (RI) on the
pharmacokinetics (PK) of filgotinib and its main metabolite.
METHODS: The effect of age was assessed in two groups of 10 elderly healthy
subjects (65-74 and ≥75 years of age) and a control group of 10 younger healthy
subjects (40-50 years of age). The impact of RI was investigated in three groups
of subjects with mild (n = 6), moderate (n = 6) and severe (n = 3) RI [estimated
glomerular filtration rate (eGFR) 60-89, 30-59 and 15-29 ml min-1 1.73 m-2 ,
respectively] and a control group (n = 9) with normal renal function (eGFR
≥90 ml min-1 1.73 m-2 ). The PK of filgotinib and its metabolite were evaluated
following filgotinib 100 mg once-daily doses for 10 days.
RESULTS: At steady state, the exposure [area under the concentration-time curve
over the dosing interval (AUC0-24 h )] of filgotinib and its metabolite was
moderately higher (1.45- and 1.33-fold, respectively) in the elderly subjects
(≥75 years) compared with younger subjects. Renal clearance for filgotinib and
its metabolite decreased with the degree of RI, leading to a maximum increase in
AUC0-24 h of 1.54-fold for filgotinib and 2.74-fold for the metabolite in
subjects with severe RI. Filgotinib was generally safe and well tolerated.
CONCLUSIONS: Age and mild to moderate impairment of renal function had limited
impact on the PK of filgotinib. In subjects with severe RI, the exposure to the
metabolite of filgotinib was elevated, consistent with its renal elimination
pathway. BACKGROUND: The Janus kinase 1 (JAK1) pathway has been implicated in the
pathogenesis of psoriatic arthritis. We aimed to investigate the efficacy and
safety of filgotinib, a selective JAK1 inhibitor, for the treatment of psoriatic
arthritis.
METHODS: The EQUATOR trial was a randomised, double-blind, placebo-controlled
phase 2 trial that enrolled adults from 25 sites in seven countries (Belgium,
Bulgaria, Czech Republic, Estonia, Poland, Spain, and Ukraine). Patients (aged
≥18 years) had active moderate-to-severe psoriatic arthritis (defined as at
least five swollen joints and at least five tender joints) fulfilling
Classification for psoriatic arthritis (CASPAR) criteria, active or a documented
history of plaque psoriasis, and an insufficient response or intolerance to at
least one conventional synthetic disease-modifying anti-rheumatic drug
(csDMARD). Patients continued to take csDMARDs during the study if they had
received this treatment for at least 12 weeks before screening and were on a
stable dose for at least 4 weeks before baseline. Using an interactive web-based
system, we randomly allocated patients (1:1) to filgotinib 200 mg or placebo
orally once daily for 16 weeks (stratified by current use of csDMARDs and
previous use of anti-tumour necrosis factor). Patients, study team, and sponsor
were masked to treatment assignment. The primary endpoint was proportion of
patients achieving 20% improvement in American College of Rheumatology response
criteria (ACR20) at week 16 in the full analysis set (patients who received at
least one dose of study drug), which was compared between groups with the
Cochran-Mantel-Haenszel test and non-responder imputation method. This trial is
registered with ClincalTrials.gov, number NCT03101670.
FINDINGS: Between March 9, and Sept 27, 2017, 191 patients were screened and 131
were randomly allocated to treatment (65 to filgotinib and 66 to placebo). 60
(92%) patients in the filgotinib group and 64 (97%) patients in the placebo
group completed the study; five patients (8%) in the filgotinib group and two
patients (3%) in the placebo group discontinued treatment. 52 (80%) of 65
patients in the filgotinib group and 22 (33%) of 66 in the placebo group
achieved ACR20 at week 16 (treatment difference 47% [95% CI 30·2-59·6],
p<0·0001). 37 (57%) patients who received filgotinib and 39 (59%) patients who
received placebo had at least one treatment-emergent adverse event. Six
participants had an event that was grade 3 or worse. The most common events were
nasopharyngitis and headache, occurring at similar proportions in each group.
One serious treatment-emergent adverse event was reported in each group
(pneumonia and hip fracture after a fall), one of which (pneumonia) was fatal in
the filgotinib group.
INTERPRETATION: Filgotinib is efficacious for the treatment of active psoriatic
arthritis, and no new safety signals were identified.
FUNDING: Galapagos and Gilead Sciences. BACKGROUND: At present, biological disease-modifying anti-rheumatic drugs
(DMARDs) are the only treatment recommended for patients with ankylosing
spondylitis who have not responded to first-line treatment with non-steroidal
anti-inflammatory drugs (NSAIDs). The TORTUGA trial investigated the efficacy
and safety of filgotinib, an oral selective Janus kinase 1 (JAK1) inhibitor, for
the treatment of patients with active ankylosing spondylitis.
METHODS: In this completed, randomised, double-blind, placebo-controlled, phase
2 trial, we enrolled adult patients from 30 sites in seven countries (Belgium,
Bulgaria, Czech Republic, Estonia, Poland, Spain, and Ukraine). Eligible
patients had active ankylosing spondylitis and an inadequate response or
intolerance to two or more NSAIDs. Patients were randomly assigned (1:1) with an
interactive web-based response system to receive filgotinib 200 mg or placebo
orally once daily for 12 weeks. Randomisation was stratified by current use of
conventional synthetic DMARDs and previous receipt of anti-tumour necrosis
factor therapy. The patients, study team, and study sponsor were masked to
treatment assignment. The primary endpoint was the change from baseline in
ankylosing spondylitis disease activity score (ASDAS) at week 12, which was
assessed in the full analysis set (ie, all randomised patients who received at
least one dose of study drug). Safety was assessed according to actual treatment
received. This trial is registered with ClinicalTrials.gov, number NCT03117270.
FINDINGS: Between March 7, 2017, and July 2, 2018, 263 patients were screened
and 116 randomly assigned to filgotinib (n=58) or placebo (n=58). 55 (95%)
patients in the filgotinib group and 52 (90%) in the placebo group completed the
study; three (5%) patients in the filgotinib group and six (10%) in the placebo
group discontinued treatment. The mean ASDAS change from baseline to week 12 was
-1·47 (SD 1·04) in the filgotinib group and -0·57 (0·82) in the placebo group,
with a least squares mean difference between groups of -0·85 (95% CI -1·17 to
-0·53; p<0·0001). Treatment-emergent adverse events were reported in 18 patients
in each group, the most common being nasopharyngitis (in two patients in the
filgotinib group and in four patients in the placebo group). Treatment-emergent
adverse events led to permanent treatment discontinuation in two patients (a
case of grade 3 pneumonia in the filgotinib group and of high creatine kinase in
the placebo group). No deaths were reported during the study.
INTERPRETATION: Filgotinib is efficacious and safe for the treatment of patients
with active ankylosing spondylitis who have not responded to first-line
pharmacological therapy with NSAIDs. Further investigation of filgotinib for
ankylosing spondylitis is warranted.
FUNDING: Galapagos and Gilead Sciences. |
Is Huntington's disease caused by a dominate or recessive gene? | Huntington's Disease (HD) is an autosomal dominant neurodegenerative disease | Huntington's disease (HD) is a late onset, incurable, autosomal
domitly-inherited, progressive neuropsychiatric disease, characterised by
chorea, changes in personality, mood and behaviour, and dementia. Huntington's
disease is a clinical diagnosis. The advent of DNA diagnosis has made
predictive, prenatal and preimplantation testing possible for at-risk persons or
asymptomatic carriers. The prevalence is estimated to be 3-10/100,000 among
individuals of European descent; HD is less common in other ethnic groups.
Huntington's disease is caused by an expanded trinucleotide CAG repeat in the HD
gene on chromosome 4. The gene encodes for the protein huntingtin, with an as
yet unknown function. The mutated huntingtin has an elongated stretch of
glutamines which leads to a gain of function such as overactivity,
excitotoxicity, or to interactions with other proteins. Huntington disease (HD) is a well-defined autosomal domit neurodegenerative
disease caused by CAG repeat expansions in HD gene. There are a significant
number of HD cases where this mutation was not found and such cases are named
HD-like phenotype (HDL). This article reports 48 patients with HDL phenotype.
Patients were analyzed on the presence of mutations in prion (PrP), ferritin and
junctophilin-3 (JP-3) genes. None of the patients showed the presence of the
mutation in analyzed genes. This could suggest that there is some other
gene/genes where the mutation can cause the disease with clinical features of
HD. Huntington disease is an autosomal-domit neurodegenerative disease of
mid-life onset caused by expansion of a polymorphic trinucleotide (CAG) repeat.
Variable penetrance for alleles carrying 36-39 repeats has been noted, but the
disease appears fully penetrant when the repeat numbers are >40. An abnormal CAG
repeat may expand, contract, or be stably transmitted when passed from parent to
child. Assays used to diagnose Huntington disease must be optimized to ensure
the accurate and unambiguous quantitation of CAG repeat length. This document
provides an overview of Huntington disease and methodological considerations for
Huntington disease testing. Examples of laboratory reports are also included. Accumulating evidence highlights the potential role of mixed proteinopathies
(i.e., abnormal protein aggregation) in the development of clinical
manifestations of neurodegenerative diseases (NDD). Huntington's disease (HD) is
an inherited NDD caused by autosomal-domit expanded CAG trinucleotide repeat
mutation in the gene coding for Huntingtin (Htt). Previous studies have
suggested the coexistence of phosphorylated-Tau, α-synuclein (α-Syn) and TAR
DNA-binding protein 43 (TDP-43) inclusions in HD. However, definite evidence
that HD pathology in humans can be accompanied by other proteinopathies is still
lacking. Using human post-mortem putamen samples from 31 controls and 56 HD
individuals, we performed biochemical analyses of the expression,
oligomerization and aggregation of Tau, α-Syn, TDP-43, and Amyloid precursor
protein (APP)/Aβ. In HD brain, we observed reduced soluble protein (but not
mRNA) levels of Htt, α-Syn, and Tau. Our results also support abnormal
phosphorylation of Tau in more advanced stages of disease. Aberrant splicing of
Tau exons 2, 3 (exclusion) and 10 (inclusion) was also detected in HD patients,
leading to higher 0N4R and lower 1N3R isoforms. Finally, following formic acid
extraction, we observed increased aggregation of TDP-43, α-Syn, and
phosphorylated-Tau during HD progression. Notably, we observed that 88% of HD
patients with Vonsattel grade 4 neuropathology displayed at least one non-Htt
proteinopathy compared to 29% in controls. Interestingly, α-Syn aggregation
correlated with Htt, TDP-43 and phosphorylated-Tau in HD but not in controls.
The impact of this work is twofold: (1) it provides compelling evidences that
Tau, α-Syn and TDP-43 proteinopathies are increased in HD, and (2) it suggests
the involvement of common mechanisms leading to abnormal accumulation of
aggregation-prone proteins in NDD. Further studies will be needed to decipher
the impact of these proteinopathies on clinical manifestation of HD. Sirtuins and their pharmacological activators/inhibitors have been associated
with a range of neuroprotective effects or disease modifying influences in
neurological disorders. Huntington's disease (HD) is an autosomal-domit,
progressive neurodegenerative disease characterized by movement disorder,
psychiatric symptoms and cognitive decline. The monogenic mutation in HD encodes
a variant of the protein Huntingtin (HTT). The disease is a consequence of a CAG
repeat extension leading to an abnormally long polyglutamine (Q) stretch at
HTT's N-terminus, which likely confers a toxic gain of function to the mutant
polypeptide. HD has currently no effective disease-modifying therapy or
preventive measures. In the past 2decades, a sizable body of work on Sirtuins'
modification of HD pathology using HD cell and animal models has accumulated. In
this chapter, evidence for Sirtuin activities as potential modifiers of HD
pathology is reviewed. The conflicting findings of the impacts of mammalian
Sirtuin paralogs on HD pathogenesis and disease progression are highlighted. The
possible cellular and molecular mechanisms underlying Sirtuin activities in HD
are discussed with reference to pathophysiological mechanisms of transcription
perturbation, proteostasis, mitochondrial function, and microtubule dynamics. A
brief therapeutic perspective on the use of Sirtuin activators and inhibitors is
also presented. Dysfunctions in brain cholesterol homeostasis have been extensively related to
brain disorders. The main pathway for brain cholesterol elimination is its
hydroxylation into 24S-hydroxycholesterol by the cholesterol 24-hydrolase,
CYP46A1. Increasing evidence suggests that CYP46A1 has a role in the
pathogenesis and progression of neurodegenerative disorders, and that increasing
its levels in the brain is neuroprotective. However, the mechanisms underlying
this neuroprotection remain to be fully understood. Huntington's disease is a
fatal autosomal domit neurodegenerative disease caused by an abnormal CAG
expansion in huntingtin's gene. Among the multiple cellular and molecular
dysfunctions caused by this mutation, altered brain cholesterol homeostasis has
been described in patients and animal models as a critical event in Huntington's
disease. Here, we demonstrate that a gene therapy approach based on the delivery
of CYP46A1, the rate-limiting enzyme for cholesterol degradation in the brain,
has a long-lasting neuroprotective effect in Huntington's disease and
counteracts multiple detrimental effects of the mutated huntingtin. In zQ175
Huntington's disease knock-in mice, CYP46A1 prevented neuronal dysfunctions and
restored cholesterol homeostasis. These events were associated to a specific
striatal transcriptomic signature that compensates for multiple mHTT-induced
dysfunctions. We thus explored the mechanisms for these compensations and showed
an improvement of synaptic activity and connectivity along with the stimulation
of the proteasome and autophagy machineries, which participate to the clearance
of mutant huntingtin (mHTT) aggregates. Furthermore, BDNF vesicle axonal
transport and TrkB endosome trafficking were restored in a cellular model of
Huntington's disease. These results highlight the large-scale beneficial effect
of restoring cholesterol homeostasis in neurodegenerative diseases and give new
opportunities for developing innovative disease-modifying strategies in
Huntington's disease. |
What is RiboTag profiling? | RiboTag is a flexible tool for measuring the translational state of targeted cells in heterogeneous cell cultures. | |
Is there an increased risk of meningiomas in atomic bomb survivors? | Yes, the incidence of meningiomas is increased in atomic bomb survivors. | Among the Nagasaki atomic-bomb survivors registered at the Scientific Data
Center for Atomic-Bomb Disaster, Nagasaki University School of Medicine, 45
cases of surgically treated intracranial meningioma were collected from 6
hospitals with departments of neurosurgery in or near Nagasaki City during the
period from 1973 to 1992. All 45 patients were over 40 years of age at the time
of diagnosis. Subsequently, the 45 cases were statistically analyzed in
relationship to the estimated distance from the hypocenter by age, gender,
intracranial location, histology and latent period. The analysis showed a high
correlation between incidence of meningiomas and distance from the hypocenter.
The incidence among Nagasaki atomic-bomb survivors over 40 years of age,
especially in those proximally exposed, appears to be increasing, in inverse
proportion to the exposure distance, since 1981, 36 years after the explosion of
the atomic bomb. Since the atomic bomb explosions in Hiroshima and Nagasaki, high incidences of
leukemia, thyroid cancer and other tumors have been reported as atomic
bomb-induced tumors. We investigated the incidence of meningioma among Hiroshima
atomic bomb survivors. Sixty-eight patients surgically treated for meningioma
who had been within 2.0 km of the hypocenter of the explosion were identified.
Six hundred and seven non-exposed patients with meningioma were also studied.
Treatment dates were from 1975 to 1992. The incidences of meningioma among 68
subjects within 2.0 km and 607 non-exposed patients were 8.7 and 3.0 cases per
10(5) persons per year, respectively. The incidences of meningioma among the
survivors of Hiroshima in 5-year intervals since 1975 were 5.3, 7.4, 10.1, and
14.9, respectively. The incidences of meningioma classified by distances from
the hypocenter of 1.5-2.0 km, 1.0-1.5 km and less than 1.0 km were 6.3, 7.6 and
20.0, respectively. The incidences of meningioma classified by doses to the
brain of 0-0.099 Sv, 0.1-0.99 Sv and more than 1.0 Sv were 7.7, 9.2 and 18.2,
respectively. The incidence of meningioma among Hiroshima atomic bomb survivors
has increased since 1975. There was a significant correlation between the
incidence and the dose of radiation to the brain. The present findings strongly
suggest that meningioma is one of the tumors induced by atomic bombing in
Hiroshima. BACKGROUND: The risk of developing nervous system tumors following exposure to
ionizing radiation is not well quantified. We characterized the incidence of
nervous system tumors among atomic bomb survivors as a function of radiation
dose.
METHODS: Tumors of the nervous system and pituitary gland diagnosed between 1958
and 1995 among 80 160 atomic bomb survivors were ascertained using the Hiroshima
and Nagasaki tumor registries, medical records, and death certificates.
Pathologists reviewed slides and medical records to provide histologic
diagnoses. Poisson regression analyses were used to characterize radiation
effects on tumor incidence, which are expressed as excess relative risk per
sievert (ERR(Sv)). All statistical tests were two-sided.
RESULTS: A statistically significant dose-related excess of nervous system
tumors was observed in the cohort (ERR(Sv) = 1.2, 95% confidence interval [CI] =
0.6 to 2.1). The highest ERR(Sv) was seen for schwannoma (4.5, 95% CI = 1.9 to
9.2). The risk for all other nervous system tumors as a group is also
statistically significantly elevated (ERR(Sv) = 0.6, 95% CI = 0.1 to 1.3). Risk
increases, although not statistically significant, were seen for meningiomas
(ERR(Sv) = 0.6, 95% CI = -0.01 to 1.8), gliomas (ERR(Sv) = 0.6, 95% CI = -0.2 to
2.0), other nervous system tumors (ERR(Sv) = 0.5, 95% CI = <-0.2 to 2.2), and
pituitary tumors (ERR(Sv) = 1.0, 95% CI = <-0.2 to 3.5). The dose-response
relationships were linear. For nervous system tumors other than schwannoma,
excess risks were higher for men than for women and for those exposed during
childhood than for those exposed during adulthood.
CONCLUSIONS: A statistically significant dose response was observed for all
nervous system tumors combined and for schwannoma considered separately,
indicating that exposure to even moderate doses (i.e., <1 Sv) of radiation is
associated with an elevated incidence of nervous system tumors. BACKGROUND: Analysis conducted in the Life Span Study (LSS) cohort of atomic
bomb survivors in Hiroshima and Nagasaki found a significant dose-related excess
of tumors of the central nervous system (CNS) and the pituitary gland. The
objective of the current study was to evaluate clinical and epidemiologic
characteristics of first primary tumors of the CNS and the pituitary gland in
this cohort and to compare them with characteristics among other populations.
METHODS: CNS and pituitary gland tumors that were diagnosed between 1958 and
1995 among 80,160 LSS cohort members were ascertained through Hiroshima and
Nagasaki tumor registries, autopsy reports, and other sources. Pathologists
reviewed all available records and slides to verify histologic diagnoses.
Poisson regression analysis was used to model background incidence rates
allowing for radiation effects.
RESULTS: Meningioma was the most common tumor among clinically diagnosed tumors,
followed by neuroepithelial tumor, schwannoma, and pituitary tumor. The overall
incidence of these tumors increased initially with age but declined among the
elderly. For all age groups and for both genders, incidence increased over time.
By contrast, when tumors diagnosed at autopsy were included, incidence rose
continuously with age and was stable over time.
CONCLUSIONS: The main characteristics of CNS and pituitary gland tumors
diagnosed in the LSS cohort were consistent with the characteristics of
"spontaneous" tumors observed in other population-based studies. The
predomice of meningiomas over neuroepithelial tumors in the Japanese
population was noteworthy and warrants further investigation. The secular rise
in incidence of all clinically diagnosed CNS and pituitary gland tumors is most
likely to be attributable to the increased use of new imaging techniques. |
What is foliglurax? | Foliglurax is a positive allosteric modulator of the metabotropic glutamate receptor 4. Foliglurax induced a robust and dose-dependent reversal of parkinsonian motor symptoms in macaques, including bradykinesia, tremor, posture, and mobility. Moreover, PXT002331 strongly decreased dyskinesia severity, thus having therapeutic efficacy on both parkinsonian motor impairment and l-dopa-induced dyskinesia. It was the first compound of its class to enter phase IIa clinical trials. | BACKGROUND: Levodopa remains the gold-standard treatment for PD. However, it
becomes less effective as the disease progresses and produces debilitating side
effects, such as motor fluctuations and l-dopa-induced dyskinesia. Modulation of
metabotropic glutamate receptor 4 represents a promising antiparkinsonian
approach in combination with l-dopa, but it has not been demonstrated in
primates.
OBJECTIVE: We studied whether a novel positive allosteric modulator of the
metabotropic glutamate receptor 4, PXT002331 (foliglurax), could reduce
parkinsonism in primate models.
METHODS: We assessed the therapeutic potential of PXT002331 in three models of
MPTP-induced parkinsonism in macaques. These models represent three different
stages of disease evolution: early stage and advanced stage with and without
l-dopa-induced dyskinesia.
RESULTS: As an adjunct to l-dopa, PXT002331 induced a robust and dose-dependent
reversal of parkinsonian motor symptoms in macaques, including bradykinesia,
tremor, posture, and mobility. Moreover, PXT002331 strongly decreased dyskinesia
severity, thus having therapeutic efficacy on both parkinsonian motor impairment
and l-dopa-induced dyskinesia. PXT002331 brain penetration was also assessed
using PET imaging in macaques, and pharmacodynamic analyses support target
engagement in the therapeutic effects of PXT002331.
CONCLUSIONS: This work provides a demonstration that a positive allosteric
modulator of metabotropic glutamate receptor 4 can alleviate the motor symptoms
of PD and the motor complications induced by l-dopa in primates. PXT002331 is
the first compound of its class to enter phase IIa clinical trials. © 2018
International Parkinson and Movement Disorder Society. |
What is the genetic basis for Cornelia de Lange's syndrome? | Mutations in five genes (NIPBL, SMC1A, SMC3, RAD21, and HDAC8), all regulators or structural components of cohesin, have been identified. | Cornelia de Lange syndrome (CdLS) is a clinically and genetically heterogeneous
developmental disorder. Clinical features include growth retardation,
intellectual disability, limb defects, typical facial dysmorphism, and other
systemic involvement. The increased understanding of the genetic basis of CdLS
has led to diagnostic improvement and expansion of the phenotype. Mutations in
five genes (NIPBL, SMC1A, SMC3, RAD21, and HDAC8), all regulators or structural
components of cohesin, have been identified. Approximately 60% of CdLS cases are
due to NIPBL mutations, 5% caused by mutations in SMC1A, RAD21, and HDAC8 and
one proband was found to carry a mutation in SMC3. To date, 311 CdLS-causing
mutations are known including missense, nonsense, small deletions and
insertions, splice site mutations, and genomic rearrangements. Phenotypic
variability is seen both intra- and intergenically. This article reviews the
spectrum of CdLS mutations with a particular emphasis on their correlation to
the clinical phenotype. |
Are gut microbiota profiles altered by irradiation? | Yes, Irradiation profoundly impacted gut microbiota profiles | In rodent studies, the gut microbiota has been implicated in facilitating both
radioresistance, by protecting the epithelium from apoptotic responses and
radiosensitivity, inducing endothelial apoptotic responses. Despite the
observation that large animal models, such as the Chinese Rhesus macaque and the
Gottingen Minipig, demonstrate similarity to human physiologic responses to
radiation, little is known about radiation-induced changes of the gut microbiome
in these models. To compare the two models, we used bioequivalent radiation
doses which resulted in an LD50 for Gottingen Minipigs and Chinese Rhesus
macaques, 1.9 Gy and 6.8 Gy, respectively. Fecal samples taken prior and 3 days
post-radiation were used for 16S rRNA gene sequence amplicon high throughput
sequencing (Illumina MiSeq). Baseline gut microbiota profiles were dissimilar
between minipigs and rhesus macaques. Irradiation profoundly impacted gut
microbiota profiles in both animals. Significant increases of intracellular
symbionts were common to both models and to reported changes in rodents
suggesting universality of these findings post-radiation. Remarkably, opposite
dynamics were observed for the main phyla, with increase of Firmicutes and
decrease of Bacteroidetes and Proteobacteria in minipigs but with enrichment of
Bacteroidetes in rhesus macaques. Minipig changes in magnitude and in variety of
species affected were more extensive than those observed in rhesus macaques.
This pilot study provides an important first step in comparing the
radiosensitive pig model to the comparatively more radioresistant macaque model,
for the identification of microbial elements which may influence
radiosensitivity. The development of effective biomarkers for detecting the magnitude of radiation
exposure and resiliency of host response is crucial to identifying appropriate
treatment strategies after radiation exposure. We hypothesized that the
gastrointestinal resident bacteria would demonstrate predictable, dose-dependent
changes after radiation exposure across two large animal models of acute
radiation syndrome. Here, Göttingen minipigs (GMP) (n = 50) and rhesus macaques
(n = 48) were exposed to five dose levels (resulting in mortality rates of
33-100% and 25-68.7%, respectively). Fecal samples taken prior to and after
irradiation (day 0 for GMP; day 0, 3 and 14 for macaques) were used for 16S rRNA
gene sequence amplicon high-throughput sequencing. Baseline gut microbiota
profiles were dissimilar between GMP and macaques, however, radiation appeared
to have similar effect at the phylum level, resulting in Bacteroidetes decrease
and Firmicutes increase in both models. The abundance of the main Bacteroidetes
genus ( Bacteroides for GMP, Prevotella for macaques) was profoundly decreased
by irradiation. Intracellular symbionts [Elusimicrobia in GMP, Treponema
(Spirochaetes) in macaques] consistently increased after irradiation, suggesting
their use as potential biomarkers of intestinal injury, and potential negative
effect on health. Prevotella, Lactobacillus, Clostridium XIVa, Oscillibacter and
Elusimicrobium/ Treponema abundances were found to be very significantly
correlated with radiation intensity. Furthermore, Prevotella, Enterorhabdus and
Ruminococcus and Enterorhabdus maintece was strongly associated with survival
in GMP, while Prevotella, Oscillibacter and Treponema were strongly associated
with survival and Streptococcus with death in macaques. Overall, we found that a
wide range of gut bacterial genera known to be abundant in the human gut
microbiota are excellent biomarkers of radiation intensity and resilience in
animal models, and that detrimental effects can be monitored, and potentially
prevented, by targeting selected genera. The sterile insect technique (SIT) as an eco-friendly and reliable strategy has
been used to control populations of insect pests of agricultural, veterinary and
human health importance. Successful applications of SIT rely on the high-level
ecological fitness of sterile males. A suitable and stable gut microbiome can
contribute to the ecological fitness of insect by influencing their
physiology, biochemistry and development processes. Here, we show that a shift
in the gut bacterial composition and structure by sterilizing irradiation,
characterized by a decrease in the major gut microbiota community
Enterobacteriaceae, an expansion of the minor members (e.g., Bacillaceae) and a
higher richness and diversity, is tightly linked to radiation-induced ecological
fitness (male mating competitiveness, flight capacity, survival rate and life
span) decline in Bactrocera dorsalis (Hendel) sterile males. Function prediction
of gut microbiota indicated that changes in microbiome taxonomy tend to drive
microbiome functional shifts. A higher nutrient consumption of the flourishing
minor gut microbiota may cause a decline in nutrients and energy metabolic
activity of host and then result in the reduced ecological fitness of irradiated
flies. Furthermore, we found that a gut bacterial strain Klebsiella oxytoca
(BD177) can restore ecological fitness by improving food intake and increasing
haemolymph sugar and amino acid levels of irradiated B. dorsalis flies. Our
findings suggest that gut symbiont-based probiotics can be used as agents for
reversing radiation-induced ecological fitness decrease. |
Is TIM-3 a target for cancer immunotherapy in NSCLC? | Yes. Furthermore, TIM-3 and CEACAM1 were strongly expressed simultaneously during long-term CIK culture and showed a significant and mutually positive correlation. | Immune checkpoints associate with dysfunctional T cells, which have a reduced
ability to clear pathogens or cancer cells. T-cell checkpoint blockade may
improve patient survival. However, checkpoint molecules on cytokine-induced
killer (CIK) cell, a non-specific adoptive immunotherapy, remain unknown. In
present study, we detected the dynamic expression of eight major checkpoint
molecules (CTLA-4, PD-1, PD-L1, TIM- 3, CEACAM-1, LAG-3, TIGIT and BTLA) on CIK
cells from NSCLC patients. The majority of these molecules, except BTLA, were
sharply elevated during the early stage of CIK cell culture. Thereafter, PD-1
and TIGIT expressions decreased gradually towards the initial level (day 0).
Moreover, CTLA-4 faded away during the later stage of CIK culture. LAG-3
expression decreased but was still significantly higher than the initial level.
Of note, PD-L1 remained stably upregulated during CIK culture compared with
PD-1, indicating that PD-L1 might act as an inhibitory molecule on CIK cells
instead of PD-1. Furthermore, TIM-3 and CEACAM1 were strongly expressed
simultaneously during long-term CIK culture and showed a significant and
mutually positive correlation. BTLA displayed a distinct pattern, and its
expression gradually decreased throughout the CIK culture. These observations
suggested that CIK cells might be partly exhausted before clinical transfusion,
characterized by the high expression of PD-L1, LAG-3, TIM- 3, and CEACAM-1 and
the low expression of TIGIT, BTLA, PD-1, and CTLA-4 compared with initial
culture. Our results imply that implementing combined treatment on CIK cells
before transfusion via antibodies targeting PD-L1, LAG-3, TIM-3, and CEACAM-1
might improve the efficiency of CIK therapy for NSCLC patients. BACKGROUND. Immune checkpoint blockade improves survival in a subset of patients
with non-small-cell lung cancer (NSCLC), but robust biomarkers that predict
response to PD-1 pathway inhibitors are lacking. Furthermore, our understanding
of the diversity of the NSCLC tumor immune microenvironment remains limited.
METHODS. We performed comprehensive flow cytometric immunoprofiling on both
tumor and immune cells from 51 NSCLCs and integrated this analysis with clinical
and histopathologic characteristics, next-generation sequencing, mRNA
expression, and PD-L1 immunohistochemistry (IHC). RESULTS. Cytometric profiling
identified an immunologically "hot" cluster with abundant CD8+ T cells
expressing high levels of PD-1 and TIM-3 and an immunologically "cold" cluster
with lower relative abundance of CD8+ T cells and expression of inhibitory
markers. The "hot" cluster was highly enriched for expression of genes
associated with T cell trafficking and cytotoxic function and high PD-L1
expression by IHC. There was no correlation between immunophenotype and KRAS or
EGFR mutation, or patient smoking history, but we did observe an enrichment of
squamous subtype and tumors with higher mutation burden in the "hot" cluster.
Additionally, approximately 20% of cases had high B cell infiltrates with a
subset producing IL-10. CONCLUSIONS. Our results support the use of immune-based
metrics to study response and resistance to immunotherapy in lung cancer.
FUNDING. The Robert A. and Renée E. Belfer Family Foundation, Expect Miracles
Foundation, Starr Cancer Consortium, Stand Up to Cancer Foundation, Conquer
Cancer Foundation, International Association for the Study of Lung Cancer,
National Cancer Institute (R01 CA205150), and the Damon Runyon Cancer Research
Foundation. The sixth "Melanoma Bridge Meeting" took place in Naples, Italy, December
1st-4th, 2015. The four sessions at this meeting were focused on: (1) molecular
and immune advances; (2) combination therapies; (3) news in immunotherapy; and
4) tumor microenvironment and biomarkers. Recent advances in tumor biology and
immunology has led to the development of new targeted and immunotherapeutic
agents that prolong progression-free survival (PFS) and overall survival (OS) of
cancer patients. Immunotherapies in particular have emerged as highly successful
approaches to treat patients with cancer including melanoma, non-small cell lung
cancer (NSCLC), renal cell carcinoma (RCC), bladder cancer, and Hodgkin's
disease. Specifically, many clinical successes have been using checkpoint
receptor blockade, including T cell inhibitory receptors such as cytotoxic
T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death-1
(PD-1) and its ligand PD-L1. Despite demonstrated successes, responses to
immunotherapy interventions occur only in a minority of patients. Attempts are
being made to improve responses to immunotherapy by developing biomarkers.
Optimizing biomarkers for immunotherapy could help properly select patients for
treatment and help to monitor response, progression and resistance that are
critical challenges for the immuno-oncology (IO) field. Importantly, biomarkers
could help to design rational combination therapies. In addition, biomarkers may
help to define mechanism of action of different agents, dose selection and to
sequence drug combinations. However, biomarkers and assays development to guide
cancer immunotherapy is highly challenging for several reasons: (i) multiplicity
of immunotherapy agents with different mechanisms of action including
immunotherapies that target activating and inhibitory T cell receptors (e.g.,
CTLA-4, PD-1, etc.); adoptive T cell therapies that include tissue infiltrating
lymphocytes (TILs), chimeric antigen receptors (CARs), and T cell receptor (TCR)
modified T cells; (ii) tumor heterogeneity including changes in antigenic
profiles over time and location in individual patient; and (iii) a variety of
immune-suppressive mechanisms in the tumor microenvironment (TME) including T
regulatory cells (Treg), myeloid derived suppressor cells (MDSC) and
immunosuppressive cytokines. In addition, complex interaction of tumor-immune
system further increases the level of difficulties in the process of biomarkers
development and their validation for clinical use. Recent clinical trial results
have highlighted the potential for combination therapies that include
immunomodulating agents such as anti-PD-1 and anti-CTLA-4. Agents targeting
other immune inhibitory (e.g., Tim-3) or immune stimulating (e.g., CD137)
receptors on T cells and other approaches such as adoptive cell transfer are
tested for clinical efficacy in melanoma as well. These agents are also being
tested in combination with targeted therapies to improve upon shorter-term
responses thus far seen with targeted therapy. Various locoregional
interventions that demonstrate promising results in treatment of advanced
melanoma are also integrated with immunotherapy agents and the combinations with
cytotoxic chemotherapy and inhibitors of angiogenesis are changing the evolving
landscape of therapeutic options and are being evaluated to prevent or delay
resistance and to further improve survival rates for melanoma patients'
population. This meeting's specific focus was on advances in immunotherapy and
combination therapy for melanoma. The importance of understanding of melanoma
genomic background for development of novel therapies and biomarkers for
clinical application to predict the treatment response was an integral part of
the meeting. The overall emphasis on biomarkers supports novel concepts toward
integrating biomarkers into personalized-medicine approach for treatment of
patients with melanoma across the entire spectrum of disease stage. Translation
of the knowledge gained from the biology of tumor microenvironment across
different tumors represents a bridge to impact on prognosis and response to
therapy in melanoma. We also discussed the requirements for pre-analytical and
analytical as well as clinical validation process as applied to biomarkers for
cancer immunotherapy. The concept of the fit-for-purpose marker validation has
been introduced to address the challenges and strategies for analytical and
clinical validation design for specific assays. Epithelial-mesenchymal transition (EMT) is able to drive metastasis during
progression of multiple cancer types, including non-small cell lung cancer
(NSCLC). As resistance to immunotherapy has been associated with EMT and immune
exclusion in melanoma, it is important to understand alterations to T-cell
infiltration and the tumor microenvironment during EMT in lung adenocarcinoma
and squamous cell carcinoma. We conducted an integrated analysis of the immune
landscape in NSCLCs through EMT scores derived from a previously established 16
gene signature of canonical EMT markers. EMT was associated with exclusion of
immune cells critical in the immune response to cancer, with significantly lower
infiltration of CD4 T-cells in lung adenocarcinoma and CD4/CD8 T-cells in
squamous cell carcinoma. EMT was also associated with increased expression of
multiple immunosuppressive cytokines, including IL-10 and TGF-β. Furthermore,
overexpression of targetable immune checkpoints, such as CTLA-4 and TIM-3 were
associated with EMT in both NSCLCs. An association may exist between immune
exclusion and EMT in NSCLC. Further investigation is merited as its mechanism is
not completely understood and a better understanding of this association could
lead to the development of biomarkers that could accurately predict response to
immunotherapy. |
How does LB-100 affect the DDR proteins (BRCA1, Chk2, and γH2AX)? | LB100 induced constitutive hyperphosphorylation of DDR proteins (BRCA1, Chk2, and gH2AX). | Despite early positive response to platinum-based chemotherapy, the majority of
ovarian carcinomas develop resistance and progress to fatal disease. Protein
phosphatase 2A (PP2A) is a ubiquitous phosphatase involved in the regulation of
DNA-damage response (DDR) and cell-cycle checkpoint pathways. Recent studies
have shown that LB100, a small-molecule inhibitor of PP2A, sensitizes cancer
cells to radiation-mediated DNA damage. We hypothesized that LB100 could
sensitize ovarian cancer cells to cisplatin treatment. We performed in vitro
studies in SKOV-3, OVCAR-8, and PEO1, -4, and -6 ovarian cancer lines to assess
cytotoxicity potentiation, cell-death mechanism(s), cell-cycle regulation, and
DDR signaling. In vivo studies were conducted in an intraperitoneal metastatic
mouse model using SKOV-3/f-Luc cells. LB100 sensitized ovarian carcinoma lines
to cisplatin-mediated cell death. Sensitization via LB100 was mediated by
abrogation of cell-cycle arrest induced by cisplatin. Loss of the
cisplatin-induced checkpoint correlated with decreased Wee1 expression,
increased cdc2 activation, and increased mitotic entry (p-histone H3). LB100
also induced constitutive hyperphosphorylation of DDR proteins (BRCA1, Chk2, and
γH2AX), altered the chronology and persistence of JNK activation, and modulated
the expression of 14-3-3 binding sites. In vivo, cisplatin sensitization via
LB100 significantly enhanced tumor growth inhibition and prevented disease
progression after treatment cessation. Our results suggest that LB100 sensitizes
ovarian cancer cells to cisplatin in vitro and in vivo by modulation of the DDR
pathway and cell-cycle checkpoint abrogation. |
What particles is Hadron therapy using? | Hadron therapy is using proton beams. | The use of hadron beams, especially proton beams, in cancer radiotherapy has
expanded rapidly in the past two decades. To fully realize the advantages of
hadron therapy over traditional x-ray and gamma-ray therapy requires accurate
positioning of the Bragg peak throughout the tumor being treated. A half century
ago, suggestions had already been made to use protons themselves to develop
images of tumors and surrounding tissue, to be used for treatment planning. The
recent global expansion of hadron therapy, coupled with modern advances in
computation and particle detection, has led several collaborations around the
world to develop prototype detector systems and associated reconstruction codes
for proton computed tomography (pCT), as well as more simple proton radiography,
with the ultimate intent to use such systems in clinical treatment planning and
verification. Recent imaging results of phantoms in hospital proton beams are
encouraging, but many technical and programmatic challenges remain to be
overcome before pCT scanners will be introduced into clinics. This review
introduces hadron therapy and the perceived advantages of pCT and proton
radiography for treatment planning, reviews its historical development, and
discusses the physics related to proton imaging, the associated experimental and
computation issues, the technologies used to attack the problem, contemporary
efforts in detector and computational development, and the current status and
outlook. The European Network for Light Ion Hadron Therapy (ENLIGHT) was established in
2002 following various European particle therapy network initiatives during the
1980s and 1990s (e.g. EORTC task group, EULIMA/PIMMS accelerator design).
ENLIGHT started its work on major topics related to hadron therapy (HT), such as
patient selection, clinical trials, technology, radiobiology, imaging and health
economics. It was initiated through CERN and ESTRO and dealt with various
disciplines such as (medical) physics and engineering, radiation biology and
radiation oncology. ENLIGHT was funded until 2005 through the EC FP5 programme.
A regular annual meeting structure was started in 2002 and continues until today
bringing together the various disciplines and projects and institutions in the
field of HT at different European places for regular exchange of information on
best practices and research and development. Starting in 2006 ENLIGHT
coordination was continued through CERN in collaboration with ESTRO and other
partners involved in HT. Major projects within the EC FP7 programme (2008-2014)
were launched for R&D and transnational access (ULICE, ENVISION) and education
and training networks (Marie Curie ITNs: PARTNER, ENTERVISION). These projects
were instrumental for the strengthening of the field of hadron therapy. With the
start of 4 European carbon ion and proton centres and the upcoming numerous
European proton therapy centres, the future scope of ENLIGHT will focus on
strengthening current and developing European particle therapy research,
multidisciplinary education and training and general R&D in technology and
biology with annual meetings and a continuously strong CERN support.
