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BackgroundRhabdomyosarcoma (RMS) is rare cancer affecting children and adults. Pleomorphic RMS histology is almost exclusive to adult patients and often resistant to chemotherapy.ObjectiveWe report the case of a 19-year-old patient who presented with a metastatic chemoresistant pleomorphic RMS.MethodsConsidering 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.ResultsWES identified a germline variation (c.1863_1864insT) in the MLH1 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 MLH1 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.ConclusionThis 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.

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

To circumvent the limitations of available preclinical models for the study of type 1 diabetes (T1D), we developed a new humanized model, the YES-RIP-hB7.1 mouse. This mouse is deficient of murine major histocompatibility complex class I and class II, the murine insulin genes, and expresses as transgenes the HLA-A*02:01 allele, the diabetes high-susceptibility HLA-DQ8A and B alleles, the human insulin gene, and the human co-stimulatory molecule B7.1 in insulin-secreting cells. It develops spontaneous T1D along with CD4 + and CD8 + T-cell responses to human preproinsulin epitopes. Most of the responses identified in these mice were validated in T1D patients. This model is amenable to characterization of hPPI-specific epitopes involved in T1D and to the identification of factors that may trigger autoimmune response to insulin-secreting cells in human T1D. It will allow evaluating peptide-based immunotherapy that may directly apply to T1D in human and complete preclinical model availability to address the issue of clinical heterogeneity of human disease.

Background Neurofibromatosis type 1 (NF1) is a common dominant tumor predisposition syndrome affecting 1 in 3,500 individuals. The hallmarks of NF1 are the development of peripheral nerve sheath tumors either benign (dermal and plexiform neurofibromas) or malignant (MPNSTs). Results To comprehensively characterize the role of microRNAs in NF1 tumorigenesis, we analyzed 377 miRNAs expression in a large panel of dermal and plexiform neurofibromas, and MPNSTs. The most significantly upregulated miRNA in plexiform neurofibromas was miR-486-3p that targets the major tumor suppressor gene, PTEN . We confirmed PTEN downregulation at mRNA level. In plexiform neurofibromas, we also report aberrant expression of four miRNAs involved in the RAS-MAPK pathway (miR-370, miR-143, miR-181a, and miR-145). In MPNSTs, significant deregulated miRNAs were involved in PTEN repression (miR-301a, miR-19a, and miR-106b), RAS-MAPK pathway regulation (Let-7b, miR-195, and miR-10b), mesenchymal transition (miR-200c, let-7b, miR-135a, miR-135b, and miR-9), HOX genes expression (miR-210, miR-196b, miR-10a, miR-10b, and miR-9), and cell cycle progression (miR-195, let-7b, miR-20a, miR-210, miR-129-3p, miR-449a, and miR-106b). Conclusion We confirmed the implication of PTEN in genesis of plexiform neurofibromas and MPNSTs in NF1. Markedly deregulated miRNAs might have potential diagnostic or prognostic value and could represent novel strategies for effective pharmacological therapies of NF1 tumors.

We report our 5-year experience in neurofibromatosis type 1 prenatal diagnosis (PND): 205 PNDs in 146 women (chorionic villus biopsies, 88% or amniocentesis, 12%). The NF1 variant was present in 85 (41%) and absent in 122 (59%) fetuses. Among 205 pregnancies (207 fetuses), 135 were carried to term (119 unaffected and 16 NF1 affected children), 69 pregnancy terminations (affected fetuses), 2 miscarriages, and 1 in utero death. The majority of PND requests came from parents with sporadic NF1. We describe two PNDs in women with mosaic NF1. In both families, direct PND showed the absence of the maternal NF1 variant in the fetus. However, microsatellite markers analysis showed that the risk haplotype had been transmitted. These rare cases of germline mosaicism illustrate the pitfall of indirect PND. Our study illustrates the crucial consequences of PND for medical and genetic counseling decisions. We also point to the challenges of germline mosaics.

