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Murviel-lès-Montpellier, France

Alix-Panabieres C.,Institute Of Recherche En Biotherapie | Alix-Panabieres C.,Montpellier University | Pierga J.-Y.,University Pierre and Marie Curie | Pierga J.-Y.,University of Paris Descartes
Bulletin du Cancer | Year: 2014

The detection and molecular characterization of circulating tumor cells (CTCs) are one of the most active areas of translational cancer research, with more than 400 clinical studies having included CTCs as a biomarker.The aims of research on CTCs include: a) estimation of the risk for metastatic relapse or metastatic progression (prognostic information); b) stratification and real-time monitoring of therapies; c) identification of therapeutic targets and resistance mechanisms; and d) understanding metastasis development in cancer patients.This review focuses on the technologies used for the enrichment and detection of CTCs. We outline and discuss the current technologies that are based on exploiting the physical and biological properties of CTCs. A number of innovative technologies to improve methods for CTC detection have recently been developed, including CTC microchips, filtration devices, quantitative reverse-transcription PCR assays, and automated microscopy systems. Molecular characterization studies have indicated, however, that CTCs are very heterogeneous, a finding that underscores the need for multiplex approaches to capture all of the relevant CTC subsets. We therefore emphasize the current challenges of increasing the yield and detection of CTCs that have undergone an epithelial-mesenchymal transition. Increasing assay analytical sensitivity may lead, however, to a decrease in analytical specificity (e.g., through the detection of circulating normal epithelial cells).A considerable number of promising CTC detection techniques have been developed in recent years. The analytical specificity and clinical utility of these methods must be demonstrated in large prospective multicenter studies to reach the high level of evidence required for their introduction into clinical practice. Copyright © 2007 John Libbey Eurotext - All rights reserved. Source

Kania D.,Center Muraz | Kania D.,et Maladies Associees Center Muraz | Kania D.,French Institute of Health and Medical Research | Kania D.,Montpellier University | And 19 more authors.
Clinical Microbiology and Infection | Year: 2013

People screened for human immunodeficiency virus (HIV) using rapid diagnostic tests (RDTs) in Africa remain generally unaware of their status for hepatitis B (HBV) and hepatitis C (HCV) infections. We evaluated a two-step screening strategy in Burkina Faso, using both HIV RDTs and Dried Blood Spot (DBS) assays to confirm an HIV-positive test, and to test for HBV and HCV infections. HIV counselling and point-of-care testing were performed at a voluntary counselling and testing centre with HBV, HCV status and HIV confirmation using DBS specimens, being assessed at a central laboratory. Serological testing on plasma was used as the reference standard assay to control for the performance of DBS assays. Nineteen out of 218 participants included in the study were positive for HIV using RDTs. A fourth-generation HIV ELISA and immunoblot assays on DBS confirmed HIV status. Twenty-four out of 25 participants infected with HBV were found positive for hepatitis B surface antigen (HBsAg) using DBS. One sample with a low HBsAg concentration on plasma was not detected on DBS. Five participants tested positive for HCV antibodies were confirmed positive with an immunoblot assay using DBS specimens. Laboratory results were communicated within 7 days to participants with no loss to follow up of participants between the first and second post-test counselling sessions. In conclusion, DBS collection during HIV point-of-care testing enables screening and confirmation of HBV, HCV and HIV infections. Diagnosis using DBS may assist with implementation of national programmes for HBV, HCV and HIV screening and clinical care in middle- to low-income countries. © 2013 European Society of Clinical Microbiology and Infectious Diseases. Source

Akkari L.,French National Center for Scientific Research | Akkari L.,Montpellier University | Haouzi D.,French National Center for Scientific Research | Haouzi D.,Montpellier University | And 11 more authors.
Journal of Cellular Physiology | Year: 2010