Collaboration with the European Particle Therapy Network (EPTN) and other
similar networks will be pursued. |
Does an interferon (IFN) signature exist for SLE patients? | Interferon type I (IFN-I) plays a pivotal role in the pathogenesis of SLE. An IFN-I score (positive or negative), as a measure of IFN-I activation, is assessed using the expression values of IFN-I signature genes (IFI44, IFI44L, IFIT1, Ly6e, MxA, IFITM1) in CD14+ monocytes of cSLE patients and healthy controls (HCs). | The expression and activation of regulatory factors (IRF) and rinterferon (IFN)
response genes were evaluated in a patient treated with autologous hematopoietic
stem cell transplant (HSCT) for refractory systemic lupus erythematosus (SLE).
In SLE patients, genetic variants of IRF5 and IRF7 have been associated with
increased serum IFNα levels, suggesting a pathogenic role in the type I IFN
response. Clinical and molecular analyses of an SLE patient treated with
high-dose immunosuppressive therapy and autologous stem cell transplant was
performed. Western blot analysis showed that induction of IRF7 protein
expression correlated with recurrent lupus disease activity. In addition,
phosphorylation of IRF3 and activation of 4 E-BP1, a translational repressor of
IRF7, preceded the disease flare. In SLE post-transplant, recurrent disease
activity and induction of IRF7 protein expression correlated with activation of
the IFN signature. This unique trend in regulation of IRF warrants further
mechanistic investigation and confirmation with increased numbers of SLE
patients. |
Is AND-1/Ctf4 essential for proliferation? | Yes. AND-1 fork protection function prevents fork resection and is essential for proliferation. | AND-1/Ctf4 bridges the CMG helicase and DNA polymerase alpha, facilitating
replication. Using an inducible degron system in avian cells, we find that AND-1
depletion is incompatible with proliferation, owing to cells accumulating in G2
with activated DNA damage checkpoint. Replication without AND-1 causes fork
speed slow-down and accumulation of long single-stranded DNA (ssDNA) gaps at the
replication fork junction, with these regions being converted to DNA double
strand breaks (DSBs) in G2. Strikingly, resected forks and DNA damage
accumulation in G2, but not fork slow-down, are reverted by treatment with
mirin, an MRE11 nuclease inhibitor. Domain analysis of AND-1 further revealed
that the HMG box is important for fast replication but not for proliferation,
whereas conversely, the WD40 domain prevents fork resection and subsequent
DSB-associated lethality. Thus, our findings uncover a fork protection function
of AND-1/Ctf4 manifested via the WD40 domain that is essential for proliferation
and averts genome instability. |
Does the BRAFV600E mutation have an effect on clinical response to radioiodine therapy? | Yes, it has been suggested that patients with papillary thyroid cancer (PTC) harbouring the BRAF(V600E) mutation have a worse prognosis. | PURPOSE: As the most frequent and specific genetic alteration in papillary
thyroid carcinoma (PTC), BRAF(V600E) has an intimate relationship with more
invasive tumour and higher postoperative recurrence risk in PTC patients. We
investigate the effect of radioactive iodine (RAI) therapy on the clinical
outcome in PTC patients with the BRAF(V600E) mutation without distant
metastases.
METHODS: This retrospective study included PTC 228 patients without distant
metastases who underwent total or near-total thyroidectomy and RAI treatment in
our hospital from January 2011 to July 2014. The BRAF(V600E) status of the
primary lesions was determined and the patients were divided into two groups
according to the presence of the mutation. Serological and imaging data were
collected at a median follow-up of 2.34 years after RAI administration.
Suppressed and stimulated thyroglobulin (Tg), Tg antibody, diagnostic whole-body
scintigraphy, and other imaging examinations were used to assess clinical
outcome, which was defined as excellent response, indeterminate response,
biochemical incomplete response and structural incomplete response.
RESULTS: The BRAF(V600E) mutation was observed in 153 of the 228 patients
(67.1 %). The clinicopathological features did not differ between the
BRAF(V600E) mutatation and wild-type groups except age at diagnosis (P = 0.000),
tumour size (P = 0.023) and TNM stage (P = 0.003). Older age and more advanced
TNM stage were prevalent in the BRAF(V600E) mutatation group, whereas tumours
were slightly larger in the BRAF(V600E) wild-type group. The response to RAI
therapy was evaluated in both the entire series and the patients with a high
recurrence risk, and no significant difference in response was found between the
BRAF(V600E) mutatation and the wild-type groups (P = 0.881 and P = 0.851,
respectively).
CONCLUSION: The clinical response to timely postsurgical RAI therapy is not
inferior in BRAF(V600E) mutation PTC patients without distant metastases, which
suggests that RAI therapy might improve the general clinical outcome in this
patient group. PURPOSE: The aim of the present study was to evaluate the possible diagnostic
role of the combined performance of BRAF mutation analysis and MIBI scintigraphy
in papillary thyroid cancer (PTC) patients with incomplete bio-chemical response
to first radioiodine therapy (RAIT) performed for thyroid remt ablation.
METHODS: The records of 15 PTC patients with bio-chemical incomplete response to
first RAIT were retrospectively analyzed. BRAFV600E analysis on primary tumor
samples was obtained in all cases along with neck ultrasonography and 99mTc-MIBI
scintigraphy of the neck-thorax regions at first follow-up. All patients then
underwent RAIT with high radioiodine activities. A post-therapy whole-body scan
(pT-WBS) was acquired 5-7 days after RAIT.
RESULTS: Abnormal radioiodine uptake was found in 10 out of the 15 patients
(67%, 131I+ve), while in the remaining 33%, no abnormal radioiodine uptake was
detected (5/15, 131I-ve). Abnormal tracer uptake was found in 6 out of 10
131I+ve patients at 99mTc-MIBI scintigraphy (MIBI+ve). BRAFV600E mutation was
not found in the majority of 131I+ve patients (9 out of 10 BRAFV600E-ve). On the
contrary, in the 5 131I-ve patients, 99mTc-MIBI scintigraphy did not show any
abnormal tracer uptake (MIBI-ve), while BRAFV600E mutation was present
(BRAFV600E+ve). Thus, in our series, the association between MIBI-ve
scintigraphy and BRAF+ve mutation was a useful diagnostic tool in predicting
negative pT-WBS outcome.
CONCLUSION: Albeit obtained in a small retrospective series, our results suggest
that the combination of BRAFV600E+ve mutation and MIBI-ve scintigraphy may be
considered a negative prognostic clue, which predicts the absence of radioiodine
uptake at pT-WBS in DTC patients with incomplete bio-chemical response to first
RAIT. OBJECTIVES: Preclinical studies showed that BRAF mutation significantly reduced
radioiodine uptake and decreased the sensitivity to radioactive iodine (RAI)
therapy. However, clinical data regarding its role in therapeutic decision
making with respect to RAI therapy are currently insufficient. Thus, this study
aimed to evaluate the effect of BRAF mutation on the clinical response to RAI
therapy for papillary thyroid microcarcinoma (PTMC) with intermediate-risk to
high-risk features.
PATIENTS AND METHODS: From January 2012 and October 2015, consecutive patients
with PTMC with intermediate-risk to high-risk features who underwent RAI therapy
were retrospectively included. The data about BRAF mutation status were also
obtained. The association between clinicopathological characteristics and
mutation was investigated. After a median follow-up of 40 months, the clinical
response to RAI therapy was also compared between positive and negative mutation
groups.
RESULTS: A total of 236 patients were included, of whom 147 (62.3%) had positive
mutation. The clinicopathological features did not show significant correlation
with BRAF mutation status except the sex, extrathytoidal extension and T stage.
Patients with PTMC with BRAF mutation showed an increased likelihood of having
advanced T stage and extrathyroidal extension. In addition, this mutation did
not affect the clinical outcome of RAI therapy.
CONCLUSION: The status of BRAF mutation may not affect the clinical response to
RAI therapy for patients with PTMC with intermediate-risk to high-risk features.
More trials examining the role of BRAF mutation in guiding postoperative RAI
therapy are needed. |
Which phosphatase is inhibited by LB-100? | LB-100 is a phosphatase 2A inhibitor | |
What are the most common side effects of amantadine ER? | The most common side effects of amantadine ER are hallucination, dizziness, orthostatic hypotension and pedal edema. | Levodopa is the most efficacious treatment for Parkinson's disease (PD).
Long-term treatment with levodopa is limited due to dyskinesia. Dyskinesia in PD
can be socially and functionally disabling. Extended-release amantadine
(amantadine ER) is the first approved medication for the treatment of
dyskinesia. When it is given at bedtime, it reaches plasma concentration
approximately twice the level achieved by amantadine immediate release.
Amantadine ER reduces the severity and duration of dyskinesia during the day,
reduces OFF time and increases ON time without troublesome dyskinesia. The most
common side effects are hallucination, dizziness, orthostatic hypotension and
pedal edema. This review discusses the safety and efficacy of amantadine ER in
dyskinesia in PD patients. |
Which symptoms comprise Abdominal aortic aneurysm rupture Triad? | Classic triad of Abdominal aortic aneurysm rupture include shock, acute abdominal pain, and pulsatile abdominal mass. | Only 50% of abdominal aortic aneurysms present with the classic triad of
hypotension, back pain and a pulsatile abdominal mass. This variability in
symptoms can delay diagnosis and treatment. We present the case of a patient
presenting with a unique combination of symptoms suggesting that decompression
of urinary retention can lead to abdominal aortic aneurysm rupture. |
List symptoms of Allgrove syndrome. | The classical clinical triad of the Allgrove syndrome includes alacrima, achalasia and adrenal insufficiency. It can be also associated with progressive peripheral neuropathy. | Allgrove syndrome (triple A syndrome) is an autosomal recessive disorder
characterised by adrenocortical insufficiency, achalasia and alacrima. Patients
also suffer from diverse neurological disorders. Allgrove syndrome is caused by
mutations in the AAAS gene located at chromosome 12q13, which encodes for a
tryptophan-aspartic acid (WD) repeat protein (aladin). The exact function of
this protein is still not known. The triple A or Allgrove syndrome is an autosomal-recessive disease (MIM*231550)
characterized by the triad of achalasia, alacrima and adrenocorticotropic
hormone (ACTH)-resistant adrenal insufficiency. Associated features of the
syndrome are neurological and dermatological abnormalities. Until the discovery
of the AAAS gene as the responsible gene in triple A syndrome, the diagnosis was
based on characteristic clinical features. Here we present the clinical and
molecular genetic data which demonstrated the marked phenotypic variability in
three unrelated patients with triple A syndrome. The final diagnosis of triple A
syndrome was confirmed by molecular analysis. In one patient with isolated
achalasia, the diagnosis of triple A syndrome could only be made on the basis of
the molecular genetic analysis of the AAAS gene. We therefore suggest that the
diagnosis of triple A syndrome should be considered in patients who exhibit only
one or two of the main symptoms (i.e. alacrima, achalasia or adrenal
insufficiency). These patients require careful neurological investigation, and
mutation analysis of the AAAS gene should be performed. Achalasia, a poorly relaxing lower esophageal sphincter, produces a functional
obstruction and the expected symptoms of dysphagia, regurgitation and eventually
weight loss. The cause of achalasia remains largely unknown in Western
countries, Chagas' disease being the most frequent etiology in Brazil. We report
on two sets of monozygotic male twins with typical manifestations of achalasia.
The majority of authors attribute a limited contribution unless achalasia is
related to a multisystem disorder, like the triple-A or Allgrove's syndrome, an
autosomal recessive disease characterized by the triad of adrenocorticotropic
hormone (ACTH) resistant adrenal insufficiency, achalasia and alacrima. The four
cases reported demonstrated the genetic influence of achalasia in patients
without multisystem disorders. We believe that idiopathic achalasia is a
syndrome with similar clinical, pathological, radiological and manometric
evolution, but with a great variety of etiological agents, one of them being the
congenital form. The triple A or Allgrove's syndrome is an autosomal recessive disorder
characterized by the triad of achalasia cardia, alacrima and ACTH resistant
adrenocortical insufficiency. Mutations of the
Achalasia-Addisonianism-Alacrima-Syndrome (AAAS) gene on chromosome 12q13 are
associated with this syndrome. We report an Indian family where two siblings
were homozygous for a known mutation of the AAAS gene and presented with the
classical triad of symptoms. The mother and the brother were heterozygous and
asymptomatic. The affected siblings had iron deficiency anemia and the younger
sister had pes cavus and palmoplantar keratosis. Neurological symptoms were
absent in both affected children. Recognition of this syndrome can lead to early
treatment of adrenal insufficency and genetic counselling. Allgrove syndrome (or triple-A syndrome) is a rare autosomal recessive disorder
characterized by alacrima, achalasia, adrenal insufficiency (glucocorticoid in
the majority of cases) and autonomic/neurological abnormalities. This disease is
now known to be caused by mutation in the AAAS gene located on chromosome 12q13.
Diagnosis should be readily available when the full-blown features are there,
but it becomes less apparent when presentation is atypical or in the evolving
process. We present a brother and sister (12 and 19 y old, respectively) born to
consanguineous parents of Palestinian origin with Allgrove syndrome. The index
patient was erroneously diagnosed to be a case of familial dysautonomia before
the diagnosis of adrenal insufficiency was made at the age of 7.5 y, while his
elder sister had only alacrima from birth and developed achalasia at the age of
15 y. She started to develop early evidence of adrenal disease at the age of 19
y. Both of them had neuroautonomic dysfunction. The diagnosis of Allgrove
syndrome was confirmed in these two patients by studying the gene mutation in
the family. The sequencing of the AAAS gene in the two patients identified a
novel homozygous mutation within intron 5 (IVS5+1G-->A). Both parents as well as
all three other children were heterozygous for the same mutation.
CONCLUSION: These two cases illustrate the heterogenous nature and the
intrafamilial phenotypic variability of Allgrove syndrome. OBJECTIVE: Allgrove syndrome is a rare autosomal recessive disorder
characterized by the triad of adrenal insufficiency, achalasia and alacrima and
many cases have multi-systems disorder: endocrine, gastrointestinal tract, eyes
and nervous system. This syndrome is also known as
achalasia-addisonianism-alacrima syndrome or triple A syndrome. Allgrove
syndrome is now known to be caused by mutations of AAAS gene encoding the aladin
protein. In the present paper, we report a Chinese mainland girl with Allgrove
syndrome with mutations in the AAAS gene.
METHOD: The patient was a 7-year-old girl complained of coma and dark skin; she
was treated as Addison disease for 2 years and had vomiting for 9 months before
the second admission. Gene analysis was performed after extracting genomic DNA
by amplification and sequencing of the specific fragments of AAA gene.
RESULTS: The patient was confirmed to have adrenal insufficiency at the age of 5
years and 6 months. During the second hospitalization, she was found to have a
remarkable brisk reflexion, bilateral optic nerve atrophy, alacrima and
achalasia besides ACTH resistance. The girl was born to consanguineous parents.
Based on these findings, she was diagnosed as having Allgrove syndrome. Mutation
analysis revealed a novel homozygous deletion of a single G, c.771delG, in exon
8 of the AAAS gene. This frame shift mutation was predicted to create a
premature stop codon at locus 290, p.R258GfsX33, leading to a truncated and
non-functioning aladin protein. Both the parents were heterozygous for the
mutation.
CONCLUSION: The clinical manifestations and AAAS gene mutations analysis
confirmed the diagnosis of Allgrove syndrome. Gene analysis indicated that this
syndrome is an autosomal recessive inherent disorder. ALADIN is significant for
the normal cell function. When compared with reported cases, it seems that there
are no remarkable relation between gene mutation loci and clinical
manifestations in Allgrove syndrome. Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder,
in 40% of patients caused by mutation in the ACTH receptor gene. In the
remaining affected persons most probably mutation refers to regulatory region of
ACTH receptor or other factors responsible for differentiation of the adrenal
cortex. FGD is characterized by elevated ACTH and low serum morning cortisol
level that does not respond to exogenous ACTH stimulation. Mineralocorticoid
function remains unaffected. Clinical symptoms of FGD are due to glucocorticoid
deficiency and are manifested in infancy or early childhood. Typically they
include skin hyperpigmentation, failure to thrive, hypoglycaemia, which in some
children may be lethal. Allgrove's syndrome, is considered to be a separate
condition, characterized by glucocorticoid deficiency along with alacrimia,
achalasia and neurological deficits. Treatment of FGD includes substitution of
glucocorticoids with dose adjustment depending on the clinical state. Such
treatment usually prevents from hypoglycaemia and provides normal growth and
development of the patient. BACKGROUND: Triple A syndrome, also known as Allgrove syndrome, is a rare
autosomal recessive disorder characterized by three cardinal symptoms: adrenal
insufficiency due to ACTH insensitivity, achalasia and alacrima. Various
progressive neurological abnormalities and skin changes have been described in
association with the syndrome. The disease is caused by mutation in the AAAS
gene on chromosome 12q13. AAAS encodes a protein named ALADIN which is part of
the nuclear pore complex (NPC). The mislocalization of mutated ALADIN proteins
in the cytoplasm and/or the nucleus results in an impaired protein function.
Phenotypes of previously reported patients with triple A syndrome varied within
and between affected families so that no genotype-phenotype could be
established.
METHODS: Genetic analysis was performed in two unrelated patients, their parents
and one sister. AAAS coding sequences including exon-intron boundaries were
amplified and sequenced using an ABI 3100 sequencing machine.
PATIENTS: We present two unrelated Swiss patients with triple A syndrome
demonstrating similar phenotypic characteristics. Both showed a progression of
the disease presenting with adrenal insufficiency and alacrima in early
childhood. At the age between 30-40 years they developed symptomatic achalasia.
The pattern and severity of progressive neurological and autonomic dysfunction
was comparable. In both patients molecular genetic analysis revealed an
identical novel homozygous mutation (c.618delC, p.Ser207fs) in the AAAS gene.
CONCLUSION: Recent genotype/phenotype studies showed a marked inter- and
intrafamiliar variability in triple A syndrome. Here we present a rather tight
genotype/phenotype correlation in two unrelated patients carrying the identical
novel p.Ser207fs mutation in the AAAS gene. Allgrove (Triple A) syndrome is a rare autosomal recessive disorder
characterized by cardinal features of adrenal insufficiency due to
adrenocorticotropic hormone (ACTH) resistance, achalasia, and alacrimia. It is
frequently associated with neurological manifestations like polyneuropathy.
Since its first description by Allgrove in 1978, approximately 100 cases have
been reported in the literature. Here we report an 18-year-old boy diagnosed as
having Allgrove syndrome, with ACTH resistant adrenal insufficiency, achalasia,
alacrimia, and severe motor polyneuropathy. Alacrimia was the earliest feature
evident at the age of 8 years. He presented with achalasia and adrenal
insufficiency at 12 and 18 years respectively and developed neurological
symptoms in the form of severe muscle wasting at the age of 15 years. Patients
with Allgrove syndrome usually manifest adrenal insufficiency and achalasia
during first decade of life. Our patient manifested adrenal insufficiency and
achalasia in the second decade and manifested neurological dysfunction before
adrenal dysfunction. INTRODUCTION: Allgrove syndrome (AS) is a rare autosomal recessive disorder
characterized by achalasia cardia, alacrimia, and adrenocorticotropic
hormone-resistant adrenal insufficiency which is sometimes associated with
autonomic dysfunction. It has also been referred to as the triple A syndrome in
view of the cardinal symptoms described above. First described by Allgrove et al
in 1978, the disorder usually presents mostly during the first decade of life.
These patients have the threat of adrenal crisis, shock, and hypoglycemia and
are usually on steroid supplementation.
CASE REPORT: The anesthesiologist's encounter with such patients, although rare,
is mostly for repair of the achalasia cardia. We thus report a similar case of
AS in a 2-year-old girl who was scheduled to undergo Heller myotomy along with
the preoperative evaluation and intraoperative management of the same.
CONCLUSION: Being aware of the pathophysiology of AS gives useful insight about
the disease and successful perioperative management in the form of the triple S
strategy, that is, stress dose of steroids, slow induction and positioning, and
finally maintece of stable hemodynamics and euglycemia. BACKGROUND Allgrove syndrome, or triple "A" syndrome (3A syndrome), is a rare
autosomal recessive syndrome with variable phenotype, and an estimated
prevalence of 1 per 1,000,000 individuals. Patients usually display the triad of
achalasia, alacrima, and adrenocorticotropin (ACTH) insensitive adrenal
insufficiency, though the presentation is inconsistent. CASE REPORT Here, the
authors report a case of Allgrove syndrome in a pediatric patient with delayed
diagnosis in order to raise awareness of this potentially fatal disease as a
differential diagnosis of alacrima. CONCLUSIONS The prevalence of Allgrove
syndrome may be much higher as a result of underdiagnosis and missed diagnosis
due to the variable presentation and sudden unexplained childhood death from
adrenal crisis. The authors review the characteristic symptoms of Allgrove
syndrome in relation to the case study in order to avoid missed or delayed
diagnosis, potentially decreasing morbidity, and mortality in those affected by
this disease. OBJECTIVE: Triple-A or Allgrove syndrome is an autosomal recessive disorder due
to mutations in the AAAS gene, which encodes a nucleoporin named ALADIN. It is
characterized by a classical clinical triad: alacrima, achalasia and adrenal
insufficiency, the canonic symptoms that are associated with progressive
peripheral neuropathy. Only a few cohorts have been reported. The objective of
the present study was to characterize the various spectra of adrenal function in
Triple-A patients.
METHODS: A retrospective clinical and biological monitoring of 14 patients (10
families) was done in a single multidisciplinary French center. All had AAAS
gene sequenced and adrenal function evaluation.
RESULTS: Nine different AAAS mutations were found, including one new mutation:
c.755G>C, p.(Trp252Ser). Regarding adrenal function, defects of the zona
fasciculata and reticularis were demonstrated by increased basal ACTH levels and
low DHEAS levels in all cases regardless of the degree of glucocorticoid
deficiency. In contrast, mineralocorticoid function was always conserved: i.e.,
normal plasma renin level associated with normal aldosterone level. The main
prognostic feature was exacerbation of neuropathy and cognitive disorders.
CONCLUSIONS: These data suggest that, in Triple-A patients, adrenal function can
be deficient, insufficient or compensated. In our cohort after the first decade
of life, there does not appear to be any degradation of adrenal function over
time. However, patients with compensated adrenal function should be informed and
educated to manage a glucocorticoid replacement therapy in case of stressful
conditions, with no need for systematic long-term treatment. Triple A syndrome (TAS) or Allgrove syndrome (OMIM #231550) is a rare autosomal
recessive disorder characterised by adrenocorticotropic hormone-resistant
adrenal insufficiency, alacrima, achalasia, and neurological and dermatological
abnormalities. Mutations in the AAAS gene on chromosome 12q13 encoding the
nuclear pore protein ALADIN have been reported in these patients. Between 2006
and 2017, we evaluated six patients with a clinical diagnosis of TAS, based on
the presence of at least two symptoms, usually adrenal insufficiency and
alacrima. In all cases, genetic analysis revealed homozygous mutations in the
AAAS gene. One novel mutation was detected: a homozygous 10-bp deletion
(c.1264_1273del, p.Q422NfsX126) in exon 14 of the AAAS gene that caused a
frameshift that introduced an aberrant stop codon after 126 amino acids. This
genetic variant is likely to be pathogenic because it caused a significant
change in protein structure. A precise genotype-phenotype correlation was
impossible to establish.
CONCLUSIONS: Based on our experience, we recommend that molecular analysis
should be performed in the presence of alacrima and at least one more symptom of
TAS. Our cases share many clinical features of TAS and underline the variability
in this syndrome, as well as the need for thorough investigation following a
multidisciplinary approach. What is known: • Triple A syndrome is characterised
by achalasia, alacrima, adrenal insufficiency, neurological impairment, and
dermatological abnormalities. • A precise genotype-phenotype correlation has
proved impossible to establish. What is new: • These cases add to a large number
of similar case reports with limited novel information. • The newly identified
AAAS gene mutation was reported. Allgrove syndrome, also known as Triple A syndrome, is a rare autosomal
recessive genetic disease characterized by three signs: esophageal achalasia,
adrenocorticotropic hormone refractoriness, and alacrima. A 31-year-old male
presented to our hospital for treatment of difficulty swallowing caused by
esophageal achalasia. Because he had complicating alacrima, a neurologic
disease, and a family history of consanguineous marriage, a genetic neurologic
disease was suspected. Then, a mutation in the achalasia-addisonianism-alacrima
syndrome gene was identified. With the diagnosis of Allgrove syndrome, a
per-oral endoscopic myotomy (POEM) was performed for esophageal achalasia. After
the POEM, the symptoms and the esophageal pressure findings ameliorated quickly,
with no recurrence noted throughout a follow-up of more than 1 year. Here, we
report the first case of POEM performed for esophageal achalasia in Allgrove
syndrome. Triple A (Allgrove) syndrome, an autosomal recessive disease is characterized by
achalasia, alacrimia and ACTH-resistant adrenal failure with progressive
neurological syndrome including central, peripheral and autonomic nervous system
impairment, and mild mental retardation. The triple A syndrome gene, designated
AAAS, localized on chromosome 12q 13 encodes for a 546 amino acid protein called
ALADIN (Alacrimia-Achlasia-Adrenal Insufficiency and Neurologic disorder). This
report relates to two sisters, aged 8 and 12 years, who had vomiting, muscle
weakness, alacrimia, excessive fatigue and dysphagia. Abdominal sonography,
esophago-gastroduodenoscopy, barium swallow, esophageal manometry, CT scan
abdomen and brain, biochemical profiles, as well as neurologic and ophthalmic
evaluations were consistent with Allgrove's syndrome. Management consisted of
pneumatic balloon dilatation for achalasia and initiation of cortisone therapy
with successful resolution of dysphagia and other symptoms. |
What is water radiolysis? | Water radiolysis involves chemical decomposition of the water molecule into free radicals after exposure to ionizing radiation. These free radicals have deleterious effects on normal cell physiology. | To elucidate microscopic details of proton cancer therapy (PCT), we apply the
simplest-level electron nuclear dynamics (SLEND) method to H+ + (H2O)1-6 at ELab
= 100 keV. These systems are computationally tractable prototypes to simulate
water radiolysis reactions-i.e. the PCT processes that generate the DNA-damaging
species against cancerous cells. To capture incipient bulk-water effects, ten
(H2O)1-6 isomers are considered, ranging from quasi-planar/multiplanar (H2O)1-6
to "smallest-drop" prism and cage (H2O)6 structures. SLEND is a time-dependent,
variational, non-adiabatic and direct method that adopts a nuclear
classical-mechanics description and an electronic single-determital
wavefunction in the Thouless representation. Short-time SLEND/6-31G* (n = 1-6)
and /6-31G** (n = 1-5) simulations render cluster-to-projectile
1-electron-transfer (1-ET) total integral cross sections (ICSs) and 1-ET
probabilities. In absolute quantitative terms, SLEND/6-31G* 1-ET ICS compares
satisfactorily with alternative experimental and theoretical results only
available for n = 1 and exhibits almost the same accuracy of the best
alternative theoretical result. SLEND/6-31G** overestimates 1-ET ICS for n = 1,
but a comparable overestimation is also observed with another theoretical
method. An investigation on H+ + H indicates that electron direct ionization
(DI) becomes significant with the large virtual-space quasi-continuum in large
basis sets; thus, SLEND/6-31G** 1-ET ICS is overestimated by DI contributions.
The solution to this problem is discussed. In relative quantitative terms, both
SLEND/6-31* and /6-31G** 1-ET ICSs precisely fit into physically justified
scaling formulae as a function of the cluster size; this indicates SLEND's
suitability for predicting properties of water clusters with varying size.
Long-time SLEND/6-31G* (n = 1-4) simulations predict the formation of the
DNA-damaging radicals H, OH, O and H3O. While "smallest-drop" isomers are
included, no early manifestations of bulk water PCT properties are observed and
simulations with larger water clusters will be needed to capture those effects.
This study is the largest SLEND investigation on water radiolysis to date. |
How do the plasma concentrations of amantadine extended release and amantadine immediate release compare? | When it is given at bedtime, it reaches plasma concentration approximately twice the level achieved by amantadine immediate release. | Levodopa is the most efficacious treatment for Parkinson's disease (PD).
Long-term treatment with levodopa is limited due to dyskinesia. Dyskinesia in PD
can be socially and functionally disabling. Extended-release amantadine
(amantadine ER) is the first approved medication for the treatment of
dyskinesia. When it is given at bedtime, it reaches plasma concentration
approximately twice the level achieved by amantadine immediate release.
Amantadine ER reduces the severity and duration of dyskinesia during the day,
reduces OFF time and increases ON time without troublesome dyskinesia. The most
common side effects are hallucination, dizziness, orthostatic hypotension and
pedal edema. This review discusses the safety and efficacy of amantadine ER in
dyskinesia in PD patients. Conflict of interest statement: CONFLICTS OF INTEREST: Robert A. Hauser is
supported in part by a Center of Excellence grant from the National Parkinson
Foundation. He received payment from Adamas Pharmaceuticals for participating as
a Steering Committee member, and reports consulting fees from Teva
Pharmaceuticals, UCB BioSciences, AbbVie, Novartis, Biotie Therapies, Lundbeck,
Pfizer, Allergan Neuroscience, Neurocrine Biosciences, Chelsea Therapeutics,
Auspex Pharmaceuticals, Acadia Pharmaceuticals, Michael J. Fox Foundation, GLG,
AstraZeneca, Acorda Therapeutics, Impax Pharmaceuticals, Cynapsus Therapeutics,
US WorldMeds, Neuropore, and Prexton Therapeutics. He is employed by the
University of South Florida (Florida). Rajesh Pahwa is receiving, or has
received, honoraria or payments for consulting from AbbVie, Acadia, Acorda,
Adamas, Sunovion, Impax, Lundbeck, Neurocrine, Sage, St. Jude Medical, Teva
Neuroscience, UCB, US WorldMeds, and Global Kinetics, and has also received
research grants from Acadia, Acorda, Adamas, Avid, Biotie, Boston Scientific,
Civitas, Cynapsus, Kyowa, NIH/NINDS, NPF, Pfizer, and PSG/University of
Rochester. He has served on the Data Monitoring Committee for Ionis and has
received personal compensation as the Co-Editor-in-Chief of the International
Journal of Neuroscience. William Wargin is an employee of Nuventra Pharma
Sciences. Cindy Souza-Prien, Rajiv Patni, Reed Johnson, Jack Nguyen, and Gregory
T. Went are employees of, and own stock in, Adamas Pharmaceuticals. Natalie
McClure was employed by Adamas Pharmaceuticals at the time this research was
undertaken, and owns stock in Adamas. ETHICS APPROVAL: All procedures performed
in studies involving human participants were in accordance with the ethical
standards of the institutional and/or national research committee and with the
1964 Helsinki declaration and its later amendments or comparable ethical
standards. |
Is the BAGEL algorithm used for arrayed CRISPR screens? | No. BAGEL (Bayesian Analysis of Gene EssentiaLity) is a supervised learning method for analyzing pooled library gene knockout screens. It offers significantly greater sensitivity than current methods, while computational optimizations reduce runtime by an order of magnitude. | BACKGROUND: The adaptation of the CRISPR-Cas9 system to pooled library gene
knockout screens in mammalian cells represents a major technological leap over
RNA interference, the prior state of the art. New methods for analyzing the data
and evaluating results are needed.
RESULTS: We offer BAGEL (Bayesian Analysis of Gene EssentiaLity), a supervised
learning method for analyzing gene knockout screens. Coupled with gold-standard
reference sets of essential and nonessential genes, BAGEL offers significantly
greater sensitivity than current methods, while computational optimizations
reduce runtime by an order of magnitude.
CONCLUSIONS: Using BAGEL, we identify ~2000 fitness genes in pooled library
knockout screens in human cell lines at 5 % FDR, a major advance over competing
platforms. BAGEL shows high sensitivity and specificity even across screens
performed by different labs using different libraries and reagents. |
What is included in the LACE Index? | The LACE index is a simple tool that includes 4 parameters: Length of stay, Acuity of admission, Comorbidity, and Emergency visits in the previous 6 months. It is used to predict early re-admission after hospital discharge. | Predictive models for hospital readmission rates are in high demand because of
the Centers for Medicare & Medicaid Services (CMS) Hospital Readmission
Reduction Program (HRRP). The LACE index is one of the most popular predictive
tools among hospitals in the United States. The LACE index is a simple tool with
4 parameters: Length of stay, Acuity of admission, Comorbidity, and Emergency
visits in the previous 6 months. The authors applied logistic regression to
develop a predictive model for a medium-sized not-for-profit community hospital
in California using patient-level data with more specific patient information
(including 13 explanatory variables). Specifically, the logistic regression is
applied to 2 populations: a general population including all patients and the
specific group of patients targeted by the CMS penalty (characterized as ages 65
or older with select conditions). The 2 resulting logistic regression models
have a higher sensitivity rate compared to the sensitivity of the LACE index.
The C statistic values of the model applied to both populations demonstrate
moderate levels of predictive power. The authors also build an economic model to
demonstrate the potential ficial impact of the use of the model for targeting
high-risk patients in a sample hospital and demonstrate that, on balance,
whether the hospital gains or loses from reducing readmissions depends on its
margin and the extent of its readmission penalties. AIMS: Reducing potentially avoidable hospital readmissions has been the target
of several healthcare initiatives, including the readmission prevention team
(RAPT) at Western Health, Melbourne. Study aims were to evaluate if the revised
LACE (length of stay, acuity of admission, Charlson Comorbidity Index, emergency
department visits in the past 6 months) index would identify high risk of early
readmission (≤30 days postdischarge), and if postdischarge clinic and community
services follow-up would reduce readmission rate.
METHODS: A prospective study was conducted among all general medicine inpatients
within a tertiary hospital in Melbourne, Australia between February to April
2016, with risk screening using the revised LACE index, alongside abbreviated
mental test and clinical frailty scale testing, with high-risk patients (revised
LACE ≥ 8) offered specialist clinic appointment and/or referral to community
services.
RESULTS: Among 781 patients (873 admission episodes), 358 (41.0%) admission
episodes were classified as high risk of early readmission. Revised LACE index
scores were equivalent for readmission vs. non-readmission episodes, {median 7
[interquartile range (IQR) 5, 8] vs. 7 [IQR 4, 8])}, as were median abbreviated
mental test (8 [IQR 6, 9] vs. 8 [IQR 6, 9]) and clinical frailty scale scores (5
[IQR 3, 6] vs. 5 [IQR 3, 6]). Early readmission rates were equivalent for those
who received compared with did not receive RAPT intervention (14.3 vs. 14.7%),
albeit confounded by lack of identification of readmission risk using the
revised LACE index. A total of 53 (14.8%) of the 358 high-risk admission
episodes formally declined RAPT follow-up.
CONCLUSION: This study highlighted the complexities of addressing hospital
readmissions, with challenges in identifying those at risk, and low uptake and
impact of current intervention strategies. Future research directions may
evaluate other contributors to readmission risk, and the development of
acceptable postdischarge interventions to effectively address risk. Identification and prediction of patients who are at risk of hospital
readmission is a critical step towards the reduction of the potential avoidable
costs for healthcare organisations. This research was focused on the evaluation
of LACE Index for Readmission - Length of stay (days), Acute (emergent)
admission, Charlson Comorbidity Index and number of ED visits within six months
(LACE) and Patients At Risk of Hospital Readmission (PARR) using New Zealand
hospital admissions. This research estimates the risk for all readmissions
rather than only those in a subset of referenced conditions. In total, 213,440
admissions between 1 Jan 2015 and 31 Dec 2016 were selected after appropriate
ethics approvals and permissions from the three hospitals. The evaluation method
used is the Receiver Operating Characteristics (ROC) analysis to evaluate the
accuracy of both the LACE and PARR models. As a result, The LACE index achieved
an Area Under the Curve (AUC) score of 0.658 in predicting 30-day readmissions.
The optimal cut-off for the LACE index is a score of 7 or more with sensitivity
of 0.752 and specificity of 0.564. Whereas, the PARR algorithm achieved an AUC
score of 0.628 in predicting 30-day readmissions. The optimal cut-off for the
PARR index is a score of 0.34 or more with sensitivity of 0.714 and specificity
of 0.542. Researchers are extensively searching for modifiable risk factors including
high-risk medications such as anticoagulation to avoid rehospitalisation. The
influence of oral anticoagulant therapy on hospital readmission is not known. We
investigated the impact of warfarin and direct oral anticoagulants (DOACs) on
all cause 30-day hospital readmission retrospectively in an academic centre. We
study the eligible cohort of 1781 discharges over 2-year period. Data on age,
gender, diagnoses, 30-day hospital readmission, discharge medications and
variables in the HOSPITAL score (Haemoglobin level at discharge, Oncology at
discharge, Sodium level at discharge, Procedure during hospitalisation, Index
admission, number of hospital Admissions, Length of stay) and LACE index (Length
of stay, Acute/emergent admission, Charlson comorbidity index score, Emergency
department visits in previous 6 months), which have higher predictability for
readmission were extracted and matched for analysis. Warfarin was the most
common anticoagulant prescribed at discharge (273 patients) with a readmission
rate of 20% (p<0.01). DOACs were used by 94 patients at discharge with a
readmission rate of 4% (p=0.219). Multivariate logistic regression showed an
increased risk of readmission with warfarin therapy (OR 1.36, p=0.045). Logistic
regression did not show DOACs to be a risk factor for hospital readmission. Our
data suggests that warfarin therapy is a risk factor for all-cause 30-day
hospital readmission. DOAC therapy is not found to be associated with a higher
risk of hospital readmission. Warfarin anticoagulation may be an important
target for interventions to reduce hospital readmissions. |
Which drugs are included in GI cocktail? | "GI cocktail" is a mixture of liquid antacid, viscous lidocaine, and an anticholinergic. | STUDY OBJECTIVE: To determine practice patterns regarding administration of the
"GI cocktail" (a mixture of liquid antacid, viscous lidocaine, and an
anticholinergic) in the emergency department in a single hospital and the
responses and final dispositions of patients who received the cocktails.
DESIGN: A retrospective review of ED charts.
SETTING: Urban university hospital ED with an annual census of 50,000 visits.
PARTICIPANTS: Ninety-seven consecutive patients who received a GI cocktail in
the ED.
RESULTS: Forty-nine patients (50%) received a GI cocktail for a chief complaint
of abdominal pain and 40 (41%) for a chief complaint of chest pain. The reason
for administration of a GI cocktail was documented on only one chart. Sixty-six
patients (68%) received at least one other drug, at a median time of 9 minutes
before administration of the GI cocktail. The most commonly coadministered drug
was a narcotic (56 patients), followed by nitroglycerin (22 patients),
antiemetics (13 patients), H2-blockers (13 patients), and aspirin (10 patients).
Thirty-three patients (34%) had symptomatic relief with the cocktail alone, 35
(36%) had symptomatic relief with the cocktail plus other drugs, 7 (7%) had no
response to the GI cocktail alone, and 5 (5%) had no response to the cocktail
with other drugs. In 17 patients (18%) the response was not documented. Chest
pain patients and abdominal pain patients had a similar frequency of response.
There was also similarity of response between admitted and discharged patients.
CONCLUSION: Although symptomatic relief after administration of a GI cocktail is
often noted, it is difficult to differentiate the effects of the cocktail from
those of other coadministered medications such as morphine or nitroglycerin. We
urge ED physicians to use the GI cocktail in a rational manner. The "GI Cocktail" is a mixture of medications often given in the Emergency
Department (ED) for dyspepsia symptoms. Several combinations are used, but the
most effective has not yet been determined. This study compared three
combinations commonly given for dyspepsia. The study was a prospective,
randomized, double-blinded trial comparing antacid (group 1); antacid + Donnatal
(group 2); antacid + Donnatal + viscous lidocaine (group 3) for acute treatment
of dyspepsia in the ED. Patients were randomly assigned to receive one of the
three medication combinations. Patients rated their discomfort on a Visual
Analog Scale (VAS) immediately before receiving the medication and 30 min later.
