Cellular Heterogeneity and Cooperativity in Glioma Persister Cells Under Temozolomide Treatment

Factor de impacto: 6,684 Q1.We have observed a drug-tolerant/persister state in a human glioblastoma (GBM) cell line after exposure to temozolomide, the standard-of-care chemotherapeutic agent for GBM. We used a multicolor lentiviral genetic barcode labeling to follow cell population evolution during temozolomide treatment. We observed no change in the distribution of the different colored populations of cells in persister or resistant cells suggesting that pre-existing minor subpopulations, which would be expected to be restricted to a single color, were not amplified/selected during the response to the drug. We have previously identified four genes (CHI3L1, FAT2, KLK5, and HB-EGF) that were over-expressed during the persister stage. Single-cell analysis of these four genes indicated that they were expressed in different individual cells ruling out the existence of a single persister-specific clone but suggesting rather a global answer. Even so, the transitory silencing of CHI3L1, FAT2, or KLK5 influenced the expression of the other three genes and the survival of U251 cells in absence of temozolomide. Since proteins encoded by the four genes are all localized in the extracellular matrix or interact within the extracellular compartment, we propose that cellular interactions and communications are important during the persister stage before the acquisition of chemo-resistance. Thus, persisters might be a new therapeutically relevant target in GBM.This research was founded by a grant from the “Ligue contre le Cancer-Grand Ouest” and a Région Pays de la Loire special fund (ERRATA program).S

Gene expression profiling in sinonasal adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>Sinonasal adenocarcinomas are uncommon tumors which develop in the ethmoid sinus after exposure to wood dust. Although the etiology of these tumors is well defined, very little is known about their molecular basis and no diagnostic tool exists for their early detection in high-risk workers.</p> <p>Methods</p> <p>To identify genes involved in this disease, we performed gene expression profiling using cancer-dedicated microarrays, on nine matched samples of sinonasal adenocarcinomas and non-tumor sinusal tissue. Microarray results were validated by quantitative RT-PCR and immunohistochemistry on two additional sets of tumors.</p> <p>Results</p> <p>Among the genes with significant differential expression we selected <it>LGALS4, ACS5, CLU, SRI and CCT5 </it>for further exploration. The overexpression of <it>LGALS4, ACS5, SRI</it>, <it>CCT5 </it>and the downregulation of <it>CLU </it>were confirmed by quantitative RT-PCR. Immunohistochemistry was performed for LGALS4 (Galectin 4), ACS5 (Acyl-CoA synthetase) and CLU (Clusterin) proteins: LGALS4 was highly up-regulated, particularly in the most differentiated tumors, while CLU was lost in all tumors. The expression of ACS5, was more heterogeneous and no correlation was observed with the tumor type.</p> <p>Conclusion</p> <p>Within our microarray study in sinonasal adenocarcinoma we identified two proteins, LGALS4 and CLU, that were significantly differentially expressed in tumors compared to normal tissue. A further evaluation on a new set of tissues, including precancerous stages and low grade tumors, is necessary to evaluate the possibility of using them as diagnostic markers.</p

Le 5-fluorouracil et les marqueurs de résistance dans les cancers colorectaux (C.C.R.)

LYON1-BU Santé (693882101) / SudocRENNES1-BU Santé (352382103) / SudocSudocFranceF

HB-EGF is associated with DNA damage and Mcl-1 turnover in human glioma cell lines treated by Temozolomide

International audienceTemozolomide (TMZ) is the main chemotherapeutic agent used for treating newly diagnosed Glioblas-toma Multiforme (GBM), the most frequent malignant brain tumors in adults. This alkylating agent induces DNA double strand breaks (DSBs) which in turn lead to apoptosis by activating the Bcl-2 controlled mitochondrial pathway. However, GBM invariably recur as tumors become resistant to TMZ. We investigated the implication of EGFR ligands in this resistance and we found that the pro Heparin Binding Epidermal Growth Factor (proHB-EGF) expression is linked to the early response to TMZ in human glioma cell lines. However, HB-EGF does not affect apoptosis per se although its expression is associated with the degradation of Mcl-1. HB-EGF is implicated in DSBs repair as silencing of HB-EGF increased γH2AX foci half-life as well as USP9X expression, two features that could be linked to the observed effect on Mcl-1. Our data demonstrate a new role for HB-EGF in TMZ treated cell lines

Wild-type isocitrate dehydrogenase under the spotlight in glioblastoma

International audienceBrain tumors actively reprogram their cellular metabolism to survive and proliferate, thus offering potential therapeutic opportunities. Over the past decade, extensive research has been done on mutant IDH enzymes as markers of good prognosis in glioblastoma, a highly aggressive brain tumor in adults with dismal prognosis. Yet, 95% of glioblastoma are IDH wild-type. Here, we review current knowledge about IDH wild-type enzymes and their putative role in mechanisms driving tumor progression. After a brief overview on tumor metabolic adaptation, we present the diverse metabolic function of IDH enzymes and their roles in glioblastoma initiation, progression and response to treatments. Finally, we will discuss wild-type IDH targeting in primary glioblastoma

Assignment of the BRCA1-associated RING domein gene (BARD1) to rat chromosome 9q34 by in situ hybridization and radiation mapping

Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Assignment of the BRCA1-associated RING domain gene (Bard1) to rat chromosome 9q34 by in situ hybridization and radiation hybrid mapping

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

NKG2D controls natural reactivity of Vγ9Vδ2 T lymphocytes against mesenchymal glioblastoma cells: Vγ9Vδ2 T lymphocytes react against mesenchymal glioblastoma

Cynthia Chauvin and Noémie Joalland contributed equally to this work. Emmanuel Scotet and Claire Pecqueur contributed equally to this work.International audiencePURPOSE:Cellular immunotherapies are currently being explored to eliminate highly invasive and chemoradioresistant glioblastoma (GBM) cells involved in rapid relapse. We recently showed that concomitant stereotactic injections of non-alloreactive allogeneic Vγ9Vδ2 T lymphocytes eradicate zoledronate-primed human GBM cells. In the present study, we investigated the spontaneous reactivity of allogeneic human Vγ9Vδ2 T lymphocytes toward primary human GBM cells, in vitro and in vivo, in absence of any prior sensitization.EXPERIMENTAL DESIGN:Through functional and trancriptomic analyses, we extensively characterized the immunoreactivity of human Vγ9Vδ2 T lymphocytes against various primary GBM cultures directly derived from patient tumors.RESULTS:We evidence that GBM cells displaying a mesenchymal subtype signature are spontaneously eliminated by allogeneic human Vγ9Vδ2 T lymphocytes, a reactivity process being mediated by γδ TCR and tightly regulated by cellular stress-associated NKG2D pathway. This led to the identification of highly-reactive Vγ9Vδ2 T lymphocyte populations, independently of a specific TCR repertoire signature. Moreover, we finally provide evidence of immunotherapeutic efficacy in vivo, in absence of any prior tumor cell sensitization.CONCLUSIONS:By identifying pathways implicated in the selective natural recognition of mesenchymal GBM cell subtypes, accounting for 30% of primary diagnosed and 60% of recurrent GBM, our results pave the way for novel targeted cellular immunotherapies.Copyright ©2019, American Association for Cancer Research