DNA methylation profiles of samples included in the EORTC 26091 TAVAREC trial
Ontology highlight
ABSTRACT:
PROVIDER: EGAS00001006015 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:The outcome of patients with anaplastic gliomas varies considerably depending on histology and single molecular markers such as codeletion of 1p/19q and mutations of the isocitrate dehydrogenase (IDH) gene. Whether a molecularly-based classification of anaplastic gliomas based on large scale genomic or epigenomic analyses is superior to histopathology, may reflect distinct biological subtypes, predict outcome and guide therapy decisions had yet to be determined. Epigenome-wide DNA methylation analysis, which also allows for the detection of copy-number aberrations, was performed in a cohort of 228 patients with anaplastic gliomas (astrocytomas, oligoastrocytomas and oligodendrogliomas), including 115 patients of the NOA-04 trial. We further compared these tumors with a group of 55 glioblastomas. Unsupervised clustering demonstrated two main groups based on IDH mutation status: CpG island methylator phenotype (CIMP) positive (77.5%) or negative (22.5%). CIMP+ (IDH mutant) tumors showed a further separation based on copy-number status of chromosome arms 1p and 19q, but not based on histopathology. CIMP- (IDH wild type) tumors on the other hand showed hallmark copy-number alterations of glioblastomas. These tumors clustered together with CIMP- glioblastomas without forming separate groups based on WHO grade. There was no Tumor classification based on CIMP and 1p/19q status was significantly associated with survival allowing a better prediction of outcome than the current histopathological classification alone: Patients with CIMP+ tumors with 1p/19q codeletion had the best prognosis, followed by patients with CIMP+ but intact 1p/19q status. Patients with CIMP- anaplastic gliomas had the worst prognosis. Collectively, our data suggest that anaplastic gliomas can be grouped into three molecular subtypes with clear association to underlying biology and clinical outcome based on IDH and 1p/19q status. The data do not provide a molecular basis for the diagnosis of anaplastic oligoastrocytoma.
2014-06-06 | GSE58218 | GEO
Project description:Oligoastrocytoma (OA) was formerly defined as a mixed glioma exhibiting histological features of both astrocytoma and oligodendroglioma. However, OA has been shown to be attributable to either glioma-type based on its molecular characteristics and was excluded from the glioma classification with the introduction of the integrated diagnosis. Nevertheless, some cases showing genetic features of both oligodendroglioma and astrocytoma have been reported since the integrated diagnosis era, and whether OA exists as a glioma-type remains controversial. All previously reported cases were mixed gliomas with and without 1p/19q-codeletion in the lineage of isocitrate dehydrogenase (IDH) mutant gliomas. Herein, we described a 33-year-old man with a progressive headache. Magnetic resonance imaging showed a large left frontal lobe tumor composed of a cystic component with contrast-enhancing walls and a non-contrast-enhancing solid component. The patient underwent a gross total removal of the tumor. Histologically, the cystic and solid components showed oligodendroglioma and astrocytoma morphology, respectively. Immunohistochemically, IDH1-R132H staining was positive in the cystic component and negative in the solid component. Sanger sequencing confirmed the IDH1-R132H mutation and the C228T mutation in the telomerase reverse transcriptase promoter (TERTp) region in the cystic component, while both IDH1/2 and TERTp were wildtype in the solid component. Fluorescence in situ hybridization revealed 1p/19q-codeletion in both areas. The integrated diagnosis led to the diagnosis of oligoastrocytoma consisting of IDH-mutant 1p/19q-codeleted oligodendroglioma and IDH-wildtype astrocytoma. Furthermore, deoxyribonucleic acid (DNA) extracted separately from each area of formalin-fixed paraffin-embedded specimen revealed a distinct methylation profile. On the other hand, the global DNA copy-number analysis derived from the microarray data showed similar copy-number profiles including 1p/19q-codeletion for both sites. This is the first report of a dual-genotype oligoastrocytoma with IDH-mutant 1p/19q-codeleted oligodendroglioma and IDH-wildtype astrocytoma. This extremely rare case provides profound insight into the process of acquiring genetic abnormalities in the development of glioma.