Change in VAS was the primary study endpoint. A 13-mm difference in VAS was
considered clinically significant. VAS change in the three groups was compared
using multivariable regression, controlling for pretreatment VAS, study drug,
previous antacid use, and gastrointestinal (GI) history. One hundred twenty
patients were enrolled between July and December 2000. One hundred thirteen
subjects (113) completed the protocol: Group 1 (N = 38); Group 2 (N = 37); Group
3 (N = 38). There was no statistically significant difference between the groups
in terms of age, gender, GI history, previous antacid use, or initial degree of
pain. Group 1 had a 25 +/- 27 mm mean (+/- SD), decrease in pain; Group 2, 23
+/- 22 mm decrease; and Group 3, 24 +/- 26 mm decrease. There was no
statistically significant difference in pain relief between the three groups on
univariate analysis or multivariable regression. In conclusion, the addition of
Donnatal or Donnatal + lidocaine to an antacid did not relieve dyspepsia better
than plain antacid. The "GI Cocktail" concoction may not be necessary. We hypothesized that Benzocaine (Hurricaine) would work as quickly and
effectively as viscous Lidocaine in this preparation. This was a prospective
randomized, single-blinded comparison between Benzocaine and Lidocaine as the
topical anesthetic in a gastrointestinal (GI) cocktail. Patients 18 years or
older were approached for participation when a GI cocktail was ordered by the
Emergency Physician. Patients were randomized to equivalent doses of either
Benzocaine or viscous Lidocaine in addition to 30 cc of Maalox and 10 cc of
Donnatal. Assessment using a visual analog pain scale occurred at time intervals
of 0, 5, 15, and 30 min. Eighty-two patients were enrolled (44 to Benzocaine, 38
to viscous Lidocaine), with each group having a statistically significant
improvement in pain (p < 0.001). There were no statistical differences between
the Benzocaine and viscous Lidocaine groups in terms of the relief of symptoms
at each of the assessment times. There were no adverse outcomes in either group. INTRODUCTION: Acute, severe dyspeptic pain is a common condition in the
emergency department. Despite the traditional "GI cocktail" (GI indicates
gastrointestinal), an intravenous (IV) proton pump inhibitor (PPI), a novel
acid-lowering drug, has recently been used to treat this condition. The aim of
this study was to evaluate the immediate effect of IV pantoprazole in addition
to the conventional GI cocktail in the relief of severe dyspeptic pain.
METHODS: This double-blind, randomized, controlled study was conducted in the
emergency department of an urban tertiary-care hospital from January 2011 to
October 2011. Selected patients with severe dyspeptic pain were randomized to
treatment with a placebo, antacid, and antispasmodic (conventional group) or IV
pantoprazole, antacid, and antispasmodic (pantoprazole group). The self-reported
100-mm visual analog scale score, adverse effects, and overall satisfaction were
evaluated in 15-minute intervals for 60 minutes.
RESULTS: Eighty-seven eligible cases were enrolled in the study. Forty-four and
43 patients were randomized in the conventional group and pantoprazole group,
respectively. There was no difference in the mean 60-minute visual analog scale
scores between the treatment groups. The rate of "responders," additional drug
use, adverse effects, and patient satisfaction were similar between the groups.
CONCLUSION: Intravenous PPI provides no additional benefit over the conventional
GI cocktail in the relief of acute, severe dyspeptic pain. Because of its
neutral effect and higher cost, the use of IV PPI to treat such conditions
should be discouraged in general clinical practice. BACKGROUND: Differentiating acute chest pain caused by myocardial ischaemia from
other, potentially more benign causes of chest pain is a frequent diagnostic
challenge faced by Emergency Department (ED) clinicians. Only 30% of patients
presenting with chest pain will have a cardiac origin for the pain, and
gastro-oesophageal disorders are one of the common sources of non-cardiac chest
pain, yet remain clinically difficult to differentiate from cardiac pain.
AIM: A systematic review of the literature was conducted to locate and evaluate
clinical trials comparing the use of an oral gastrointestinal (GI) cocktail
(oral viscous lidocaine/ antacid ± anticholinergic) to standard diagnostic
protocols (serial electrocardiograms (ECGs), serial biomarkers, imaging and/ or
provocative testing) to differentiate emergency patients presenting with acute
chest pain caused by gastro-oesophageal disease from those with other
aetiologies.
METHODS: Studies were identified by searching electronic databases, scanning
reference lists of articles, and searching clinical trial databases for
relevantly currently registered trials. The search included PubMed (1966 -
present), Embase (1980 - present) and Cochrane Central Register of Controlled
Trials (CENTRAL). The identified studies were evaluated with a modified QUADAS
tool.
RESULTS: A total of four studies were identified for inclusion in the review.
Studies were of low methodological quality with heterogeneous results. There
were no adequately powered and appropriately designed studies identified.
DISCUSSION: Current diagnostic protocols for Acute Coronary Syndrome (ACS)
revolve around early and serial ECG monitoring and cardiac biomarker testing,
imaging and careful clinical examination. In patients with chest pain and
suspected ACS, the use of a GI cocktail compared with standard diagnostic
protocols (serial ECG and biomarkers and provocative testing or imaging) is not
proven to improve accuracy of diagnosis, and cannot reliably exclude myocardial
ischaemia. |
Is AZD5153 active in prostate cancer? | Yes, AZD5153 was shown to be effective in treatment of prostate cancer. | BACKGROUNDS/AIMS: Bromodomain-containing protein 4 (BRD4) overexpression
participates in prostate cancer progression by enhancing the transcriptional
activity and expression of several key oncogenes. AZD5153 is a novel BRD4
inhibitor.
METHODS: Prostate cancer cells were treated with AZD5153. Cell survival was
tested by MTT assay and clonogenicity assay. Cell proliferation was tested by
[H3] DNA incorporation assay. Cell apoptosis was tested by caspase-3/-9 activity
assay, Histone DNA ELISA assay, Annexin V FACS assay and TUNEL staining assay.
Cell cycle progression was tested by propidium iodide (PI) FACS assay. Signaling
was tested by Western blotting assay. The nude mice PC-3 xenograft model was
applied to test AZD5153's activity in vivo.
RESULTS: AZD5153 inhibited proliferation and survival of established and primary
prostate cancer cells. AZD5153 induced apoptosis activation and cell cycle
arrest in prostate cancer cells. AZD5153 was non-cytotoxic to the prostate
epithelial cells. AZD5153 downregulated BRD4 targets (cyclin D1, Myc, Bcl-2,
FOSL1 and CDK4) in PC-3 and primary prostate cancer cells. Further studies show
that AKT could be the primary resistance factor of AZD5153. Pharmacological
inhibition or genetic depletion of AKT induced BRD4 downregulation, sensitizing
AZD5153-induced cytotoxicity in PC-3 cells. In vivo, AZD5153 oral administration
inhibited PC-3 xenograft tumor growth in nude mice. Its anti-tumor activity was
further enhanced with co-treatment of the AKT specific inhibitor MK-2206.
CONCLUSION: Together, our results indicate a promising therapeutic value of the
novel BRD4 inhibitor AZD5153 against prostate cancer cells. |
Is GRG5 involved only in late embryonic mouse development? | No. Groucho related gene 5 (GRG5) is a multifunctional protein that has been implicated in both early and late embryonic mouse development. | Groucho related gene 5 (GRG5) is a multifunctional protein that has been
implicated in late embryonic and postnatal mouse development. Here, we describe
a previously unknown role of GRG5 in early developmental stages by analyzing its
function in stem cell fate decisions. By both loss and gain of function
approaches we demonstrate that ablation of GRG5 deregulates the Embryonic Stem
Cell (ESC) pluripotent state whereas its overexpression leads to enhanced
self-renewal and acquisition of cancer cell-like properties. The maligt
characteristics of teratomas generated by ESCs that overexpress GRG5 reveal its
pro-oncogenic potential. Furthermore, transcriptomic analysis and cell
differentiation approaches underline GRG5 as a multifaceted signaling regulator
that represses mesendodermal-related genes. When ESCs exit pluripotency, GRG5
promotes neuroectodermal specification via Wnt and BMP signaling suppression.
Moreover, GRG5 promotes the neuronal reprogramming of fibroblasts and maintains
the self-renewal of Neural Stem Cells (NSCs) by sustaining the activity of
Notch/Hes and Stat3 signaling pathways. In summary, our results demonstrate that
GRG5 has pleiotropic roles in stem cell biology functioning as a stemness factor
and a neural fate specifier. |
Are astronauts in higher risk for developing cancer? | No significant associations between space radiation dose and mortality were found using logistic regression with an internal reference group, adjusting for medical radiation. | Despite years of research, understanding of the space radiation environment and
the risk it poses to long-duration astronauts remains limited. There is a
disparity between research results and observed empirical effects seen in human
astronaut crews, likely due to the numerous factors that limit terrestrial
simulation of the complex space environment and extrapolation of human clinical
consequences from varied animal models. Given the intended future of human
spaceflight, with efforts now to rapidly expand capabilities for human missions
to the moon and Mars, there is a pressing need to improve upon the understanding
of the space radiation risk, predict likely clinical outcomes of interplanetary
radiation exposure, and develop appropriate and effective mitigation strategies
for future missions. To achieve this goal, the space radiation and aerospace
community must recognize the historical limitations of radiation research and
how such limitations could be addressed in future research endeavors. We have
sought to highlight the numerous factors that limit understanding of the risk of
space radiation for human crews and to identify ways in which these limitations
could be addressed for improved understanding and appropriate risk posture
regarding future human spaceflight. |
Describe the mechanism of action of a drug Elagolix. | Elagolix is a novel, orally active, non-peptide, competitive gonadotropin-releasing hormone (GnRH) receptor antagonist. It is in development for the management of endometriosis with associated pain and heavy menstrual bleeding due to uterine fibroids. | CONTEXT: Parenteral administration of peptide GnRH analogs is widely employed
for treatment of endometriosis and fibroids and in assisted-reproductive therapy
protocols. Elagolix is a novel, orally available nonpeptide GnRH antagonist.
OBJECTIVE: Our objective was to evaluate the safety, pharmacokinetics, and
inhibitory effects on gonadotropins and estradiol of single-dose and 7-d
elagolix administration to healthy premenopausal women.
DESIGN: This was a first-in-human, double-blind, placebo-controlled, single- and
multiple-dose study with sequential dose escalation.
PARTICIPANTS: Fifty-five healthy, regularly cycling premenopausal women
participated.
INTERVENTIONS: Subjects were administered a single oral dose of 25-400 mg or
placebo. In a second arm of the study, subjects received placebo or 50, 100, or
200 mg once daily or 100 mg twice daily for 7 d. Treatment was initiated on d 7
(+/-1) after onset of menses.
MAIN OUTCOME MEASURES: Safety, tolerability, pharmacokinetics, and serum LH,
FSH, and estradiol concentrations were assessed.
RESULTS: Elagolix was well tolerated and rapidly bioavailable after oral
administration. Serum gonadotropins declined rapidly. Estradiol was suppressed
by 24 h in subjects receiving at least 50 mg/d. Daily (50-200 mg) or twice-daily
(100 mg) administration for 7 d maintained low estradiol levels (17 +/- 3 to 68
+/- 46 pg/ml) in most subjects during late follicular phase. Effects of the
compound were rapidly reversed after discontinuation.
CONCLUSIONS: Oral administration of a nonpeptide GnRH antagonist, elagolix,
suppressed the reproductive endocrine axis in healthy premenopausal women. These
results suggest that elagolix may enable dose-related pituitary and gonadal
suppression in premenopausal women as part of treatment strategies for
reproductive hormone-dependent disease states. This randomized double-blind study, with 24-week treatment and 24-week
posttreatment periods, evaluated the effects of elagolix (150 mg every day, 75
mg twice a day) versus subcutaneous depot medroxyprogesterone acetate (DMPA-SC)
on bone mineral density (BMD), in women with endometriosis-associated pain (n =
252). All treatments induced minimal mean changes from baseline in BMD at week
24 (elagolix 150 mg: -0.11%/-0.47%, elagolix 75 mg: -1.29%/-1.2%, and DMPA-SC:
0.99%/-1.29% in the spine and total hip, respectively), with similar or less
changes at week 48 (posttreatment). Elagolix was associated with improvements in
endometriosis-associated pain, assessed with composite pelvic signs and symptoms
score (CPSSS) and visual analogue scale, including statistical noninferiority to
DMPA-SC in dysmenorrhea and nonmenstrual pelvic pain components of the CPSSS.
The most common adverse events (AEs) in elagolix groups were headache, nausea,
and nasopharyngitis, whereas the most common AEs in the DMPA-SC group were
headache, nausea, upper respiratory tract infection, and mood swings. This study
showed that similar to DMPA-SC, elagolix treatment had minimal impact on BMD
over a 24-week period and demonstrated similar efficacy on
endometriosis-associated pain. PURPOSE: Limitated studies have reported the efficacy of GnRH antagonist on
endometriosis symptoms. The aim of our study was to review all available trials
to investigate the medical treatment of endometriosis with only GnRH
antagonists, with special attention to pharmacodynamic activity, safety, and
efficacy.
METHODS: Pub Med and Sciencedirect database were searched using terms of
"endometriosis treatment", "GnRH antagonist", and "Elagolix". The search was
limited to clinical studies published in English. Title and abstract were
screened to identify relevant articles.
RESULTS: Five studies covering use of GnRH antagonist were found. A phase 1
study evaluated the safety, pharmacokinetics, and inhibitory effects on
gonadotropins and estradiol of single dose and 7 day elagolix administration to
healthy premenopausal women; two phase II studies evaluated efficacy in patient
with endometriosis. Moreover, there are two Phase III clinical trials just
completed.
CONCLUSION: GnRH antagonists may have the advantage of oral administration and
lower incidence of adverse events. Currently, only Phase II studies have been
published demonstrating promising results in terms of efficacy, safety, and
tolerability. From the results of the phase III studies, elagolix may become a
valuable addition to the armamentarium of pharmacological agents to treat
endometriosis-related pain. CONTEXT: Elagolix is a nonpeptide, oral gonadotropin-releasing hormone (GnRH)
antagonist being developed for sex-hormone-dependent diseases in women.
OBJECTIVE: We evaluated the pharmacokinetics and pharmacodynamics of elagolix.
DESIGN, SETTING, AND PARTICIPANTS: This study was a randomized, double-blind,
placebo-controlled, multiple-ascending dose study in 45 healthy premenopausal
women at a research unit.
INTERVENTIONS: Elagolix [150 mg once daily or 100, 200, 300, or 400 mg twice
daily (BID)] or placebo was administered for 21 days.
MAIN OUTCOME MEASURES: Main outcome measures were elagolix pharmacokinetics,
suppression of gonadotropics [follicle-stimulating hormone (FSH), luteinizing
hormone (LH)] and ovarian hormones [estradiol (E2), progesterone (P)], and
adverse events.
RESULTS: Elagolix was rapidly absorbed after oral dosing, reaching maximum
concentrations at 1.0 to 1.5 hours, with a half-life of 4 to 6 hours. FSH, LH,
and E2 were suppressed within hours of elagolix administration on day 1.
Dose-dependent suppression of E2 was observed, with maximum suppression achieved
with elagolix 200 mg BID. Dose-dependent suppression of FSH and LH was also
observed, with maximal or near-maximal suppression achieved at 300 mg BID and
200 mg BID, respectively. At elagolix doses ≥100 mg BID, P concentrations
remained at anovulatory levels throughout 21 days of dosing. The most frequently
reported adverse events were headache and hot flush.
CONCLUSIONS: Elagolix administration allows for modulation of gonadotropin and
ovarian hormone concentrations, from partial suppression at lower doses to
nearly full suppression at higher doses. The results of this study provide a
rationale for elagolix dose selection for treatment of sex hormone-dependent
diseases in women. BACKGROUND: Endometriosis is a chronic, estrogen-dependent condition that causes
dysmenorrhea and pelvic pain. Elagolix, an oral, nonpeptide,
gonadotropin-releasing hormone (GnRH) antagonist, produced partial to nearly
full estrogen suppression in previous studies.
METHODS: We performed two similar, double-blind, randomized, 6-month phase 3
trials (Elaris Endometriosis I and II [EM-I and EM-II]) to evaluate the effects
of two doses of elagolix - 150 mg once daily (lower-dose group) and 200 mg twice
daily (higher-dose group) - as compared with placebo in women with surgically
diagnosed endometriosis and moderate or severe endometriosis-associated pain.
The two primary efficacy end points were the proportion of women who had a
clinical response with respect to dysmenorrhea and the proportion who had a
clinical response with respect to nonmenstrual pelvic pain at 3 months. Each of
these end points was measured as a clinically meaningful reduction in the pain
score and a decreased or stable use of rescue analgesic agents, as recorded in a
daily electronic diary.
RESULTS: A total of 872 women underwent randomization in Elaris EM-I and 817 in
Elaris EM-II; of these women, 653 (74.9%) and 632 (77.4%), respectively,
completed the intervention. At 3 months, a significantly greater proportion of
women who received each elagolix dose met the clinical response criteria for the
two primary end points than did those who received placebo. In Elaris EM-I, the
percentage of women who had a clinical response with respect to dysmenorrhea was
46.4% in the lower-dose elagolix group and 75.8% in the higher-dose elagolix
group, as compared with 19.6% in the placebo group; in Elaris EM-II, the
corresponding percentages were 43.4% and 72.4%, as compared with 22.7% (P<0.001
for all comparisons). In Elaris EM-I, the percentage of women who had a clinical
response with respect to nonmenstrual pelvic pain was 50.4% in the lower-dose
elagolix group and 54.5% in the higher-dose elagolix group, as compared with
36.5% in the placebo group (P<0.001 for all comparisons); in Elaris EM-II, the
corresponding percentages were 49.8% and 57.8%, as compared with 36.5% (P=0.003
and P<0.001, respectively). The responses with respect to dysmenorrhea and
nonmenstrual pelvic pain were sustained at 6 months. Women who received elagolix
had higher rates of hot flushes (mostly mild or moderate), higher levels of
serum lipids, and greater decreases from baseline in bone mineral density than
did those who received placebo; there were no adverse endometrial findings.
CONCLUSIONS: Both higher and lower doses of elagolix were effective in improving
dysmenorrhea and nonmenstrual pelvic pain during a 6-month period in women with
endometriosis-associated pain. The two doses of elagolix were associated with
hypoestrogenic adverse effects. (Funded by AbbVie; Elaris EM-I and EM-II
ClinicalTrials.gov numbers, NCT01620528 and NCT01931670 .). Much research has gone into developing medications that can be used to alleviate
endometriosis-associated symptoms. In addition to already established
medications, a new GnRH antagonist, elagolix, is in development. The novelty of
this drug compared to other GnRH antagonists, is its nonpeptide structure,
allowing it to be administered orally. Areas covered: We analyzed several Phase
I, II and III clinical trials that have evaluated the safety and efficacy of
this new medication. Expert opinion: Since many medications have been put on the
market and have gained popularity for the treatment of endometriosis-associated
symptoms, the demonstration of equality or superiority of effect, tolerability,
as well as patient compliance should be assessed when introducing a new drug.
While elagolix may have an advantage over established GnRH agonists, in that it
does not lead to a 'flare-up' effect, it too, takes a toll on bone mineral
density. Nevertheless, studies have shown that this new oral GnRH antagonist is
well tolerated, and the side effects have been described as 'mild or moderate'.
However, in order to examine whether elagolix can compete with or even surpass
established gold-standard medical treatments in this field, further studies that
directly compare elagolix to said treatments, might be necessary. OBJECTIVE: To evaluate the efficacy and safety of elagolix, an oral, nonpeptide
gonadotropin-releasing hormone antagonist, over 12 months in women with
endometriosis-associated pain.
METHODS: Elaris Endometriosis (EM)-III and -IV were extension studies that
evaluated an additional 6 months of treatment after two 6-month, double-blind,
placebo-controlled phase 3 trials (12 continuous treatment months) with two
elagolix doses (150 mg once daily and 200 mg twice daily). Coprimary efficacy
endpoints were the proportion of responders (clinically meaningful pain
reduction and stable or decreased rescue analgesic use) based on average monthly
dysmenorrhea and nonmenstrual pelvic pain scores. Safety assessments included
adverse events, clinical laboratory tests, and endometrial and bone mineral
density assessments. The power of Elaris EM-III and -IV was based on the
comparison to placebo in Elaris EM-I and -II with an expected 25% dropout rate.
RESULTS: Between December 28, 2012, and October 31, 2014 (Elaris EM-III), and
between May 27, 2014, and January 6, 2016 (Elaris EM-IV), 569 participants were
enrolled. After 12 months of treatment, Elaris EM-III responder rates for
dysmenorrhea were 52.1% at 150 mg once daily (Elaris EM-IV 550.8%) and 78.2% at
200 mg twice daily (Elaris EMIV 575.9%). Elaris EM-III nonmenstrual pelvic pain
responder rates were 67.5% at 150 mg once daily (Elaris EM-IV 566.4%) and 69.1%
at 200 mg twice daily (Elaris EM-IV 567.2%).”After 12 months of treatment,
Elaris EM-III dyspareunia responder rates were 45.2% at 150 mg once daily
(Elaris EM-IV=45.9%) and 60.0% at 200 mg twice daily (Elaris EM-IV=58.1%). Hot
flush was the most common adverse event. Decreases from baseline in bone mineral
density and increases from baseline in lipids were observed after 12 months of
treatment. There were no adverse endometrial findings.
CONCLUSION: Long-term elagolix treatment provided sustained reductions in
dysmenorrhea, nonmenstrual pelvic pain, and dyspareunia. The safety was
consistent with reduced estrogen levels and no new safety concerns were
associated with long-term elagolix use.
CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT01760954 and NCT02143713. Endometriosis is a chronic benign disease that affects women of reproductive
age. Medical therapy is often the first line of management for women with
endometriosis in order to ameliorate symptoms or to prevent post-surgical
disease recurrence. Currently, there are several medical options for the
management of patients with endometriosis. Non-steroidal anti-inflammatory drugs
(NSAIDs) are widely used in the treatment of chronic inflammatory conditions,
being efficacious in relieving primary dysmenorrhea. Combined oral
contraceptives (COCs) and progestins, available for multiple routes of
administration, are effective first-line hormonal options. In fact, several
randomized controlled trials (RCTs) demonstrated that they succeed in improving
pain symptoms in the majority of patients, are well tolerated and not expensive.
Second-line therapy is represented by gonadotropin-releasing hormone (GnRH)
agonists. Even if these drugs are efficacious in treating women not responding
to COCs or progestins, they are not orally available and have a less favorable
tolerability profile (needing an appropriate add-back therapy). The use of
danazol is limited by the large availability of other better-tolerated hormonal
drugs. Because few data are available on long-term efficacy and safety of
aromatase inhibitors they should be administered only in women with symptoms
refractory to other conventional therapies in a clinical research setting.
Promising preliminary data have emerged from multicenter Phase III trials on
elagolix, a new oral GnRH antagonist but non-inferiority RCT data are required
to compare elagolix with first-line therapies for endometriosis. Elagolix (ORILISSA™), an orally bioavailable, second-generation, non-peptide
gonadotropin-releasing hormone (GnRH) receptor antagonist, is being developed
AbbVie and Neurocrine Biosciences for the treatment of reproductive
hormone-dependent disorders in women. In July 2018, the US FDA approved elagolix
tablets for the management of moderate to severe pain associated with
endometriosis. This approval was based on positive results in two replicate
phase III trials; additional phase III trials in the USA, Canada and Puerto Rico
are currently evaluating elagolix as both monotherapy and in combination with
low-dose hormone add-back therapy in the same indication. Elagolix with and
without low-dose hormone add-back therapy is also undergoing phase III clinical
development for heavy menstrual bleeding associated with uterine fibroids in the
aforementioned locations. This article summarizes the milestones in the
development of elagolix leading to its first approval for the management of
moderate to severe pain associated with endometriosis. OBJECTIVE: To evaluate elagolix, an oral gonadotropin-releasing hormone receptor
antagonist, alone or with add-back therapy, in premenopausal women with heavy
menstrual bleeding (greater than 80 mL per month) associated with uterine
leiomyomas.
METHODS: This double-blind, randomized, placebo-controlled, parallel-group study
evaluated efficacy and safety of elagolix in cohorts 1 (300 mg twice daily) and
2 (600 mg daily) with four arms per cohort: placebo, elagolix alone, elagolix
with 0.5 mg estradiol/0.1 norethindrone acetate, and elagolix with 1.0 mg
estradiol/0.5 mg norethindrone acetate. A sample size of 65 per group was
planned to compare elagolix with add-back to placebo on the primary end point:
the percentage of women who had less than 80 mL menstrual blood loss and 50% or
greater reduction in menstrual blood loss from baseline to the last 28 days of
treatment. Safety assessments included changes in bone mineral density.
RESULTS: From April 8, 2013, to December 8, 2015, 571 women were enrolled, 567
were randomized and treated (cohort 1=259; cohort 2=308), and 80% and 75%
completed treatment, respectively. Participants had a mean±SD age of 43±5 years
(cohort 2, 42±5 years), and 70% were black (cohort 2, 74%). Primary end point
responder rates in cohort 1 (cohort 2) were 92% (90%) for elagolix alone, 85%
(73%) for elagolix with 0.5 mg estradiol/0.1 mg norethindrone acetate, 79% (82%)
for elagolix with 1.0 mg estradiol/0.5 mg norethindrone acetate, and 27% (32%)
for placebo (all P<.001 vs placebo). Elagolix groups had significant decreases
compared with placebo in lumbar spine bone mineral density, which was attenuated
by adding 1.0 mg estradiol/0.5 mg norethindrone acetate.
CONCLUSION: Elagolix with and without add-back significantly reduced menstrual
blood loss in women with uterine leiomyomas. Add-back therapy reduced
hypoestrogenic effects on bone mineral density.
CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT01817530; EU Clinical Trial
Register, 2013-000082-37. OBJECTIVE: The aim of this study was to estimate the efficacy of elagolix, an
oral gonadotropin-releasing hormone (GnRH) antagonist, for the treatment of
endometriosis-associated pelvic pain.
METHODS: This was a phase II, randomized, placebo-controlled parallel group
study conducted at 37 US centers, consisting of an 8-week double-blind period
followed by a 16-week open-label period. Patients were 137 women aged 18 to 49,
with laparoscopically confirmed endometriosis and moderate to severe
nonmenstrual pelvic pain and dysmenorrhea, who were administered elagolix 150 mg
daily or placebo. The primary outcomes of the study were the daily assessment of
dysmenorrhea, nonmenstrual pelvic pain and dyspareunia using a modified
Biberoglu-Behrman scale.
RESULTS: During the double-blind period, there were significantly greater mean
reductions from baseline to week 8 in dysmenorrhea (-1.13 ± 0.11 vs. -0.37 ±
0.11, p<0.0001), nonmenstrual pelvic pain (-0.47 ± 0.07 vs. -0.19 ± 0.07, p =
0.0066), and dyspareunia scores (-0.61 ± 0.10 vs. -0.23 ± 0.10, p = 0.0070) in
the elagolix group compared with placebo. Continued improvements were observed
during the open-label treatment regardless of initial treatment allocation.
Elagolix treatment was also associated with significant improvements in
quality-of-life measures during the double-blind and open-label periods. The
most common adverse events occurring with elagolix were nausea, headache and hot
flush, each in 9.9% of patients.
CONCLUSION: Elagolix effectively reduced endometriosis-associated pelvic pain
over a 24-week period and was well-tolerated. Elagolix, an orally active non-peptidic GnRH antagonist, has been approved by
the Food and Drug Administration for the management of moderate to severe pain
associated with endometriosis. As the degree of ovarian suppression obtained
with elagolix is dose-dependent, pain relief may be achieved by modulating the
level of hypo-oestrogenism while limiting side effects. Elagolix may thus be
considered a novelty in terms of its endocrine and pharmacological properties
but not for its impact on the pathogenic mechanisms of endometriosis, as the
target of this new drug is, yet again, alteration of the hormonal milieu. Given
the oestrogen-dependent nature of endometriosis, a reduction of side effects may
imply a proportionate decrease in pain relief. Furthermore, if low elagolix
doses are used, ovulation is not consistently inhibited, and patients should use
non-hormonal contraceptive systems and perform serial urine pregcy tests to
rule out unplanned conception during periods of treatment-induced amenorrhoea.
If high elagolix doses are used to control severe pain for long periods of time,
add-back therapies should be added, similar to that prescribed when using GnRH
agonists. To date, the efficacy of elagolix has only been demonstrated in
placebo-controlled explanatory trials. Pragmatic trials comparing elagolix with
low-dose hormonal contraceptives and progestogens should be planned to verify
the magnitude of the incremental benefit, if any, of this GnRH antagonist over
currently used standard treatments. The price of elagolix may impact on patient
adherence and, hence, on clinical effectiveness. In the USA, the manufacturer
AbbVie Inc. priced elagolix (OrilissaTM) at around $10 000 a year, i.e. $845 per
month. When faced with unaffordable treatments, some patients may choose to
forego care. If national healthcare systems are funded by the tax payer, the
approval and the use of a new costly drug to treat a chronic condition, such as
endometriosis, means that some finite ficial resources will be diverted from
other areas, or that similar patients will not receive the same level of care.
Thus, defining the overall 'value' of a new drug for endometriosis also has
ethical implications, and trade-offs between health outcomes and costs should be
carefully weighed up. The clinical pharmacology of elagolix was extensively evaluated in clinical
studies in healthy subjects and in women with endometriosis. Elagolix
pharmacokinetics (PK) show significant population variability, however they are
minimally affected by patients' baseline characteristics and demographics,
except for clinically relevant extrinsic and intrinsic factors such as
coadministrated strong organic anion transporting polypeptide (OATP) 1B1
inhibitors and severe hepatic impairment, which are contraindications for the
use of elagolix. These studies enabled a comprehensive understanding of elagolix
mechanism of action and the downstream pharmacodynamic (PD) effects on
gonadotropin and ovarian hormones, as well as full characterization of the PK/PD
(PKPD) relationships of elagolix at various dosages, including the approved
150 mg once daily and 200 mg twice daily dosing regimens for the management of
moderate to severe pain associated with endometriosis. Several model-based
analyses have contributed to understanding of the benefit-risk profile of
elagolix in patients with endometriosis, through characterization of the
exposure relationship with responder rates, with changes in bone mineral density
over time, as well as the interaction with coadministered drugs. Collectively,
these studies and analyses served as supportive evidence for the effectiveness
of the approved dosages and provided general dosing instructions of the first
approved oral gonadotropin-releasing hormone receptor antagonist. |
Describe mechanism of action of volanesorsen. | Volanesorsen, is an antisense oligonucleotid that inhibits the production of the Apo C-III which is crucial in regulating TGs metabolism because it inhibits lipoprotein lipase (LPL) and hepatic lipase activity but also hepatic uptake of TGs-rich particles. It has been shown to decrease TGs by 70-80%. | OBJECTIVE: To determine the effects of volanesorsen (ISIS 304801), a
second-generation 2'-O-methoxyethyl chimeric antisense inhibitor of
apolipoprotein (apo)C-III, on triglyceride (TG) levels and insulin resistance in
patients with type 2 diabetes.
RESEARCH DESIGN AND METHODS: A randomized, double-blind, placebo-controlled
trial was performed in 15 adult patients with type 2 diabetes (HbA1c >7.5% [58
mmol/mol]) and hypertriglyceridemia (TG >200 and <500 mg/dL). Patients were
randomized 2:1 to receive volanesorsen 300 mg or placebo for a total of 15
subcutaneous weekly doses. Glucose handling and insulin sensitivity were
measured before and after treatment using a two-step hyperinsulinemic-euglycemic
clamp procedure.
RESULTS: Treatment with volanesorsen significantly reduced plasma apoC-III
(-88%, P = 0.02) and TG (-69%, P = 0.02) levels and raised HDL cholesterol
(HDL-C) (42%, P = 0.03) compared with placebo. These changes were accompanied by
a 57% improvement in whole-body insulin sensitivity (P < 0.001). Importantly, we
found a strong relationship between enhanced insulin sensitivity and both plasma
apoC-III (r = -0.61, P = 0.03) and TG (r = -0.68, P = 0.01) suppression.
Improved insulin sensitivity was sufficient to significantly lower glycated
albumin (-1.7%, P = 0.034) and fructosamine (-38.7 μmol/L, P = 0.045) at the end
of dosing and HbA1c (-0.44% [-4.9 mmol/mol], P = 0.025) 3 months postdosing.
CONCLUSIONS: Volanesorsen reduced plasma apoC-III and TG while raising HDL-C
levels. Importantly, glucose disposal, insulin sensitivity, and integrative
markers of diabetes also improved in these patients after short-term treatment. BACKGROUND: Routine apolipoprotein (apo) measurements for cardiovascular disease
(CVD) are restricted to apoA-I and apoB. Here, the authors measured an
unprecedented range of apolipoproteins in a prospective, population-based study
and relate their plasma levels to risk of CVD.
OBJECTIVES: This study sought to measure apolipoproteins directly by mass
spectrometry and compare their associations with incident CVD and to obtain a
system-level understanding of the correlations of apolipoproteins with the
plasma lipidome and proteome.
METHODS: Associations of 13 apolipoproteins, 135 lipid species, and 211 other
plasma proteins with incident CVD (91 events), defined as stroke, myocardial
infarction, or sudden cardiac death, were assessed prospectively over a 10-year
period in the Bruneck Study (N = 688) using multiple-reaction monitoring mass
spectrometry. Changes in apolipoprotein and lipid levels following treatment
with volanesorsen, a second-generation antisense drug targeting apoC-III, were
determined in 2 human intervention trials, one of which was randomized.
RESULTS: The apolipoproteins most significantly associated with incident CVD
were apoC-II (hazard ratio per 1 SD [HR/SD]: 1.40; 95% confidence interval [CI]:
1.17 to 1.67), apoC-III (HR/SD: 1.38; 95% CI: 1.17 to 1.63), and apoE (HR/SD:
1.31; 95% CI: 1.13 to 1.52). Associations were independent of high-density
lipoprotein (HDL) and non-HDL cholesterol, and extended to stroke and myocardial
infarction. Lipidomic and proteomic profiles implicated these 3 very-low-density
lipoprotein (VLDL)-associated apolipoproteins in de novo lipogenesis, glucose
metabolism, complement activation, blood coagulation, and inflammation. Notably,
apoC-II/apoC-III/apoE correlated with a pattern of lipid species previously
linked to CVD risk. ApoC-III inhibition by volanesorsen reduced plasma levels of
apoC-II, apoC-III, triacylglycerols, and diacylglycerols, and increased apoA-I,
apoA-II, and apoM (all p < 0.05 vs. placebo) without affecting apoB-100 (p =
0.73).
CONCLUSIONS: The strong associations of VLDL-associated apolipoproteins with
incident CVD in the general community support the concept of targeting
triacylglycerol-rich lipoproteins to reduce risk of CVD. PURPOSE OF REVIEW: Apolipoprotein CIII (ApoCIII) is now recognized as a key
regulator in severe hypertriglyceridemia, chylomicronemia, and conditions of
triglyceride-rich lipoprotein (TRL) remt excess due to its inhibition of
lipoprotein lipase (LPL) and hepatic lipase, leading to decreased hepatic
reuptake of TRLs, as well as enhanced synthesis and secretion of VLDL from the
liver. ApoCIII gain-of-function mutations are associated with atherosclerosis
and coronary heart disease (CHD), and contribute to the development of
cardiometabolic syndrome, hypertriglyceridemia, and type 2 diabetes mellitus.
Conversely, loss-of-function mutations in ApoCIII are associated with lower
levels of plasma triglycerides (TG), attenuation of vascular inflammatory
processes such as monocyte adhesion and endothelial dysfunction, and
potentially, a reduction in the incidence and progression of atherosclerosis and
cardioprotection.
RECENT FINDINGS: Evidence is now emerging that volanesorsen, a second-generation
antisense oligonucleotide drug targeting ApoCIII messenger RNA resulting in
decreases in TG in patients with familial chylomicronemia syndrome, severe
hypertriglyceridemia, and metabolic dyslipidemia with type 2 diabetes giving
support to the hypothesis that ApoCIII is a powerful inhibitor of LPL, and when
reduced, endogenous clearance of TRLs can result in substantial reductions in TG
levels. Discovery of the ApoCIII inhibitor volanesorsen opens a new era of
lipid-lowering drugs for reduction in TG and potentially for reduction in LDL-C.
Herein, this review will provide an update on the pathophysiology of
ApoCIII-linked atherosclerosis and the development of the first drug to target
ApoCIII, volanesorsen, as a promising lipid-lowering agent. PURPOSE OF REVIEW: Apolipoprotein (apo) C-III is a key player in
triglyceride-rich lipoprotein metabolism and strongly associated with elevated
plasma triglyceride levels. Several new studies added important insights on
apoC-III and its physiological function confirming its promise as a valid
therapeutic target.
RECENT FINDINGS: APOC3 is expressed in liver and intestine and regulates
triglyceride-rich lipoprotein (TRL) catabolism and anabolism. The
transcriptional regulation in both organs requires different regulatory
elements. Clinical and preclinical studies established that apoC-III raises
plasma triglyceride levels predomitly by inhibiting hepatic TRL clearance.
Mechanistic insights into missense variants indicate accelerated renal clearance
of apoC-III variants resulting in enhanced TRL catabolism. In contrast, an APOC3
gain-of-function variant enhances de novo lipogenesis and hepatic TRL
production. Multiple studies confirmed the correlation between increased
apoC-III levels and cardiovascular disease. This has opened up new therapeutic
avenues allowing targeting of specific apoC-III properties in triglyceride
metabolism.
SUMMARY: Novel in vivo models and APOC3 missense variants revealed unique
mechanisms by which apoC-III inhibits TRL catabolism. Clinical trials with
Volanesorsen, an APOC3 antisense oligonucleotide, report very promising
lipid-lowering outcomes. However, future studies will need to address if acute
apoC-III lowering will have the same clinical benefits as a life-long reduction. A spectrum of disorders, ranging from rare severe cases of homozygous null
lipoprotein lipase deficiency (LPLD)-familial chylomicronemia syndrome (FCS) to
heterozygous missense LPLD or polygenic causes, result in hypertriglyceridemia
and pancreatitis. The effects of mutations are exacerbated by environmental
factors such as diet, pregcy, and insulin resistance. Areas covered: In this
review, authors discuss chronic treatment of FCS by ultra-low fat diets allied
with the use of fibrates, omega-3 fatty acids, niacin, statins, and
insulin-sensitizing therapies depending on the extent of residual lipoprotein
lipase (LPL) activity; novel therapies in development target triglyceride
(TG)-rich lipoprotein particle clearance. Previously, a gene therapy approach to
LPL-alipogene tiparvovec showed that direct targeting of LPL function reduced
pancreatitis events. An antisense oligonucleotide to apolipoprotein-C3,
volanesorsen has been shown to decrease TGs by 70-80% and possibly to reduce
rates of pancreatitis admissions. Studies are underway to validate its long-term
efficacy and safety. Other approaches investigating the role of LPL modulating
proteins such as angiopoietin-like petide-3 (ANGPTL3) are under consideration.
Expert opinion: Current therapeutic options are not sufficient for management of
many cases of FCS. The availability of antisense anti-apoC3 therapies and, in
the future, ANGPTL3 therapies may remedy this. BACKGROUND: Volanesorsen, an investigational inhibitor of apoC-III synthesis,
significantly reduced triglyceride levels in clinical trials in patients with
familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized
by marked chylomicronemia leading to a spectrum of symptoms, including recurrent
abdominal pain and episodes of potentially fatal acute pancreatitis (AP).
OBJECTIVE: To determine the effect of volanesorsen on burden of disease on
patients with FCS Methods: ReFOCUS was a retrospective global web-based survey
open to patients with FCS who received volanesorsen for ≥3 months in an
open-label extension study. The survey included questions about patients'
experiences before and after volanesorsen treatment.
RESULTS: Twenty-two respondents had received volanesorsen for a median of
222 days. Volanesorsen significantly reduced the number of symptoms per patient
across physical, emotional, and cognitive domains. Significant reductions from
baseline were reported for steatorrhea, pancreatic pain, and constant worry
about an attack of pain/AP. Respondents reported that volanesorsen improved
overall management of symptoms and reduced interference of FCS with work/school
responsibilities. Reductions in the negative impact of FCS on personal, social,
and professional life were also reported.
CONCLUSIONS: Treatment with volanesorsen has the potential to reduce disease
burden in patients with FCS through modulation of multiple symptom domains. BACKGROUND: Apolipoprotein C-III (apo C-III) is a key regulator of triglycerides
metabolism. The aim of this meta-analysis was to assess the effect of fish
omega-3 polyunsaturated fatty acids (PUFAs) on apo C-III levels.
METHODS: Randomized placebo-controlled trials investigating the impact of
omega-3 on apo C-III levels were searched in PubMed-Medline, SCOPUS, Web of
Science and Google Scholar. A random-effects model and generic inverse variance
method were used for quantitative data synthesis. Sensitivity analysis was
conducted using the leave-one-out method. A weighted random-effects
meta-regression was performed to evaluate the impact of potential confounders on
glycemic parameters.
RESULTS: This meta-analysis comprising 2062 subjects showed a significant
reduction of apo C-III concentrations following treatment with omega-3 (WMD:
-22.18 mg/L, 95% confidence interval: -31.61, -12.75, p < .001; I2: 88.24%).