The wide clinical spectrum of the ABCB4 gene (ATP-binding cassette subfamily B member 4) deficiency syndromes in humans includes low phospholipid-associated cholelithiasis (LPAC), intrahepatic cholestasis of pregnancy (ICP), oral contraceptives-induced cholestasis (CIC), and progressive familial intrahepatic cholestasis type 3 (PFIC3). No ABCB4 mutations are found in a significant proportion of patients with these syndromes. In the present study, 102 unrelated adult patients with LPAC (43 patients) or CIC/ICP (59 patients) were screened for ABCB4 mutations using DNA sequencing. Heterozygous ABCB4 point or short insertion/deletion mutations were found in 37% (16/43) of the LPAC patients and in 27% (16/59) of the ICP/CIC patients. High-resolution gene dosage methodologies were used in the 70 negative patients. Here, we describe for the first time ABCB4 partial or complete heterozygous deletions in 7% (3/43) of the LPAC patients, and in 2% (1/59) of the ICP/CIC patients. Our observations urge to systematically test patients with LPAC, ICP/CIC, and also children with PFIC3 for the presence of ABCB4 deletions using molecular tools allowing detection of gross rearrangements. In clinical practice, a comprehensive ABCB4 alteration-screening algorithm will permit the use of ABCB4 genotyping to confirm the diagnosis of LPAC or ICP/CIC, and allow familial testing. An early diagnosis of these biliary diseases may be beneficial because of the preventive effect of ursodeoxycholic acid on biliary complications. Further comparative studies of patients with well-characterized genotypes (including deletions) and phenotypes will help determine whether ABCB4 mutation types influence clinical outcomes.

The preoperative diagnosis of intraductal papillary mucinous neoplasms (IPMN) of the pancreas must be as reliable as possible because large or even total pancreatectomy may be necessary. Early diagnosis of malignant forms is important to improve prognosis. The diagnostic accuracy of fluid analysis using endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been confirmed in cystic lesions of the pancreas. It is not known if these results can be applied to IPMN. To determine the levels of biochemical and tumor markers in fluid from EUS-FNA in patients with IPMN and to assess the impact on the diagnosis of IPMN. In total, 41 patients (14 men, median age 64 yr) underwent EUS-FNA before surgical resection of IPMN in our center. Levels of amylase, lipase, carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19.9, and CA 72.4 were measured in the cyst fluid. The performance of the markers was retrospectively evaluated for: (a) a positive diagnosis of IPMN, using cutoffs validated in the literature for mucinous pancreatic lesions and (b) an assessment of malignancy (i.e., high-grade dysplasia or invasive carcinoma) compared with the final pathological examination of the surgical specimen. EUS-FNA was performed in dilated branch ducts (BD) in 39 cases and in the main pancreatic duct in 2 cases. No serious complications occurred. The median fluid levels of amylase, lipase, CEA, CA 19.9, and CA 72.4 were 20,155 U/mL, 59,500 U/mL, 173 ng/mL, 6,400 U/mL, and 11.5 U/mL, respectively. A CEA level >200 ng/mL and a CA 72.4 >40 U/mL had a 44% and a 39% sensitivity, respectively, for the diagnosis of IPMN. The levels of CEA, CA 19.9, and CA 72.4 were significantly different between benign and malignant IPMN. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of a CEA level >200 ng/mL for the diagnosis of malignant IPMN were 90%, 71%, 50%, and 96%, respectively. The sensitivity, specificity, PPV, and NPV of a CA 72.4 level >40 U/mL for this purpose were 87.5%, 73%, 47%, and 96%, respectively. CEA and CA 72.4 in pancreatic cyst fluid have excellent NPVs in the preoperative differential diagnosis of benign versus malignant IPMN, and might reinforce the decision of not to operate on patients with BD-type without predictive factors of malignancy.