2025-10-31 | GSE280730 | GEO
Project description:The outcome of patients with anaplastic gliomas varies considerably depending on histology and single molecular markers such as codeletion of 1p/19q and mutations of the isocitrate dehydrogenase (IDH) gene. Whether a molecularly-based classification of anaplastic gliomas based on large scale genomic or epigenomic analyses is superior to histopathology, may reflect distinct biological subtypes, predict outcome and guide therapy decisions had yet to be determined. Epigenome-wide DNA methylation analysis, which also allows for the detection of copy-number aberrations, was performed in a cohort of 228 patients with anaplastic gliomas (astrocytomas, oligoastrocytomas and oligodendrogliomas), including 115 patients of the NOA-04 trial. We further compared these tumors with a group of 55 glioblastomas. Unsupervised clustering demonstrated two main groups based on IDH mutation status: CpG island methylator phenotype (CIMP) positive (77.5%) or negative (22.5%). CIMP+ (IDH mutant) tumors showed a further separation based on copy-number status of chromosome arms 1p and 19q, but not based on histopathology. CIMP- (IDH wild type) tumors on the other hand showed hallmark copy-number alterations of glioblastomas. These tumors clustered together with CIMP- glioblastomas without forming separate groups based on WHO grade. There was no Tumor classification based on CIMP and 1p/19q status was significantly associated with survival allowing a better prediction of outcome than the current histopathological classification alone: Patients with CIMP+ tumors with 1p/19q codeletion had the best prognosis, followed by patients with CIMP+ but intact 1p/19q status. Patients with CIMP- anaplastic gliomas had the worst prognosis. Collectively, our data suggest that anaplastic gliomas can be grouped into three molecular subtypes with clear association to underlying biology and clinical outcome based on IDH and 1p/19q status. The data do not provide a molecular basis for the diagnosis of anaplastic oligoastrocytoma. We investigated a subset of 228 anaplastic gliomas using the Illumina 450k methylation array.
2014-06-06 | E-GEOD-58218 | biostudies-arrayexpress
Project description:Oligodendroglioma is a primary central nervous system tumor classified by the presence of isocitrate dehydrogenase (IDH) mutations and codeletion of 1p/19q. Here we describe the generation of an IDH-mutant 1p/19q-codeleted oligodendroglioma mouse model using in utero electroporation. We identified IDH1R132H, PIK3CAE545K, CicKO, Fubp1KO and Cdkn2aKO as the optimal combination (termed OligoCdkn2a) to drive fully penetrant tumors that histologically resemble human grade II/III IDH-mutant, 1p/19q-codeleted oligodendroglioma. Replacing Cdkn2a with Trp53 loss in this mouse model shifted tumor histology towards high grade astrocytoma. OligoCdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. OligoCdkn2a tumors represent the first mouse model system to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas, offering a platform to further dissect tumor biology and test new therapeutic strategies.
2026-04-15 | GSE326991 | GEO
Project description:Oligodendroglioma is a primary central nervous system tumor classified by the presence of isocitrate dehydrogenase (IDH) mutations and codeletion of 1p/19q. Here we describe the generation of an IDH-mutant 1p/19q-codeleted oligodendroglioma mouse model using in utero electroporation. We identified IDH1R132H, PIK3CAE545K, CicKO, Fubp1KO and Cdkn2aKO as the optimal combination (termed OligoCdkn2a) to drive fully penetrant tumors that histologically resemble human grade II/III IDH-mutant, 1p/19q-codeleted oligodendroglioma. Replacing Cdkn2a with Trp53 loss in this mouse model shifted tumor histology towards high grade astrocytoma. OligoCdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. OligoCdkn2a tumors represent the first mouse model system to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas, offering a platform to further dissect tumor biology and test new therapeutic strategies.
2026-04-15 | GSE326990 | GEO
Project description:The combination of bevacizumab with temozolomide and radiotherapy was shown to prolong progression-free survival in newly diagnosed glioblastoma patients, and this emphasizes the potential of bevacizumab as a glioma treatment. However, while bevacizumab effectively inhibits angiogenesis, it has also been reported to induce invasive proliferation. This study examined gene expression in glioma cells to investigate the mechanisms of bevacizumab-induced invasion. We made a human glioma U87ΔEGFR cell xenograft model by stereotactically injecting glioma cells into the brain of animals. We administered bevacizumab intraperitoneally three times per week. At 18 days after tumor implantation, the brains were removed for histopathology and mRNA was extracted. In vivo, bevacizumab treatment increased glioma cell invasion. qRT-PCR array analysis were perfomed.