Subgroup analysis showed a significant reduction of plasma apo C-III
concentrations by eicosapentaenoic acid (EPA) ethyl esters but not omega-3
carboxylic acids or omega-3 ethyl esters. There was a greater apo C-III
reduction with only EPA as compared with supplements containing EPA and
docosahexaenoic acid (DHA) or only DHA. A positive association between the apo
C-III-lowering effect of omega-3 with baseline apo C-III concentrations and
treatment duration was found.
CONCLUSIONS: This meta-analysis has shown that omega-3 PUFAs might significantly
decrease apo C-III. Key messages Omega-3 PUFA supplements significantly reduce
apo C-III plasma levels, particularly in hypertriglyceridemic patients when
applied in appropriate dose (more than 2 g/day) Triglyceride (TG)-lowering
effect is achieved via peroxisome proliferator-activated receptors α Further
studies should address the effect of omega-3 PUFAs alone or with other
lipid-lowering drugs in order to provide a final answer whether apo C-III could
be an important target for prevention of cardiovascular disease New apo C-III
antisense oligonucleotide drug (Volanesorsen) showed to be promising in
decreasing elevated TGs by reducing levels of apo C-III mRNA. Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder
typically caused by mutations in genes for lipoprotein lipase (LPL),
apolipoprotein C-II (Apo-CII), apolipoprotein A-V (Apo-AV), lipase maturation
factor 1 (LMF1) and glycosylphosphatidylinositol-anchored high-density
lipoprotein-binding protein 1 (GPI-HBP1). FCS is associated with severe
morbidity that includes recurrent pancreatitis and other problems. Effective
treatment to reliably prevent complications has been unavailable, so there is a
quest to identify novel interventions to achieve sustained triglyceride lowering
and prevention of pancreatitis. Apolipoprotein C-III (Apo-CIII) interferes with
triglyceride clearance by blocking LPL and alternative pathways. Volanesorsen is
an experimental antisense oligonucleotide that inhibits translation of Apo-CIII
mRNA, thereby substantially lowering plasma levels of Apo-CIII and
triglycerides. It is being developed for treatment of patients with FCS and
refractory hypertriglyceridemia. Data from a variety of clinical trials have
been very encouraging, with documentation of excellent triglyceride-lowering
efficacy, but there have been concerns about the risk of drug-related
thrombocytopenia and bleeding that contributed to the recent decision by the
Food and Drug Administration (FDA) to not approve the drug for clinical use.
Clinical trials testing the safety and efficacy of volanesorsen are ongoing, so
there is hope that the drug ultimately will be approved and available for
treatment of high-risk patients with FCS. Volanesorsen (previously known as ISIS 304801) is a 20-nucleotide partially
2'-O-(2-methoxyethyl) (2'-MOE)-modified antisense oligonucleotide (ASO) gapmer,
which was recently approved in the European Union as a novel, first-in-class
treatment in the reduction of triglyceride levels in patients with familial
chylomicronemia syndrome. We characterized the absorption, distribution,
metabolism, and excretion characteristics of volanesorsen in mice, rats,
monkeys, and humans, in either radiolabeled or nonradiolabeled studies. This
also included the characterization of all of the observed ASO metabolite species
excreted in urine. Volanesorsen is highly bound to plasma proteins that are
similar in mice, monkeys, and humans. In all species, plasma concentrations
declined in a multiphasic fashion, characterized by a relatively fast initial
distribution phase and then a much slower terminal elimination phase following
subcutaneous bolus administration. The plasma metabolite profiles of
volanesorsen are similar across species, with volanesorsen as the major
component. Various shortened oligonucleotide metabolites (5-19 nucleotides long)
were identified in tissues in the multiple-dose mouse and monkey studies, but
fewer in the [3H]-volanesorsen rat study, likely due to a lower accumulation of
metabolites following a single dose in rats. In urine, all metabolites
identified in tissues were observed, consistent with both endo- and
exonuclease-mediated metabolism and urinary excretion being the major
elimination pathway for volanesorsen and its metabolites. SIGNIFICANCE
STATEMENT: We characterized the absorption, distribution, metabolism, and
excretion (ADME) of volanesorsen, a partially 2'-MOE-modified antisense
oligonucleotide, from mouse to man utilizing novel extraction and quantitation
techniques in samples collected from preclinical toxicology studies, a 3H rat
ADME study, and a phase 1 clinical trial. |
What is the cyberknife used for? | CyberKnife(r) is a robotic stereotactic radiotherapy system | BACKGROUND: CyberKnife® stereotactic radiosurgery is a new treatment option for
uveal melanoma.
OBJECTIVE: This review outlines the technique of robot-assisted CyberKnife®
therapy, as well as the pros and cons in the treatment of uveal melanoma.
METHODS: The study provides a PubMed literature review and own preliminary
clinical experiences.
RESULTS: CyberKnife® therapy for choroidal and ciliary body melanomas shows
comparable results concerning local tumor control and overall survival matching
those of conventional therapies. With only low complication rates, a high level
of quality of life can be conserved by possible preservation of visual acuity as
well as the ocular globe.
CONCLUSION: Stereotactic radiosurgery using CyberKnife® seems to be an efficient
and safe therapeutic option for maligt melanomas affecting the choroid and
ciliary body. Comparative studies with conventional radiation strategies are now
a high priority. |
Is Niraparib effective for ovarian cancer? | Yes. Niraparib is an oral poly(ADP ribose) polymerase (PARP) inhibitor that is approved by the United States Food and Drug Administration and the European Medicines Agency for the maintenance treatment of women with recurrent ovarian cancer who are in complete or partial response to platinum-based chemotherapy. | Author information:
(1)From the Nordic Society of Gynecological Oncology and
Rigshospitalet-Copenhagen University Hospital, Copenhagen (M.R.M.), Odense
University Hospital (J.H.) and European Network for Gynacological Oncological
Trial and Research Unit of General Practice, Institute of Public Health,
University of Southern Denmark, Odense (R.D.C.) - all in Denmark; University of
Arizona and Creighton University-Phoenix, Phoenix (B.J.M.), and Arizona Oncology
Associates, Tuscon (B.J.M., J.B.) - all in Arizona; Princess Margaret
Consortium, Princess Margaret Cancer Centre, University Health Network,
University of Toronto, Toronto (A.M.O.), British Columbia Cancer Agency,
Vancouver (A.V.T.), and McGill University-McGill University Health Centre,
Montreal (L.G.) - all in Canada; Arbeitsgemeinschaft Gynäkologische Onkologie
(AGO) and the University of Munich, Munich (S.M.), and Kliniken Essen Mitte,
Essen (A.B.) - both in Germany; Grupo Español de Investigación en Cáncer de
Ovario (GEICO) and Hospital Universitario La Paz (A.R.), and GEICO and M.D.
Anderson Cancer Center Madrid (A.G.-M.), Madrid; French Investigator Group for
Ovarian and Breast Cancer (GINECO) and Institut du Cancer de Montpellier,
Montpellier (M.F.), and GINECO and Centre Antoine Lacassagne, Nice (P.F.) - both
in France; National Cancer Research Institute and UCL Cancer Institute,
University College London, London (J.A.L.); Multicenter Italian Trials in
Ovarian Cancer/Mario Negri Gynecologic Oncology Group, Fondazione Istituto di
Ricovero e Cura a Carattere Scientifico, Istituto Nazionale dei Tumori, Milan
(D.L.); Belgium and Luxembourg Gynecological Oncology Group and University of
Leuven, Leuven, Belgium (I.V.); Kaplan Medical Center, Rehovot, Israel
(N.E.B.-B.); AGO-Austria and Medical University Innsbruck, Innsbruck, Austria
(C.M.); Central and Eastern European Gynecologic Oncology Group and Uniwersytet
Medyczny w Poziu, Poz, Poland (R.M.); Stanford Comprehensive Cancer
Institute, Stanford (J.S.B.), and Cedars-Sinai Medical Center, West Hollywood
(B.J.R.) - both in California; Oslo University Hospital, Radiumhospitalet, Oslo
(A.D.); Northside Hospital, Atlanta (B.B.); Universitetssjukhuset, Linköping,
Sweden (P.R.); and Veristat, Southborough (J.P.B.), Tesaro, Waltham (S.A.), and
Dana-Farber Cancer Institute, Boston (U.A.M.) - all in Massachusetts. Results from a phase III trial indicate that maintece therapy with the PARP
inhibitor niraparib is more effective than placebo in slowing the progression of
recurrent platinum-sensitive ovarian cancer. Improved progression-free survival
was seen regardless of the presence or absence of germline BRCA mutations, or of
homologous recombination deficiency; however, patients who had these mutations
or defective DNA repair did better. Oral niraparib, a highly-selective, potent poly(ADP-ribose) polymerase (PARP)-1
and PARP-2 inhibitor, is approved in the USA for the maintece treatment of
adult patients with recurrent epithelial ovarian, fallopian tube or primary
peritoneal cancer who are in a complete or partial response to platinum-based
chemotherapy. It is also under regulatory review in the EU for use in
maintece treatment in patients with platinum-sensitive, recurrent epithelial
ovarian cancer who are in response to platinum-based chemotherapy. In the
multinational, phase 3 NOVA trial in adult patients with platinum-sensitive,
recurrent ovarian cancer, niraparib significantly prolonged median
progression-free survival, irrespective of the presence or absence of a germline
BRCA (gBRCA) mutation and irrespective of the presence or absence of homologous
recombit deficiency. Niraparib is also in development for use in other solid
tumours, including breast and prostate cancer. This article summarizes the
milestones in the development of niraparib leading to its first global approval
for the maintece treatment of adult patients with recurrent epithelial
ovarian, fallopian tube or primary peritoneal cancer. INTRODUCTION: Poly(ADP-ribose) polymerase (PARP) inhibitors are a targeted
therapy option for ovarian cancer. The goal of this review was to organize and
summarize the clinical trials evaluating PARP inhibitor therapy in ovarian
cancer as monotherapy, maintece therapy after partial or complete remission
to therapy or as a part of a combination regimen.
EVIDENCE ACQUISITION: PubMed, ClinicalTrials.gov, data from the United States
Food and Drug Administration (US FDA) and proceedings from scientific
conferences were searched for published and unpublished data pertaining to
clinical trials and approvals of PARP inhibitor use in ovarian cancer.
EVIDENCE SYNTHESIS: There have been 36 published phase 1, 2 and 3 studies
evaluating the use of olaparib, niraparib, veliparib and rucaparib in ovarian
cancer. Olaparib and rucaparib have been approved by the US FDA as monotherapy
for advanced recurrent ovarian cancer. Niraparib and olaparib have been approved
by the US FDA for maintece therapy after partial or complete remission in
recurrent ovarian cancer. There are currently ten phase 3 trials evaluating PARP
inhibitors at various timepoints in ovarian cancer therapy including at the time
of primary adjuvant therapy, as maintece therapy after primary chemotherapy,
as monotherapy for recurrent cancer and as maintece therapy after
chemotherapy for recurrence.
CONCLUSIONS: The landscape of PARP inhibitor use for ovarian cancer is rapidly
evolving and PARP inhibitors have become more available as a targeted therapy
option for ovarian cancer treatment. PURPOSE OF REVIEW: The recent United States Food and Drug Administration
approvals of niraparib and olaparib as maintece monotherapy for
platinum-sensitive, high-grade ovarian cancers independent of BRCA status
reflect a willingness to seek indications for poly-ADP-ribose polymerase (PARP)
inhibitors beyond cancers with deleterious breast cancer 1 and breast cancer 2
mutations. In this review, I describe the rationale behind current PARP
combination clinical trials with chemotherapies, angiogenesis inhibitors, cell
cycle checkpoint inhibitors, and inhibitors of the phosphoinositide 3-kinase/AK
thymoma/mechanistic target of rapamycin pathway.
RECENT FINDINGS: PARP inhibitors have primarily been studied as monotherapy in
cancers with homologous recombination repair defects based on an early
understanding of PARP-1 as a base excision repair enzyme and the idea that
abrogation of two DNA repair pathways cripples rapidly dividing cancer cells. It
is now known that PARP-1 is a DNA damage sensor with much wider reaching roles
in DNA repair processes and normal cellular functions, opening possibilities for
PARP inhibitor use in other clinical contexts.
SUMMARY: PARP inhibitor combination clinical trials are in the early stages, but
will deepen our understanding of DNA repair mechanisms, cancer biology, and
targeted therapies, thus contributing to the next iteration of therapeutic
options for our patients. Niraparib is an oral poly(ADP ribose) polymerase (PARP) inhibitor that is
currently approved by the United States Food and Drug Administration (US FDA) as
well as recently approved by the European Medicines Agency (EMA) for the
maintece treatment of women with recurrent ovarian cancer who are in complete
or partial response to platinum-based chemotherapy. The mechanisms of action of
niraparib include inhibition of PARP enzymatic activity as well as increased
formation of PARP-DNA complexes through "trapping" the PARP enzyme on damaged
DNA. Phase I and III studies have demonstrated activity and benefit of niraparib
in both BRCA mutated (BRCAm) and BRCA wild-type (BRCAwt) cancers. Phase I
testing of niraparib established the maximally tolerated dose of 300mg by mouth
(PO) daily, and the phase 3 ENGOT-OV16/NOVA study demonstrated the benefit of
niraparib maintece therapy compared to placebo after completion of and
response to platinum-based chemotherapy in both BRCAm and BRCAwt ovarian cancer
patient populations. Toxicities seen with niraparib include hematologic,
gastrointestinal, fatigue, and cardiovascular. Hematologic toxicities include
thrombocytopenia, anemia, neutropenia and leukopenia; upfront dose modification
to 200mg niraparib for patients with baseline weight of ≤77kg and/or baseline
platelets of ≤150,000K/uL should be considered to avoid significant hematologic
toxicity, especially thrombocytopenia, based on recent analyses of the
ENGOT-OV16/NOVA study. Cardiovascular toxicities include hypertension,
tachycardia, as well as palpitations, and patients should be monitored for
hypertension. PARP inhibitors have been associated with low risks of acute
myelogenous leukemia (AML) and myelodysplastic syndrome (MDS), and the overall
risk of AML and MDS is 0.9% of all patients treated with niraparib. Niraparib
testing is ongoing in newly diagnosed ovarian cancer patients as maintece
therapy following completion of platinum-based chemotherapy, in BRCAwt cancers
as treatment, as well as in combinations with other biologic drugs such as
immunotherapy and anti-angiogenic agents. Niraparib, an orally available selective inhibitor of poly(adenosine
diphosphate-ribose) polymerase (PARP), is the first PARP inhibitor approved for
use in patients with ovarian cancer who do not harbor a germ-line or somatic
mutation in the breast cancer gene (BRCA). Overall, niraparib is well tolerated
and its toxicities, primarily hematologic, are manageable especially with
recently released initial dose modification guidelines based on weight and
baseline platelet count. The role of niraparib as maintece following
frontline platinum-based chemotherapy as well as in the treatment of recurrent
high-grade serous ovarian cancer is an active area of investigation. Areas
covered: This review focuses on niraparib, its pharmacology, clinical efficacy,
and adverse effects as evidenced by prospective clinical trials, and licensed
indications. Expert commentary: Niraparib introduced the use of PARP inhibitors
regardless of biomarker status. Recent studies highlight the critical need for
more accurate biomarkers to identify patients most likely to benefit from
treatment with PARP inhibitors. In the next 5 years, we anticipate further
expansion of and elucidation regarding the optimal indication for use of
niraparib in the treatment of ovarian cancer. Niraparib (Zejula®), a poly (ADP-ribose) polymerase (PARP) inhibitor, is
approved for the maintece treatment of recurrent, epithelial ovarian,
fallopian tube, or primary peritoneal cancer in patients who are in complete or
partial response to platinum-based chemotherapy. Approval was based on the
results of the randomized, double-blind, placebo-controlled phase III NOVA
trial. In NOVA, niraparib significantly prolonged progression-free survival
(primary endpoint), chemotherapy-free interval and time to first subsequent
therapy compared with placebo in patients with recurrent, platinum-sensitive,
high grade serous ovarian, fallopian tube or primary peritoneal cancer. The
beneficial effects of niraparib were consistent regardless of BRCA mutation or
homologous recombination deficiency (HRD) status. Niraparib had a manageable
tolerability profile, with the majority of grade 3 or 4 adverse events being
haematologic abnormalities (e.g. thrombocytopenia, anaemia, neutropenia).
Adverse events were generally well managed with dose interruption or
modification of niraparib. Current evidence suggests that niraparib is an
effective new option with a manageable tolerability profile for the maintece
treatment of recurrent, platinum-sensitive epithelial ovarian, fallopian tube,
or primary peritoneal cancer in adults, with or without BRCA1/2 mutation or HRD. Ovarian cancer is the second most common and the most lethal gynecological
maligcy in the western world. Unfortunately, there are lack of methods for
early screening and diagnosis of the disease. Because of this, most of the cases
are diagnosed at an advanced stage and have poor prognosis. The standard
treatment of ovarian cancer is maximal cytoreductive surgical debulking followed
by platinum-based chemotherapy. There are new molecular agents available for
maintece therapy of ovarian cancer including anti-angiogenic therapies, poly
adenosine diphosphate ribose polymerase inhibitors, inhibitors of growth factor
signaling, or folate receptor inhibitors, as well as several immunotherapeutic
approaches. Niraparib is a poly adenosine diphosphate ribose polymerase
inhibitor that has shown to be clinically effective as maintece therapy in
patients with platinum sensitive, recurrent ovarian cancer. Studies have shown
the median duration of progression-free survival was significantly longer among
those receiving niraparib than among those receiving placebo, regardless of
presence or absence of BRCA gene mutations or homologous recombination
deficiency status. Studies have shown that treatment-emergent Grade 3 or Grade 4
hematological events were observed in patients receiving niraparib including
thrombocytopenia (33.8%), anemia (25.3%) and neutropenia (19.6%). Most of the
hematological laboratory abnormalities occurred within the first three treatment
cycles. After dose adjustment, the incidence of hematological abnormalities was
infrequent beyond cycle 3. We are reporting two cases of Grade III/IV
neutropenia and thrombocytopenia in patients treated with niraparib in our
institution. Unfortunately, one of the patients succumbed to septic shock
secondary to right lower lobe pneumonia while severely neutropenic. The second
patient's blood counts improved after discontinuing the medication and with
supportive transfusions during the hospitalization. |
Which portal has been developed to explore protein-protein interactions in cancer cell lines? | The OncoPPi Portal has been developed as an interactive web resource that allows investigators to access, manipulate and interpret a high-quality cancer-focused network of protein-protein interactions (PPIs) experimentally detected in cancer cell lines. To facilitate prioritization of PPIs for further biological studies, this resource combines network connectivity analysis, mutual exclusivity analysis of genomic alterations, cellular co-localization of interacting proteins and domain-domain interactions. Estimates of PPI essentiality allow users to evaluate the functional impact of PPI disruption on cancer cell proliferation. Furthermore, connecting the OncoPPi network with the approved drugs and compounds in clinical trials enables discovery of new tumor dependencies to inform strategies to interrogate undruggable targets like tumor suppressors. The OncoPPi Portal serves as a resource for the cancer research community to facilitate discovery of cancer targets and therapeutic development. | MOTIVATION: As cancer genomics initiatives move toward comprehensive
identification of genetic alterations in cancer, attention is now turning to
understanding how interactions among these genes lead to the acquisition of
tumor hallmarks. Emerging pharmacological and clinical data suggest a highly
promising role of cancer-specific protein-protein interactions (PPIs) as
druggable cancer targets. However, large-scale experimental identification of
cancer-related PPIs remains challenging, and currently available resources to
explore oncogenic PPI networks are limited.
RESULTS: Recently, we have developed a PPI high-throughput screening platform to
detect PPIs between cancer-associated proteins in the context of cancer cells.
Here, we present the OncoPPi Portal, an interactive web resource that allows
investigators to access, manipulate and interpret a high-quality cancer-focused
network of PPIs experimentally detected in cancer cell lines. To facilitate
prioritization of PPIs for further biological studies, this resource combines
network connectivity analysis, mutual exclusivity analysis of genomic
alterations, cellular co-localization of interacting proteins and domain-domain
interactions. Estimates of PPI essentiality allow users to evaluate the
functional impact of PPI disruption on cancer cell proliferation. Furthermore,
connecting the OncoPPi network with the approved drugs and compounds in clinical
trials enables discovery of new tumor dependencies to inform strategies to
interrogate undruggable targets like tumor suppressors. The OncoPPi Portal
serves as a resource for the cancer research community to facilitate discovery
of cancer targets and therapeutic development.
AVAILABILITY AND IMPLEMENTATION: The OncoPPi Portal is available at
http://oncoppi.emory.edu.
CONTACT: [email protected] or [email protected]. |
Are genes that escape X-chromosome inactivation related to mental impairment? | Yes. Genes that escape X-inactivation in humans have high intraspecific variability in expression, are associated with mental impairment but are not slow evolving. | Mental retardation affects 2 to 3% of the population and is marked by
significant etiological heterogeneity, including genetic and non genetic causes.
FRAXA (FMR1) trinucleotide expansion is widely searched in routine screening,
but found in only about 2% of the patients tested. Mutations of the MECP2
(methyl-CpG-binding protein) gene mainly cause Rett syndrome but were also shown
to be involved in mental retardation. This study aimed to estimate the frequency
of MECP2 gene mutations in a large group of mentally retarded patients without
FRAXA expansion. Screening by heteroduplex analysis and SSCP followed by DNA
sequencing of shifted bands were performed on 613 patients, including 442 males
and 171 females. Eleven sequence variants were found, including nine
polymorphisms. The two others may be pathogenetic. The first one, the double
nucleotide substitution c.1162_1163delinsTA leading to a premature stop codon
(p.Pro388X) was found in a female patient with random X-inactivation, presenting
with borderline mental impairment without any features of Rett syndrome. The
second one, the c.679C>G substitution, changing a glutamine to a glutamate in
the transcriptional repression functional domain (p.Gln227Glu), was found in a
female patient with a moderately biased X-chromosome inactivation profile and
presenting with mild intellectual delay and minor psychotic features. The low
mutation rate suggests that a large-scale routine screening for MECP2 in
mentally retarded subjects is not cost-effective in clinical practice. Screening
may be improved by a pre-selection based on clinical features that remain to be
established. In female mammals most X-linked genes are subject to X-inactivation. However, in
humans some X-linked genes escape silencing, these escapees being candidates for
the phenotypic aberrations seen in polyX karyotypes. These escape genes have
been reported to be under stronger purifying selection than other X-linked
genes. Although it is known that escape from X-inactivation is much more common
in humans than in mice, systematic assays of escape in humans have to date
employed only interspecies somatic cell hybrids. Here we provide the first
systematic next-generation sequencing analysis of escape in a human cell line.
We analyzed RNA and genotype sequencing data obtained from B lymphocyte cell
lines derived from Europeans (CEU) and Yorubans (YRI). By replicated detection
of heterozygosis in the transcriptome, we identified 114 escaping genes,
including 76 not previously known to be escapees. The newly described escape
genes cluster on the X chromosome in the same chromosomal regions as the
previously known escapees. There is an excess of escaping genes associated with
mental retardation, consistent with this being a common phenotype of polyX
phenotypes. We find both differences between populations and between individuals
in the propensity to escape. Indeed, we provide the first evidence for there
being both hyper- and hypo-escapee females in the human population, consistent
with the highly variable phenotypic presentation of polyX karyotypes.
Considering also prior data, we reclassify genes as being always, never, and
sometimes escape genes. We fail to replicate the prior claim that genes that
escape X-inactivation are under stronger purifying selection than others. |
Which biological process takes place in nuclear speckles? | Speckles are subnuclear structures that are enriched in pre-messenger RNA splicing factors and are located in the interchromatin regions of the nucleoplasm of mammalian cells. They serve as splicing factor storage sites and play important roles in regulation of pre-mRNA splicing. | Nuclear speckles (speckles) represent a distinct nuclear compartment within the
interchromatin space and are enriched in splicing factors. In a previous study
(Melcák et al., 2001), it has been shown that the pre-spliceosomal assembly on
microinjected splicing-competent precursor mRNA takes place in the speckles, and
it has been suggested that the targeting of RNA into speckes consists of two
interdependent steps, namely the diffusion process, followed by the
energy-dependent translocation of RNA into the speckles. In the present study,
we confirm the existence of these two steps and show that this latter
translocation is ATP dependent. Speckles are subnuclear structures that are enriched in pre-messenger RNA
splicing factors and are located in the interchromatin regions of the
nucleoplasm of mammalian cells. At the fluorescence-microscope level they appear
as irregular, punctate structures, which vary in size and shape, and when
examined by electron microscopy they are seen as clusters of interchromatin
granules. Speckles are dynamic structures, and both their protein and
RNA-protein components can cycle continuously between speckles and other nuclear
locations, including active transcription sites. Studies on the composition,
structure and behaviour of speckles have provided a model for understanding the
functional compartmentalization of the nucleus and the organization of the
gene-expression machinery. In vertebrates, the majority of mRNAs that encode secreted, membrane-bound or
mitochondrial proteins contain RNA elements that activate an alternative mRNA
nuclear export (ALREX) pathway. Here we demonstrate that mRNAs containing
ALREX-promoting elements are trafficked through nuclear speckles. Although
ALREX-promoting elements enhance nuclear speckle localization, additional
features within the mRNA largely drive this process. Depletion of two
TREX-associated RNA helicases, UAP56 and its paralog URH49, or inhibition of the
TREX-associated nuclear transport factor, TAP, not only inhibits ALREX, but also
appears to trap these mRNAs in nuclear speckles. mRNAs that contain
ALREX-promoting elements associate with UAP56 in vivo. Finally, we demonstrate
that mRNAs lacking a poly(A)-tail are not efficiently exported by the ALREX
pathway and show enhanced association with nuclear speckles. Our data suggest
that within the speckle, ALREX-promoting elements, in conjunction with the
poly(A)-tail, likely stimulate UAP56/URH49 and TAP dependent steps that lead to
the eventual egress of the export-competent mRNP from these structures. C3G (Crk SH3 domain binding guanine nucleotide releasing factor) (Rap guanine
nucleotide exchange factor 1), essential for mammalian embryonic development, is
ubiquitously expressed and undergoes regulated nucleocytoplasmic exchange. Here
we show that C3G localizes to SC35-positive nuclear speckles and regulates
splicing activity. Reversible association of C3G with speckles was seen on
inhibition of transcription and splicing. C3G shows partial colocalization with
SC35 and is recruited to a chromatin and RNase-sensitive fraction of speckles.
Its presence in speckles is dependent on intact cellular actin cytoskeleton and
is lost on expression of the kinase Clk1. Rap1, a substrate of C3G, is also
present in nuclear speckles, and inactivation of Rap signaling by expression of
GFP-Rap1GAP alters speckle morphology and number. Enhanced association of C3G
with speckles is seen on glycogen synthase kinase 3 beta inhibition or
differentiation of C2C12 cells to myotubes. CRISPR/Cas9-mediated knockdown of
C3G resulted in altered splicing activity of an artificial gene as well as
endogenous CD44. C3G knockout clones of C2C12 as well as MDA-MB-231 cells showed
reduced protein levels of several splicing factors compared with control cells.
Our results identify C3G and Rap1 as novel components of nuclear speckles and a
role for C3G in regulating cellular RNA splicing activity. DNAJC17 is a heat shock protein (HSP40) family member, identified in mouse as
susceptibility gene for congenital hypothyroidism. DNAJC17 knockout mouse
embryos die prior to implantation. In humans, germline homozygous mutations in
DNAJC17 have been found in syndromic retinal dystrophy patients, while
heterozygous mutations represent candidate pathogenic events for
myeloproliferative disorders. Despite widespread expression and involvement in
human diseases, DNAJC17 function is still poorly understood. Herein, we have
investigated its function through high-throughput transcriptomic and proteomic
approaches. DNAJC17-depleted cells transcriptome highlighted genes involved in
general functional categories, mainly related to gene expression. Conversely,
DNAJC17 interactome can be classified in very specific functional networks, with
the most enriched one including proteins involved in splicing. Furthermore,
several splicing-related interactors, were independently validated by
co-immunoprecipitation and in vivo co-localization. Accordingly, co-localization
of DNAJC17 with SC35, a marker of nuclear speckles, further supported its
interaction with spliceosomal components. Lastly, DNAJC17 up-regulation enhanced
splicing efficiency of minigene reporter in live cells, while its knockdown
induced perturbations of splicing efficiency at whole genome level, as
demonstrated by specific analysis of RNAseq data. In conclusion, our study
strongly suggests a role of DNAJC17 in splicing-related processes and provides
support to its recognized essential function in early development. A significant fraction of mRNAs are degraded by the nuclear exosome in normal
cells. Here, we studied where and when these exosome target mRNAs are sorted
away from properly exported ones in the cells. We show that upon exosome
inactivation, polyA RNAs are apparently accumulated in nuclear foci that are
distinct from nuclear speckles (NSs), and provide several lines of evidence
supporting that these polyA RNAs mainly correspond to accumulating exosome
target mRNAs. These results suggest that exosomal mRNA degradation mostly occurs
outside of NSs. In support of this possibility, targeting exosome target mRNAs
to NSs stabilizes them by preventing exosomal degradation. Furthermore,
inhibiting mRNA release from NSs does not attenuate exosomal degradation in
normal cells, and results in polyA RNA accumulation both inside and outside of
NSs in exosome inactivated cells, suggesting that passage through NSs is not
required for sorting mRNAs for degradation or export. Indeed, exosome target
mRNAs that normally do not enter NSs are exported upon exosome inactivation.
Together, our data suggest that exosome target mRNAs are mainly degraded in the
nucleoplasm before entering NSs and rapid removal of these mRNAs is important
for preventing their nuclear export. Nuclear speckles (NSs) serve as splicing factor storage sites. In this study, we
unexpectedly found that many endogenous intronless mRNAs, which do not undergo
splicing, associate with NSs. These associations do not require transcription,
polyadenylation, or the polyA tail. Rather, exonic splicing enhancers present in
intronless mRNAs and their binding partners, SR proteins, promote intronless
mRNA localization to NSs. Significantly, speckle targeting of mRNAs promotes the
recruitment of the TREX export complex and their TREX-dependent nuclear export.
Furthermore, TREX, which accumulates in NSs, is required for releasing
intronless mRNAs from NSs, whereas NXF1, which is mainly detected at nuclear
pores, is not. Upon NXF1 depletion, the TREX protein UAP56 loses speckle
concentration but coaccumulates with intronless mRNAs and polyA RNAs in the
nucleoplasm, and these RNAs are trapped in NSs upon UAP56 codepletion. We
propose that the export-competent messenger RNP assembly mainly occurs in NSs
for intronless mRNAs and that entering NSs serves as a quality control step in
mRNA export. |
What is the effect of HMGB2 loss on CTCF clustering? | Depletion of the abundant HMGB2 protein occurs early on the path to senescence and coincides with the dramatic spatial clustering of CTCF. Knocking down HMGB2 suffices for senescence-induced CTCF clustering and for loop reshuffling, while ectopically expressing HMGB2 rescues these effects. | Author information:
(1)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany.
(2)German Cancer Research Center and Bioquant, 69120 Heidelberg, Germany.
(3)School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh,
UK.
(4)Institute of Molecular Biology, 55128 Mainz, Germany.
(5)Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany.
(6)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany; Cologne Center for Genomics, University of Cologne, 50931 Cologne,
Germany.
(7)Helmholtz Institute for Biomedical Engineering, RWTH Aachen University
Medical School, 52074 Aachen, Germany.
(8)Clinic I of Internal Medicine and Center for Integrated Oncology, University
Hospital Cologne, 50931 Cologne, Germany.
(9)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany; Interdisciplinary Centre for Clinical Research, RWTH Aachen University
Medical School, 52062 Aachen, Germany.
(10)Interdisciplinary Centre for Clinical Research, RWTH Aachen University
Medical School, 52062 Aachen, Germany.
(11)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany; Clinic I of Internal Medicine and Center for Integrated Oncology,
University Hospital Cologne, 50931 Cologne, Germany.
(12)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany; Cologne Center for Genomics, University of Cologne, 50931 Cologne,
Germany; Cologne Excellence Cluster on Cellular Stress Responses in
Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne,
Germany.
(13)Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne,
Germany. Electronic address: [email protected]. |
Has LB-100 been tested in clinical trials? | Yes, a phase I trial has been performed to assess the safety, tolerability, and potential activity of LB-100, a first-in-class small-molecule inhibitor of protein phosphatase 2A (PP2A) in adult patients with progressive solid tumors. | |
Which algorithms have been developed for analysing CRISPR/Cas9 knockout screens data? | HiTSelect and MAGeCK (Model-based Analysis of Genome-wide CRISPR/Cas9 Knockout) | Author information:
(1)Institute for Human Genetics, University of California, San Francisco, CA,
USA The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell
Research, University of California, San Francisco, CA, USA Department of
Epidemiology and Biostatistics, University of California, San Francisco, CA,
USA.
(2)The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell
Research, University of California, San Francisco, CA, USA Departments of
Obstetrics and Gynecology and Pathology and Center for Reproductive Sciences,
University of California, San Francisco, CA, USA Diabetes Center, University of
California, San Francisco, CA, USA.
(3)The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell
Research, University of California, San Francisco, CA, USA Departments of
Obstetrics and Gynecology and Pathology and Center for Reproductive Sciences,
University of California, San Francisco, CA, USA Diabetes Center, University of
California, San Francisco, CA, USA [email protected].
(4)Institute for Human Genetics, University of California, San Francisco, CA,
USA The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell
Research, University of California, San Francisco, CA, USA Department of
Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
[email protected]. We propose the Model-based Analysis of Genome-wide CRISPR/Cas9 Knockout (MAGeCK)
method for prioritizing single-guide RNAs, genes and pathways in genome-scale
CRISPR/Cas9 knockout screens. MAGeCK demonstrates better performance compared
with existing methods, identifies both positively and negatively selected genes
simultaneously, and reports robust results across different experimental
conditions. Using public datasets, MAGeCK identified novel essential genes and
pathways, including EGFR in vemurafenib-treated A375 cells harboring a BRAF
mutation. MAGeCK also detected cell type-specific essential genes, including BCR
and ABL1, in KBM7 cells bearing a BCR-ABL fusion, and IGF1R in HL-60 cells,
which depends on the insulin signaling pathway for proliferation. |
Which cells are affected in radiation-induced leukemias? | Hemopoietic stem cells, the possible target cells for radiation-induced leukemias. | The host-defense mechanisms against cancers are known to be modulated by
changing the environmental factor(s). The spontaneous incidence of myeloid
leukemia is about 1% in C3H/He mice, and the incidence increases up to 23.3%
when a single dose of radiation, 3 Gy X-ray, is exposed to a whole-body. Since
calorie restriction was known to reduce the incidence of spontaneous tumors, a
question as to whether such radiation induced-increase of myeloid leukemia would
be also decreased by calorie restriction, was aimed to answer to elucidate
possible mechanism of radiation-induced myeloid leukemia. By the calorie
restriction, the incidence of myeloid leukemia was significantly decreased. In
addition, the latent period of the myeloid leukemia in the groups for calorie
restriction was significantly extended at a greater extent as compared with the
control diet groups. Number of hemopoietic stem cells, the possible target cells
for radiation-induced leukemias, in the groups for the calorie restriction
demonstrated a significant decrease, especially in the spleen, as compared with
that in the control, when the evaluation was made at the time of radiation
exposure. BACKGROUND: Because many cancer patients are diagnosed earlier and live longer
than in the past, second cancers induced by radiation therapy have become a
clinically significant issue. An earlier biologically based model that was
designed to estimate risks of high-dose radiation-induced solid cancers included
initiation of stem cells to a premaligt state, inactivation of stem cells at
high radiation doses, and proliferation of stem cells during cellular
repopulation after inactivation. This earlier model predicted the risks of solid
tumors induced by radiation therapy but overestimated the corresponding leukemia
risks.
METHODS: To extend the model to radiation-induced leukemias, we analyzed--in
addition to cellular initiation, inactivation, and proliferation--a repopulation
mechanism specific to the hematopoietic system: long-range migration through the
blood stream of hematopoietic stem cells (HSCs) from distant locations.
Parameters for the model were derived from HSC biologic data in the literature
and from leukemia risks among atomic bomb survivors who were subjected to much
lower radiation doses.
RESULTS: Proliferating HSCs that migrate from sites distant from the high-dose
region include few preleukemic HSCs, thus decreasing the high-dose leukemia
risk. The extended model for leukemia provides risk estimates that are
consistent with epidemiologic data for leukemia risk associated with radiation
therapy over a wide dose range. For example, when applied to an earlier
case-control study of 110,000 women undergoing radiotherapy for uterine cancer,
the model predicted an excess relative risk (ERR) of 1.9 for leukemia among
women who received a large inhomogeneous fractionated external beam dose to the
bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95%
confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases
observed). As a corresponding example for brachytherapy, the predicted ERR of
0.80 among women who received an inhomogeneous low-dose-rate dose to the bone
marrow (mean = 2.5 Gy) was consistent with the measured ERR (0.62, 95% CI = -0.2
to 1.9).
CONCLUSIONS: An extended, biologically based model for leukemia that includes
HSC initiation, inactivation, proliferation, and, uniquely for leukemia,
long-range HSC migration predicts, with reasonable accuracy, risks for
radiation-induced leukemia associated with exposure to therapeutic doses of
radiation. |
PDQ39 questionnaires is design for which disease? | PDQ39 is Parkinson's Disease Questionnaire that is used for assessment of quality of life in patients with Parkinson's Disease. | BACKGROUND: The well known global improvement of quality of life (QoL) after
bilateral high frequency chronic deep brain stimulation of the subthalamic
nucleus (STN DBS) in Parkinson's disease (PD) is in contrast to behavioral
disturbances as observed after surgery. Indeed the impact of DBS on physical
versus mental aspects of QoL in PD remains unknown.
OBJECTIVE: To assess the influence of bilateral STN DBS on physical versus
mental aspects of QoL in Parkinson's disease.
METHODS: The results of 27 patients for the Unified Parkinson's disease Rating
Scale (UPDRS), Parkinson's Disease Questionnaire 39 (PDQ39) and Short Form 36
health survey questionnaire (SF36) were compared before surgery and after 12
months of bilateral STN DBS.
RESULTS: Comparing off-dopa conditions before versus 12 months after surgery,
both UPDRS part II and part III significantly improved: 32.6% and 52%,
respectively. UPDRS part I scores did not change significantly at 12 months. As
for PDQ39, the global score significantly improved after surgery (21.1 %) as did
four subscores: mobility (25.6 %), activity of daily living (34.5 %), stigma
(40.1 %) and bodily discomfort (30 %). Three PDQ39 subscores, however, showed no
significant changes: emotional well-being (10.7 %), social support (3.2%) and
cognition (8.5 %) and one item even worsened: communication (-7.7 %). In SF36,
only physical items significantly improved.
CONCLUSION: Using clinician's based rating scale, bilateral STN DBS showed
significant improvement in PD patients at 12 month follow up. However, using
patient's self-assessment scales, the clinical benefit of STN DBS was more
subtle: physical items of QoL significantly improved, whereas mental items such
as emotional well-being, social support, cognition and communication showed no
improvement. Our results are suggestive of a dissociation of motor and non-motor
symptoms control after bilateral STN DBS in PD patients. OBJECTIVE: To investigate the efficacy and the rate of adverse events of chronic
low-dose levodopa-carbidopa therapy in Japanese patients with Parkinson's
disease (PD).
PATIENTS AND METHODS: A total of 92 Japanese PD patients treated with low doses
of levodopa from the outset were studied. Both disease-specific motor
disabilities and quality of life (QOL) in the patients were evaluated using the
Unified Parkinson's Disease Rating Scale (UPDRS) and the Parkinson's Disease 39
Quality of Life Questionnaire (PDQ39), respectively.
RESULTS: In the overall patient group, the mean duration of treatment, the mean
daily dose of levodopa, the disability scores and the motor scores of UPDRS were
6.2 years, 186.4 mg, 8.0 and 19.2, respectively. The rates of motor
fluctuations, dyskinesias and hallucinations were 8.7%, 6.5% and 14.1%,
respectively. The mean summary index of PDQ39 scores was 23.1. Patients with
motor fluctuations showed a significantly earlier disease onset. Dose of
levodopa, age at onset, and treatment duration were not associated with the
occurrence of dyskinesias. Patients with hallucination had higher doses of
levodopa and dopamine agonist.
