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Objectives To evaluate a testing algorithm for the rapid identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that includes the use of PCR-based targeted single nucleotide polymorphism (SNP) detection assays preceded by a multiplex PCR sensitive to S-Gene Target Failure (SGTF). Methods PCR SNP assays targeting SARS-CoV-2 S-gene mutations ΔH69–V70, L452R, E484K, N501Y, H655Y and P681R using melting curve analysis were performed on 567 samples in which SARS-CoV-2 viral RNA was detected by a multiplex PCR. Viral whole-genome sequencing (WGS) was performed to confirm the presence of SNPs and to identify the Pangolin lineage. Additionally, 1133 SARS-CoV-2 positive samples with SGTF were further assessed by WGS to determine the presence of ΔH69–V70. Results The N501Y-specific assay (n = 567) had an overall percentage agreement (OPA) of 98.5%. The ΔH69-V70-specific (n = 178) and E484K-specific (n = 401) assays had OPA of 96.6% and 99.7%, respectively. Assessment of H655Y (n = 139) yielded a 100.0% concordance when applied in the proposed algorithm. The L452R-specific (n = 67) and P681R-specific (n = 62) assays had an OPA of 98.2% and 98.1%, respectively. The proposed algorithm identified six variants of concern/interest (VOC/VOI)—Alpha (n = 149), Beta (n = 65), Gamma (n = 86), Delta (n = 49), Eta (n = 6), Kappa (n = 6)—and 205 non-VOC/VOI strains—including the variants under monitoring B.1.214.2 (n = 43) and B.1.1.318 (n = 18) and Epsilon (n = 1). An excellent concordance was observed for the identification of all SARS-CoV-2 lineages evaluated. Conclusions We present a flexible testing algorithm for the rapid detection of current and emerging SARS-CoV-2 VOC/VOIs, which can be easily adapted based on the local endemicity of specific variants.

Gliomas account for more than 50% of all primary brain tumors. The worst prognosis is associated with gliomas of astrocytic origin, whereas gliomas with an oligodendroglial origin offer higher sensitivity to chemotherapy, especially when oligodendroglioma cells display 1p19q deletions. Temozolomide (TMZ) provides therapeutic benefits and is commonly used with radiotherapy in highly malignant astrocytic tumors, including glioblastomas. The actual benefits of TMZ during long-term treatment in oligodendroglioma patients have not yet been clearly defined. In this study, we have investigated the effects of such a long-term TMZ treatment in the unique Hs683 oligodendroglioma model. We have observed increased TMZ sensitivity of Hs683 orthotopic tumors that were previously treated in vitro with months of progressive exposure to increasing TMZ concentrations before being xenografted into the brains of immunocompromised mice. Whole-genome and proteomic analyses have revealed that this increased TMZ sensitivity of Hs683 oligodendroglioma cells previously treated for long periods with TMZ can be explained, at least partly, by a TMZ-induced p38-dependant dormancy state, which in turn resulted in changes in amino acid metabolism balance, in growth delay, and in a decrease in Hs683 oligodendroglioma cell-invasive properties. Thus, long-term TMZ treatment seems beneficial in this Hs683 oligodendroglioma model, which revealed itself unable to develop resistance against TMZ., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

Les gliomes representent les tumeurs cerebrales primitives les plus frequentes et regroupent differentes entites au pronostic tres different. L’examen anatomopathologique est le gold standard pour le diagnostic de ces tumeurs. Cependant, les pathologistes peuvent rencontrer des difficultes diagnostiques dues entre autres a l’heterogeneite tumorale ou a la petite taille des prelevements. Nous avons assiste, ces dernieres annees, a des avancees majeures dans la decouverte des alterations moleculaires de ces cancers qui ont mene au developpement de nouveaux marqueurs moleculaires, certains avec un role diagnostic, d’autres avec un impact pronostic et/ou predictif de la reponse therapeutique. Dans la pratique quotidienne, il est donc devenu primordial de tester la presence de differentes alterations moleculaires telles que la codeletion 1p/19q, les mutations des genes IDH, la deletion de p16, l’amplification du gene EGFR ou la methylation du promoteur du gene MGMT, afin de confirmer le diagnostic, d’evaluer le pronostic des patients ainsi que d’orienter les choix therapeutiques.

Le next generation sequencing (NGS) est une technologie qui permet de sequencer simultanement des millions de courts fragments d’ADN. Cette technologie offre un grand avantage par rapport aux techniques de sequencage traditionnelles de part son debit, son cout reduit, sa rapidite et sa grande sensibilite pour la detection de mutations dans l’ADN. Le NGS permet differentes applications comme le sequencage de genomes entiers, d’exome, de transcriptome ou le sequencage cible de multiples regions. De plus ce sequencage peut etre effectue a partir de seulement 10 ng d’ADN permettant ainsi de sequencer de tres petits echantillons FFPE tels que ceux le plus couramment disponible dans la pratique clinique. De nombreuses etudes ont ainsi demontre la faisabilite et les avantages du sequencage cible par NGS pour la caracterisation moleculaire de differents types de cancers tel que les cancers colorectaux et pulmonaires, et l’interet d’integrer ces methodes a la pratique clinique.