Summary HCV infection is a global health problem that affects 170 million people worldwide. The severity of the disease varies from asymptomatic chronic infection to cirrhosis and hepatocellular ...carcinoma (HCC). Recently, the standard of care for genotype 1 patients has greatly improved with the addition of protease inhibitors (telaprevir or boceprevir) to pegylated interferon (PegIFN) and ribavirin (RBV). The prediction of fibrosis progression and the response to antiviral treatment are two major issues in the management of patients with chronic hepatitis C. Differential expression of mRNAs was first analyzed for both progression of fibrosis and treatment response. Specific polymorphisms, associated with either fibrosis or viral response, were identified thanks to major improvements in genome scanning technologies. Since 2009, several independent genome wide association studies (GWAS) have reported an association between genetic polymorphisms within the IL-28B promoter and both natural and treatment-induced clearance in genotype 1 infected patients. These different studies showed the strong association and the importance of IL-28B polymorphisms in the treatment response. Combining the different genetic factors could improve their predictive value and help identify patients at a high risk of progression of fibrosis as well as those with a lower chance of responding to treatment. The aim of this review was to discuss the genomic factors (mRNAs, miRNAs, and SNPs) and HCV infection with clinical implications for either progression of fibrosis or treatment response. Recent findings on the IL-28B polymorphism and its application in clinical practice will also be discussed.
Clinical overlap between neurofibromatosis type 2 (NF2), schwannomatosis, and meningiomatosis can make clinical diagnosis difficult. Hence, molecular investigation of germline and tumor tissues may ...improve the diagnosis.
We present the targeted next-generation sequencing (NGS) of NF2, SMARCB1, LZTR1, SMARCE1, and SUFU tumor suppressor genes, using an amplicon-based approach. We analyzed blood DNA from a cohort of 196 patients, including patients with NF2 (N = 79), schwannomatosis (N = 40), meningiomatosis (N = 12), and no clearly established diagnosis (N = 65). Matched tumor DNA was analyzed when available. Forty-seven NF2-/SMARCB1-negative schwannomatosis patients and 27 NF2-negative meningiomatosis patients were also evaluated.
A NF2 variant was found in 41/79 (52%) NF2 patients. SMARCB1 or LZTR1 variants were identified in 5/40 (12.5%) and 13/40 (∼32%) patients in the schwannomatosis cohort. Potentially pathogenic variants were found in 12/65 (18.5%) patients with no clearly established diagnosis. A LZTR1 variant was identified in 16/47 (34%) NF2/SMARCB1-negative schwannomatosis patients. A SMARCE1 variant was found in 3/39 (∼8%) meningiomatosis patients. No SUFU variant was found in the cohort. NGS was an effective and sensitive method to detect mutant alleles in blood or tumor DNA of mosaic NF2 patients. Interestingly, we identified a 4-hit mechanism resulting in the complete NF2 loss-of-function combined with SMARCB1 and LZTR1 haploinsufficiency in two-thirds of tumors from NF2 patients.
Simultaneous investigation of NF2, SMARCB1, LZTR1, and SMARCE1 is a key element in the differential diagnosis of NF2, schwannomatosis, and meningiomatosis. The targeted NGS strategy is suitable for the identification of NF2 mosaicism in blood and for the investigation of tumors from these patients.
Abnormalities in neuronal cholesterol homeostasis have been suspected or observed in several neurodegenerative disorders including Alzheimer's disease, Parkinson's disease and Huntington's disease. ...However, it has not been demonstrated whether an increased abundance of cholesterol in neurons in vivo contributes to neurodegeneration. To address this issue, we used RNA interference methodology to inhibit the expression of cholesterol 24-hydroxylase, encoded by the Cyp46a1 gene, in the hippocampus of normal mice. Cholesterol 24-hydroxylase controls cholesterol efflux from the brain and thereby plays a major role in regulating brain cholesterol homeostasis. We used an adeno-associated virus vector encoding short hairpin RNA directed against the mouse Cyp46a1 mRNA to decrease the expression of the Cyp46a1 gene in hippocampal neurons of normal mice. This increased the cholesterol concentration in neurons, followed by cognitive deficits and hippocampal atrophy due to apoptotic neuronal death. Prior to neuronal death, the recruitment of the amyloid protein precursor to lipid rafts was enhanced leading to the production of β-C-terminal fragment and amyloid-β peptides. Abnormal phosphorylation of tau and endoplasmic reticulum stress were also observed. In the APP23 mouse model of Alzheimer's disease, the abundance of amyloid-β peptides increased following inhibition of Cyp46a1 expression, and neuronal death was more widespread than in normal mice. Altogether, these results suggest that increased amounts of neuronal cholesterol within the brain may contribute to inducing and/or aggravating Alzheimer's disease.