CONCLUSIONS: Our results demonstrate that chronic administration of a low-dose
levodopa preparation can provide satisfactory benefit with a low incidence of
motor complications, and can result in good QOL in Japanese patients with PD.
The concomitant use of a small amount of dopamine agonist and amantadine from
the outset has partly contributed to a reduced dose of levodopa and the lesser
occurrence of motor complications. The psychometric properties of the Dutch version of the Parkinson's disease
questionnaire 39 (PDQ39-DV) were tested in 177 patients with Parkinson's disease
(PD). Internal consistency of 7 of the 8 scales was adequate (>or=0.70), but was
insufficient for 'bodily discomfort' (0.59). Correlation between the PDQ39 and
other instruments in this study, the SCOPA-psychosocial questionnaire,
Euroqol-5D, hospital anxiety and depression scale, and a visual analogue scale
for quality of life, were 0.82, 0.74, 0.63 and -0.54, respectively. The factor
analysis yielded 8 factors, which accounted for 65% of the variance and revealed
only small differences with the original UK version. We conclude that the
PDQ39-DV displays satisfactory psychometric properties and is an appropriate
instrument to assess quality of life in Dutch patients with PD. A body of literature now exists, which demonstrates that idiopathic Parkinson's
disease (PD) has a major negative impact on quality of life (QoL), and that
depression and cognitive impairment are among the main predictors of poor QoL in
this disorder. Relatively little work has been done to assess the differential
contribution of the specific symptoms of PD to QoL, which was the aim of this
study. One hundred thirty patients with PD completed a booklet of
questionnaires, which included the PDQ39 as a disease-specific measure of QoL, a
symptom checklist, a mobility checklist, as well as patient ratings of disease
stage and disability. The results indicated that the contribution of physical,
medication-related, and cognitive/psychiatric symptoms to QoL can be
significant. Sudden unpredictable on/off states, difficulty in dressing,
difficulty in walking, falls, depression, and confusion were PD symptoms, which
significantly influenced QoL scores. Among the mobility problems associated with
PD, start hesitation, shuffling gait, freezing, festination, propulsion, and
difficulty in turning had a significant effect on QoL scores. In addition to
depression and anxiety, the major predictors of QoL were shuffling, difficulty
turning, falls, difficulty in dressing, fatigue, confusion, autonomic
disturbance particularly urinary incontinence, unpredictable on/off
fluctuations, and sensory symptoms such as pain. The implications of these
results for the medical management of PD are discussed. This study explored whether reflexology could improve or sustain the wellbeing
of people with Parkinosn's Disease [PD] using the PDQ39 wellbeing tool designed
specifically for use with people with PD. The treatmnt protocal involved giving
8 therapy sessions to 16 people with varying derees of PD in a cross-over design
to enable a longitudinal survey of impact. Whilst the results reflected the
progressive nature of PD deterioration over time there was an improvement in
wellbeing over the active therapy phase. These results suggest that continuous
two- three weekly reflexology may limit further deteroration or maintain
improvement of wellbeing. A further study is indicated to study this hypothesis. Parkinson's disease is a disabling and progressive neurological condition
characterized by multiple motor and non motor symptoms that contribute to
deterioration in quality of life. The diversity of symptoms associated with the
disease and its management affect the patients on their physical, social and
mental quality of life. The aim of this study was to identify key dimensions of
health related quality of life (HRQOL) in a population affected with Parkinson's
disease with a degree of mild-moderate impairment. Thirty six patients with
Parkinson were recruited. The Hoehn and Yarh scale, the Unified Parkinson's
Disease Rate Scale, the scale of activities of daily life and Schwab & England
Get Up & Go Test were applied. HRQOL was assessed with the EuroQol-5D and the
specific questionnaire Parkinson's Disease Questionnaire-39 items. The
dimensions of the PDQ-39, except the PDQ-39 Pain domain and the EuroQol-5D
correlated significantly with the severity of the disease. HRQOL was correlated
with the functional status of patients. Only the PDQ-39 pain domain correlated
with the risk of falls. Our results suggest that the HRQOL of patients with PD,
in a state of mild-moderate impairment, is strongly influenced by disease
severity and functional status. In this review report, current possibilities of evaluation of quality of life in
Parkinson's disease have been critically presented. Health Related Quality of
Life (-HRQoL) comprises a wide spectrum of consequences of the disease.
Measurement of quality of life has become increasingly relevant as an outcome
parameter, especially in long-term trials. Most of the available QoL instruments
depend on patient self-reports. The data can be collected by written
questionnaires. There are universal questionnaires of QoL--for many diseases and
the specific ones--specially created for one disease. Among universal
questionnaires, the Sickness Impact Profile (SIP) and the Short-Form Health
Status Survey (SF-36) are the most popular in Parkinson's disease. As for
specific questionnaires: the Parkinson`s Disease Questionnaire (PDQ-39) and the
Parkinson's Disease Quality of Life Questionnaire (PDQL) have been described. Author information:
(1)University of Washington, Department of Environmental and Occupational Health
Sciences, Seattle, WA, USA. Electronic address: [email protected].
(2)University of California San Diego, Department of Family and Preventive
Medicine, La Jolla, CA, USA. Electronic address: [email protected].
(3)Washington University School of Medicine, Department of Neurology, St. Louis,
MO, USA; American Parkinson Disease Association Advanced Center for Parkinson
Research, St. Louis, MO, USA. Electronic address: [email protected].
(4)Washington University School of Medicine, Department of Neurology, St. Louis,
MO, USA. Electronic address: [email protected].
(5)Washington University School of Medicine, Department of Neurology, St. Louis,
MO, USA. Electronic address: [email protected].
(6)Washington University School of Medicine, Department of Neurology, St. Louis,
MO, USA; American Parkinson Disease Association Advanced Center for Parkinson
Research, St. Louis, MO, USA. Electronic address: [email protected].
(7)Washington University School of Medicine, Department of Internal Medicine,
St. Louis, MO, USA. Electronic address: [email protected].
(8)Washington University School of Medicine, Department of Neurology, St. Louis,
MO, USA; American Parkinson Disease Association Advanced Center for Parkinson
Research, St. Louis, MO, USA; University of the Witwatersrand, School of Public
Health, Faculty of Health Sciences, Parktown, Johannesburg, South Africa.
Electronic address: [email protected]. Author information:
(1)Department of Neurology, Seoul Paik Hospital, Inje University College of
Medicine, Seoul, Korea.
(2)Department of Neurology, College of Medicine, The Catholic University of
Korea, Seoul, Korea.
(3)Department of Neurology, Korea University Guro Hospital, Korea University
College of Medicine, Seoul, Korea.
(4)Department of Neurology, Kyung Hee University College of Medicine, Seoul,
Korea.
(5)Department of Neurology, Busan Paik Hospital, Inje University College of
Medicine, Busan, Korea.
(6)Department of Neurology, Dong-A University College of Medicine, Busan, Korea.
(7)Department of Neurology and Neuroscience Center, Samsung Medical Center,
Sungkyunkwan University School of Medicine, Seoul, Korea.
(8)Department of Neurology, Hallym University College of Medicine, Anyang,
Korea.
(9)Department of Neurology, Yeungnam University College of Medicine, Daegu,
Korea.
(10)Department of Neurology, Sanggye Paik Hospital, Inje University College of
Medicine, Seoul, Korea.
(11)Department of Neurology, Severance Hospital, Yonsei University College of
Medicine, Seoul, Korea.
(12)Department of Neurology, Parkinson/Alzheimer Center, Asan Medical Center,
University of Ulsan College of Medicine, Seoul, Korea.
(13)Department of Neurology, Seoul National University College of Medicine,
Seoul National University Bundang Hospital, Seongnam, Korea.
(14)Department of Neurology, Seoul National University Hospital, Seoul National
University College of Medicine, Seoul, Korea.
(15)Department of Neurology, College of Medicine, Gachon University, Incheon,
Korea.
(16)Department of Neurology, Korea University Ansan Hospital, Korea University
College of Medicine, Ansan, Korea.
(17)Department of Neurology, Pusan National University Yangsan Hospital,
Yangsan, Korea.
(18)Department of Neurology, Seoul Metropolitan Government-Seoul National
University Boramae Medical Center, College of Medicine, Seoul National
University, Seoul, Korea.
(19)Department of Neurology, Chungbuk National University School of Medicine,
Chungbuk National University Hospital, Cheongju, Korea.
(20)Department of Neurology, Ewha Womans University School of Medicine, Ewha
Womans University Mokdong Hospital, Seoul, Korea.
(21)Department of Neurology, Konkuk University Medical Center, Seoul, Korea.
(22)Department of Neurology, Yonsei University Wonju College of Medicine, Wonju,
Korea.
(23)Department of Neurology, Bobath Memorial Hospital, Seongnam, Korea.
(24)Department of Neurology, Soonchunhyang University Seoul Hospital,
Soonchunhyang University School of Medicine, Seoul, Korea.
(25)Department of Neurology, Chungnam National University School of Medicine,
Chungnam National University Hospital, Daejeon, Korea.
(26)Department of Neurology, Ulsan University Hospital, University of Ulsan
College of Medicine, Ulsan, Korea.
(27)Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University
School of Medicine, Seoul, Korea.
(28)Department of Neurology, Keimyung University School of Medicine, Daegu,
Korea.
(29)Department of Neurology, Soonchunhyang University Gumi Hospital,
Soonchunhyang University School of Medicine, Gumi, Korea.
(30)Department of Neurology, Hanyang University College of Medicine, Seoul,
Korea. BACKGROUND: Quality of life (QoL) is the sense of well-being perceived by
people. The improvement of parkinsonian patient's QoL is a crucial goal for
clinicians involved in rehabilitative care. In order to provide an appropriate
endpoint for the assessment of the effectiveness of rehabilitation treatments on
QoL of patients with Parkinson's Disease (PD), in this study we have first
translated and then validated the Belastungsfragebogen Parkinson kurzversion
(BELA-P-k). This tool allows evaluating separately two crucial aspects: i) the
loss of personal autonomy in activities of daily life and ii) the psychological
and psychosocial impact of the disease.
METHODS: The BELA-P-k was translated from Dutch into Italian. Subsequently 202
PD patients filled out the questionnaire. Patients were also evaluated by using
the Parkinson Disease Questionnaire -39 (PDQ39), the Unified Parkinson's Disease
Rating Scale (UPDRS), the Mini Mental State Examination (MMSE) and the Frontal
Assessment Battery (FAB).
RESULTS: The internal consistency for total of two different scores Bothered by
(Bb) and Need for Help (NfH) was excellent (p = 0.91) for both categories. The
correlation between Bb and NfH categories was significant and strong,
very-strong, ranging from 0.78 to 0.88 (all p < 0.0001). Finally, the value of
Spearman r for the relationship between Bb and NfH items and PDQ 39 values were
significant (p ≤ 0.003).
CONCLUSIONS: In conclusion, we validated the BELA-P-k and demonstrated that it
is an appropriate and potentially useful tool for assessing QoL in the
management of PD.
TRIALS REGISTRATION: This trial was retrospectively registered with
ClinicalTrials.gov, NCT03073044. BACKGROUND: Patients with Parkinson's Disease (PD) undergo motor injuries, which
decrease their quality of life (QL). Dance, added to drug therapy, can help
treating these patients AIMS: To conduct a systematic review with meta-analysis
with the aim to analyze the effects of dance classes in comparison to other
interventions or to the absence of intervention, in randomized clinical trials
(RCTs), on functional mobility, motor symptoms and QL of PD patients METHODS:
The search was conducted in MEDLINE, LILACS, SciELO, Cochrane and PsycINFO (last
searched in August 2017). RCTs analyzing dance effects in comparison to other
physical training types or to no intervention, on functional mobility, motor
symptoms and QL of PD patients were selected. The outcomes assessed were motor
symptoms with Unified PD Rating Scale III (UPDRSIII), functional mobility with
Timed Up and Go Test (TUG), endurance with 6 min walking test (6MWT), freezing
of gait with Freezing of Gait Questionnaire (FOG_Q), walking velocity with
GAITRite and QL with PD Questionnaire (PDQ39). Two reviewers independently
extracted methodological quality and studies data. Results are presented as
weighted mean differences.
RESULTS: Five RCTs were included, totaling 159 patients. Dance promoted
significant improvements on UPDRSIII, and a decrease in TUG time when compared
to other types of exercise. In comparison to the absence of intervention, dance
practice also showed significant improvements in motor scores.
CONCLUSION: Dance can improve motor parameters of the disease and patients'
functional mobility. Psychiatric symptoms and motor impairment are major contributions to the poor
quality of life in patients with Parkinson's disease (PD). Here, we applied a
novel diffusion-weighted imaging approach, diffusion MRI connectometry, to
investigate the correlation of quality of life, evaluated by Parkinson's Disease
Questionnaire (PDQ39) with the white matter structural connectivity in 27
non-demented PD patients (disease duration of 5.3 ± 2.9 years, H and Y
stage = 1.5 ± 0.6, UPDRS-III = 13.7 ± 6.5, indicating unilateral and mild motor
involvement). The connectometry analysis demonstrated bilateral posterior limbs
of the internal capsule (PLIC) with increased connectivity related to the higher
quality of life (FDR = 0.027) in a multiple regression model. The present study
suggests for the first time a neural basis of the quality of life in PD in the
light of major determits of poor quality of life in these patients: anxiety,
depression, apathy and motor impairment. Results in our sample of non-demented
PD patients with relatively mild motor impairment and no apparent sign of
depression/anxiety also identify a unique and inexplicable association of the
PLIC to the quality of life in PD patients. It is common in medicine to titrate therapy according to target ranges of
objectively measured parameters. Objective measurement of motor function is
available for Parkinson's Disease (PD), making it possible to optimise therapy
and clinical outcomes. In this study, an accelerometry based measurement and
predefined target ranges were used to assess motor function in a Northern
Tasmania PD cohort managed by a Movement Disorder clinic. Approximately 40%
(n = 103) of the total PD population participated in this study and motor scores
were within target in 22%. In the 78% above target, changes in oral therapy were
recommended in 74%, Advanced Therapy in 12% and treatment was contraindicated in
9%. Following changes in oral therapy, there was a further objective measurement
and clinical consultation to establish whether scores had reached target range:
if so subjects left the study, otherwise further changes of therapy were
recommended (unless contraindications were present). Seventy-seven cases
completed the study, with 48% achieving target (including 22% at outset),
Advanced Therapy recommended in 19% and contraindications preventing any change
in therapy in 17%. In the 43% of cases in whom oral therapy was changed, total
UPDRS improved significantly (effect size = 8) as did the PDQ39 in cases
reaching target. NMS Quest and MOCA scores also improved significantly. This
study shows that many people in a representative cohort of PD would benefit from
objective assessment and treatment of their PD features against a target. BACKGROUND: Non-motor symptoms (NMSs) are a real burden in Parkinson's disease
(PD). They may appear in early pre-symptomatic stage as well as throughout the
disease course. However, their relationship with the deterioration of the
patient's quality of life (QoL) is still under debate. This study aimed to
investigate the prevalence of NMSs and their impact on the QoL in a cohort of
Moroccan patients.
METHODS: We carried out a cross-transactional study, where a total of 117
patients were submitted to a structured clinical interview and examination
investigating motor and NMSs based on common and conventional scales. Motor
symptoms were assessed by the UPDRS I-VI during ON condition. The NMSs were
evaluated with common scales and their relationship with the QoL was
investigated.
RESULTS: The mean patient's age was 60.77 ± 11.36 years old, and the median
disease duration was 6 years [2.5-9.5]. Motor's phenotype subtypes were the
mixed form in 40.2% of patients, akinetic-rigid in 20.5% and a tremor-domit
form in 39.3%. The median Hoehn and Yahr staging was 2 [1-2.5]. Regarding NMSs,
the most common were urinary dysfunctions (82.6%), sleep (80.6%), and
gastrointestinal (80%) disorders. Other autonomic dysfunctions were also
frequent: thermoregulatory dysfunctions 58.6%, cardiovascular troubles 50.9%,
and sexual dysfunctions 47.9%. Depression was present in 47.9% and fatigue
symptoms in 23.1%. The median score of SCOPA-AUT was 14 [7.75-21.80]. The median
PD questionnaire 39-score index (PDQ39-SI) was 23.22% and the most affected
dimension was "mobility." Univariate and multivariate analyses showed that the
SCOPA-AUT score impacted the QoL (p = 0.001), especially the gastrointestinal
(p = 0.007), and cardiovascular (p = 0.049) dimensions.
CONCLUSION: Our data show that all patients have presented at least one NMS.
Autonomic and sleep disorders were the most frequent, and in contrast to other
studies, digestive and cardiovascular disorders were rather the factors
influencing negatively the QoL of patients. Understanding the pathophysiology of
these NMSs should be placed at the forefront in order to develop new therapeutic
approaches by improving the QoL of PD patients. BACKGROUND: Treatment of advanced-stage idiopathic Parkinson's disease (PD) is a
demanding challenge, and in Germany, medication regimen adjustments are often
made during inpatient stays. Admissions often follow an acute worsening of
symptoms and functioning. In order to reduce long and expensive inpatient stays,
and to provide more frequent consultations, a 24/7 live stream telemedicine home
treatment service was established.
METHODS: A pilot study was conducted in which laptops were distributed to 50
patients for 1 year to see whether such a service was feasible (in terms of
patient participation and compliance) and whether this intervention affected the
patient's condition, measured in UPDRS, Mini-Mental Status Examination (MMSE),
39-item Parkinson's Disease Questionnaire (PDQ39), and H & Y Scale.
RESULTS: Seventy-two percent (36) of the patients were compliant and did not
experience technical issues. Patients lived, on average, 198 ± 183 km away from
the specialist clinic. In total, 264 video conversations took place with 6.9 ±
7.2 (0-29) calls per patient. We found a significant improvement in PDQ39
scores, but not in UPDRS, MMSE, or H & Y scores, at 1 year.
CONCLUSIONS: Our data shows that 24/7 live stream telemedicine is feasible and
can help to improve quality of life. However, a detailed preliminary review of
the patient's willingness to use such a service should be made to obtain the
best results. Improvement of the technical setup and network coverage would
facilitate an improved service and increase efficiency. |
Is palbociclib effective for glioblastoma? | No. In a clinical trial palbociclib monotherapy was not an effective treatment for recurrent glioblastoma. | INTRODUCTION: Alterations in the CDK4/6-RB signaling pathway are common causes
of cell cycle dysregulation in many cancers, including glioblastoma. Palbociclib
is an oral inhibitor of CDK4/6, which leads to phosphorylation of RB1 and
cell-cycle arrest. We conducted a two-arm study evaluating efficacy and tissue
pharmacokinetics/pharmacodynamics of palbociclib in patients with recurrent
glioblastoma.
METHODS: Eligibility criteria included confirmation of RB1 proficiency by IHC;
≤ 3 relapses; KPS ≥ 60; no limit on prior treatments. Arm 1 received palbociclib
for 7 days prior to indicated resection followed by adjuvant palbociclib. Arm 2
received palbociclib without resection. Primary objective was PFS6; secondary
included toxicity, OS, and ORR. Exploratory aims included biomarker assessment
and pharmacokinetic/pharmacodynamic effects in surgical patients.
RESULTS: Total of 22 patients were enrolled; 6 on Arm 1 and 16 on Arm 2. Trial
was stopped early secondary to lack of efficacy, with 95% of evaluable patients
progressing within 6 months. Median PFS was 5.14 weeks (range 5 days-142 weeks)
and median OS was 15.4 weeks (range 2-274 weeks). Two patients (10%) had related
grade ≥ 3 AEs. In Arm 1, 5 patients had tissue concentrations of palbociclib
felt to be sufficient for biological effect and paired samples available for RB1
IHC. There were no consistent changes in RB1 expression or cell proliferation in
the paired tissue.
CONCLUSION: In this trial, despite adequate tissue PK, palbociclib monotherapy
was not an effective treatment for recurrent glioblastoma. However, these were
heavily pretreated patients and targeting the CDK4/6 pathway may still deserve
further exploration. |
List five proteins with antioxidant properties? | thioredoxin 1 (Trx1),
peroxiredoxin 1 (Prx1),
GSH reductase (GSR),
phosphatase and tensin homolog (PTEN)
superoxide dismutase (SOD) | Arginine is a conditionally essential amino acid. To elucidate the influence of
l-arginine on the activation of endogenous antioxidant defence, male Wistar rats
were orally administered daily with l-arginine at different levels of 25, 50,
100 mg/100 g body weight. After 7 and 14 days feeding, the antioxidative
capacities and glutathione (GSH) contents in the plasma and in the liver were
uniformly enhanced with the increasing consumption of l-arginine, whereas the
oxidative stress was effectively suppressed by l-arginine treatment. After 14
days feeding, the mRNA levels and protein expressions of Keap1 and Cul3 were
gradually reduced by increasing l-arginine intake, resulting that the nuclear
factor Nrf2 was activated. Upon activation of Nrf2, the expressions of
antioxidant responsive element (ARE)-dependent genes and proteins (GCLC, GCLM,
GS, GR, GST, GPx, CAT, SOD, NQO1, HO-1) were up-regulated by l-arginine feeding,
indicating an upward trend in antioxidant capacity uniformly with the increasing
consumption of l-arginine. The present study demonstrates that the
supplementation of l-arginine stimulates GSH synthesis and activates Nrf2
pathway, leading to the up-regulation of ARE-driven antioxidant expressions via
Nrf2-Keap1 pathway. Results suggest the availability of l-arginine is a critical
factor to suppress oxidative stress and induce an endogenous antioxidant
response. |
Does the Mcm2-Ctf4-Polα axis play a role in transfer of histones to leading strand DNA at the replication forks? | No, the Mcm2-Ctf4-Pola axis facilitates parental histone H3-H4 transfer to lagging strands. | |
What is Scalp cirsoid aneurysms? | Cirsoid aneurysms are rare arteriovenous malformations of the scalp, which are usually of congenital etiology. They often present as an enlarging pulsatile scalp mass. | BACKGROUND: Cirsoid aneurysms are uncommon arteriovenous fistulas of the scalp.
Surgery for these lesions can be difficult; transarterial embolization is rarely
curative, while embolization of the venous pouch with permanent agents usually
necessitates subsequent surgical removal of the embolic material. The ideal
embolic agent would be one that is safe and effective, commercially available,
and would not require subsequent removal.
METHODS: We treated an arteriovenous fistula of the scalp with direct puncture
and injection of sodium tetradecyl sulfate, a commercially available sclerosing
agent.
RESULTS: Control angiography immediately following percutaneous injection of
sotradecol into the fistula showed decreased flow but not complete closure of
the lesion. However, within several days of the embolization, the patient's
scalp pain and mass resolved. Four months after embolization, MRA demonstrated
no evidence of residual or recurrent fistula. Color doppler flow imaging
demonstrated only slightly decreased vascular resistance in the distal
superficial temporal artery, possibly indirect evidence of persistent
micro-fistulae. Twenty-three months after the procedure, the patient continued
to be asymptomatic and had no palpable lesion.
CONCLUSIONS: Percutaneous injection of sotradecol can be considered as one of
the treatment options for arteriovenous fistula of the scalp. Further experience
is needed to compare the safety and effectiveness of sotradecol with other
agents currently used in the treatment of scalp arteriovenous fistulae. Cirsoid aneurysms are rare arteriovenous malformations of the scalp, which are
usually of congenital etiology. We describe the case of a young Sri Lankan
farmer who presented with a progressively enlarging scalp mass of interesting
character, yielding unique images on plain radiography before more advanced
imaging and subsequent definitive treatment were performed. The utility of this
simple imaging technique in underdeveloped settings is highlighted, and further
diagnostic and treatment options are discussed in brief. OBJECTIVE: We report an interesting case of a right temporal pre-auricular
arteriovenous fistula (cirsoid aneurysm) causing intractable tinnitus
successfully managed by transarterial n-butyl cyanoacrylate glue embolisation.
CASE REPORT: A 52-year-old female presented with a one-year history of tinnitus
and pulsatile swelling in the right pre-auricular region. A colour Doppler
ultrasound test and magnetic resoce angiography revealed a high-flow scalp
arteriovenous fistula with a feeder vessel from the distal superficial temporal
artery, which drained into the corresponding, dilated, tortuous vein. The
patient underwent diagnostic digital subtraction angiography. This was followed
by transarterial embolisation of the fistula using a 50 per cent mixture of
n-butyl cyanoacrylate glue and Lipiodol®, with manual distal venous occlusion. A
successful outcome was achieved with instant relief of symptoms.
CONCLUSION: Cirsoid aneurysms of the facial region, an uncommon cause of
tinnitus, can be effectively managed by endovascular embolisation. This
treatment obviates the need for surgery, which is associated with an increased
risk of complications such as scarring, deformity and bleeding. Cirsoid aneurysms, also known as scalp arteriovenous malformations (AVM), are
rare congenital extracranial vascular anomalies that often present as an
enlarging pulsatile scalp mass. A 14-yr-old male presented with a pulsatile
scalp lesion that was first noticed 3 yr prior and had progressively enlarged.
No history of trauma was reported. MRI demonstrated a 4 cm wide and 2 cm tall
nidus and catheter angiography was performed to further define the vascular
supply and drainage. The patient underwent transvenous endovascular embolization
followed by surgical excision via a bicoronal incision, as shown in this
operative video. Care was taken to identify, cauterize, and transect feeding
vessels from the superficial temporal, supratrochlear, and supraorbital arteries
circumferentially to completely devascularize and resect the galeal nidus from
overlying scalp tissue and underlying pericranium. Previously unreported in the
literature, transosseous emissary veins partially draining the lesion were noted
on angiography and were waxed thoroughly during surgery. Six-month follow-up
examination demonstrated a well-healed incision without evidence of AVM
recurrence. The unique venous drainage of this cirsoid aneurysm highlights the
value of diagnostic angiography to fully characterize these rare and complex
vascular lesions prior to pursuing definitive treatment. IRB approval was
obtained from the Ann & Robert H. Lurie Children's Hospital of Chicago
Institutional Review Board (IRB #2018-1799). The IRB waives the requirement of
obtaining informed consent for this study in accordance with 45 CFR 46.116(d). BACKGROUND: Scalp cirsoid aneurysms are rare subcutaneous arteriovenous fistulae
affecting the scalp. They can be easily misdiagnosed and mistreated.
OBJECTIVE: To review reported cases of scalp cirsoid aneurysms for their
incidence, etiology, clinical presentation, treatment, and outcomes using an
illustrative case.
METHODS: We conducted a PUBMED, SCOPUS, OVID SP, SciELO, and INFORMA search
using the keywords; "cirsoid," "aneurysm," "arteriovenous," "malformation,"
"scalp," "vascular," and "fistula." We identified 74 pertinent papers, reporting
242 cases in addition to our reported index case.
RESULTS: Median age at presentation was 25 yr (range 1-72 yr); male to female
ratio was 2.5:1. The most common symptoms were a pulsatile mass (94% of
patients), headaches (25%), and tinnitus (20%). The median duration of symptoms
was 3 yr (6 d to 31 yr), with 60.2% occurring spontaneously, 32.23% traumatic,
and the rest iatrogenic. A total of 58.5% of cases were managed with surgical
excision only, 21.6% with endovascular embolization only, and 14.5% with a
combination of both methods. The complication rate observed in the endovascular
embolization treatment cohort (55.8%) was significantly higher than that
observed in the surgical excision only cohort (9.9%) (P < .00001) and in the
combined therapy cohort (0%) (P < .00001). There is a low recurrence rate after
treatment irrespective of modality: surgical excision only (6.3%), endovascular
embolization only (8.3%), and combined therapy (0%).
CONCLUSION: Scalp cirsoid aneurysms are associated with good prognoses when
recognized and managed appropriately. We suggest combining surgery with
endovascular embolization as the optimum treatment modality. |
Which gene is frequently involved in autosomal dominant adult-onset demyelinating leukodystrophy (ADLD)? | Autosomal dominant leukodystrophy (ADLD) is an adult onset demyelinating disorder that is caused by duplications of the lamin B1 (LMNB1) gene. | Adult-onset autosomal domit leukodystrophy (ADLD) is a slowly progressive
neurological disorder characterized by symmetrical widespread myelin loss in the
central nervous system, with a phenotype similar to chronic progressive multiple
sclerosis. In this study, we identify a genomic duplication that causes ADLD.
Affected individuals carry an extra copy of the gene for the nuclear laminar
protein lamin B1, resulting in increased gene dosage in brain tissue from
individuals with ADLD. Increased expression of lamin B1 in Drosophila
melanogaster resulted in a degenerative phenotype. In addition, an abnormal
nuclear morphology was apparent when cultured cells overexpressed this protein.
This is the first human disease attributable to mutations in the gene encoding
lamin B1. Antibodies to lamin B are found in individuals with autoimmune
diseases, and it is also an antigen recognized by a monoclonal antibody raised
against plaques from brains of individuals with multiple sclerosis. This raises
the possibility that lamin B may be a link to the autoimmune attack that occurs
in multiple sclerosis. BACKGROUND AND PURPOSE: Duplications of lamin B1 (LMNB1) at 5q23 are implicated
in adult-onset autosomal domit leukodystrophy (ADLD) having been described in
six families with diverse ethnic background but with a homogeneous phenotype. In
a large Italian family, we recently identified a variant form of ADLD
characterized clinically by absence of the autonomic dysfunction at onset
described in ADLD and, on MRI, by milder cerebellar involvement with sparing of
hemispheric white matter. Aim of this study was to investigate the genetic basis
of this variant form of ADLD.
METHODS: We carried out a genome-wide linkage analysis using microsatellite
markers, and the genes in the candidate region were screened for point
mutations. LMNB1 was also screened for deletions/duplications by real-time PCR,
multiplex ligation-dependent probe amplification and Southern blot.
RESULTS: We mapped the variant ADLD locus to 5q23.2-q23.3, a genomic region
containing 11 genes including LMNB1. Neither gene copy-number defects nor point
mutations in the LMNB1 gene were found. We also excluded point mutations in the
coding exons of the other ten genes in the candidate region. However, expression
of lamin B1 evaluated in lymphoblastoid cells was higher in patients than in
healthy controls, and was similar to the lamin B1 expression levels found in a
patient with LMNB1 duplication.
CONCLUSIONS: This observation suggests that a mutation in an LMNB1 regulatory
sequence underlies the variant ADLD phenotype. Thus, adult forms of ADLD linked
to 5q23 appear to be more heterogeneous clinically and genetically than
previously thought. Adult-onset autosomal domit leukodystrophy (ADLD) is a slowly progressive
neurological disorder characterised by pyramidal, cerebellar, and autonomic
disturbances. Duplication of the LMNB1 gene is the genetic cause of ADLD, yet
the pathogenetic mechanism is not defined. In this study, we analysed cells and
muscle tissue from three patients affected by ADLD, carrying an extra copy of
the LMNB1 gene. Lamin B1 levels were dramatically increased in ADLD nuclei, both
in skin fibroblasts and skeletal muscle fibres. Since lamin B1 is known to bind
Oct-1, a transcription factor involved in the oxidative stress pathway, we
investigated Oct-1 fate in ADLD. Oct-1 recruitment to the nuclear periphery was
increased in ADLD cells, while nucleoplasmic localisation of the transcription
factor under oxidative stress conditions was reduced. Importantly, lamin B1
degradation occurring in some, but not all ADLD cell lines, slowed down lamin B1
and Oct-1 accumulation. In skeletal muscle, focal disorganisation of sarcomeres
was observed, while IIB-myosin heavy chain, an Oct-1 target gene, was
under-expressed and rod-containing fibres were formed. These data show that a
high degree of regulation of lamin B1 expression is implicated in the different
clinical phenotypes observed in ADLD and show that altered Oct-1 nuclear
localisation contributes to the disease phenotype. Autosomal domit leukodystrophy (ADLD) is an adult onset demyelinating
disorder that is caused by duplications of the lamin B1 (LMNB1) gene. However,
as only a few cases have been analyzed in detail, the mechanisms underlying
LMNB1 duplications are unclear. We report the detailed molecular analysis of the
largest collection of ADLD families studied, to date. We have identified the
minimal duplicated region necessary for the disease, defined all the duplication
junctions at the nucleotide level and identified the first inverted LMNB1
duplication. We have demonstrated that the duplications are not recurrent;
patients with identical duplications share the same haplotype, likely inherited
from a common founder and that the duplications originated from intrachromosomal
events. The duplication junction sequences indicated that nonhomologous end
joining or replication-based mechanisms such fork stalling and template
switching or microhomology-mediated break induced repair are likely to be
involved. LMNB1 expression was increased in patients' fibroblasts both at mRNA
and protein levels and the three LMNB1 alleles in ADLD patients show equal
expression, suggesting that regulatory regions are maintained within the
rearranged segment. These results have allowed us to elucidate duplication
mechanisms and provide insights into allele-specific LMNB1 expression levels. Adult-onset autosomal-domit leukodystrophy (ADLD) is a progressive and fatal
neurological disorder characterized by early autonomic dysfunction, cognitive
impairment, pyramidal tract and cerebellar dysfunction, and white matter loss in
the central nervous system. ADLD is caused by duplication of the LMNB1 gene,
which results in increased lamin B1 transcripts and protein expression. How
duplication of LMNB1 leads to myelin defects is unknown. To address this
question, we developed a mouse model of ADLD that overexpresses lamin B1. These
mice exhibited cognitive impairment and epilepsy, followed by age-dependent
motor deficits. Selective overexpression of lamin B1 in oligodendrocytes also
resulted in marked motor deficits and myelin defects, suggesting these deficits
are cell autonomous. Proteomic and genome-wide transcriptome studies indicated
that lamin B1 overexpression is associated with downregulation of proteolipid
protein, a highly abundant myelin sheath component that was previously linked to
another myelin-related disorder, Pelizaeus-Merzbacher disease. Furthermore, we
found that lamin B1 overexpression leads to reduced occupancy of Yin Yang 1
transcription factor at the promoter region of proteolipid protein. These
studies identify a mechanism by which lamin B1 overexpression mediates
oligodendrocyte cell-autonomous neuropathology in ADLD and implicate lamin B1 as
an important regulator of myelin formation and maintece during aging. Chromosomal rearrangements with duplication of the lamin B1 (LMNB1) gene
underlie autosomal domit adult-onset demyelinating leukodystrophy (ADLD), a
rare neurological disorder in which overexpression of LMNB1 causes progressive
central nervous system demyelination. However, we previously reported an ADLD
family (ADLD-1-TO) without evidence of duplication or other mutation in LMNB1
despite linkage to the LMNB1 locus and lamin B1 overexpression. By custom
array-CGH, we further investigated this family and report here that patients
carry a large (∼660 kb) heterozygous deletion that begins 66 kb upstream of the
LMNB1 promoter. Lamin B1 overexpression was confirmed in further ADLD-1-TO
tissues and in a postmortem brain sample, where lamin B1 was increased in the
frontal lobe. Through parallel studies, we investigated both loss of genetic
material and chromosomal rearrangement as possible causes of LMNB1
overexpression, and found that ADLD-1-TO plausibly results from an enhancer
adoption mechanism. The deletion eliminates a genome topological domain
boundary, allowing normally forbidden interactions between at least three
forebrain-directed enhancers and the LMNB1 promoter, in line with the observed
mainly cerebral localization of lamin B1 overexpression and myelin degeneration.
This second route to LMNB1 overexpression and ADLD is a new example of the
relevance of regulatory landscape modifications in determining Mendelian
phenotypes. Autosomal Domit Leukodystrophy (ADLD), a fatal adult onset demyelinating
disorder, is the only human disease that has been linked to mutations of the
nuclear lamina protein, lamin B1, and is primarily caused by duplications of the
LMNB1 gene. Why CNS myelin is specifically targeted and the mechanisms
underlying ADLD are unclear. Recent work from our group has demonstrated that
over expression of lamin B1 in oligodendrocytes, the myelin producing cells in
the CNS, resulted in age dependent epigenetic modifications, transcriptional
down-regulation of lipogenic gene expression and significant reductions of
myelin-enriched lipids. Given the high lipid content of meylin, we hypothesize
that lipid loss is one of the primary drivers of the demyelination phenotype.
These results can, at least partially, explain the age dependence and cell type
specificity in ADLD and are discussed in the context of the existing literature,
in an attempt to delineate potential pathways underlying the disease phenotype. Autosomal domit adult-onset demyelinating leukodystrophy (ADLD) is a very
rare neurological disorder featured with late onset, slowly progressive central
nervous system demyelination. Duplication or over expression of the lamin B1
(LMNB1) gene causes ADLD. In this study, we undertook a comprehensive clinical
evaluation and genetic detection for a Chinese family with ADLD. The proband is
a 52-year old man manifested with autonomic abnormalities, pyramidal tract
dysfunction. MRI brain scan identified bilateral symmetric white matter (WM)
hyper-intensities in periventricular and semi-oval WM, cerebral peduncles and
middle cerebellar peduncles. The proband has a positive autosomal domit
family history with similar clinical manifestations with a trend of genetic
anticipation. In order to understand the genetic cause of the disease in this
family, target exome capture based next generation sequencing has been done, but
no causative variants or possibly pathogenic variants has been identified.
However, Multiplex ligand-dependent probe amplification (MLPA) showed whole
duplication of LMNB1 gene which is co-segregated with the disease phenotype in
this family. This is the first genetically confirmed LMNB1 associated ADLD
pedigree from China. OBJECTIVE: To characterize the genetic and clinical features of patients with
autosomal domit adult-onset demyelinating leukodystrophy (ADLD) carrying
duplication and deletion upstream of lamin B1 (LMNB1).
METHODS: Ninety-three patients with adult-onset leukoencephalopathy of unknown
etiology were genetically analyzed for copy numbers of LMNB1 and its upstream
genes. We examined LMNB1 expression by reverse transcription-qPCR using total
RNA extracted from peripheral leukocytes. Clinical and MRI features of the
patients with ADLD were retrospectively analyzed.
RESULTS: We identified 4 patients from 3 families with LMNB1 duplication. The
duplicated genomic regions were different from those previously reported. The
mRNA expression level of LMNB1 in patients with duplication was significantly
increased. The clinical features of our patients with LMNB1 duplication were
similar to those reported previously, except for the high frequency of cognitive
impairment in our patients. We found 2 patients from 1 family carrying a 249-kb
genomic deletion upstream of LMNB1. Patients with the deletion exhibited
relatively earlier onset, more prominent cognitive impairment, and fewer
autonomic symptoms than patients with duplication. The presence of cerebellar
symptoms and lesions may be characteristic in our patients with the deletion
compared with the previously reported family with the deletion. Magnetic
resoce images of patients with the deletion exhibited a widespread
distribution of white matter lesions including the anterior temporal region.
CONCLUSIONS: We identified 4 Japanese families with ADLD carrying duplication or
deletion upstream of LMNB1. There are differences in clinical and MRI features
between the patients with the duplication and those with the deletion upstream
of LMNB1. The nuclear lamina is a fibrous meshwork of proteins found adjacent to the inner
nuclear membrane that plays a critical role in the maintece of nuclear
architecture. Made up of A and B type lamins, the nuclear lamina has recently
been shown to contribute to numerous cellular functions such as chromatin
organization, DNA replication, cellular proliferation, senescence, and aging.
While at least a dozen disorders are associated with LMNA, the focus of this
review is Autosomal Domit Leukodystrophy (ADLD), the only disease associated
with the lamin B1 gene (LMNB1). ADLD is a fatal, adult onset CNS demyelinating
disorder that is caused by either genomic duplications involving LMNB1 or
deletions upstream of the gene. Both mutation types result in increased LMNB1
gene expression. How the increased levels of this widely expressed nuclear
structural component results a phenotype as specific as demyelination is a great
mystery. This review summarizes what is currently known about the disease and
describes recent work using animal and cell culture models that have provided
critical insights into ADLD pathological mechanisms. The delineation of these
pathways provides a fascinating glimpse into entirely novel roles for the
nuclear lamina and will be critical for the identification of therapies for this
fatal disease. Allele-specific silencing by RNA interference (ASP-siRNA) holds promise as a
therapeutic strategy for downregulating a single mutant allele with minimal
suppression of the corresponding wild-type allele. This approach has been
effectively used to target autosomal domit mutations and single nucleotide
polymorphisms linked with aberrantly expanded trinucleotide repeats. Here, we
propose ASP-siRNA as a preferable choice to target duplicated disease genes,
avoiding potentially harmful excessive downregulation. As a proof-of-concept, we
studied autosomal domit adult-onset demyelinating leukodystrophy (ADLD) due
to lamin B1 (LMNB1) duplication, a hereditary, progressive and fatal disorder
affecting myelin in the CNS. Using a reporter system, we screened the most
efficient ASP-siRNAs preferentially targeting one of the alleles at rs1051644
(average minor allele frequency: 0.45) located in the 3' untranslated region of
the gene. We identified four siRNAs with a high efficacy and allele-specificity,
which were tested in ADLD patient-derived fibroblasts. Three of the small
interfering RNAs were highly selective for the target allele and restored both
LMNB1 mRNA and protein levels close to control levels. Furthermore, small
interfering RNA treatment abrogates the ADLD-specific phenotypes in fibroblasts
and in two disease-relevant cellular models: murine oligodendrocytes
overexpressing human LMNB1, and neurons directly reprogrammed from patients'
fibroblasts. In conclusion, we demonstrated that ASP-silencing by RNA
interference is a suitable and promising therapeutic option for ADLD. Moreover,
our results have a broad translational value extending to several pathological
conditions linked to gene-gain in copy number variations. |
What is the radiation-induced CD8 lymphocyte apoptosis (RILA) assay used for? | Radiation-induced lymphocyte apoptosis (RILA) has been suggested as a predictive assay for adverse late reactions after radiotherapy. | PURPOSE: 454 patients with prostate adenocarcinoma were accidentally overexposed
to radiation in Epinal hospital, France, between August 1999 and January 2007.
