Project description:Brain tumors are among the most malignant cancers and can arise from neural stem cells or oligodendrocyte progenitor cells (OPCs). Glioma-propagating cells (GPCs) that have stem-like properties have been derived from tumor variants such as glioblastoma multiforme (GBM) and oligodendroglial tumors, the latter being more chemosensitive with better prognosis. It has been suggested that such differences in chemosensitivity arise from the different profiles of OPCs versus neural stem cells. We thus explored if GPCs derived from these glioma variants can serve as reliable in vitro culture systems for studies. We utilized gene expression analyses, since GBM and oligodendrogliomas can be molecularly classified. Accordingly, we derived a gene signature distinguishing oligodendroglial GPCs from GBM GPCs collated from different studies, which was enriched for the Wnt, Notch and TGF-beta pathways. Using a novel method in glioma biology, the Connectivity Map, we mapped the strength of gene signature association with patient gene expression profiles in 2 independent glioma databases [GSE16011, http://caintegrator-info.nci.nih.gov/rembrandt]. Our gene signature consistently stratified survival in glioma patients. This data would suggest that in vitro low passage GPCs are similarly driven by transcriptomic changes that characterize the favorable outcome of oligodendrogliomas over GBM. Additionally, the gene signature was associated with the 1p/19q co-deletion status, the current clinical indicator of chemosensitivity. Our gene signature detects molecular heterogeneity in oligodendroglioma patients that cannot be accounted for by histology or the 1p/19q status alone, and highlights the limitation of morphology-based histological analyses in tumor classification, consequently impacting on treatment decisions. Total RNA obtained from primary neurosphere culture from brain tumor specimens of 6 patients were compared. Replicate arrays were performed for all 6 neurosphere cultures.
Project description:Brain tumors are among the most malignant cancers and can arise from neural stem cells or oligodendrocyte progenitor cells (OPCs). Glioma-propagating cells (GPCs) that have stem-like properties have been derived from tumor variants such as glioblastoma multiforme (GBM) and oligodendroglial tumors, the latter being more chemosensitive with better prognosis. It has been suggested that such differences in chemosensitivity arise from the different profiles of OPCs versus neural stem cells. We thus explored if GPCs derived from these glioma variants can serve as reliable in vitro culture systems for studies. We utilized gene expression analyses, since GBM and oligodendrogliomas can be molecularly classified. Accordingly, we derived a gene signature distinguishing oligodendroglial GPCs from GBM GPCs collated from different studies, which was enriched for the Wnt, Notch and TGF-beta pathways. Using a novel method in glioma biology, the Connectivity Map, we mapped the strength of gene signature association with patient gene expression profiles in 2 independent glioma databases [GSE16011, http://caintegrator-info.nci.nih.gov/rembrandt]. Our gene signature consistently stratified survival in glioma patients. This data would suggest that in vitro low passage GPCs are similarly driven by transcriptomic changes that characterize the favorable outcome of oligodendrogliomas over GBM. Additionally, the gene signature was associated with the 1p/19q co-deletion status, the current clinical indicator of chemosensitivity. Our gene signature detects molecular heterogeneity in oligodendroglioma patients that cannot be accounted for by histology or the 1p/19q status alone, and highlights the limitation of morphology-based histological analyses in tumor classification, consequently impacting on treatment decisions.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:'A Cartes d''Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.'
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:This study addresses long-term effects of clinically relevant regimens of radiation in human glioma stem cells. Our investigations reveal a strikingly diverse spectrum of changes in cell behavior, gene expression patterns and tumor-propagating capacities evoked by radiation in different types of glioma stem cells. Evidence is provided that degree of cellular plasticity but not the propensity to self-renew is an important factor influencing radiation-induced changes in the tumor-propagating capacity of glioma stem cells. Gene expression analyses indicate that paralell transcriptomic responses to radiation underlie similarity of clinically relevant cellular outcomes such as the ability to promote tumor growth after radiation. Our findings underscore the importance of longitudinal characterizations of molecular and cellular responses evoked by cytotoxic treatrments in glioma stem cells.