The tumor suppressor gene neurofibromin 1 (NF1) is a major regulator of the RAS‐MAPK pathway. NF1 mutations occur in lung cancer but were not extensively explored. We hypothesized that NF1‐mutated tumors could define a specific population with a distinct clinical and molecular profile. We performed NF1 sequencing using next generation sequencing (NGS) in 154 lung adenocarcinoma surgical specimens with known KRAS, EGFR, TP53, BRAF, HER2, and PIK3CA status, to evaluate the molecular and clinical specificities of NF1‐mutated lung cancers. Clinical data were retrospectively collected, and their associations with molecular profiles assessed. In this series, 24 tumors were NF1 mutated (17.5%) and 11 were NF1 deleted (8%). There was no mutation hotspot. NF1 mutations were rarely associated with other RAS‐MAPK pathway mutations. Most of patients with NF1 alterations were males (74.3%) and smokers (74.3%). Overall survival and disease‐free survival were statistically better in patients with NF1 alterations (N = 34) than in patients with KRAS mutations (N = 30) in univariate analysis. Our results confirm that NF1 is frequently mutated and represents a distinct molecular and clinical subtype of lung adenocarcinoma. Although NF1 gene is a regulator of RAS‐MAPK pathway, only few studies describe NF1 mutations in lung adenocarcinoma. In this study, we found that 17.5% were NF1 mutations and 8% were NF1 deletions: these NF1 alterations define a distinct clinical and molecular entity of lung adenocarcinoma.

Patients with NF1 microdeletion develop more neurofibromas at a younger age, and have an increased risk of malignant peripheral nerve sheath tumors (MPNSTs). We postulated that the increased risk of malignancy could be due to inactivation, in addition to NF1 , of a second tumor suppressor gene located in the typical 1.4-Mb microdeletion found in most of the microdeleted patients. We investigated the expression of NF1 , the other 16 protein-coding genes and the 2 microRNAs located in the 1.4-Mb microdeletion by means of real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) in a large series of human dermal and plexiform neurofibromas and MPNSTs. Five genes were significantly upregulated: OMG and SUZ12 in plexiform neurofibromas and ATAD5, EVI2A and C17 orf79 in MPNSTs. More interestingly, two genes were significantly downregulated ( RNF135 and CENTA2 ) in tumor Schwann cells from MPNST biopsies and in MPNST cell lines. This study points to the involvement of several genes (particularly RNF135 and CENTA2 ) in the increased risk of malignancy observed in NF1-microdeleted patients.

Connective tissue growth factor (CTGF) is a 38-kd protein involved in several human fibrotic disorders including atherosclerosis and skin and renal fibrosis. Although it has been shown that human and experimental liver fibrosis is associated with CTGF expression through up-regulation of CTGF mRNA by hepatic stellate cells (HSC), the role of CTGF in the liver has not yet been determined. The aim of the present study was to assess the effects of CTGF on rat primary HSC and its regulation in a well-established model of in vitro liver fibrogenesis. Incubation of primary HSC with recombinant CTGF induced a significant migratory (2.3-fold, 50 ng/ml CTGF) and proliferative effect (1.8-fold, 100 ng/ml CTGF). Type I collagen mRNA expression, as assessed by a real-time RT-PCR procedure, was also increased when cells were incubated in the presence of CTGF (2-fold, 50 ng/ml). Transforming growth factor-β1 (TGF-β1) strongly stimulated CTGF mRNA expression, a direct mechanism observed in the absence of any intermediate protein synthesis. Furthermore, spontaneous activation of HSC plated on plastic and stimulation by vascular endothelial growth factor, lipid peroxidation products (HNE, MDA), acetaldehyde, and platelet-derived growth factor (PDGF)-BB significantly up-regulated CTGF mRNA expression in HSC. PDGF-induced CTGF stimulation might be related in part to TGF-β1 secretion because CTGF mRNA up-regulation observed after PDGF-BB stimulation was abrogated in the presence of neutralizing TGF-β1 antibody. In conclusion, this study extends the role of CTGF in HSC activation and suggests that CTGF up-regulation might be a central pathway during HSC activation.