Alterations of chromatin modifiers are frequent in cancer, but their functional consequences often remain unclear. Focusing on the Polycomb protein EZH2 that deposits the H3K27me3 (trimethylation of ...Lys27 of histone H3) mark, we showed that its high expression in solid tumors is a consequence, not a cause, of tumorigenesis. In mouse and human models, EZH2 is dispensable for prostate cancer development and restrains breast tumorigenesis. High EZH2 expression in tumors results from a tight coupling to proliferation to ensure H3K27me3 homeostasis. However, this process malfunctions in breast cancer. Low EZH2 expression relative to proliferation and mutations in Polycomb genes actually indicate poor prognosis and occur in metastases. We show that while altered EZH2 activity consistently modulates a subset of its target genes, it promotes a wider transcriptional instability. Importantly, transcriptional changes that are consequences of EZH2 loss are predominantly irreversible. Our study provides an unexpected understanding of EZH2's contribution to solid tumors with important therapeutic implications.
Pegylated interferon alfa‐2a (PEG‐IFN) may induce sustained virological response (SVR) in 20% of hepatitis B e antigen (HBeAg)‐negative chronic hepatitis B (CHB) patients. In addition, loss of ...hepatitis B surface antigen (HBsAg) is achieved with a 10% yearly rate after treatment cessation in sustained responders. The aim of this study was to assess on‐treatment serum HBsAg kinetics to predict SVR in HBeAg‐negative patients treated with PEG‐IFN. Forty‐eight consecutive patients were treated with PEG‐IFN (180 μg/week) for 48 weeks. Serum hepatitis B virus (HBV) DNA (COBAS TaqMan) and HBsAg (Abbott Architect HBsAg QT assay) were assessed at baseline, during treatment (weeks 12, 24, and 48), and during follow‐up (weeks 72 and 96). SVR was defined as undetectable serum HBV DNA (<70 copies/mL) 24 weeks after treatment cessation. Twenty‐five percent of patients achieved SVR. They were not different from those who failed treatment regarding age, sex, ethnicity, HBV genotype, baseline serum HBV DNA and HBsAg levels, or liver histology. During treatment, serum HBsAg levels decreased only in patients who developed SVR, with mean decreases of 0.8 ± 0.5, 1.5 ± 0.6, and 2.1 ± 1.2 log10 IU/mL at weeks 12, 24, and 48, respectively. A decrease of 0.5 and 1 log10 IU/mL in serum HBsAg levels at weeks 12 and 24 of therapy, respectively, had high predictive values of SVR (negative predictive value NPV 90%, positive predictive value PPV 89% for week 12; NPV 97%, PPV 92% for week 24). HBsAg loss was observed in three patients, all with SVR. Conclusion: Early serum HBsAg drop has high predictive values of SVR to PEG‐IFN in HBeAg‐negative CHB patients. Serum quantitative HBsAg may be a useful tool to optimize the management of PEG‐IFN therapy in these patients. (HEPATOLOGY 2009.)
Background
Neurofibromatosis type 1 (NF1) is a tumor predisposition syndrome with a worldwide birth incidence of one in 2500. Genetic factors unrelated to the NF1 locus are thought to influence the ...number of plexiform neurofibromas (PNFs) in patients with NF1, but no factors have been identified to date.
Methods
We used high-resolution array comparative genomic hybridization of tissue from 22 PNFs obtained from 18 NF1 patients to identify modifier genes involved in PNF development. We used a family-based association test for five previously identified cancer-susceptibility tag single-nucleotide polymorphisms (rs1063192, rs2151280, rs2218220, rs10757257, and rs7023329) located in chromosomal region 9p21.3 in 1105 subjects (740 NF1 patients and 365 non-affected relatives) from 306 families. To confirm the functional role of rs2151280, we used real-time quantitative reverse transcription-polymerase chain reaction to analyze the expression of cyclin-dependent kinase inhibitor 2A (CDKN2A), CDKN2B, alternate reading frame (ARF), and antisense noncoding RNA in the INK4 locus (ANRIL) in the peripheral blood of 124 NF1 patients. Relationships between CDKN2A, CDKN2B, ARF, and ANRIL expression and the rs2151280 genotype were tested by the Kruskal-Wallis test. All statistical tests were two-sided.
Results
In NF1-associated PNFs, 9p21.3 deletions (including the CDKN2A/B-ANRIL locus) were found as the only recurrent somatic alterations. Single-nucleotide polymorphism rs2151280 (located in ANRIL) was statistically significantly associated with the number of PNFs (P < .001) in NF1 patients. In addition, allele T of rs2151280 was statistically significantly associated with reduced ANRIL transcript levels (P < .001), suggesting that modulation of ANRIL expression mediates PNF susceptibility.
Conclusion
Identification of ANRIL as a modifier gene in NF1 may offer clues to the molecular pathogenesis of PNFs, particularly neurofibroma formation, and emphasizes the unanticipated role of large noncoding RNA in activation of critical regulators of tumor development.
Rhabdomyosarcoma (RMS) is rare cancer affecting children and adults. Pleomorphic RMS histology is almost exclusive to adult patients and often resistant to chemotherapy.
