Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage. 80 tumor samples, one normal tissue sample (brain)
Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage.
Project description:We used whole genome microarray expression profiling as a discovery platform to identify high grade diffuse glioma associated differently expressed genes comparing with low grade diffuse glioma.
Project description:Adult diffuse gliomas are the deadliest brain tumours including IDH-wildtype glioblastomas of worst prognosis and diffuse low grade IDH-mutant astrocytomas and oligodendrogliomas. These glial tumours display distinct tumoral cell population defeating current therapies. Our group has unveiled the role of NOTCH signalling in glioblastoma cell plasticity and in the conversion of oligodendrocytic-like to astrocytic-like tumoral cells in IDH-mutant low-grade gliomas which escalate inevitably to higher grade malignant gliomas. To gain insight into signalling pathways regulating glioma cell plasticity and malignancy, we focused our work on endothelin signalling including endothelin peptide ligands (ET-1, ET-2, ET-3) binding to G-protein coupled endothelin receptors A and B (EDNRA, EDNRB). Here, using glioma patient samples and glioma patient-derived cell lines, we showed that endothelin reduces glioma cell proliferation while increasing migration initiating a proneural to mesenchymal transition. Mechanistically, EDNRB activation led to IP3-dependent calcium mobilization, apamin-sensitive KCNN2/KCNN3 potassium currents and phosphorylation of ERK1/2 and STAT3 in glioma cells. Finally, we studied endothelin receptor regulation by tumoral microenvironment stimuli highlighting a role for EDNRA induced by NOTCH and hypoxia in perivascular hypoxic area in glioblastoma. Altogether, this study demonstrates endothelin signalling as a key player in mesenchymal transformation of diffuse IDH-mutant gliomas and glioblastomas.
Project description:Adult diffuse gliomas are the deadliest brain tumours including IDH-wildtype glioblastomas of worst prognosis and diffuse low grade IDH-mutant astrocytomas and oligodendrogliomas. These glial tumours display distinct tumoral cell population defeating current therapies. Our group has unveiled the role of NOTCH signalling in glioblastoma cell plasticity and in the conversion of oligodendrocytic-like to astrocytic-like tumoral cells in IDH-mutant low-grade gliomas which escalate inevitably to higher grade malignant gliomas. To gain insight into signalling pathways regulating glioma cell plasticity and malignancy, we focused our work on endothelin signalling including endothelin peptide ligands (ET-1, ET-2, ET-3) binding to G-protein coupled endothelin receptors A and B (EDNRA, EDNRB). Here, using glioma patient samples and glioma patient-derived cell lines, we showed that endothelin reduces glioma cell proliferation while increasing migration initiating a proneural to mesenchymal transition. Mechanistically, EDNRB activation led to IP3-dependent calcium mobilization, apamin-sensitive KCNN2/KCNN3 potassium currents and phosphorylation of ERK1/2 and STAT3 in glioma cells. Finally, we studied endothelin receptor regulation by tumoral microenvironment stimuli highlighting a role for EDNRA induced by NOTCH and hypoxia in perivascular hypoxic area in glioblastoma. Altogether, this study demonstrates endothelin signalling as a key player in mesenchymal transformation of diffuse IDH-mutant gliomas and glioblastomas.
Project description:Adult diffuse gliomas are the deadliest brain tumours including IDH-wildtype glioblastomas of worst prognosis and diffuse low grade IDH-mutant astrocytomas and oligodendrogliomas. These glial tumours display distinct tumoral cell population defeating current therapies. Our group has unveiled the role of NOTCH signalling in glioblastoma cell plasticity and in the conversion of oligodendrocytic-like to astrocytic-like tumoral cells in IDH-mutant low-grade gliomas which escalate inevitably to higher grade malignant gliomas. To gain insight into signalling pathways regulating glioma cell plasticity and malignancy, we focused our work on endothelin signalling including endothelin peptide ligands (ET-1, ET-2, ET-3) binding to G-protein coupled endothelin receptors A and B (EDNRA, EDNRB). Here, using glioma patient samples and glioma patient-derived cell lines, we showed that endothelin reduces glioma cell proliferation while increasing migration initiating a proneural to mesenchymal transition. Mechanistically, EDNRB activation led to IP3-dependent calcium mobilization, apamin-sensitive KCNN2/KCNN3 potassium currents and phosphorylation of ERK1/2 and STAT3 in glioma cells. Finally, we studied endothelin receptor regulation by tumoral microenvironment stimuli highlighting a role for EDNRA induced by NOTCH and hypoxia in perivascular hypoxic area in glioblastoma. Altogether, this study demonstrates endothelin signalling as a key player in mesenchymal transformation of diffuse IDH-mutant gliomas and glioblastomas.
Project description:Adult diffuse gliomas are the deadliest brain tumours including IDH-wildtype glioblastomas of worst prognosis and diffuse low grade IDH-mutant astrocytomas and oligodendrogliomas. These glial tumours display distinct tumoral cell population defeating current therapies. Our group has unveiled the role of NOTCH signalling in glioblastoma cell plasticity and in the conversion of oligodendrocytic-like to astrocytic-like tumoral cells in IDH-mutant low-grade gliomas which escalate inevitably to higher grade malignant gliomas. To gain insight into signalling pathways regulating glioma cell plasticity and malignancy, we focused our work on endothelin signalling including endothelin peptide ligands (ET-1, ET-2, ET-3) binding to G-protein coupled endothelin receptors A and B (EDNRA, EDNRB). Here, using glioma patient samples and glioma patient-derived cell lines, we showed that endothelin reduces glioma cell proliferation while increasing migration initiating a proneural to mesenchymal transition. Mechanistically, EDNRB activation led to IP3-dependent calcium mobilization, apamin-sensitive KCNN2/KCNN3 potassium currents and phosphorylation of ERK1/2 and STAT3 in glioma cells. Finally, we studied endothelin receptor regulation by tumoral microenvironment stimuli highlighting a role for EDNRA induced by NOTCH and hypoxia in perivascular hypoxic area in glioblastoma. Altogether, this study demonstrates endothelin signalling as a key player in mesenchymal transformation of diffuse IDH-mutant gliomas and glioblastomas.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Developing a classification model based on differential expression miRNAs profile in serum WHO CNS5 adult-type diffuse glioma samples to improve of diagnosis of grade 4 glioma.
Project description:Gene expression profiling in 50 glial brain tumors and 4 normal brains using 42,000-feature cDNA microarrays (from total RNA). Tumors: 50 fresh-frozen glioma specimens subjected to standard WHO classification. Specimens included astrocytic [2 juvenile pilocytic astrocytomas, 1 low-grade astrocytic glioma, 1 anaplastic astrocytomas, 31 glioblastomas (of these 2 secondary glioblastomas and 2 gliosarcomas)], oligodendroglial [5 oligodendrogliomas, 3 anaplastic oligodendrogliomas], and 6 anaplastic oligoastrocytomas tumors. One tumor had been classified as glioneuronal neoplasm. Normal brain was purchased from Stratagene. Stratagene Universal Common Reference was used as reference RNA. The results provide insights into molecular mechanisms and pathways associated with gliomagenesis.