2019-02-07 | GSE126168 | GEO
Project description:Treatment modalities for patients with low grade glioma (LGG) WHO grade II are controversial. Overall survival ranges from 2 to over 15 years depending on molecular and clinical factors. Hence, risk adjusted treatments are required to preserve cognitive function and quality of life. We aim at identifying mechanisms and associated molecular markers predicting benefit from radiotherapy (RT) or temozolomide (TMZ) on progression free survival in 120 isocitrate dehydrogenase 1 or 2 (IDHmt) mutant LGG treated in the randomized phase III trial EORTC 22033. IDH mutations, the characteristic hallmark of LGG, are associated with a CpG island methylator phenotype (CIMP). Given the genotoxic treatments in this study we determined the DNA methylome of DNA damage response (DDR) genes and assessed the association with progression free survival (PFS). We identified 62 functional CpGs corresponding to 24 of 410 DDR genes in the multidimensional LGG dataset from The Cancer Genome Atlas. Despite the low-powered study, the simulations suggested that seven CpGs, associated with 4 genes could be predictive for PFS in EORTC 22033. Most interestingly, two of the CpGs correspond to MGMT and consisted of the 2 probes used in the MGMT-STP27 classifier. The extent of methylation was predictive for PFS in the TMZ, but not the RT arm. LGG IDHmt and 1p and 19q codeleted that overlap largely with oligodendroglioma displayed a higher extent of MGMT methylation than the IDHmt non-codeleted tumors based on several independent LGG datasets. This is consistent with a better PFS of codeleted patients in the TMZ arm as compared to the non-codeleted patients, while no difference was observed in the RT-arm.
2018-01-31 | GSE104293 | GEO
Project description:Glial cell-derived brain tumors (gliomas) are devastating diseases without effective curative therapies. Gliomas are classified according to various schemes including the cancer-initiating cell type, World Health Organization tumor grades, and genetic markers such as Isocitrate dehydrogenase (IDH) mutations and chromosomal 1p/19q codeletion status. Genomics, transcriptomics and methylomics approaches are emerging as powerful means to refine classification. However, various aspects of cancer biology are solely reflected on the proteomelevel. Here, we employ mass spectrometry (MS) to characterize the proteomes and phospho-proteomes of IDHmut glioma entities with and without 1p/19q codeletion, IDHwt gliomas and control tissue from a total of 42 patients. Our data-dependent acquisition MS workflow on average quantifies more than 5000 proteins and 3000 phospho-sites per sample of formalin-fixed paraffin-embedded (FFPE) brain sections. The tumor proteomes reflected genetic alterations such as the loss of chromosome 1p/19q proteins, the loss of ATRX in non-codeletion IDHmut glioma, and the frequent loss and amplification of chromosomes 10 and 7, respectively,in IDH-wild type glioma. Nevertheless, 1p/19q codeletion status was not the major determinant of IDHmut glioma proteomes. Instead, the proteome profiles suggest an alternative classification of IDHmut gliomas that correlates with the loss of mitochondrial DNA-encoded proteins, the abundance of respiratory chain proteins, a distinct tumor suppressor and oncoprotein profile, an extracellular matrix signature, and alterations in the phospho-proteome. Moreover, the glioma association of numerous proteins implicated in other cancers by this dataset provides a resource for further mechanistic investigation of glioma genesis and progression.
2022-11-09 | PXD024427 | Pride
Project description:In the current study, we used exon arrays and clinical samples from a previous trial (SAKK 19/05) to investigate the expression variations at the exon-level of 3 genes potentially playing a key role in modulating treatment response (EGFR, KRAS, VEGFA). Exon-level biomarkers for the response to targeted therapy bevacizumab/erlotinib were identified in patients with metastatic non-small cell lung cancer Multicenter, prospective, open-label, single-arm, phase II trial.
2013-07-30 | E-GEOD-37138 | biostudies-arrayexpress
Project description:Background: Oligodendroglioma is a primary central nervous system tumor classified by the presence of isocitrate dehydrogenase (IDH) mutations and codeletion of 1p/19q. A lack of faithful preclinical model systems for this disease has limited progress in understanding the biology of this genetically unique subtype of adult diffuse-type glioma and in developing new effective therapies. To address this unmet need, we sought to establish a mouse model that faithfully recapitulates the genetic and phenotypic features of human IDH-mutant 1p/19q codeleted oligodendroglioma. Methods: We performed in utero electroporation to introduce distinct combinations of genetic alterations and evaluated their potential to form tumors. Resulting tumors were characterized by histology, metabolite profiling, RNA-sequencing and single cell RNA-sequencing. Results: We identified co-expression of IDH1R132H and PIK3CAE545K together with loss of Cic, Fubp1 and Cdkn2a (termed OligoCdkn2a) as the optimal genetic combination to drive fully penetrant tumors that histologically resemble human grade II/III IDH-mutant 1p/19q-codeleted oligodendroglioma. Substituting Cdkn2a loss with Trp53 deletion decreased latency and shifted tumors toward high-grade astrocytoma histology. OligoCdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. Conclusions: To our knowledge, OligoCdkn2a tumors represent the first autochthonous, genetically engineered mouse model to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas. This model will provide a valuable platform to further dissect mechanisms of tumorigenesis and test novel therapeutic strategies for this molecularly distinct glioma subtype.
2026-04-15 | GSE326763 | GEO