Cellular differentiation relies on both physical and chemical environmental cues. The bipotential mouse embryonic liver (BMEL) cells are early progenitors of liver epithelial cells with an apparently infinite proliferative potential. These cells, which remain undifferentiated in a monolayer culture, differentiate upon release from geometrical constraints imposed by growth on a stiff plastic plate. In a complex three dimensional environment of a Matrigel extracellular matrix, BMEL cells form two types of polarized organoids of distinct morphologies: cyst-like structures suggesting cholangiocyte-type organization or complex organoids, reminiscent of liver parenchyma and associated with acquisition of hepatocyte-specific phenotypic markers. The choice of the in vitro differentiation lineage is governed by Transforming Growth Factor-β (TGF-β) signaling. Our results suggest that morphological cues initiate the differentiation of early hepatic precursors and confirm the inhibitory role of TGF-β on hepatocytic lineage differentiation. © 2010 Wiley-Liss, Inc. Source

Pangault C.,Rennes University Hospital Center | Pangault C.,University of Rennes 1 | Ame-Thomas P.,Rennes University Hospital Center | Ame-Thomas P.,University of Rennes 1 | And 17 more authors.
Leukemia | Year: 2010

Follicular lymphoma (FL) B cells contract tight connections with their microenvironment, which governs the pathogenesis and progression of the disease. Indeed, specific immune response gene signatures, obtained from whole biopsy samples, have been associated with patient survival. In this study, we performed gene expression profiling of purified B cell and non-B cell compartments obtained from FL and reactive lymph nodes. We identified 677 non-redundant genes defining the FL interface and involving 26 FL-specific functional networks. This approach highlighted an interleukin-4 (IL-4)-centered pathway associated with an activation of signal transducer and activator of transcription 6 (STAT6), which favors overexpression of IL-4-target genes. In addition, FL microenvironment was characterized by a strong enrichment in follicular helper T cells (TFH), as demonstrated through transcriptomic and flow cytometry analyses. The majority of phospho-STAT6 pos B cells were located at the vicinity of cells expressing the programmed death 1 (PD-1) TFH marker. Moreover, purified FL-derived TFH, expressed IL4 at very high levels compared with purified tonsil-derived TFH or non-T FH microenvironment. Altogether, our study demonstrated that tumor-infiltrating TFH specifically express functional IL-4 in FL, creating an IL-4-dependent TFH-B cell axis. This cross talk could sustain FL pathogenesis and represent a new potential therapeutic target. © 2010 Macmillan Publishers Limited All rights reserved. Source

Bai Q.,French Institute of Health and Medical Research | Bai Q.,Montpellier University | Bai Q.,Institute Of Recherche En Biotherapie | Bai Q.,Chongqing Medical University | And 14 more authors.
Stem Cells and Development | Year: 2015

Simplified culture conditions are essential for large-scale drug screening and medical applications of human pluripotent stem cells (hPSCs). However, hPSCs [ie, human embryonic stem cells (hESCs), and human induced pluripotent stem cells (iPSCs) are prone to genomic instability, a phenomenon that is highly influenced by the culture conditions. Enzymatic dissociation, a cornerstone of large-scale hPSC culture systems, has been reported to be deleterious, but the extent and the timeline of the genomic alterations induced by this passaging technique are still unclear. We prospectively monitored three hESC lines that were initially derived and cultured on human feeders and passaged mechanically before switching to enzymatic single-cell passaging. We show that karyotype abnormalities and copy number variations are not restricted to long-term culture, but can occur very rapidly, within five passages after switching hESCs to enzymatic dissociation. Subchromosomal abnormalities preceded or accompanied karyotype abnormalities and were associated with increased occurrence of DNA double-strand breaks. Our results indicate that enzymatic single-cell passaging can be highly deleterious to the hPSC genome, even when used only for a limited period of time. Moreover, hPSC culture techniques should be reappraised by complementing the routine karyotype analysis with more sensitive techniques, such as microarrays, to detect subchromosomal abnormalities. Copyright 2015, Mary Ann Liebert, Inc. Source

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