We aimed toevaluate whether radiation-induced CD4 or CD8 T-lymphocyte apoptosis
(RILA) correlates with the severity of radiation toxicity.
METHODS: Between 2007 and 2013, all patients who received more than 108% of the
prescribed radiation dose, after correction of the treatment plan, were
convened, and blood was sampled at 6-months follow-up. Maximal Digestive
toxicity (MDT) and maximal urinary toxicity (MUT) were graded using the Common
Terminology Criteria for Adverse Events (NCI-CTCAE) v3.0 scale. RILA was
assessed using flow cytometry.
RESULTS: 245 patients were included in our study. After a median follow-up of
4.8 years, the MDT and MUT reached grade 3-4 in 37 patients and 56 patients,
respectively. Patients with prostatectomy exhibited a statistically higher grade
of MUT compared with those treated with definitive radiotherapy (p=0.03). The
median RILA values were 11.8% and 15.3% for CD4 and CD8 T-lymphocytes,
respectively. We found no significant correlation between CD4 or CD8 RILA and
either MDT or MUT.
CONCLUSION: RILA does not correlate with the inter-individual variation in MDT
or MUT in the largest cohort of patients overexposed to radiation. The magnitude
of the overdosage probably overrides biological predictors of toxicity,
including individual radiosensitivity. PURPOSE: Radiation-induced lymphocyte apoptosis (RILA) has been suggested as a
predictive assay for adverse late reactions after radiotherapy. Thus, low RILA
values of T-lymphocyte subpopulations have been associated with increased risk
for various endpoints at 2 to 3 years of follow-up. The purpose was to test if
such associations persist for specific endpoints (subcutaneous fibrosis,
telangiectasia) in breast cancer patients with at least 10 years of
follow-up.Experimental Design: Two hundred and seventy-two female patients who
had received breast-conserving therapy within the German ISE study were included
(median follow-up: 11.6 years). Radiotherapy-induced side effects were scored
according to the Late Effects in Normal Tissues-Subjective, Objective,
Management, and Analytic (LENT-SOMA) classification system. RILA in the CD4+,
CD8+, and natural killer (NK) subpopulations from peripheral blood was analyzed
by flow cytometry. Multivariate predictive modeling was performed including
relevant clinical risk factors.
RESULTS: Low CD4+ RILA was associated with increased risk for both fibrosis (P =
0.011) and telangiectasia (P < 0.001). For fibrosis, the association was
stronger outside the surgical area (Fibout; P = 0.004) than within (Fibin; P =
0.17). Predictive multivariate modeling including clinical risk factors yielded
OR of 3.48 (95% confidence interval, 1.84-6.58) for any fibrosis and 8.60
(2.71-27.3) for telangiectasia. Addition of CD4+ RILA to the clinical variables
improved discrimination (c statistics) from 0.62 to 0.68 for any fibrosis, 0.62
to 0.66 for Fibin, 0.61 to 0.69 for Fibout, and from 0.65 to 0.76 for
telangiectasia. CD8+ and NK RILA were not significantly associated with
radiotherapy-related late reactions.
CONCLUSIONS: The results provide first evidence that low CD4+ RILA is associated
with increased subcutaneous fibrosis and telangiectasia even after 10 years.
This supports the potential usefulness for predicting individual clinical risk. |
What are the puQTLs (promoter-usage Quantitative Trait Loci)? | The identification of genetic variants affecting gene expression, namely expression quantitative trait loci (eQTLs), has contributed to the understanding of mechanisms underlying human traits and diseases. The majority of these variants map in non-coding regulatory regions of the genome and their identification remains challenging. Regulatory variants associated with promoter usage (puQTLs) and enhancer activity (eaQTLs) have been mapped from 154 EBV-transformed lymphoblastoid cell lines, derived from unrelated individuals. There are five categories of genes associated with puQTLs, distinguishing single from multi-promoter genes. Among multi-promoter genes, puQTL effects are either specific to a single promoter or to multiple promoters with variable effect orientations. Regulatory variants associated with opposite effects on different mRNA isoforms suggest compensatory mechanisms occurring between alternative promoters. | The identification of genetic variants affecting gene expression, namely
expression quantitative trait loci (eQTLs), has contributed to the understanding
of mechanisms underlying human traits and diseases. The majority of these
variants map in non-coding regulatory regions of the genome and their
identification remains challenging. Here, we use natural genetic variation and
CAGE transcriptomes from 154 EBV-transformed lymphoblastoid cell lines, derived
from unrelated individuals, to map 5376 and 110 regulatory variants associated
with promoter usage (puQTLs) and enhancer activity (eaQTLs), respectively. We
characterize five categories of genes associated with puQTLs, distinguishing
single from multi-promoter genes. Among multi-promoter genes, we find puQTL
effects either specific to a single promoter or to multiple promoters with
variable effect orientations. Regulatory variants associated with opposite
effects on different mRNA isoforms suggest compensatory mechanisms occurring
between alternative promoters. Our analyses identify differential promoter usage
and modulation of enhancer activity as molecular mechanisms underlying eQTLs
related to regulatory elements. |
Which is the main epigenetic difference between poised and constitutive enhancers? | We find that histone H3K27ac distinguishes active enhancers from inactive/poised enhancer elements containing H3K4me1 alone. | Developmental programs are controlled by transcription factors and chromatin
regulators, which maintain specific gene expression programs through epigenetic
modification of the genome. These regulatory events at enhancers contribute to
the specific gene expression programs that determine cell state and the
potential for differentiation into new cell types. Although enhancer elements
are known to be associated with certain histone modifications and transcription
factors, the relationship of these modifications to gene expression and
developmental state has not been clearly defined. Here we interrogate the
epigenetic landscape of enhancer elements in embryonic stem cells and several
adult tissues in the mouse. We find that histone H3K27ac distinguishes active
enhancers from inactive/poised enhancer elements containing H3K4me1 alone. This
indicates that the amount of actively used enhancers is lower than previously
anticipated. Furthermore, poised enhancer networks provide clues to unrealized
developmental programs. Finally, we show that enhancers are reset during nuclear
reprogramming. Specific gene transcription is a key biological process that underlies cell fate
decision during embryonic development. The biological process is mediated by
transcription factors which bind genomic regulatory regions including enhancers
and promoters of cardiac constitutive genes. DNA is wrapped around histones that
are subjected to chemical modifications. Modifications of histones further lead
to repressed, activated or poised gene transcription, thus bringing another
level of fine tuning regulation of gene transcription. Embryonic Stem cells (ES
cells) recapitulate within embryoid bodies (i.e., cell aggregates) or in 2D
culture the early steps of cardiac development. They provide in principle enough
material for chromatin immunoprecipitation (ChIP), a technology broadly used to
identify gene regulatory regions. Furthermore, human ES cells represent a human
cell model of cardiogenesis. At later stages of development, mouse embryonic
tissues allow for investigating specific epigenetic landscapes required for
determination of cell identity. Herein, we describe protocols of ChIP,
sequential ChIP followed by PCR or ChIP-sequencing using ES cells, embryoid
bodies and cardiac specific embryonic regions. These protocols allow to
investigating the epigenetic regulation of cardiac gene transcription. Histone modifications are frequently used as markers for enhancer states, but
how to interpret enhancer states in the context of embryonic development is not
clear. The poised enhancer signature, involving H3K4me1 and low levels of
H3K27ac, has been reported to mark inactive enhancers that are poised for future
activation. However, future activation is not always observed, and alternative
reasons for the widespread occurrence of this enhancer signature have not been
investigated. By analyzing enhancers during dorsal-ventral (DV) axis formation
in the Drosophila embryo, we find that the poised enhancer signature is
specifically generated during patterning in the tissue where the enhancers are
not induced, including at enhancers that are known to be repressed by a
transcriptional repressor. These results suggest that, rather than serving
exclusively as an intermediate step before future activation, the poised
enhancer state may be a mark for spatial regulation during tissue patterning. We
discuss the possibility that the poised enhancer state is more generally the
result of repression by transcriptional repressors. Expression of histone H3.3K27M mutant proteins in human diffuse intrinsic
pontine glioma (DIPG) results in a global reduction of tri-methylation of H3K27
(H3K27me3), and paradoxically, H3K27me3 peaks remain at hundreds of genomic
loci, a dichotomous change that lacks mechanistic insights. Here, we show that
the PRC2 complex is sequestered at poised enhancers, but not at active promoters
with high levels of H3.3K27M proteins, thereby contributing to the global
reduction of H3K27me3. Moreover, the levels of H3.3K27M proteins are low at the
retained H3K27me3 peaks and consequently having minimal effects on the PRC2
activity at these loci. H3K27me3-mediated silencing at specific tumor suppressor
genes, including Wilms Tumor 1, promotes proliferation of DIPG cells. These
results support a model in which the PRC2 complex is redistributed to poised
enhancers in H3.3K27M mutant cells and contributes to tumorigenesis in part by
locally enhancing H3K27me3, and hence silencing of tumor suppressor genes. |
What is PRL3-zumab? | PRL3-zumab is a first-in-class humanized antibody (PRL3-zumab) against PRL-3, an intracellular tumor-associated phosphatase upregulated in multiple human cancers, for unconventional cancer immunotherapies. PRL3-zumab specifically blocked PRL-3+, but not PRL-3-, orthotopic gastric tumors. In this setting, PRL3-zumab had better therapeutic efficacy as a monotherapy, rather than simultaneous combination with 5-fluorouracil or 5-fluorouracil alone. PRL3-zumab could also prevent PRL-3+ tumor recurrence. Mechanistically, we found that intracellular PRL-3 antigens could be externalized to become "extracellular oncotargets" that serve as bait for PRL3-zumab binding to potentially bridge and recruit immunocytes into tumor microenvironments for killing effects on cancer cells. | Novel, tumor-specific drugs are urgently needed for a breakthrough in cancer
therapy. Herein, we generated a first-in-class humanized antibody (PRL3-zumab)
against PRL-3, an intracellular tumor-associated phosphatase upregulated in
multiple human cancers, for unconventional cancer immunotherapies. We focused on
gastric cancer (GC), wherein elevated PRL-3 mRNA levels significantly correlated
with shortened overall survival of GC patients. PRL-3 protein was overexpressed
in 85% of fresh-frozen clinical gastric tumor samples examined but not in
patient-matched normal gastric tissues. Using human GC cell lines, we
demonstrated that PRL3-zumab specifically blocked PRL-3+, but not PRL-3-,
orthotopic gastric tumors. In this setting, PRL3-zumab had better therapeutic
efficacy as a monotherapy, rather than simultaneous combination with
5-fluorouracil or 5-fluorouracil alone. PRL3-zumab could also prevent PRL-3+
tumor recurrence. Mechanistically, we found that intracellular PRL-3 antigens
could be externalized to become "extracellular oncotargets" that serve as bait
for PRL3-zumab binding to potentially bridge and recruit immunocytes into tumor
microenvironments for killing effects on cancer cells. In summary, our results
document a comprehensive cancer therapeutic approach to specific
antibody-targeted therapy against the PRL-3 oncotarget as a case study for
developing antibodies against other intracellular targets in drug discovery. |
Which receptor is inhibited by Tivozanib? | Tivozanib is a selective inhibitor of vascular endothelial growth factor receptors (VEGFRs) 1, 2 and 3 tyrosine kinases. | PURPOSE: To assess the maximum tolerated dose (MTD)/dose-limiting toxicities
(DLT), safety, pharmacokinetics, and pharmacodynamics of tivozanib, a potent and
selective oral VEGF receptor (VEGFR) tyrosine kinase inhibitor.
EXPERIMENTAL DESIGN: Dose levels of 1.0, 1.5, and 2.0 mg/d tivozanib for 28 days
followed by 14 days of medication were explored in patients with advanced solid
tumors.
RESULTS: Forty-one patients were enrolled. Animal data incorrectly predicted
toxicity, resulting in DLTs at the starting dose (2.0 mg) consisting of grade 3
proteinuria and hypertension and grade 3 ataxia. At 1.0 mg, no DLT was observed.
At an intermediate dose (1.5 mg), 1 patient experienced DLT consisting of grade
3 hypertension. This dose was determined as the MTD. Of 10 additional patients
treated at 1.5 mg, 1 patient each experienced grade 3 hypertension and grade 3
fatigue, and 2 patients experienced grade 3 and 4 transaminase elevation. In 12
additional patients treated at 1.0 mg, no DLT was observed. Pharmacokinetics
displayed long absorption time, dose proportional exposure, and a half-life of
4.7 days. Plasma levels of VEGF-A and soluble VEGFR-2 showed dose-dependent
increases and decreases, respectively. Dynamic contrast-enhanced MRI indicated
reduction in tumor perfusion. Clinical activity was observed in renal cell
cancer, colorectal cancer, and other tumors.
CONCLUSION: Tivozanib was well tolerated with manageable side effects. The
pharmacokinetics profile revealed that tivozanib was suitable for once-daily
dosing. Encouraging and durable clinical activity was observed. The recommended
daily dose of tivozanib in a 4-week-on and 2-week-off dosing regimen is 1.5 mg. PURPOSE: The antitumor activity and safety of tivozanib, which is a potent and
selective vascular endothelial growth factor receptor-1, -2, and -3 inhibitor,
was assessed in patients with advanced/metastatic renal cell carcinoma (RCC).
PATIENTS AND METHODS: In this phase II, randomized discontinuation trial, 272
patients received open-label tivozanib 1.5 mg/d (one cycle equaled three
treatment weeks followed by a 1-week break) orally for 16 weeks. Thereafter, 78
patients who demonstrated ≥ 25% tumor shrinkage continued to take tivozanib, and
118 patients with less than 25% tumor change were randomly assigned to receive
tivozanib or a placebo in a double-blind manner; patients with ≥ 25% tumor
growth were discontinued. Primary end points included safety, the objective
response rate (ORR) at 16 weeks, and the percentage of randomly assigned
patients who remained progression free after 12 weeks of double-blind treatment;
secondary end points included progression-free survival (PFS).
RESULTS: Of 272 patients enrolled onto the study, 83% of patients had clear-cell
histology, 73% of patients had undergone nephrectomy, and 54% of patients were
treatment naive. The ORR after 16 weeks of tivozanib treatment was 18% (95% CI,
14% to 23%). Of the 118 randomized patients, significantly more patients who
were randomly assigned to receive double-blind tivozanib remained progression
free after 12 weeks versus patients who received the placebo (49% v 21%; P =
.001). Throughout the study, the ORR was 24% (95% CI, 19% to 30%), and the
median PFS was 11.7 months (95% CI, 8.3 to 14.3 months) in the overall study
population. The most common grade 3 and 4 treatment-related adverse event was
hypertension (12%).
CONCLUSION: Tivozanib was active and well tolerated in patients with advanced
RCC. These data support additional development of tivozanib in advanced RCC. INTRODUCTION: Tivozanib is a novel tyrosine kinase inhibitor (TKI) which
inhibits vascular endothelial growth factor (VEGF) receptors-1, -2, and -3 at
omolar concentrations.
AREAS COVERED: A comprehensive MEDLINE and American Society of Clinical Oncology
abstract search was performed to gather all relevant clinical and translational
data related to tivozanib. We discuss pre-clinical studies associated with
tivozanib, and the results of a Phase I assessment in advanced solid tumors. We
highlight combination studies with tivozanib, including pairings of tivozanib
with cytotoxic therapy in patients with colorectal cancer and breast cancer. A
randomized discontinuation Phase II study and a randomized Phase III study
assessing the activity of tivozanib in metastatic renal cell carcinoma (mRCC)
are described in detail.
EXPERT OPINION: Tivozanib will face the challenge of entering an already crowded
therapeutic space in mRCC-emerging combination studies and biomarker assessments
may distinguish this agent among other VEGF-TKIs. The current review will
outline the development pathway of tivozanib to date, and offer lessons learned
and future opportunities. Tivozanib hydrochloride monohydrate (tivozanib; formerly KRN-951, AV-951) is a
potent pan-VEGF receptor tyrosine kinase inhibitor. The biological activity of
tivozanib seems to outstand that of other VEGF tyrosine kinase inhibitors. In
Phase I studies, observed side effects are generally mild, with hypertension
being the most common adverse event. In single-agent Phase II and III studies in
patients with advanced or metastatic renal cell carcinoma, tivozanib has
demonstrated convincing clinical activity. Further clinical trials of tivozanib
combined with various cytotoxic drug regimens as well as other classes of
target-specific anticancer agents (e.g., mTOR inhibitors) for other indications
are underway. Tivozanib has not yet been approved for regular use. Tivozanib is a potent and selective inhibitor of vascular endothelial growth
factor receptor (VEGFR) tyrosine kinases. A previous clinical trial in the EU
and USA indicated that tivozanib at the maximum tolerated dose of 1.5 mg/day
showed an antitumor activity in patients with renal cell carcinoma. This
Japanese phase I study was designed to determine the recommended phase II dose
of tivozanib for Japanese patients; secondary objectives included
pharmacokinetic/pharmacodynamic profiles and preliminary efficacy. Daily
treatment with tivozanib in a 3-weeks-on/1-week-off cycle was examined in nine
Japanese patients with advanced solid tumors in the 3 + 3 design (Level 1, 1.0
mg; Level 2, 1.5 mg). No dose-limiting toxicity was observed throughout the
study, and the maximum tolerated dose was not reached. The most commonly
observed drug-related adverse events were diarrhea, dysphonia, rash, thyroid
stimulating hormone increase, and with severity grade ≥3, hand-foot skin
reaction, hypertension, and proteinuria. Those adverse events were generally
well-manageable and mostly resolved within the tolerability evaluation period.
Serum exposure to tivozanib resulted in t1/2 of more than >60 h. Increase of
plasma VEGF and decrease of plasma VEGFR-1 and VEGFR-2 were observed 1-3 weeks
after tivozanib treatment. Although no complete or partial response was
observed, long-term stable disease continuing more than 170 days was observed in
three renal cell carcinoma patients who had failed prior VEGFR inhibitors. In
conclusion, 1.5 mg/day of tivozanib in a 3-weeks-on/1-week-off setting was
tolerable in Japanese patients, and was recommended for further clinical trials
in the Japanese population. Clinical trial Registration No: JapicCTI-090854. PURPOSE: Tivozanib is a potent and selective tyrosine kinase inhibitor of
vascular endothelial growth factor receptor 1 (VEGFR1), -2, and -3. This phase
III trial compared tivozanib with sorafenib as initial targeted therapy in
patients with metastatic renal cell carcinoma (RCC).
PATIENTS AND METHODS: Patients with metastatic RCC, with a clear cell component,
prior nephrectomy, measurable disease, and 0 or 1 prior therapies for metastatic
RCC were randomly assigned to tivozanib or sorafenib. Prior VEGF-targeted
therapy and mammalian target of rapamycin inhibitor were not permitted. The
primary end point was progression-free survival (PFS) by independent review.
RESULTS: A total of 517 patients were randomly assigned to tivozanib (n = 260)
or sorafenib (n = 257). PFS was longer with tivozanib than with sorafenib in the
overall population (median, 11.9 v 9.1 months; hazard ratio [HR], 0.797; 95% CI,
0.639 to 0.993; P = .042). One hundred fifty-six patients (61%) who progressed
on sorafenib crossed over to receive tivozanib. The final overall survival (OS)
analysis showed a trend toward longer survival on the sorafenib arm than on the
tivozanib arm (median, 29.3 v 28.8 months; HR, 1.245; 95% CI, 0.954 to 1.624; P
= .105). Adverse events (AEs) more common with tivozanib than with sorafenib
were hypertension (44% v 34%) and dysphonia (21% v 5%). AEs more common with
sorafenib than with tivozanib were hand-foot skin reaction (54% v 14%) and
diarrhea (33% v 23%).
CONCLUSION: Tivozanib demonstrated improved PFS, but not OS, and a
differentiated safety profile, compared with sorafenib, as initial targeted
therapy for metastatic RCC. AIM: This study aimed to investigate the mechanism of reversal of multidrug
resistance mediated by ABC transporters with tivozanib (AV-951 and KRN-951).
Tivozanib is a potent inhibitor of VEGF-1, -2 and -3 receptors.
MATERIALS & METHODS: ABCB1- and ABCG2-overexpressing cell lines were treated
with respective substrate antineoplastic agents in the presence or absence of
tivozanib.
RESULTS: The results indicate that tivozanib can significantly reverse
ABCB1-mediated resistance to paclitaxel, vinblastine and colchicine, as well as
ABCG2-mediated resistance to mitoxantrone, SN-38 and doxorubicin. Drug efflux
assays showed that tivozanib increased the intracellular accumulation of
substrates by inhibiting the ABCB1 and ABCG2 efflux activity. Furthermore, at a
higher concentration, tivozanib inhibited the ATPase activity of both ABCB1 and
ABCG2 and inhibited the photolabeling of ABCB1 or ABCG2.
CONCLUSION: We conclude that tivozanib at noncytotoxic concentrations has the
previously unknown activity of reversing multidrug resistance mediated by ABCB1
and ABCG2 transporters. BACKGROUND: Tivozanib hydrochloride (tivozanib) is a potent and selective
tyrosine kinase inhibitor of all 3 vascular endothelial growth factor receptors
with antitumor activity additive to 5-fluorouracil in preclinical models. This
study was conducted to determine maximum tolerated dose (MTD), dose-limiting
toxicities (DLTs), pharmacokinetics (PKs), and antitumor activity of escalating
doses of tivozanib with a modified (m)FOLFOX-6 (leucovorin, 5-fluorouracil
[5-FU], and 85 mg/kg(2) oxaliplatin) regimen in patients with advanced
gastrointestinal tumors.
PATIENTS AND METHODS: Tivozanib was administered orally once daily for 21 days
in 28-day cycles, with mFOLFOX-6 administered every 14 days. Patients were
allowed to continue tivozanib after discontinuation of mFOLFOX-6.
RESULTS: Thirty patients were assigned to tivozanib 0.5 mg (n = 9), 1.0 mg (n =
3), or 1.5 mg (n = 18) with mFOLFOX-6. Patients received a median of 5.2 (range,
0.03-26.9) months of tivozanib. DLTs were observed in 2 patients: Grade 3/4
transaminase level increases with tivozanib 0.5 mg, and Grade 3 dizziness with
tivozanib 1.5 mg. Other Grade 3/4 adverse events included hypertension (n = 8),
fatigue (n = 8), and neutropenia (n = 6). MTD for tivozanib with mFOLFOX-6 was
confirmed as 1.5 mg. No PK interactions between tivozanib and mFOLFOX-6 were
observed. One patient had an ongoing clinical complete response, 10 had a
partial response, and 11 obtained prolonged stable disease.
CONCLUSION: Tivozanib and mFOLFOX-6 is feasible and appears to be safe. The
recommended dose for tivozanib with mFOLFOX-6 is 1.5 mg/d. Observed clinical
activity merits further exploration in gastrointestinal tumors. Tivozanib is a potent and highly specific orally available, tyrosine kinase
inhibitor that targets vascular endothelial growth factor (VEGF) receptor-1,
VEGF receptor-2, and VEGF receptor-3 at very low concentrations with a long
half-life (4 days). After its promising activity in xenograft and preclinical
models, tivozanib was evaluated in early phase clinical trials in various solid
tumors. The phase III trial (TIVO-1) compared tivozanib with sorafenib in
metastatic clear cell renal cell carcinoma (RCC). Because of detrimental overall
survival (OS), Oncology Drug Advisory Committee (ODAC) voted against its
approval in RCC. Tivozanib is also being evaluated in various other solid tumors
like breast, gastrointestinal cancers, hepatocellular cancer, sarcomas, and
gynecological cancer. In BATON-CRC trial, low-serum neuropilin-1 (NRP-1) levels
were associated with better progression-free survival (PFS) in patients treated
with tivozanib. The NRP-1 will be evaluated as a biomarker for tivozanib
response in future clinical trials. Ongoing clinical trial will further
characterize activity of tivozanib in hepatocellular carcinoma, sarcomas, and
gynecologic cancers. Tivozanib is a potent and selective tyrosine kinase inhibitor of vascular
endothelial growth factor receptor-1(VEGFR1), -2(VEGFR2), and -3(VEGFR3). Analog
of Tivozanib with deuterium-for-hydrogen replacement in metabolically active
site was prepared and evaluated in vitro. Compared to its prototype, deuterated
Tivozanib compound HC-1144 retained in vitro activity against VEGFR tyrosine
kinases. In vivo pharmacokinetic studies indicated HC-1144 clearly altered the
blood circulation behavior, which was proved by significantly prolonged blood
circulation half life time (t1/2) and increased AUC0-∞. Therefore, HC-1144 has
the potential to be a novel inhibitor against VEGFR tyrosine kinases with
long-acting plasma exposure. Targeting tumor angiogenesis is a potential therapeutic strategy for
glioblastoma because of its high vascularization. Tivozanib is an oral pan-VEGF
receptor tyrosine kinase inhibitor that hits a central pathway in glioblastoma
angiogenesis. We conducted a phase II study to test the effectiveness of
tivozanib in patients with recurrent glioblastoma. Ten adult patients were
enrolled and treated with tivozanib 1.5 mg daily, 3 weeks on/1 week off in
28-day cycles. Brain MRI and blood biomarkers of angiogenesis were performed at
baseline, within 24-72 h of treatment initiation, and monthly thereafter.
Dynamic contrast enhanced MRI, dynamic susceptibility contrast MRI, and vessel
architecture imaging were used to assess vascular effects. Resting state MRI was
used to assess brain connectivity. Best RANO criteria responses were: 1 complete
response, 1 partial response, 4 stable diseases, and 4 progressive disease (PD).
Two patients were taken off study for toxicity and 8 patients were taken off
study for PD. Median progression-free survival was 2.3 months and median overall
survival was 8.1 months. Baseline abnormal tumor vascular permeability, blood
flow, tissue oxygenation and plasma sVEGFR2 significantly decreased and plasma
PlGF and VEGF increased after treatment, suggesting an anti-angiogenic effect of
tivozanib. However, there were no clear structural changes in vasculature as
vessel caliber and enhancing tumor volume did not significantly change. Despite
functional changes in tumor vasculature, tivozanib had limited anti-tumor
activity, highlighting the limitations of anti-VEGF monotherapy. Future studies
in glioblastoma should leverage the anti-vascular activity of agents targeting
VEGF to enhance the activity of other therapies. Epithelial ovarian cancer (EOC) is the most fatal gynaecological maligcy.
Despite initial therapeutic response, the majority of advanced-stage patients
relapse and succumb to chemoresistant disease. Overcoming drug resistance is the
key to successful treatment of EOC. Members of vascular endothelial growth
factor (VEGF) family are overexpressed in EOC and play key roles in its
maligt progression though their contribution in development of the
chemoresistant disease remains elusive. Here we show that expression of the VEGF
family is higher in therapy-resistant EOC cells compared to sensitive ones.
Overexpression of VEGFR2 correlated with resistance to cisplatin and combination
with VEGFR2-inhibitor apatinib synergistically increased cisplatin sensitivity.
Tivozanib, a pan-inhibitor of VEGF receptors, reduced proliferation of the
chemoresistant EOC cells through induction of G2/M cell cycle arrest and
apoptotic cell death. Tivozanib decreased invasive potential of these cells,
concomitant with reduction of intercellular adhesion molecule-1 (ICAM-1) and
diminishing the enzymatic activity of urokinase-type plasminogen activator (uPA)
and matrix metalloproteinase-2 (MMP-2). Moreover, tivozanib synergistically
enhanced anti-tumour effects of EGFR-directed therapies including erlotinib.
These findings suggest that the VEGF pathway has potential as a therapeutic
target in therapy-resistant EOC and VEGFR blockade by tivozanib may yield
stronger anti-tumour efficacy and circumvent resistance to EGFR-directed
therapies. Tivozanib (Fotivda®) is an oral, potent and highly selective vascular
endothelial growth factor receptor (VEGFR) inhibitor that has been approved in
the EU, Iceland and Norway for the first-line treatment of adult patients with
advanced renal cell carcinoma (RCC) and for adult patients who are VEGFR and
mammalian target of rapamycin (mTOR) pathway inhibitor-naive following disease
progression after one prior treatment with cytokine therapy for advanced RCC.
Tivozanib is at various stages of development in other countries for advanced
RCC and advanced solid tumours. This article summarizes the milestones in the
development of tivozanib leading to this first global approval in Europe for the
treatment of adults with advanced RCC. BACKGROUND: Tivozanib is a selective inhibitor of vascular endothelial growth
factor receptors 1, 2 and 3 tyrosine kinases. This open-label, crossover
clinical study (AV-951-09-902) provided access to tivozanib for patients who
progressed on sorafenib in TIVO-1, comparing tivozanib with sorafenib in
patients with advanced renal cell carcinoma (RCC).
METHODS: Patients enrolled in this single-arm, phase 2 crossover study were
previously randomised to sorafenib on TIVO-1, progressed and then crossed over
to tivozanib. Patients received tivozanib (1.5 mg/day orally; 3 weeks on/1 week
off) within 4 weeks after their last sorafenib dose.
FINDINGS: Crossover patients were exposed to tivozanib for a median of eight
cycles. From the start of tivozanib treatment, median progression-free survival
was 11.0 months (95% confidence interval [CI]: 7.3-12.7) and median overall
survival was 21.6 months (95% CI: 17.0-27.6). Best overall response was partial
response in 29 (18%) patients and stable disease in 83 (52%) patients, with a
median duration of response of 15.2 and 12.7 months, respectively. About 77% of
patients experienced adverse events, most frequently hypertension (26%),
followed by diarrhoea (14%) and fatigue (13%); 53% of patients had
treatment-related adverse events, including 24% grade ≥3. About 9% and 16% of
patients had dose reductions and dose interruptions due to adverse events,
respectively. A total of 30% of patients had serious adverse events, and 4% had
treatment-related serious adverse events.
INTERPRETATION: This crossover study of patients with advanced RCC demonstrated
potent tivozanib anti-tumour activity. Safety and tolerability profiles were
acceptable and consistent with the established adverse event profile of
tivozanib. The efficacy of VEGF-targeting therapies in clinical trials led to their
recommendation in clinical guidelines for use across the advanced or metastatic
renal cell carcinoma (RCC) treatment landscape, however, tolerability (including
off-target effects) has remained a challenge. Tivozanib is a selective inhibitor
of all three VEGFRs, with limited off-target interaction, which demonstrates
efficacy with improved tolerability relative to multikinase VEGFR-TKIs. Areas
covered: Covered here is the clinical development of tivozanib in advanced RCC,
including the pivotal Phase III, multicenter, open-label, randomized clinical
study comparing tivozanib with sorafenib for the treatment of VEGF- and mTOR
therapy-naïve advanced RCC patients. Also covered are ongoing trials, exploring
the efficacy and safety of tivozanib in the setting of refractory disease and
the utility of tivozanib in combination with checkpoint inhibitors for advanced
RCC. Combination of a VEGFR-TKI and immunotherapy is promising in advanced RCC,
if the treatment regimens have acceptable tolerability. Here the selectivity of
tivozanib may contribute to an acceptable tolerability profile when used in
combination therapy. Expert commentary: The approval of tivozanib provides an
additional option for the first-line treatment of advanced or metastatic RCC
patients in Europe and allows use of a VEGFR-TKI with selectivity for VEGFRs in
this setting. |
Can discharge destinations be accurately predicted using the Risk Assessment and Prediction Tool (RAPT)? | Yes. The Risk Assessment and Prediction Tool (RAPT) appears to be a valuable predictor of discharge destination after orthopedic surgery and neurosurgical procedures. | OBJECTIVE: To assess the relevance of the RAPT (Risk Assessment and Prediction
Tool), among a cohort of patients undergoing total hip arthroplasty (THA).
METHOD: Prospective study of a cohort of patients evaluated before and after
THA. The difference between the postoperative orientation predicted by the RAPT
and the real one is assessed. Clinical, environmental and psychosocial criteria
that could significantly change the orientation are discussed.
RESULTS: One hundred and thirty-four patients (94 women and 40 men) were
included. The average age was 71.6 (±10) years. Primary hip osteoarthritis was
the indication for surgery in 78% of cases. The average length of stay in the
surgery ward was 10 (±3) days. It was significantly higher for patients referred
to a rehabilitation ward (P<0.0001). Sixty-six percent of patients were referred
to a rehabilitation ward and 34% returned directly home. The average length of
stay in rehabilitation ward was 27 (±13) days. The validity of the RAPT as a
help decision tool has been confirmed. Thus, a low RAPT score was significantly
associated with more frequent referral to a rehabilitation ward, conversely, a
high RAPT score is significantly related to more frequent direct return to home.
CONCLUSION: This study confirmed the usefulness of the RAPT to help in patient
orientation decision after total hip arthroplasty. The patient preference
remains the main variable for orientation after THA. By the way, the patient
preference must not be integrated into the RAPT, but need to be collected and be
discussed with the patient. BACKGROUND: Payers of health services and policymakers place a major focus on
cost containment in health care. Studies have shown that early planning of
discharge is essential in reducing length of stay and achieving ficial
benefit; tools that can help predict discharge disposition would therefore be of
use. The Risk Assessment and Prediction Tool (RAPT) is a preoperative survey
constructed to predict discharge disposition after total joint arthroplasty
(TJA). The RAPT was developed and tested on a population of Australian patients
undergoing joint replacement, but its validity in other populations is unknown.
A low RAPT score is reported to indicate a high risk of needing any form of
inpatient rehabilitation after TJA, including short-term nursing facilities.
QUESTIONS/PURPOSES: This study attempts (1) to assess predictive accuracy of the
RAPT on US patients undergoing total hip and knee arthroplasty (THA/TKA); and
(2) to determine predictive accuracy of each individual score (1-12).
METHODS: Between June 2006 and December 2011, RAPT scores of 3213 patients (1449
THAs; 1764 TKAs) were prospectively captured during the preoperative clinical
visit. Scores were stored along with other clinical data, including discharge
disposition, in a dedicated database on a secure server. The database was
queried by the nursing case manager to retrieve the RAPT scores of all patients
captured during this time period. Binary logistic regression was used to analyze
the scores and determine predictive accuracy.
RESULTS: Overall predictive accuracy was 78%. RAPT scores<6 and >10 (of 12)
predicted with >90% accuracy discharge to inpatient rehabilitation and home,
respectively. Predictive accuracy was lowest for scores between 7 and 10 at
65.2% and almost 50% of patients received scores in this range. Based on our
findings, the risk categories in our populations should be high risk<7,
intermediate risk 7 to 10, and low risk>10.
CONCLUSIONS: The RAPT accurately predicted discharge disposition for high- and
low-risk patients in our cohort. Based on our data, intermediate-risk patients
should be defined as those with scores of 7 to 10. Predictive accuracy for these
patients could potentially be improved through the identification and addition
of other factors correlated to discharge disposition. The RAPT allows for
identification of patients who are likely to be discharged home or to
rehabilitation, which may facilitate preoperative planning of postoperative
care. Additionally, it identifies intermediate-risk patients and could be used
to implement targeted interventions to facilitate discharge home in this group
of patients.
LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors
for a complete description of levels of evidence. PURPOSE: The aim of this study was to evaluate the value of conventional
factors, the Risk Assessment and Predictor Tool (RAPT) and performance-based
functional tests as predictors of delayed recovery after total hip arthroplasty
(THA).
METHOD: A prospective cohort study in a regional hospital in the Netherlands
with 315 patients was attending for THA in 2012. The dependent variable recovery
of function was assessed with the Modified Iowa Levels of Assistance scale.
Delayed recovery was defined as taking more than 3 days to walk independently.
Independent variables were age, sex, BMI, Charnley score, RAPT score and scores
for four performance-based tests [2-minute walk test, timed up and go test
(TUG), 10-meter walking test (10 mW) and hand grip strength].
RESULTS: Regression analysis with all variables identified older age (>70
years), Charnley score C, slow walking speed (10 mW >10.0 s) and poor functional
mobility (TUG >10.5 s) as the best predictors of delayed recovery of function.
This model (AUC 0.85, 95% CI 0.79-0.91) performed better than a model with
conventional factors and RAPT scores, and significantly better (p = 0.04) than a
model with only conventional factors (AUC 0.81, 95% CI 0.74-0.87).
CONCLUSIONS: The combination of performance-based tests and conventional factors
predicted inpatient functional recovery after THA.
IMPLICATIONS FOR REHABILITATION: Two simple functional performance-based tests
have a significant added value to a more conventional screening with age and
comorbidities to predict recovery of functioning immediately after total hip
surgery. Patients over 70 years old, with comorbidities, with a TUG score >10.5
s and a walking speed >1.0 m/s are at risk for delayed recovery of functioning.
Those high risk patients need an accurate discharge plan and could benefit from
targeted pre- and postoperative therapeutic exercise programs. BACKGROUND: Bundled care payments are increasingly being explored for
neurosurgical interventions. In this setting, skilled nursing facility (SNF) is
less desirable from a cost perspective than discharge to home, underscoring the
need for better preoperative prediction of postoperative disposition.
OBJECTIVE: To assess the capability of the Risk Assessment and Prediction Tool
(RAPT) and other preoperative variables to determine expected disposition prior
to surgery in a heterogeneous neurosurgical cohort, through observational study.
METHODS: Patients aged 50 yr or more undergoing elective neurosurgery were
enrolled from June 2016 to February 2017 (n = 623). Logistic regression was used
to identify preoperative characteristics predictive of discharge disposition.
Results from multivariate analysis were used to create novel grading scales for
the prediction of discharge disposition that were subsequently compared to the
RAPT Score using Receiver Operating Characteristic analysis.
RESULTS: Higher RAPT Score significantly predicted home disposition (P < .001).
Age 65 and greater, dichotomized RAPT walk score, and spinal surgery below L2
were independent predictors of SNF discharge in multivariate analysis. A grading
scale utilizing these variables had superior discriminatory power between SNF
and home/rehab discharge when compared with RAPT score alone (P = .004).
CONCLUSION: Our analysis identified age, lower lumbar/lumbosacral surgery, and
RAPT walk score as independent predictors of discharge to SNF, and demonstrated
superior predictive power compared with the total RAPT Score when combined in a
novel grading scale. These tools may identify patients who may benefit from
expedited discharge to subacute care facilities and decrease inpatient hospital
resource utilization following surgery. BACKGROUND: The Risk Assessment and Prediction Tool (RAPT) is used to predict
patient discharge disposition after total joint arthroplasty. Following a
comprehensive, multidisciplinary redesign, our institution noticed a trend
toward home discharge in patients with RAPT scores that historically predicted
discharge to acute care facilities, presenting an opportunity to redefine the
predictive ranges for RAPT.
METHODS: Retrospectively collected data were analyzed from a single institution
in patients undergoing elective primary total joint arthroplasty from January
2016 to April 2017. Predictive accuracy (PA) was calculated for each RAPT score
(1-12), RAPT score risk ranges (low, intermediate, and high), as well as
overall. Other factors evaluated included patient-reported discharge
expectation, body mass index, and American Society of Anesthesiologists scores
as related to discharge disposition and the PA of RAPT.
RESULTS: Overall PA of RAPT was 88% (n = 1024 patients). Patients were high risk
for acute care facility with a RAPT score of 1 to 3 (PA ≥ 83%), intermediate
risk 4 to 7 (PA, 52%-79%), and low risk 8 to 12 (PA ≥ 89%). In multivariable
analysis, RAPT score and patient-reported discharge expectation had the
strongest correlation with actual discharge disposition.