We report the case of a ...19-year-old patient who presented with a metastatic chemoresistant pleomorphic RMS.
Considering the poor prognosis and the few systemic therapeutic options, we decided to carry out a whole exome sequencing (WES) of the tumour and germline DNA.
WES identified a germline variation (c.1863_1864insT) in the
gene corresponding to a pathogenic mutation: (p. Leu622Serfs*10), whereas the family history did not fit with classical criteria for Lynch syndrome. Loss-of-heterozygosity at
locus was found in the tumour. Immunohistochemistry showed loss of MLH1 and PMS2 nuclear expression in the tumour cells. In view of the mismatch repair defects and a high programmed cell death ligand 1 (PD-L1) expression (60% of tumour cells expressed PD-L1), we administrated an anti-PD-1 antibody to the patient. He achieved a rapid complete response of the lung metastases, which appears sustained after a 1-year follow-up.
This observation of an RMS revealing an unexpected Lynch syndrome underlines the overlap between tumorous and germline molecular genetics and emphasises the major impact of cancer genomic medicine in clinical practice for guiding treatment decision.
Clear cell meningioma (CCM) is a rare grade II histopathological subtype that usually occurs in young patients and displays high recurrence rate. Germline SMARCE1 mutations have been described in ...hereditary forms of this disease and more recently in small syndromic and sporadic CCM series. The diagnostic value of SMARCE1 in distinguishing between CCM and other meningioma variants has not been yet established. The aim of our study was to investigate the status of SMARCE1 in a series of CCMs and its morphological mimickers. We compared the performance of an anti‐SMARCE1 antibody and the molecular analysis of the SMARCE1 gene in a retrospective multicenter series of CCMs. All CCMs lossed SMARCE1 immunoexpression. Bi‐allelic inactivating events were found by NGS‐based sequencing in all of these cases, except for one, which was incompletely explored, but had a wild‐type sequence. We then validated the anti‐SMARCE1 antibody specificity by analyzing additional 305 pediatric and adult meningiomas of various subtypes and 15 non‐meningioma clear cell tumors by SMARCE1 immunohistochemistry. A nuclear immunostaining was preserved in all other meningioma variants, as well as non‐meningioma clear cell tumors. In conclusion, our series showed, for the first time, that SMARCE1 immunostaining is a highly sensitive biomarker for CCM, useful as a routine diagnostic biomarker.
Key requirements in type 1 diabetes are in setting up new assays as diagnostic biomarkers that will apply to prediabetes, likely T-lymphocyte assays, and in designing antigen-specific therapies to ...prevent its development. New preclinical models of T1D will be required to help advancing both aims. By crossing mouse strains that lack either murine major histocompatibility complex class-I, class-II genes and insulin genes, we developed YES mice that instead expresses human HLA-A*02:01, HLA-DQ8 and insulin genes as transgenes. The metabolic and immune phenotype of YES mice is basically identical to that of the parental strains. YES mice remain insulitis- and diabetes-free up to one year of follow up, maintain normoglycemia to an intraperitoneal glucose challenge in the long-term range, have a normal β-cell mass and show normal immune responses to conventional antigens. This new model has been designed to evaluate adaptive immune responses to human insulin on a genetic background that recapitulate human high susceptibility HLA-DQ8 genetic background. Although insulitis-free, YES mice develop T1D when challenged with polyInosinic-polyCytidylic acid. They allow characterizing preproinsulin epitopes recognized by CD8
and CD4
T-lymphocytes upon immunization against human preproinsulin or along diabetes development.
Nasopharyngeal sampling for nucleic acid amplification testing (NAAT) is the standard diagnostic test of coronavirus disease 2019. Our objectives were to assess, in real-life conditions, the ...diagnostic accuracy of a nasopharyngeal point-of-care antigen (Ag) test and of saliva NAAT for detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in ambulatory care. This was a prospective cohort study from 19 October through 18 December 2020 in two community COVID-19 screening centers in Paris, France. Two nasopharyngeal swabs and one saliva sample were simultaneously collected. Diagnostic accuracies of nasopharyngeal Ag testing and of three saliva NAAT methods were assessed as compared to nasopharyngeal NAAT. A total of 1452 ambulatory children and adults were included. Overall, 129/1443 (9%) participants tested positive on nasopharyngeal NAAT (102/564 18% in symptomatic and 27/879 3% in asymptomatic participants). Sensitivity was 94%, 23%, 96%, and 94% for the three different protocols of saliva NAAT and for the nasopharyngeal Ag test, respectively. Estimates of specificity were above 95% for all methods. Diagnostic accuracy was similar in symptomatic and asymptomatic individuals. Diagnostic accuracy of nasopharyngeal Ag testing and of saliva NAAT is similar to that of nasopharyngeal NAAT, subject to compliance with specific protocols for saliva. Registration number: NCT04578509
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