CONCLUSION: Our multidisciplinary redesign has impacted the PA of RAPT. The
original predictive ranges should be modified to reflect the increasing
proportion of patients being discharged home following elective arthroplasty
procedures. We have identified patient-expected discharge destination as a
powerful modulator of the RAPT score and suggest that it be taken into
consideration for discharge planning. |
What is Perturb-seq? | Perturb-seq is a technique that combines single-cell RNA sequencing (RNA-seq) and clustered regularly interspaced short palindromic repeats (CRISPR)-based perturbations to perform many such assays in a pool. Perturb-seq accurately identifies individual gene targets, gene signatures, and cell states affected by individual perturbations and their genetic interactions. By decomposing many high content measurements into the effects of perturbations, their interactions, and diverse cell metadata, Perturb-seq dramatically increases the scope of pooled genomic assays. | Author information:
(1)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Harvard-MIT
Division of Health Sciences and Technology, Cambridge, MA 02139, USA.
(2)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
(3)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of
Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
(4)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Computational
and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02140,
USA.
(5)Department of Cellular and Molecular Pharmacology, California Institute of
Quantitative Biosciences, Center for RNA Systems Biology, University of
California, San Francisco, San Francisco, CA 94158, USA.
(6)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of
Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Department of
Biology, Massachusetts Institute of Technology, Cambridge, MA 02140, USA.
(7)Department of Cellular and Molecular Pharmacology, California Institute of
Quantitative Biosciences, Center for RNA Systems Biology, University of
California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical
Institute, Chevy Chase, MD 20815, USA.
(8)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; School of
Engineering and Computer Science and Institute of Life Sciences, The Hebrew
University of Jerusalem, Jerusalem 91904, Israel.
(9)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of
Biology, Massachusetts Institute of Technology, Cambridge, MA 02140, USA; Howard
Hughes Medical Institute, Chevy Chase, MD 20815, USA. Electronic address:
[email protected]. |
What is the content of the REPAIRtoire database? | The REPAIRtoire database collects and organizes the following types of information: (i) DNA damage linked to environmental mutagenic and cytotoxic agents, (ii) pathways comprising individual processes and enzymatic reactions involved in the removal of damage, (iii) proteins participating in DNA repair and (iv) diseases correlated with mutations in genes encoding DNA repair proteins. REPAIRtoire provides also links to publications and external databases. | REPAIRtoire is the first comprehensive database resource for systems biology of
DNA damage and repair. The database collects and organizes the following types
of information: (i) DNA damage linked to environmental mutagenic and cytotoxic
agents, (ii) pathways comprising individual processes and enzymatic reactions
involved in the removal of damage, (iii) proteins participating in DNA repair
and (iv) diseases correlated with mutations in genes encoding DNA repair
proteins. REPAIRtoire provides also links to publications and external
databases. REPAIRtoire contains information about eight main DNA damage
checkpoint, repair and tolerance pathways: DNA damage signaling, direct reversal
repair, base excision repair, nucleotide excision repair, mismatch repair,
homologous recombination repair, nonhomologous end-joining and translesion
synthesis. The pathway/protein dataset is currently limited to three model
organisms: Escherichia coli, Saccharomyces cerevisiae and Homo sapiens. The DNA
repair and tolerance pathways are represented as graphs and in tabular form with
descriptions of each repair step and corresponding proteins, and individual
entries are cross-referenced to supporting literature and primary databases.
REPAIRtoire can be queried by the name of pathway, protein, enzymatic complex,
damage and disease. In addition, a tool for drawing custom DNA-protein complexes
is available online. REPAIRtoire is freely available and can be accessed at
http://repairtoire.genesilico.pl/. |
Has amantadine ER been approved by the FDA? | Yes, amantadine ER is an US FDA-approved treatment. | BACKGROUND: Although levodopa is considered the most effective pharmacotherapy
for motor symptoms of Parkinson's disease (PD), chronic use is associated with
motor complications, including fluctuating response and unpredictable,
involuntary movements called dyskinesia. ADS-5102 (amantadine) extended-release
(ER) capsules (GOCOVRITM) is a recent US FDA-approved treatment for dyskinesia
in PD patients. ADS-5102 is a high-dose, ER formulation of amantadine,
administered orally once daily at bedtime, that achieves high plasma drug
concentrations throughout the day.
OBJECTIVE: In this study, we present pooled results from two randomized,
double-blind, placebo-controlled, phase III ADS-5102 trials.
PATIENTS AND METHODS: The two studies in PD patients with dyskinesia shared
design and eligibility criteria, differing only in treatment duration. Results
from common assessment time points were pooled.
RESULTS: At 12 weeks, the least squares (LS) mean change in total score on the
Unified Dyskinesia Rating Scale among 100 patients randomized to ADS-5102 and 96
patients randomized to placebo was - 17.7 (standard error [SE] 1.3) vs. - 7.6
(1.3) points, respectively (- 10.1 points, 95% confidence interval [CI] - 13.8,
- 6.5; p < 0.0001). The relative treatment difference between groups was 27.3%
(p < 0.0001). At 12 weeks, the LS mean change in OFF time was - 0.59 (0.21) vs.
+0.41 (0.20) h/day, a difference of - 1.00 h/day (95% CI - 1.57, - 0.44;
p = 0.0006). For both efficacy measures, a significant difference from placebo
was attained by two weeks, the first post-baseline assessment, and was
maintained throughout 12 weeks. In the pooled ADS-5102 group, the most common
adverse events were hallucination, dizziness, dry mouth, peripheral edema,
constipation, falls, and orthostatic hypotension.
CONCLUSIONS: These analyses provide further evidence supporting ADS-5102 as an
adjunct to levodopa for treating both dyskinesia and OFF time in PD patients
with dyskinesia. Clinicaltrials.gov identifier: NCT02136914 and NCT02274766. |
Can PRL3-zumab inhibit PRL3+ cancer cells in vitro and in vivo? | PRL3-zumab specifically inhibits PRL3+ cancer cells in vivo, but not in vitro. | |
How rare are CTCs (circulating tumour cells) in the plasma of patients? | Circulating tumour cells (CTCs) are significantly rare entity in the blood of patients with non-small cell lung cancer (NSCLC) patients as well as in other types of cancer. Small-cell lung cancer cells are typically quiescent, whereas CTCs can be up-regulated in response to radiation or chemical agents and may contribute to tumorigenesis as an endogenous red cell marker. | The enumeration of circulating tumor cells has long been regarded as an
attractive diagnostic tool, as circulating tumor cells are thought to reflect
aggressiveness of the tumor and may assist in therapeutic decisions in patients
with solid maligcies. However, implementation of this assay into clinical
routine has been cumbersome, as a validated test was not available until
recently. Circulating tumor cells are rare events which can be detected
specifically only by using a combination of surface and intracellular markers,
and only recently a number of technical advances have made their reliable
detection possible. Most of these new techniques rely on a combination of an
enrichment and a detection step. This review addresses the assays that have been
described so far in the literature, including the enrichment and detection steps
and the markers used in these assays. We have focused on breast cancer as most
clinical studies on CTC detection so far have been done in these patients. Circulating tumor cells (CTCs) served as an important biomarker for tumor
recurrence and prediction of prognosis. However, selective capture and
quantification of CTCs from whole blood was still full of challenge due to the
extremely scare number of CTCs. Moreover, how to keep a high cell viability
after capture remained to be solved. Here, we described a ratiometric
fluorescent probe for the efficient capture and accurate determination of CTCs
by conjugating graphitic carbon nitride quantum dots (g-CNQDs) with gold
oclusters (AuNCs) and further linking with anti-EpCAM antibody to acquire the
CTC-specific immune probe. In this probe, AuNCs protected by albumin V bovine
played the role as the fluorophore reference and anti-EpCAM-attached g-CNQDs
acted as both the response signal and specific recognition element for sensing
CTCs. In the presence of CTCs, the quenched fluorescence of the immune probe at
500 nm was recovered due to the detachment of anti-EpCAM from the probe, whereas
the intensity at 650 nm was essentially unchanged. This strategy realized the
highly sensitive detection of CTCs in whole blood down to one CTC. Furthermore,
it was demonstrated that the designed probe allowed capturing living CTCs with
minimal cell damage. The subsequent reculture of captured cells for
proliferation revealed that after a 7 day proliferation, almost 28 MCF-7 cells
were obtained from one target cell. The immune probe was successfully applied
into capture and detection of CTCs from clinical cancer patients. Our data
suggested the good potential of fluorescent probe for the clinical diagnosis of
cancers. This work demonstrated an effective strategy for the capture, identification and
determination of multiple types of circulating tumor cells (CTCs) on functional
and biocompatible immunomagnetic osphere interfaces (IMNs). The IMNs were
achieved by functionalizing superparamagnetic iron oxide ospheres (Fe3O4)
with polymerized ionic liquid (PIL), and then coating with
epithelial-cell-adhesion-molecule antibody (anti-EpCAM). The IMNs exhibited
outstanding cell capture efficiency (above 95%) and specificity when employed to
separate multiple EpCAM-positive tumor cells, due to the abundant carboxyl
groups in the structure of PIL, which enhanced the coupling efficiency of MNs
with anti-EpCAM by chemical bonding between carboxyls and amines, thereby
enabling more target cells adhered onto IMNs. Under the optimized capture
conditions, IMNs were shown an excellent cell capture performance in the range
of 5-400 cells/mL in three different cases (e.g., PBS, MCF-7 and THP-1 mixed
cell suspension, lysed blood). More significantly, our results indicated that
with modification of PIL, in addition to the capture efficiency, the cell
viability rate of CTCs was also greatly improved (98%) owing to the nontoxic and
biocompatible properties of PIL, which realized the proliferation of the rare
number CTCs for further molecular characterization. Finally, the IMNs were
successfully applied to the isolation and detection of CTCs in cancer patient
peripheral blood samples and as low as one CTC in the whole blood was captured
and identified by the ICC method. |
What is gamma sterilization used for? | Gamma sterilization of bone allografts is used as a gold standard method to provide safety against disease transmission. Also, gamma (g)-sterilization has been commonly employed for wide range of products as indicated by the pharmacopoeias. | The long-term clinical success of autologous vein and synthetic vascular grafts
are limited because of the development of anastomotic intimal hyperplasia (IH).
We have previously published data suggesting that cyclosporine (CyA) may reduce
the development of IH in a canine model (Hirko et al., J Vasc Surg
1993;17:877-887). However, systemic administration of CyA could create serious
adverse effects. Therefore, it is our long-term goal to test the hypothesis that
the controlled local release of CyA from a polymeric vascular wrap would prevent
the development of IH. To test this hypothesis, we developed a controlled
release polymeric ring that could be placed around anastomotic sites to deliver
therapeutic drugs locally. The ring is a composite polymeric device consisting
of poly(DL-lactide-co-glycolide) (PLGA) microspheres embedded in a poly(ethylene
glycol) hydrogel. Several in vitro studies were conducted to evaluate the
effects of different sterilization procedures on the properties of the device.
It was determined that gamma sterilization was the preferred sterilization
method of choice for this device. In vivo studies were conducted on a swine
model to evaluate the biocompatibility of the ring. The histological findings of
the ring implants at 2 and 4 weeks demonstrate the biocompatibility of this
device. Gamma sterilization is usually used to minimize the risk of infection
transmission through bone allografts. However, it is believed that gamma
irradiation affects the mechanical properties of allografts and free radical
scavengers can be used to alleviate the radiation-induced degradation of these
properties. The aim of this study was to investigate the radioprotective effects
of N-Acetyl-L-Cysteine (NAC) free radical scavenger on the material properties
of sterilized bovine cortical bone at microstructure level. Forty-two cortical
tissue specimens were excised from three bovine femurs and irradiated to 35 and
70 kGy gamma rays in the presence of 5, 50, and 100 mM concentrations of NAC.
The localized variations in microhardness were evaluated via indentation in the
radial and longitudinal directions to examine different regions of the
microstructures of the specimens, including the osteonal and interstitial
tissues. A significant increase was observed in the hardness of osteonal,
interstitial, and longitudinal combined microstructures exposed to 35 and 70 kGy
radiations (P < 0.05), whereas a relative reduction of the hardness was observed
in the radial direction. Furthermore, it was found that the application of 50
and 100 mM NAC during gamma irradiation significantly subsided the hardening in
longitudinal combined microstructure. Moreover, the reduction of hardness in
radial direction was suppressed in the presence of 100 mM of NAC. In conclusion,
the results indicated that NAC free radical scavenger can protect the cortical
bone against deteriorative effects of ionizing radiation and can be used to
improve the material properties of sterilized allografts. CONTEXT: There is a great necessity to find and use accomplished terminal
sterilization technique for industrial manufacturing, research and development
studies. Gamma (γ)-sterilization has been commonly employed for wide range of
products as indicated by the pharmacopoeias. However, carefully examination
should be performed prior to administration since γ-radiation can cause changes
in drug and polymer excipients. No information is available in literature about
γ-sterilization effects on vancomycin HCl-loaded poly (ɛ-caprolactone) (PCL)
microspheres.
OBJECTIVE: Formulations were developed using a different preparation approach
for the treatment of medical device-related osteomyelitis, and γ-sterilization
effects on the physicochemical characterization of the formulations were
examined.
METHODS: Water-in-oil-in-water (w/o/w) emulsion technique using polyvinyl
alcohol (PVA) in inner and outer phase was applied to prepare formulations.
Physicochemical properties of the formulations were investigated before and
after γ-sterilization and the antibacterial activity against Staphylococcus
aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) were
measured.
RESULTS: The particle size of the nonsterilized formulations were between 58 and
134 μm. 60% or 20% of vancomycin HCl were released from 42.500 Mn or
70.000-90.000 Mn PCL microspheres, respectively, in 24 h. No difference was
observed in the particle size, drug-loading efficiency, morphology, in vitro
release and antimicrobial activity of the formulations after γ-sterilization
(p > 0.05). |
Does Estrogen lead to forkhead FoxA1 activation? | The pioneer transcription factor FoxA1 plays an important role in estrogen signaling by opening closed chromatin and promoting recruitment of the estrogen receptor to its target regions in DNA. | Estrogen plays an essential physiologic role in reproduction and a pathologic
one in breast cancer. The completion of the human genome has allowed the
identification of the expressed regions of protein-coding genes; however, little
is known concerning the organization of their cis-regulatory elements. We have
mapped the association of the estrogen receptor (ER) with the complete
nonrepetitive sequence of human chromosomes 21 and 22 by combining chromatin
immunoprecipitation (ChIP) with tiled microarrays. ER binds selectively to a
limited number of sites, the majority of which are distant from the
transcription start sites of regulated genes. The unbiased sequence
interrogation of the genuine chromatin binding sites suggests that direct ER
binding requires the presence of Forkhead factor binding in close proximity.
Furthermore, knockdown of FoxA1 expression blocks the association of ER with
chromatin and estrogen-induced gene expression demonstrating the necessity of
FoxA1 in mediating an estrogen response in breast cancer cells. Transcription activation by estrogen receptor (ER) is rapid and dynamic. How the
prompt and precise ER response is established and maintained is still not fully
understood. Here, we report that two boundary elements surrounding the well
defined ERalpha target TFF1 locus are occupied by the CCCTC-binding factor
(CTCF). These elements are separated by 40 kb but cluster in the nuclear space
depending on CTCF but independent of estrogen and transcription. In contrast, in
estrogen non-responsive breast cancer cells, the spatial proximity of these two
elements is lost and the entire locus instead displays a polycomb repressive
complex 2-controlled heterochromatin characteristic. We showed that CTCF acts
upstream of the "pioneer" factor FOXA1 in determining the genomic response to
estrogen. We propose that the CTCF-bound boundary elements demarcate active
versus inactive regions, building a framework of adjacent chromosome territory
that predisposes ERalpha-regulated transcription. Estrogen receptor-α (ER) is the key feature of most breast cancers and binding
of ER to the genome correlates with expression of the Forkhead protein FOXA1
(also called HNF3α). Here we show that FOXA1 is a key determit that can
influence differential interactions between ER and chromatin. Almost all
ER-chromatin interactions and gene expression changes depended on the presence
of FOXA1 and FOXA1 influenced genome-wide chromatin accessibility. Furthermore,
we found that CTCF was an upstream negative regulator of FOXA1-chromatin
interactions. In estrogen-responsive breast cancer cells, the dependency on
FOXA1 for tamoxifen-ER activity was absolute; in tamoxifen-resistant cells, ER
binding was independent of ligand but depended on FOXA1. Expression of FOXA1 in
non-breast cancer cells can alter ER binding and function. As such, FOXA1 is a
major determit of estrogen-ER activity and endocrine response in breast
cancer cells. Chromatin immunoprecipitation followed by massively parallel sequencing
(ChIP-seq) is rapidly enabling the comprehensive characterization of genome-wide
transcription factor-binding sites, thus defining the cistrome (cis-acting DNA
targets of a trans-acting factor). Estrogen receptor (ER) ChIP-seq studies have
been performed mainly in cell lines, but Ross-Innes and colleagues have now
completed the first such study in clinical breast cancer samples. The study
aimed at determining the dynamics of ER binding and differences between more and
less aggressive primary breast tumors and metastases. The authors found that ER
bound to DNA in both aggressive and drug-resistant tumors but to different sites
and with different affinities. Given previous findings from cell lines, FoxA1
appears to play a critical role in this reprogramming of ER binding. BACKGROUND: Recent studies have indicated that the response to chemotherapy and
the prognostic impact of a pathological complete response (pCR) after
neoadjuvant chemotherapy differ among breast cancer subtypes. Predictors of
response to chemotherapy and prognostic factors for survival might be different
in estrogen receptor (ER)-positive breast cancer.
METHODS: Women with Stage II to III ER-positive HER2-negative breast cancer
treated with anthracycline and taxane-containing neoadjuvant chemotherapy
between 2003 and 2011 were retrospectively analyzed. Expression of forkhead box
A1 (FOXA1), B cell lymphoma 2 (BCL2) and microtubule-associated protein tau
(MAPT) as well as ER, progesterone receptor, HER2 and Ki67 was examined by
immunohistochemistry in pre- and post-treatment specimens. Factors predictive of
response to neoadjuvant chemotherapy and distant disease-free survival were
analyzed.
RESULTS: Tumor grade was positively correlated with Ki67 expression. Expression
levels of ER were positively correlated with expression levels of HER2, BCL2,
FOXA1 and MAPT in pre-treatment tumors. The Ki67 labeling index was the only
factor that was significantly associated with clinical response measured by the
reduction of tumor volume and pCR. Lymph node status, expression of ER before
neoadjuvant chemotherapy and expression of FOXA1 after neoadjuvant chemotherapy
were significantly associated with distant disease-free survival, both by
univariate and multivariate analyses.
CONCLUSIONS: Patients with ER-positive HER2-negative breast cancer should be
selected for neoadjuvant chemotherapy. FOXA1 expression could be a prognostic
marker in ER-positive breast cancer. PURPOSE: Most estrogen receptor (ER)-positive breast cancer responds poorly to
chemotherapy and no single cost-effective biomarker capable of selecting
chemosensitive ones has been found yet. We investigated FOXA1 for its role in
predicting chemosensitivity of this subgroup in neoadjuvant chemotherapy
settings.
METHODS: We reviewed pathologic slides of 123 patients who were diagnosed with
ER-positive breast cancer on core needle biopsy and underwent neoadjuvant
chemotherapy at our institution between 2002 and 2012. FOXA1 expression and
pathologic response were evaluated. We then statistically analyzed FOXA1
expression and its relationship with chemosensitivity.
RESULTS: FOXA1 expression before NAC was correlated with poor chemoresponse in
ER-positive as well as luminal A and luminal B breast cancer patients (p =
0.002, 0.001, and 0.049 respectively). Significant association between change of
FOXA1 staining position after NAC and chemosensitivity also was observed (p =
0.024). Multivariate analysis identified FOXA1 expression before NAC as an
independent predictor of chemosensitivity in ER-positive and luminal A breast
cancer patients [p = 0.002; relative risk (RR) 0.163; 95 % confidence interval
(CI) 0.053-0.500, and p = 0.002; RR 0.055; 95 % CI 0.008-0.353, respectively].
Additionally, change of FOXA1 staining position after NAC was shown to be an
independent predictor of chemoresponse in luminal B subtype breast cancer
patients (p = 0.012; RR 0.153; 95 % CI 0.035-0.665).
CONCLUSIONS: FOXA1 expression can independently predict chemosensitivity of
ER-positive breast cancer patients. |
What is detected by the UV-damaged DNA-binding protein (UV-DDB) complex? | Upon UV irradiation of primate cells, UV-DDB associates tightly with chromatin and is involved in global genomic nucleotide excision repair (NER) in mammalian cells. | Xeroderma pigmentosum (XP) is a heritable human disorder characterized by
defects in nucleotide excision repair (NER) and the development of skin cancer.
Cells from XP group E (XP-E) patients have a defect in the UV-damaged
DNA-binding protein complex (UV-DDB), involved in the damage recognition step of
NER. UV-DDB comprises two subunits, products of the DDB1 and DDB2 genes,
respectively. Mutations in the DDB2 gene account for the underlying defect in
XP-E. The UV-DDB complex is a component of the newly identified cullin 4A-based
ubiquitin E3 ligase, DDB1-CUL4A(DDB2). The E3 ubiquitin ligases recognize
specific substrates and mediate their ubiquitination to regulate protein
activity or target proteins for degradation by the proteasomal pathway. In this
study, we have addressed the role of the UV-DDB-based E3 in NER and sought a
physiological substrate. We demonstrate that monoubiquitinated histone H2A in
native chromatin coimmunoprecipitates with the endogenous DDB1-CUL4A(DDB2)
complex in response to UV irradiation. Further, mutations in DDB2 alter the
formation and binding activity of the DDB1-CUL4A(DDB2) ligase, accompanied by
impaired monoubiquitination of H2A after UV treatment of XP-E cells, compared
with repair-proficient cells. This finding indicates that DDB2, as the substrate
receptor of the DDB1-CUL4A-based ligase, specifically targets histone H2A for
monoubiquitination in a photolesion-binding-dependent manner. Given that the
loss of monoubiquitinated histone H2A at the sites of UV-damaged DNA is
associated with decreased global genome repair in XP-E cells, this study
suggests that histone modification, mediated by the XPE factor, facilitates the
initiation of NER. |
What is the current regulation of eye lens radiation exposure? | The reduction of the dose limit for eye lens from 150 to 20 mSv yr-1 must be implemented by EU member states by February 2018. Consequently, there is a requirement for all employers engaged with work with ionising radiation to have appropriate monitoring arrangements in place by this date to demonstrate that they can meet this new limit for all workers. Eye lens dose is conventionally monitored by specific dosemeters worn near the eye.
The yearly ocular lens dose, particularly for interventionists dealing with complex interventions, could cross the permitted yearly limit set by the new Euratom directive. Therefore, X-ray safety glasses would become mandatory for complex radiological vascular interventions. | The reduction of the dose limit for eye lens from 150 to 20 mSv yr-1 must be
implemented by EU member states by February 2018. Consequently, there is a
requirement for all employers engaged with work with ionising radiation to have
appropriate monitoring arrangements in place by this date to demonstrate that
they can meet this new limit for all workers. Eye lens dose is conventionally
monitored by specific dosemeters worn near the eye. However, it is usually
impractical for these dosemeters to be worn at all times in the workplace which
can lead to problems accounting for any periods of work when an eye lens
dosemeter has not been worn. The Berkeley Approved Dosimetry Service provides a
monitoring service for 22 nuclear sites in the UK using active personal
dosemeters (APDs) for measuring H p(10) and H p(0.07). TLDs for extremity and
eye are also issued as appropriate for the working conditions. An analysis of
the data from 2007 to 2016 concludes that the values for H p(0.07) as monitored
indirectly by APDs worn on the trunk are comparable to the values assessed by
specific H p(3) eye TLDs. This paper sets out evidence that compliance with the
20 mSv dose limit for the eye lens can be demonstrated using routine issue APDs
although specific eye TLDs may still be required to meet international guidance
for non-uniform workplace fields. This evidence supports the recent statement
from International Radiation Protection Association that 'for the nuclear
industry and other non-medical sectors the use of a whole body dosimeter is
considered likely to be sufficient for the majority of workers'. PURPOSE: The annual permissible radiation ocular lens dose has been reduced to
20 millisieverts (mSv) in the current European directive 2013/59/Euratom. The
aim of this study was to evaluate the personal radiation dose for vascular
interventions with special focus on ocular lens dose.
MATERIALS AND METHODS: From May 2016 to October 2016, the personal radiation
doses of two interventionists and four technicians were prospectively recorded
during 206 vascular interventions. The position of personnel, intervention type
and fluoroscopy time were recorded. Parameters evaluated were total body dose
measured by film dosimeter, hand dose measured by ring thermoluminescent
dosimeter (TLD) and ocular lens dose measured by TLD placed in front of the
safety glasses. Linear regression analysis was used to estimate the dose at 2
and 5 years.
RESULTS: The ocular lens dose, hand and total body dose of the two
interventionists were 11/5, 56/47 and 0.6 mSv each, respectively. The estimated
5-year ocular dose was 113.08 mSv (95% CI 38.2-187.97)/40.95 (95% CI 16.9-64.7).
Similarly, hand dose was 608.4 mSv (95% CI 442.78-774.38)/514.47 (95% CI
329.83-699.10) and body dose 6.07 mSv (95% CI 4.70-8.22)/5.12 (95% CI
3.65-6.59), respectively. Amongst four technicians, only the first assistant
showed recordings of 0.3 mSv body dose, 2 mSv ocular lens dose and 5 mSv hand
dose.
CONCLUSION: The yearly ocular lens dose, particularly for interventionists
dealing with complex interventions, could cross the permitted yearly limit set
by the new Euratom directive. Therefore, X-ray safety glasses would become
mandatory for complex radiological vascular interventions.
LEVEL OF EVIDENCE: Level III, non-randomized controlled cohort/follow-up study. Staff at nuclear medicine departments receive doses of ionising radiation higher
than the staff of radiotherapy and radiology departments, with the exception of
interventional radiologists. Due to the updated lower occupational exposure
limit for the lens of the eye, we measured eye exposure in workers of the
Nuclear Medicine Department, Pomeranian Medical University in Szczecin, Poland.
EYE-D™ dosimeters were used for 3 months by 10 employees working with sources of
ionising radiation. Personal dosimeters also measured the exposure of the whole
body and hands. The 3-month dose equivalents for the lens of the eye in the
employees was 0.20-0.72 mSv. Staff at NMD PMU do not require regular routine eye
lens dose monitoring. Eye lens doses were well within the new annual limit of 20
mSv. Doses to the whole body may be used as an indicator of the eye lens doses
in the monitored department. |
Does association with the nuclear pore promote gene silencing? | MicroRNA (miRNA)-guided mRNA repression, mediated by the miRNA-induced silencing complex (miRISC), is an important component of post-transcriptional gene silencing. The nucleoporin Nup358 plays an important role in this process | Tpr is a 267-kDa protein forming coiled coil-dominated homodimers that locate at
the nucleoplasmic side of the nuclear pore complex (NPC). The proteins that
tether Tpr to this location are unknown. Moreover, the question whether Tpr
itself might act as a scaffold onto which other NPC components need to be
assembled has not been answered to date. To assess Tpr's role as an
architectural element of the NPC, we have studied the sequential disassembly and
reassembly of NPCs in mitotic cells, paralleled by studies of cells depleted of
Tpr as a result of posttranscriptional tpr gene silencing by RNA interference
(RNAi). NPC assembly and recruitment of several nucleoporins, including Nup50,
Nup93, Nup96, Nup98, Nup107, and Nup153, in anaphase/early telophase is shown to
precede NPC association of Tpr in late telophase. In accordance, cellular
depletion of Tpr by RNAi does not forestall binding of these nucleoporins to the
NPC. In a search for proteins that moor Tpr to the NPC, we have combined the
RNAi approach with affinity-chromatography and yeast two-hybrid interaction
studies, leading to the identification of nucleoporin Nup153 as the binding
partner for Tpr. The specificity of this interaction is demonstrated by its
sensitivity to Tpr amino acid substitution mutations that abolish Tpr's ability
to adhere to the NPC and affect the direct binding of Tpr to Nup153.
Accordingly, cellular depletion of Nup153 by RNAi is shown to result in
mislocalization of Tpr to the nuclear interior. Nup153 deficiency also causes
mislocalization of Nup50 but has no direct effect on NPC localization of the
other nucleoporins studied in this investigation. In summary, these results
render Tpr a protein only peripherally attached to the NPC that does not act as
an essential scaffold for other nucleoporins. The nuclear pore complex (NPC) is both the major conduit for nucleocytoplasmic
trafficking and a platform for organizing macromolecules at the nuclear
envelope. We report that yeast Esc1, a non-NPC nuclear envelope protein, is
required both for proper assembly of the nuclear basket, a structure extending
into the nucleus from the NPC, and for normal NPC localization of the Ulp1 SUMO
protease. In esc1Delta cells, Ulp1 and nuclear basket components Nup60 and Mlp1
no longer distribute broadly around the nuclear periphery, but co-localize in a
small number of dense-staining perinuclear foci. Loss of Esc1 (or Nup60) alters
SUMO conjugate accumulation and enhances ulp1 mutant defects. Similar to
previous findings with Mlp1, both Esc1 and Ulp1 help retain unspliced pre-mRNAs
in the nucleus. Therefore, these proteins are essential for proper nuclear
basket function, which includes mRNA surveillance and regulation of SUMO protein
dynamics. The results raise the possibility that NPC-localized protein
desumoylation may be a key regulatory event preventing inappropriate pre-mRNA
export. Amassments of heterochromatin in somatic cells occur in close contact with the
nuclear envelope (NE) but are gapped by channel- and cone-like zones that appear
largely free of heterochromatin and associated with the nuclear pore complexes
(NPCs). To identify proteins involved in forming such heterochromatin exclusion
zones (HEZs), we used a cell culture model in which chromatin condensation
induced by poliovirus (PV) infection revealed HEZs resembling those in normal
tissue cells. HEZ occurrence depended on the NPC-associated protein Tpr and its
large coiled coil-forming domain. RNAi-mediated loss of Tpr allowed condensing
chromatin to occur all along the NE's nuclear surface, resulting in HEZs no
longer being established and NPCs covered by heterochromatin. These results
assign a central function to Tpr as a determit of perinuclear organization,
with a direct role in forming a morphologically distinct nuclear sub-compartment
and delimiting heterochromatin distribution. BACKGROUND: Tpr is a large coiled-coil protein located in the nuclear basket of
the nuclear pore complex for which many different functions were proposed from
yeast to human.
METHODOLOGY/PRINCIPAL FINDINGS: Here we show that depletion of Tpr by RNA
interference triggers G0-G1 arrest and ultimately induces a senescent-like
phenotype dependent on the presence of p53. We also found that Tpr depletion
impairs the NES [nuclear export sequence]-dependent nuclear export of proteins
and causes partial co-depletion of Nup153. In addition Tpr depletion impacts on
level and function of the SUMO-protease SENP2 thus affecting SUMOylation
regulation at the nuclear pore and overall SUMOylation in the cell.
CONCLUSIONS: Our data for the first time provide evidence that a nuclear pore
component plays a role in controlling cellular senescence. Our findings also
point to new roles for Tpr in the regulation of SUMO-1 conjugation at the
nuclear pore and directly confirm Tpr involvement in the nuclear export of
NES-proteins. |
Which methods are used for genome segmentation of gene expression data? | Most of the used methods are variations of Markov Models such as Markov Chain Monte Carlo (MCMC) or Combinatorial methods. | The existence of whole genome sequences makes it possible to search for global
structure in the genome. We consider modeling the occurrence frequencies of
discrete patterns (such as starting points of ORFs or other interesting
phenomena) along the genome. We use piecewise constant intensity models with
varying number of pieces, and show how a reversible jump Markov Chain Monte
Carlo (RJMCMC) method can be used to obtain a posteriori distribution on the
intensity of the patterns along the genome. We apply the method to modeling the
occurrence of ORFs in the human genome. The results show that the chromosomes
consist of 5-35 clearly distinct segments, and that the posteriori number and
length of the segments shows significant variation. On the other hand, for the
yeast genome the intensity of ORFs is nearly constant. We introduce Markov models for segmentation of symbolic sequences, extending a
segmentation procedure based on the Jensen-Shannon divergence that has been
introduced earlier. Higher-order Markov models are more sensitive to the details
of local patterns and in application to genome analysis, this makes it possible
to segment a sequence at positions that are biologically meaningful. We show the
advantage of higher-order Markov-model-based segmentation procedures in
detecting compositional inhomogeneity in chimeric DNA sequences constructed from
genomes of diverse species, and in application to the E. coli K12 genome,
boundaries of genomic islands, cryptic prophages, and horizontally acquired
regions are accurately identified. Current genome-wide ChIP-seq experiments on different epigenetic marks aim at
unraveling the interplay between their regulation mechanisms. Published
evaluation tools, however, allow testing for predefined hypotheses only. Here,
we present a novel method for annotation-independent exploration of epigenetic
data and their inter-correlation with other genome-wide features. Our method is
based on a combinatorial genome segmentation solely using information on
combinations of epigenetic marks. It does not require prior knowledge about the
data (e.g. gene positions), but allows integrating the data in a straightforward
manner. Thereby, it combines compression, clustering and visualization of the
data in a single tool. Our method provides intuitive maps of epigenetic patterns
across multiple levels of organization, e.g. of the co-occurrence of different
epigenetic marks in different cell types. Thus, it facilitates the formulation
of new hypotheses on the principles of epigenetic regulation. We apply our
method to histone modification data on trimethylation of histone H3 at lysine 4,
9 and 27 in multi-potent and lineage-primed mouse cells, analyzing their
combinatorial modification pattern as well as differentiation-related changes of
single modifications. We demonstrate that our method is capable of reproducing
recent findings of gene centered approaches, e.g. correlations between
CpG-density and the analyzed histone modifications. Moreover, combining the
clustered epigenetic data with information on the expression status of
associated genes we classify differences in epigenetic status of e.g.
house-keeping genes versus differentiation-related genes. Visualizing the
distribution of modification states on the chromosomes, we discover strong
patterns for chromosome X. For example, exclusively H3K9me3 marked segments are
enriched, while poised and active states are rare. Hence, our method also
provides new insights into chromosome-specific epigenetic patterns, opening up
new questions how "epigenetic computation" is distributed over the genome in
space and time. |
Which receptor is inhibited by Teprotumumab? | Teprotumumab is a monoclonal inhibitory antibody targeting IGF-1 receptor. | PURPOSE OF REVIEW: In recent years, immunosuppressive therapy, as an alternative
to corticosteroids, has been proposed as novel agents which target the various
antigens involved in the pathogenesis of Graves' ophthalmopathy. Although the
lack of randomized and controlled studies suggests caution in generalizing
results, some data show interesting results.
RECENT FINDINGS: Potential targets for immune therapy in Graves' ophthalmopathy
are the antigens expressed on the target organ of inflammation, namely the
receptor and the insulin growth factor -1 receptor on fibroblasts, inflammatory
cytokines, and B and T cells. The most promising results are observed with small
thyroid stimulating hormone receptor molecules interacting with the receptor on
thyrocytes and fibroblasts and with the anti-IGF-1 receptor antibody
teprotumumab. A recent open study with tocilizumab, an anti-soluble
interleukin-6 receptor, has shown inactivation of Graves' ophthalmopathy.
Consistent reports on the efficacy of rituximab will have to be confirmed by
randomized controlled trials, which are now in progress.
SUMMARY: Current clinical practice for Graves' ophthalmopathy will greatly
benefit from the availability of immunosuppressors that act as disease-modifying
drugs, as compared to steroids, the current standard treatment for Graves'
ophthalmopathy. Rituximab seems to be a good candidate, as preliminary results
from ongoing randomized trials suggest good efficacy with a relative well
tolerated profile. PURPOSE: Fibrocytes (FC) are bone marrow-derived progenitor cells that are more
abundant and infiltrate the thyroid and orbit in Graves orbitopathy (GO). FCs
express high levels of thyrotropin receptor (TSHR) and insulin-like growth
factor-1 receptor (IGF-1R). These receptors are physically and functionally
associated, but their role in GO pathogenesis is not fully delineated. Treatment
of FCs with thyroid stimulating hormone (TSH) or M22 (activating antibody to
TSHR) induces the production of numerous cytokines, including tumor necrosis
factor α (TNFα). Teprotumumab (TMB) is a human monoclonal IGF-1R blocking
antibody currently in clinical trial for GO and inhibits TSHR-mediated actions
in FCs.
AIM: To characterize the molecular mechanisms underlying TSH-induced TNFα
production by FCs, and the role of IGF-1R blockade by TMB.
DESIGN: FCs from healthy and GD patients were treated with combinations of TSH,
M22, MG132 and AKTi (inhibitors of NF-κB and Akt, respectively), and TMB. TNFα
protein production was measured by Luminex and flow cytometry. Messenger RNA
expression was quantified by real time PCR.
RESULTS: Treatment with TSH/M22 induced TNFα protein and mRNA production by FCs,
both of which were reduced when FCs were pretreated with MG132 and AKTi
(p<0.0001). TMB decreased TSH-induced TNFα protein production in circulating FCs
from mean fluorescent index (MFI) value of 2.92 to 1.91, and mRNA expression in
cultured FCs from 141- to 52-fold expression (p<0.0001). TMB also decreased
M22-induced TNFα protein production from MFI of 1.67 to 1.12, and mRNA
expression from 6- to 3-fold expression (p<0.0001).
CONCLUSION: TSH/M22 stimulates FC production of TNFα mRNA and protein. This
process involves the transcription factor NF-κB and its regulator Akt. Blocking
IGF-1R attenuates TSH/M22-induced TNFα production. This further delineates the
interaction of TSHR and IGF1-R signaling pathways. By modulating the
proinflammatory properties of FCs such as TNFα production, TMB may be a
promising therapeutic agent for GO. CD34(+) fibrocytes are bone marrow-derived monocyte progenitor cells that
traffic to sites of tissue injury and repair. They putatively infiltrate the
orbit in thyroid-associated ophthalmopathy where they appear to transition into
CD34(+) orbital fibroblasts (OFs) that interact with residential CD34(-)
fibroblasts. A unique phenotypic attribute of fibrocytes and CD34(+) OFs is
their expression of the functional thyrotropin receptor (TSHR) and other
"thyroid-specific" proteins. When activated through TSHR, fibrocytes express a
number of cytokines and other inflammatory genes. Here we sought to determine
whether pentraxin-3 (PTX-3), an acute-phase protein involved in inflammation and
autoimmunity, might be induced by TSH in fibrocytes and OFs. These cells were
collected from patients with Graves disease and healthy individuals. PTX-3 mRNA
levels were determined by real-time PCR, protein was determined by ELISA and
Western blot, and PTX-3 gene promoter activity was assessed with reporter
assays. PTX-3 expression was induced by TSH in both cell types, regardless of
the health status of the donor and was a consequence of increased steady-state
PTX-3 mRNA levels. M22, a TSHR-activating monoclonal antibody, also induced
PTX-3. The induction could be attenuated by dexamethasone and by IGF-I
receptor-blocking antibodies, teprotumumab and 1H7. TSH effects were mediated
through phosphatidylinositol 3-kinase/AKT, mammalian target of
rapamycin/p70(s6k), Janus tyrosine kinase 2 pathways, and enhanced PTX-3 mRNA
stability. These findings indicate that PTX-3 is a TSH target gene, the
expression of which can be induced in fibrocytes and OFs. They suggest that
PTX-3 might represent a previously unidentified nexus between the thyroid axis
and the mechanisms involved in tissue remodeling. Graves' ophthalmopathy is defined as autoimmune inflammation of extraocular
muscles and orbital fat or connective tissue, usually in patients with Graves'
disease. About one in 20 patients with Graves' hyperthyroidism has
moderate-to-severe Graves' ophthalmopathy. Corticosteroids have been the
mainstay of treatment, but new evidence about immune mechanisms has provided a
basis to explore other drug classes. Intravenous methylprednisolone pulses are
more effective and better tolerated than oral prednisone in the treatment of
active, moderate-to-severe Graves' ophthalmopathy. Rituximab has also been
suggested as a possible replacement for intravenous corticosteroids. Two
randomised controlled trials of rituximab reached seemingly contradictory
conclusions-rituximab was not better with respect to the primary outcome
(clinical activity score) than placebo in one trial (which, however, was
confounded by rather long Graves' ophthalmopathy duration), but was slightly
better than intravenous methylprednisolone pulses in the other (disease
flare-ups occurred only in the latter group). On the basis of evidence published
so far, rituximab cannot replace intravenous methylprednisolone pulses, but
could have a role in corticosteroid-resistant cases. Open-label studies of
tumour-necrosis-factor-α blockade had limited efficacy, but other studies showed
that interleukin-6 receptor antibodies were effective. Results of randomised
controlled trials investigating the efficacy of the IGF-1 receptor antibody
teprotumumab and the interleukin-6 receptor antibody tocilizumab are expected
shortly. Approaches that target the causal mechanism of Graves' ophthalmopathy
(antibodies or antagonists that block thyroid-stimulating-hormone receptors)
also look promising. BACKGROUND: Thyroid-associated ophthalmopathy, a condition commonly associated
with Graves' disease, remains inadequately treated. Current medical therapies,
which primarily consist of glucocorticoids, have limited efficacy and present
safety concerns. Inhibition of the insulin-like growth factor I receptor
(IGF-IR) is a new therapeutic strategy to attenuate the underlying autoimmune
pathogenesis of ophthalmopathy.
METHODS: We conducted a multicenter, double-masked, randomized,
placebo-controlled trial to determine the efficacy and safety of teprotumumab, a
human monoclonal antibody inhibitor of IGF-IR, in patients with active,
moderate-to-severe ophthalmopathy. A total of 88 patients were randomly assigned
to receive placebo or active drug administered intravenously once every 3 weeks
for a total of eight infusions. The primary end point was the response in the
study eye. This response was defined as a reduction of 2 points or more in the
Clinical Activity Score (scores range from 0 to 7, with a score of ≥3 indicating
active thyroid-associated ophthalmopathy) and a reduction of 2 mm or more in
proptosis at week 24. Secondary end points, measured as continuous variables,
included proptosis, the Clinical Activity Score, and results on the Graves'
ophthalmopathy-specific quality-of-life questionnaire. Adverse events were
assessed.
RESULTS: In the intention-to-treat population, 29 of 42 patients who received
teprotumumab (69%), as compared with 9 of 45 patients who received placebo
(20%), had a response at week 24 (P<0.001). Therapeutic effects were rapid; at
week 6, a total of 18 of 42 patients in the teprotumumab group (43%) and 2 of 45
patients in the placebo group (4%) had a response (P<0.001). Differences between
the groups increased at subsequent time points. The only drug-related adverse
event was hyperglycemia in patients with diabetes; this event was controlled by
adjusting medication for diabetes.
CONCLUSIONS: In patients with active ophthalmopathy, teprotumumab was more
effective than placebo in reducing proptosis and the Clinical Activity Score.
(Funded by River Vision Development and others; ClinicalTrials.gov number,
NCT01868997 .). Thyroid-associated ophthalmopathy (TAO) is a vexing and poorly understood
autoimmune process involving the upper face and tissues surrounding the eyes. In
TAO, the orbit can become inflamed and undergo substantial remodeling that is
disfiguring and can lead to loss of vision. There are currently no approved
medical therapies for TAO, the consequence of its uncertain pathogenic nature.
It usually presents as a component of the syndrome known as Graves' disease
where loss of immune tolerance to the thyrotropin receptor (TSHR) results in the
generation of activating antibodies against that protein and hyperthyroidism.
The role for TSHR and these antibodies in the development of TAO is considerably
less well established. We have reported over the past 2 decades evidence that
the insulin-like growth factorI receptor (IGF1R) may also participate in the
pathogenesis of TAO. Activating antibodies against IGF1R have been detected in
patients with GD. The actions of these antibodies initiate signaling in orbital
fibroblasts from patients with the disease. Further, we have identified a
functional and physical interaction between TSHR and IGF1R. Importantly, it
appears that signaling initiated from either receptor can be attenuated by
inhibiting the activity of IGF1R. These findings underpin the rationale for
therapeutically targeting IGF1R in active TAO. A recently completed therapeutic
trial of teprotumumab, a human IGF1R inhibiting antibody, in patients with
moderate to severe, active TAO, indicates the potential effectiveness and safety
of the drug. It is possible that other autoimmune diseases might also benefit
from this treatment strategy. Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to
emerge from autoimmunity occurring in the thyroid gland, most frequently in
Graves disease (GD). It is disfiguring and potentially blinding, culminating in
orbital tissue remodeling and disruption of function of structures adjacent to
the eye. There are currently no medical therapies proven capable of altering the
clinical outcome of TAO in randomized, placebo-controlled multicenter trials.
The orbital fibroblast represents the central target for immune reactivity.
Recent identification of fibroblasts that putatively originate in the bone
marrow as monocyte progenitors provides a plausible explanation for why
antigens, the expressions of which were once considered restricted to the
thyroid, are detected in the TAO orbit. These cells, known as fibrocytes,
express relatively high levels of functional TSH receptor (TSHR) through which
they can be activated by TSH and the GD-specific pathogenic antibodies that
underpin thyroid overactivity. Fibrocytes also express insulin-like growth
factor I receptor (IGF-IR) with which TSHR forms a physical and functional
signaling complex. Notably, inhibition of IGF-IR activity results in the
attenuation of signaling initiated at either receptor. Some studies suggest that
IGF-IR-activating antibodies are generated in GD, whereas others refute this
concept. These observations served as the rationale for implementing a recently
completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody
targeting IGF-IR in TAO. Results of that trial in active, moderate to severe
disease revealed dramatic and rapid reductions in disease activity and severity.
The targeting of IGF-IR with specific biologic agents may represent a paradigm
shift in the therapy of TAO. Thyroid eye disease is a disabling autoimmune disease associated with orbital
inflammation and tissue remodeling which can result in significant proptosis,
leading to visual alterations and is potentially sight threatening. Current
evidence indicates that autoantibodies to the insulin-like growth factor 1
receptor (IGF-1R), along with the thyroid-stimulating hormone receptor (TSHR),
mediate the pathogenesis in susceptible individuals. Teprotumumab, a monoclonal
IGF-1R antagonist, has demonstrated previously in a 24 week, randomized,
controlled trial to produce significant changes in composite outcomes of
proptosis and clinical activity score as compared with placebo. Further
examination of the proptosis results reported here, indicate that the proptosis
outcome (≥ 2 mm reduction) was met in 71.4% of the teprotumumab-treated patients
as compared with 20% of the placebo-treated patients (p < 0.001). Additionally,
the proptosis benefit was observed early in the trial (study week 6), and all
individual patients demonstrated some benefit at week 24. Improvement was noted
among smokers, non-smokers, men and women, and particularly those with higher
levels of proptosis at baseline. The level of proptosis reduction with
teprotumumab reported here is similar to that seen with decompression surgery.
If these results are confirmed in the ongoing Phase 3 trial, teprotumumab will
offer an alternative to surgery and its associated complications. |
What is the cause of the disease Xeroderma Pigmentosum? | Mutations in the ERCC1 or ERCC4 genes cause a remarkable array of rare inherited human disorders including specific forms of xeroderma pigmentosum. Individuals with NER-defective xeroderma pigmentosum (XP), in which bulky DNA lesions are not efficiently removed, are cancer-prone and suffer neurodegeneration. | Nucleotide excision repair (NER) in higher organisms repair massive DNA
abrasions caused by ultraviolet rays, and various mutagens, where Xeroderma
pigmentosum group A (XPA) protein is known to be involved in damage recognition
step. Any mutations in XPA cause classical Xeroderma pigmentosum disease. The
extent to which XPA is required in the NER is still unclear. Here, we present
the comparative study on the structural and conformational changes in globular
DNA binding domain of XPA98-210 in DNA bound and DNA free state. Atomistic
molecular dynamics simulation was carried out for both XPA98-210 systems using
AMBER force fields. We observed that XPA98-210 in presence of damaged DNA
exhibited more structural changes compared to XPA98-210 in its free form. When
XPA is in contact with DNA, we found marked stability of the complex due to the
formation of characteristic longer antiparallel β-sheets consisting mainly
lysine residues. Pathogenic variants in genes, which encode DNA repair and damage response
proteins, result in a number of genomic instability syndromes with features of
accelerated aging. ERCC4 (XPF) encodes a protein that forms a complex with ERCC1
and is required for the 5' incision during nucleotide excision repair. ERCC4 is
also FANCQ, illustrating a critical role in interstrand crosslink repair.
Pathogenic variants in this gene cause xeroderma pigmentosum, XFE progeroid
syndrome, Cockayne syndrome (CS), and Fanconi anemia. We performed massive
parallel sequencing for 42 unsolved cases submitted to the International
Registry of Werner Syndrome. Two cases, each carrying two novel heterozygous
ERCC4 variants, were identified. The first case was a compound heterozygote for:
c.2395C > T (p.Arg799Trp) and c.388+1164_792+795del (p.Gly130Aspfs*18). Further
molecular and cellular studies indicated that the ERCC4 variants in this patient
are responsible for a phenotype consistent with a variant of CS. The second case
was heterozygous for two variants in cis: c.[1488A > T; c.2579C > A]
(p.[Gln496His; Ala860Asp]). While the second case also had several phenotypic
features of accelerated aging, we were unable to provide biological evidence
supporting the pathogenic roles of the associated ERCC4 variants. Precise
genetic causes and disease mechanism of the second case remains to be
determined. Author information:
(1)Department of Neurology and Stroke Medicine, Yokohama City University
Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004,
Japan. [email protected].
(2)Department of Neurology and Stroke Medicine, Yokohama City University
Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004,
Japan.
(3)Department of Human Genetics, Yokohama City University Graduate School of
Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
(4)Clinical Genetics Department, Yokohama City University Hospital, Yokohama,
236-0004, Japan.
(5)Department of Pharmacology, National Defense Medical College, 3-2 Namiki,
Tokorozawa, Saitama, 359-8513, Japan.
(6)Department of Genome Repair, Atomic Bomb Disease Institute, Nagasaki
University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
(7)Department of Environmental Immuno-Dermatology, Yokohama City University
Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004,
Japan.
(8)Department of Pediatrics, National Hospital Organization Higashisaitama
Hospital, Hasuda, 4147 Kurohama, Saitama, 349-0196, Japan.
(9)Department of Neurology, National Hospital Organization Higashisaitama
Hospital, Hasuda, 4147 Kurohama, Saitama, 349-0196, Japan.
(10)Department of Genetics, Research Institute of Environmental Medicine, Nagoya
University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
(11)Department of Neurology and Stroke Medicine, Yokohama City University
Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004,
Japan. [email protected]. |
List Alkaptonuria Triad. | Alkaptonuria is a rare inherited genetic disorder of tyrosine metabolism characterized by a triad of homogentisic aciduria, ochronosis, and arthritis. | Alkaptonuria is a rare autosomal recessive disorder of metabolism caused by
deficiency of homogentisic acid oxidase and resulting in accumulation of
homogentisic acid in collagenous structures. This causes the classic clinical
triad: (1) homogentisic aciduria (urine blackens on standing when oxidized or
alkalinized); (2) eumelanin-like pigmentation of skin, sclera, cartilages, etc
and (3) degenerative ochronic arthropathies usually in the fourth decade of
life. Other important but more rare consequences of alkaptonuric ochronosis are
cardiovascular and urinary tract involvement. We present a case of ochronosis
with multiple visceral involvement: skin (fingers, ear sclera), severe
spondylarthropaty with extensive calcifications of intervertebral discs and
reduced mobility, osteoarthritis of both knees, right hip ostonecrosis,
cardiovascular involvement (severe stenosis and insufficiency of aortic valve
that) and urinary tract involvement (nephrolitiasis) Alkaptonuria is a rare inherited genetic disorder of tyrosine metabolism
characterized by a triad of homogentisic aciduria, ochronosis, and arthritis.
The most common clinical manifestations of ochronosis involve the
musculoskeletal, respiratory, airway, cardiovascular, genitourinary, cutaneous,
and ocular systems. We report the perioperative anesthetic management of a
56-year-old alkaptonuric patient, with multiple comorbidities scheduled, for
revision total hip replacement. A review of her medical history revealed
alkaptonuria, hypothyroidism, rheumatoid arthritis, hypertension, diabetes
mellitus, and Pott's spine with disc prolapse. We want to highlight the need of
thorough preoperative evaluation in patients of alkaptonuria, as it is
associated with multiple comorbidities. The systemic involvement should
determine the anesthetic plan. Caution should be exercised during positioning to
prevent injury to the joints and the spine. Alkaptonuria (AKU) is an autosomal recessive disorder due to homogentisate
1,2-dioxygenase (HGD) deficiency in the liver and characterized by a triad of
signs, according to chronology of appearance: homogentisic aciduria (HGA) or
alkaptonuria, ochronosis then ochronotic arthropathy. This inborn error of
metabolism is caused by mutations in the HGD gene. In this work we report
observations of 96 AKU French patients from 81 families collected in the
literature since 1882 and from our personal contribution since 1986, giving an
incidence of the disease of around 1:680,000 (96/64.10(6)). As expected for an
autosomal recessive disorder the main findings of this study were: a slight
predomice of males (51/93, 54,8%) over females (42/93, 45,2%), a strong
predomice of sibships with one affected individual (68/81, 84,0%) over
sibships with two (11/81, 13.6%) and three(2/81, 2.4%) affected individuals. AKU
families are scaterred among the French territory suggesting that most cases
occured in non-consanguineous unions. Consanguinity was only found in five
families. Other peculiarities of this study were (a) ten of these families have
both parents from a foreign geographical origin: Poland(3), Italy(3),
Portugal(2), Ukraine(1) and India(1) and four families with only one foreign
parent (Algeria, Armenia, Serbia, UK), (b) HGD mutations were found in 23
families, (c) four of theses 96 patients were seen by us respectively 28, 29, 39
and 45 years after their report in the literature and (d) seven patients present
cardiac and/or renal complications. Alkaptonuria, a metabolic disorder characterized by a triad of homogentisic
aciduria, arthritis and ochronosis is one of the first conditions in the charter
of group of inborn errors of metabolism proposed to have Mendelian recessive
inheritance. It is due to the deficiency of the enzyme homogentisic acid oxidase
which catalyzes the conversion of homogentisic acid to maleylacetoacetic acid in
the catabolism of tyrosine. Homogentisic acid thus accumulates in cells and body
fluids and its oxidized polymers bind to collagen, leading to progressive
deposition of grey to bluish black pigment resulting in degenerative changes in
cartilage, intervertebral disc and other connective tissues, leading to
arthritis which is the only disabling effect in an affected older individual.
However the diagnosis can be made in neonates when blackish stain is noticed in
an unwashed diaper. Alkaptonuria is treated symptomatically, surgical
intervention necessitates in advanced stages, treatment with ascorbic acid
(Vitamin C) and dietary restrictions of food containing phenylalanine and
tyrosine have proved to be successful in alleviating the symptoms. The hypothesis that is proposed is that tyrosinase, an enzyme widely found
within the human body is implicated in the ochronosis that occurs in
alkaptonuria; an autosomal recessive condition first used by Archibald Garrod to
describe the theory of "Inborn Errors of Metabolism." The disease results from
the absence of a single enzyme in the liver that breaks down homogentisic acid;
this molecule becomes systemically elevated in sufferers. The condition is
characterised by a clinical triad of symptoms; homogentisic aciduria from birth,
ochronosis (darkening) of collagenous tissues (from ∼30years of age) and
ochronotic osteoarthropathy in weight bearing joints due to long term ochronosis
in them (from ∼40years of age). Tyrosinase, a polyphenol oxidase has been shown
in many species to contribute to the darkening of tissues in many organisms;
including humans in the production of melanin. Tyrosinase under the right
conditions shows alterations in its substrate specificity and may contribute to
the darkening seen in AKU where it moves away from polymerising tyrosine but
also homogentisic acid, the causative molecule in alkaptonuria, that is present
in excess. Cardiac ochronosis is a rare complication of alkaptonuria, a disorder of
tyrosine metabolism characterized by a triad of dark urine, pigmentation of
tissues, and ochronotic arthropathies. When present, cardiac ochronosis
generally affects the aortic valve, resulting in aortic stenosis. More rarely,
it may affect the mitral valve and the coronary arteries. This report describes
the case of a 67-year-old woman with a history of alkaptonuria with severe
ochronosis of the coronary arteries and mitral valve who required coronary
artery bypass and mitral valve replacement. OBJECTIVE: Alkaptonuria (AKU) is a rare, inherited disorder of tyrosine
metabolism, where patients are unable to breakdown homogentisic acid (HGA),
which increases systemically over time. It presents with a clinical triad of
features; HGA in urine, ochronosis of collagenous tissues, and the subsequent
ochronotic arthritis of these tissues. In recent years the advance in the
understanding of the disease and the potential treatment of the disorder looks
promising with the data on the efficacy of nitisinone. However, there are
limited methods for the detection and monitoring of ochronosis in vivo, or for
treatment monitoring. The study aim was to test the hypothesis that Raman
spectra would identify a distinct chemical fingerprint for the non-ochronotic,
compared to ochronotic cartilage.
DESIGN: Ochronotic and non-ochronotic cartilage from human hips and ears were
analysed using Raman spectroscopy.
RESULTS: Non-ochronotic cartilage spectra were similar and reproducible and
typical of normal articular cartilage. Conversely, the ochronotic cartilage
samples were highly fluorescent and displayed limited or no discernible Raman
peaks in the spectra, in stark contrast to their non-ochronotic pairs.
Interestingly, a novel peak was observed associated with the polymer of HGA in
the ochronotic cartilage that was confirmed by analysis of pigment derived from
synthetic HGA.
CONCLUSION: This technique reveals novel data on the chemical differences in
ochronotic compared with non-ochronotic cartilage, these differences are
detectable by a technique that is already generating in vivo data and
demonstrates the first possible procedure to monitor the progression of
ochronosis in tissues of patients with AKU. |
Can LB-100 sensitize ovarian carcinoma to cisplatin? | Yes, LB100 sensitizes ovarian carcinoma cells to cisplatin-mediated cytotoxicity. | Despite early positive response to platinum-based chemotherapy, the majority of
ovarian carcinomas develop resistance and progress to fatal disease. Protein
phosphatase 2A (PP2A) is a ubiquitous phosphatase involved in the regulation of
DNA-damage response (DDR) and cell-cycle checkpoint pathways. Recent studies
have shown that LB100, a small-molecule inhibitor of PP2A, sensitizes cancer
cells to radiation-mediated DNA damage. We hypothesized that LB100 could
sensitize ovarian cancer cells to cisplatin treatment. We performed in vitro
studies in SKOV-3, OVCAR-8, and PEO1, -4, and -6 ovarian cancer lines to assess
cytotoxicity potentiation, cell-death mechanism(s), cell-cycle regulation, and
DDR signaling. In vivo studies were conducted in an intraperitoneal metastatic
mouse model using SKOV-3/f-Luc cells. LB100 sensitized ovarian carcinoma lines
to cisplatin-mediated cell death. Sensitization via LB100 was mediated by
abrogation of cell-cycle arrest induced by cisplatin. Loss of the
cisplatin-induced checkpoint correlated with decreased Wee1 expression,
increased cdc2 activation, and increased mitotic entry (p-histone H3). LB100
also induced constitutive hyperphosphorylation of DDR proteins (BRCA1, Chk2, and
γH2AX), altered the chronology and persistence of JNK activation, and modulated
the expression of 14-3-3 binding sites. In vivo, cisplatin sensitization via
LB100 significantly enhanced tumor growth inhibition and prevented disease
progression after treatment cessation. Our results suggest that LB100 sensitizes
ovarian cancer cells to cisplatin in vitro and in vivo by modulation of the DDR
pathway and cell-cycle checkpoint abrogation. |
List T-UCRs that have been implicated in breast cancer | Long non-coding RNAs (lncRNAs) are transcripts longer than 200 bp with no protein-coding capacity. Transcribed ultraconserved regions (T-UCRs) are a type of lncRNA and are conserved among human, chick, dog, mouse and rat genomes. These sequences are involved in cancer biology and tumourigenesis. Overexpression of one specific T-UCRs named uc.63 is associated with bad outcome in luminal A subtype of breast cancer patients. Uc.38 negatively regulates the expression of the pre-B-cell leukaemia homeobox 1 (PBX1) protein and subsequently affects the expression of Bcl-2 family members, ultimately inducing breast cancer cell apoptosis. | Transcribed-ultraconserved regions (T-UCRs) are long non-coding RNAs (lncRNA)
encoded by a subset of long ultraconserved stretches in the human genome. Recent
studies revealed that the expression of several T-UCRs is altered in cancer and
growing evidences underline the importance of T-UCRs in oncogenesis, offering
also potential new strategies for diagnosis and prognosis. We found that
overexpression of one specific T-UCRs named uc.63 is associated with bad outcome
in luminal A subtype of breast cancer patients. uc.63 is localized in the third
intron of exportin-1 gene (XPO1) and is transcribed in the same orientation of
its host gene. Interestingly, silencing of uc.63 induces apoptosis in vitro.
However, silencing of host gene XPO1 does not cause the same effect suggesting
that the transcription of uc.63 is independent of XPO1. Our results reveal an
important role of uc.63 in promoting breast cancer cells survival and offer the
prospect to identify a signature associated with poor prognosis. Long non-coding RNAs (lncRNAs) are transcripts longer than 200 bp with no
protein-coding capacity. Transcribed ultraconserved regions (T-UCRs) are a type
of lncRNA and are conserved among human, chick, dog, mouse and rat genomes.
These sequences are involved in cancer biology and tumourigenesis. Nevertheless,
the clinical significance and biological mechanism of T-UCRs in breast cancer
remain largely unknown. The expression of uc.38, a T-UCR, was down-regulated in
both breast cancer tissues and breast cancer cell lines. However, uc.38 was
expressed at significantly lower levels in larger tumours and tumours of more
advanced stages. Based on the results of in vitro and in vivo experiments,
up-regulation of uc.38 expression inhibited cell proliferation and induced cell
apoptosis. Thus, uc.38 suppressed breast cancer. Additional experiments revealed
that uc.38 negatively regulated the expression of the pre-B-cell leukaemia
homeobox 1 (PBX1) protein and subsequently affected the expression of Bcl-2
family members, ultimately inducing breast cancer cell apoptosis. Describing the
uc.38/PBX1 axis has improved our understanding of the molecular mechanisms
involved in breast cancer apoptosis and has suggested that this axis is a
potential therapeutic target for breast cancer. |
How many different miRNAs can be upregulated by LB-100? | LB-100 has been reported to upregulate one miRNA, namely miR-181b-1. | Author information:
(1)Department of Hematology, The First Affiliated Hospital, College of Medicine,
Zhejiang University, Hangzhou, 310003, People's Republic of China.
(2)Department of Hematology, Hangzhou First People's Hospital, Hangzhou, 310006,
Zhejiang Province, People's Republic of China.
(3)Myelodysplastic Syndromes Diagnosis and Therapy Center, The First Affiliated
Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, People's
Republic of China.
(4)Department of Hematology, Yin Zhou People's Hospital, Ningbo, 315040,
Zhejiang Province, People's Republic of China.
(5)Surgical Neurology Branch, National Institute of Neurological Disorders and
Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
(6)Surgical Neurology Branch, National Institute of Neurological Disorders and
Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
[email protected].
(7)Department of Hematology, The First Affiliated Hospital, College of Medicine,
Zhejiang University, Hangzhou, 310003, People's Republic of China.
[email protected].
(8)Myelodysplastic Syndromes Diagnosis and Therapy Center, The First Affiliated
Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, People's
Republic of China. [email protected]. |
Which T-UCRs have been implicated in gastric cancer? | Uc.160 is significantly down-regulated in gastric carcinomas and can inhibit the tumor growth both in vitro and in vivo, suggesting that uc.160 may be used as a diagnostic marker and therapeutic target of gastric malignancies. Uc.416+A is overexpressed in GC and is associated with cell growth through the regulation of IGFBP6 (insulin-like growth factor-binding protein 6) in gastric cancer (GC). | The transcribed-ultraconserved regions (T-UCRs) are a novel class of non-coding
RNAs, which are absolutely conserved (100%) between the orthologous regions of
the human, rat and mouse genomes. Previous studies have described that several
T-UCRs show differential expressions in cancers and might be involved in cancer
development. We investigated the transcriptional levels of representative 26
T-UCRs and determined the regions that were differently expressed in prostate
cancer (PCa) and gastric cancer (GC). A quantitative reverse
transcription-polymerase chain reaction analysis revealed the downregulation of
Uc.158+A expression by a DNA methylation-associated mechanism, which was
restored by 5-Aza-dC (5-aza-2'-deoxycytidine) treatment. Bisulfite genomic
sequencing using cell lines and tissue samples demonstrated cancer-specific CpG
hypermethylation in both GC and PCa. However, Uc.416+A was only overexpressed in
GC and we identified an miR-153 binding site in the possible regulatory region
of Uc.416+A using online databases. Along with a forced expression or knockdown
of miR-153 in MKN-74 GC cells, the transcriptional levels of Uc.416+A were
significantly disturbed. A luciferase reporter gene assay supported the direct
regulation of Uc.416+A expression by miR-153. Furthermore, Uc.416+A was
associated with cell growth through the regulation of IGFBP6 (insulin-like
growth factor-binding protein 6) in GC. These findings suggest an oncogenic role
of Uc.416+A in GC, which suggests that our approach would provide new insights
into functional studies of T-UCRs in cancer biology. BACKGROUND: Transcribed ultraconserved regions (T-UCRs) are a novel class of
noncoding RNAs that are highly conserved among the orthologous regions in most
vertebrates. It has been reported that T-UCRs have distinct signatures in human
cancers. We previously discovered the downregulation of T-UCR expression in
gastric cancer (GC), indicating that T-UCRs could play an important role in GC
biology. Uc.160+, a T-UCR reported to be downregulated in human cancer, has not
been examined in GC.
METHODS: We analyzed the expression pattern of Uc.160+ in nonneoplastic and
tumor tissues of the stomach by using uantitative reverse transcription
polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH),
specifically focusing on the mechanism of transcriptional regulation and target
genes that are regulated by T-UCRs. We also attempted to determine the effect of
Uc.160+ expression on biological features of GC cell lines by Western blotting.
RESULTS: On the basis of the qRT-PCR and ISH results, Uc.160+ expression in
adenoma and GC tissues was clearly downregulated compared with that in
nonneoplastic mucosa tissues of the stomach. Cancer-specific DNA methylation in
the promoter region of Uc.160 was observed by bisulfite genomic DNA sequencing
analysis. The effect of DNA methylation on Uc.160+ expression was further
confirmed by reporter gene assay. We also revealed that Uc.160+ inhibited the
phosphorylation of Akt by regulating phosphatase and tensin homolog (PTEN)
expression.
CONCLUSIONS: These results indicate that Uc.160+ could possibly have a tumor
suppressive role in GC. BACKGROUND: Transcribed ultraconserved regions (T-UCRs) are a subset of long
noncoding RNAs. It has been reported that T-UCRs are dysregulated in cancers and
play an important role in the development and progression of maligcies.
uc.160 was found to be a suppressive factor of cancer development, but its role
has not been fully elucidated.
METHODS: The uc.160 expression was examined in gastric cancer tissues and
established cell lines by quantitative reverse transcription polymerase chain
reaction (qRT-PCR). The biological function of gastric cancer cells with uc.160
over-expression were investigated, and the interaction between uc.160 and
microRNA miR-155 was examined by dual-luciferase reporter assay. PTEN levels
were detected by Western blotting. Anti-tumor effects of uc.160 were further
explored in tumor transplantation models.
RESULTS: uc.160 expression was significantly down-regulated in gastric cancer
tissues and gastric cell lines as compared to adjacent normal tissues and
immortalized gastric epithelial cell line (GES-1), respectively. Over-expression
of uc.160 in SGC-7901 and AGS gastric cancer cells significantly suppressed
their proliferation in vitro and in vivo. Moreover, uc.160 positively regulated
the tumor suppressor protein PTEN. Interestingly, uc.160 was inhibited by
microRNA miR-155 that is also a negative regulator of gastric cancer.
CONCLUSION: uc.160 is significantly down-regulated in gastric carcinomas and can
inhibit the tumor growth both in vitro and in vivo, suggesting that uc.160 may
be used as a diagnostic marker and therapeutic target of gastric maligcies. |
Which disease can be treated with Anifrolumab? | Anifrolumab is a type I interferon (IFN) receptor antagonist that has been shown to be effective for moderate-to-severe systemic lupus erythematosus (SLE). | Systemic lupus erythematosus (SLE) is an autoimmune disease with a polymorphic
presentation. The variability in the clinical expression and severity of SLE
makes new treatments both essential and challenging to develop. Several
biotherapies targeting different pathophysiological pathways have been developed
over the past 15 years. The results of Phase II trials were encouraging but
rarely borne out by Phase III trials. Recent data, which are discussed in detail
in this review, allowed belimumab - a monoclonal antibody against BLyS
(B-lymphocyte stimulator) - to become the first biotherapy approved for use in
SLE. Other molecules targeting B cells include the two anti-BLyS antibodies
tabalumab and blisibimod; atacicept, which targets both BLyS and APRIL (a
proliferation-inducing ligand); and the monoclonal antibody to CD22 epratuzumab.
The rekindling of interest in the B-cell pathway has also driven new clinical
research into rituximab, a monoclonal antibody targeting CD20 with evaluations
of new strategies. A new and promising approach is the use of inhibitors of the
type 1 interferon (IFN) pathway, of which the most promising is anifrolumab, a
monoclonal antibody targeting the type 1 IFN receptor. In this review, we
discuss study findings and their clinical relevance, present the most promising
targets, and analyze possible explanations to negative results, such as
inappropriate patient selection and treatment response criteria or the erratic
use of high-dose glucocorticoid therapy. OBJECTIVE: To assess the efficacy and safety of anifrolumab, a type I interferon
(IFN) receptor antagonist, in a phase IIb, randomized, double-blind,
placebo-controlled study of adults with moderate-to-severe systemic lupus
erythematosus (SLE).
METHODS: Patients (n = 305) were randomized to receive intravenous anifrolumab
(300 mg or 1,000 mg) or placebo, in addition to standard therapy, every 4 weeks
for 48 weeks. Randomization was stratified by SLE Disease Activity Index 2000
score (<10 or ≥10), oral corticosteroid dosage (<10 or ≥10 mg/day), and type I
IFN gene signature test status (high or low) based on a 4-gene expression assay.
The primary end point was the percentage of patients achieving an SLE Responder
Index (SRI[4]) response at week 24 with sustained reduction of oral
corticosteroids (<10 mg/day and less than or equal to the dose at week 1 from
week 12 through 24). Other end points (including SRI[4], British Isles Lupus
Assessment Group [BILAG]-based Composite Lupus Assessment [BICLA], modified
SRI[6], and major clinical response) were assessed at week 52. The primary end
point was analyzed in the modified intent-to-treat (ITT) population and type I
IFN-high subpopulation. The study result was considered positive if the primary
end point was met in either of the 2 study populations. The Type I error rate
was controlled at 0.10 (2-sided), within each of the 2 study populations for the
primary end point analysis.
RESULTS: The primary end point was met by more patients treated with anifrolumab
(34.3% of 99 for 300 mg and 28.8% of 104 for 1,000 mg) than placebo (17.6% of
102) (P = 0.014 for 300 mg and P = 0.063 for 1,000 mg, versus placebo), with
greater effect size in patients with a high IFN signature at baseline (13.2% in
placebo-treated patients versus 36.0% [P = 0.004] and 28.2% [P = 0.029]) in
patients treated with anifrolumab 300 mg and 1,000 mg, respectively. At week 52,
patients treated with anifrolumab achieved greater responses in SRI(4) (40.2%
versus 62.6% [P < 0.001] and 53.8% [P = 0.043] with placebo, anifrolumab 300 mg,
and anifrolumab 1,000 mg, respectively), BICLA (25.7% versus 53.5% [P < 0.001]
and 41.2% [P = 0.018], respectively), modified SRI(6) (28.4% versus 49.5%
[P = 0.002] and 44.7% [P = 0.015], respectively), major clinical response (BILAG
2004 C or better in all organ domains from week 24 through week 52) (6.9% versus
19.2% [P = 0.012] and 17.3% [P = 0.025], respectively), and several other global
and organ-specific end points. Herpes zoster was more frequent in the
anifrolumab-treated patients (2.0% with placebo treatment versus 5.1% and 9.5%
with anifrolumab 300 mg and 1,000 mg, respectively), as were cases reported as
influenza (2.0% versus 6.1% and 7.6%, respectively), in the anifrolumab
treatment groups. Incidence of serious adverse events was similar between groups
(18.8% versus 16.2% and 17.1%, respectively).
CONCLUSION: Anifrolumab substantially reduced disease activity compared with
placebo across multiple clinical end points in the patients with
moderate-to-severe SLE. OBJECTIVES: In a post-hoc analysis, we aimed to validate the Lupus Low Disease
Activity State (LLDAS) definition as an endpoint in an systemic lupus
erythematosus (SLE) Phase IIb randomised controlled trial (RCT) (MUSE
[NCT01438489]) and then utilize LLDAS to discriminate between anifrolumab and
placebo.
METHODS: Patients received intravenous placebo (n=102) or anifrolumab (300 mg,
n=99; 1,000 mg, n=104) Q4W plus standard of care for 48 weeks. LLDAS attainment
(SLE Disease Activity Index 2000 ≤4 without major organ activity, no new disease
activity, Physician's Global Assessment ≤1, prednisolone ≤7.5 mg/d and standard
immunosuppressant dosage tolerance) was assessed. Associations with endpoints
and LLDAS attainment differences between treatments were explored.
RESULTS: LLDAS attainment at Week 52 was associated with SLE Responder Index 4
(SRI[4]) and British Isles Lupus Assessment Group-based Composite Lupus
Assessment (BICLA) (74/85[87%] and 62/84[74%] were also SRI[4] and BICLA
responders, respectively; both nominal p<0.001). Only 74/159 (47%) of SRI(4) and
62/121 (51%) of BICLA responders reached LLDAS.Anifrolumab-treated patients
achieved earlier LLDAS, and more spent at least half their observed time in
LLDAS (OR vs. placebo; 300 mg: 3.04, 95% CI 1.34 to 6.92, nominal p=0.008;
1,000 mg: 2.17, 95% CI 0.93 to 5.03, nominal p=0.072) vs placebo-treated
patients. At Week 52, 17/102 (17%), 39/99 (39%) and 29/104 (28%) of patients on
placebo, anifrolumab 300 and 1,000 mg, respectively, attained LLDAS (OR vs.
placebo; 300 mg: 3.41, 95% CI 1.73 to 6.76, p<0.001; 1,000 mg: 2.03, 95% CI 1.01
to 4.07, nominal p=0.046).
CONCLUSIONS: LLDAS attainment represents a clinically meaningful SLE outcome
measure, and anifrolumab is associated with more patients who met LLDAS criteria
versus placebo. These data support LLDAS as an SLE RCT endpoint.
TRIAL REGISTRATION NUMBER: NCT1438489; Post-results. OBJECTIVES: To compare the pharmacokinetics (PK), safety and tolerability of
subcutaneous (SC) and intravenous anifrolumab, an anti-type I interferon
receptor monoclonal antibody in development for SLE, in healthy volunteers.
METHODS: In this Phase I randomised, placebo-controlled study, 30 adults were
assigned to three treatment cohorts (anifrolumab 300 mg SC (n=6), anifrolumab
300 mg intravenous (n=6), anifrolumab 600 mg SC (n=6)) and placebo (n=4/cohort).
Serial blood samples were collected up to Day 84 to measure anifrolumab
concentrations and antidrug antibodies (ADAs). PK parameters were estimated by
noncompartmental analysis.
RESULTS: Maximum serum concentrations in SC cohorts occurred after 4-7 days.
Anifrolumab serum concentrations were below the limit of detection in all
individuals by Day 84. Exposure to SC anifrolumab increased dose proportionally
from 300 mg to 600 mg based on area under the serum concentration-time curve.
Anifrolumab 300 mg SC exposure reached 87% of the intravenous exposure.
Anifrolumab 300 mg SC and placebo administration elicited minimal injection-site
reactions. Transient injection-site induration occurred in five of six
individuals after anifrolumab 600 mg SC and two of four individuals after
placebo. Transient, mild to moderate injection-site induration and pruritus
occurred simultaneously in two of six individuals after anifrolumab 600 mg SC.
Adverse events were reported by 50% (n=9) of anifrolumab-treated individuals and
33% (n=4) of placebo-treated individuals. ADAs were detected in only one
individual in the anifrolumab 300-mg intravenous group at the Day 84 assessment.
CONCLUSION: Anifrolumab 300-mg SC exposure was 87% of intravenous
administration, with single SC anifrolumab administrations well tolerated in
healthy volunteers. OBJECTIVE: We investigated the mechanistic and pharmacological properties of
anifrolumab, a fully human, effector-null, anti-type I interferon (IFN) alpha
receptor 1 (IFNAR1) monoclonal antibody in development for SLE.
METHODS: IFNAR1 surface expression and internalisation on human monocytes before
and after exposure to anifrolumab were assessed using confocal microscopy and
flow cytometry. The effects of anifrolumab on type I IFN pathway activation were
assessed using signal transducer and activator of transcription 1 (STAT1)
phosphorylation, IFN-stimulated response element-luciferase reporter cell assays
and type I IFN gene signature induction. The ability of anifrolumab to inhibit
plasmacytoid dendritic cell (pDC) function and plasma cell differentiation was
assessed by flow cytometry and ELISA. Effector-null properties of anifrolumab
were assessed in antibody-dependent cell-mediated cytotoxicity (ADCC) and
complement-dependent cytotoxicity (CDC) assays with B cells.
RESULTS: Anifrolumab reduced cell surface IFNAR1 by eliciting IFNAR1
internalisation. Anifrolumab blocked type I IFN-dependent STAT1 phosphorylation
and IFN-dependent signalling induced by recombit and pDC-derived type I IFNs
and serum of patients with SLE. Anifrolumab suppressed type I IFN production by
blocking the type I IFN autoamplification loop and inhibited proinflammatory
cytokine induction and the upregulation of costimulatory molecules on stimulated
pDCs. Blockade of IFNAR1 suppressed plasma cell differentiation in pDC/B cell
co-cultures. Anifrolumab did not exhibit CDC or ADCC activity.
CONCLUSIONS: Anifrolumab potently inhibits type I IFN-dependent signalling,
including the type I IFN autoamplification loop, and is a promising therapeutic
for patients with SLE and other diseases that exhibit chronic dysfunctional type
I IFN signalling. OBJECTIVE: This post hoc analysis compared anifrolumab 300 mg every 4 weeks with
placebo on rash and arthritis measures with different stringency in patients
with moderate to severe SLE (phase IIb; MUSE; NCT01438489). Subgroups were
analysed by type I interferon gene signature (IFNGS test-high or test-low).
METHODS: Rash was measured with the SLE Disease Activity Index 2000 (SLEDAI-2K),
British Isles Lupus Assessment Group (BILAG) Index and modified Cutaneous Lupus
Erythematosus Disease Area and Severity Index (mCLASI). Arthritis was evaluated
using SLEDAI-2K, BILAG and swollen and tender joint counts. Outcomes were
measured at week 52.
RESULTS: More anifrolumab-treated patients demonstrated resolution of rash by
SLEDAI-2K versus placebo: 39/88 (44.3%) versus 13/88 (14.8%), OR (90% CI) 4.56
(2.48 to 8.39), p<0.001; improvement of BILAG: 48/82 (58.5%) versus 24/85
(28.2%), OR (90% CI) 3.59 (2.08 to 6.19), p<0.001; and ≥50% improvement by
mCLASI: 57/92 (62.0%) versus 30/89 (33.7%), OR (90% CI) 3.31 (1.97 to 5.55),
p<0.001. More anifrolumab-treated patients had improved arthritis by SLEDAI-2K
versus placebo: 55/97 (56.7%) versus 42/99 (42.4%), OR (90% CI) 1.88 (1.16 to
3.04), p=0.032; and BILAG: 65/94 (69.1%) versus 47/95 (49.5%), OR (90% CI) 2.47
(1.48 to 4.12), p=0.003; and mean (SD) swollen and tender joint reductions: -5.5
(6.3) versus -3.4 (5.9), p=0.004. Comparable results were demonstrated in IFNGS
test-high patients (n=151). In IFNGS test-low patients (n=50), substantial
numerical differences in partial rash and arthritis responses were observed in
anifrolumab-treated patients versus placebo, with statistical significance only
for rash by BILAG in this small population.
CONCLUSIONS: Anifrolumab treatment was associated with improvements versus
placebo in specific SLE features of arthritis and rash using measures of
different stringency. Although driven by robust data in the prevalent IFNGS
test-high population, further evaluation in IFNGS test-low patients is
warranted. |
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