Project description:This SuperSeries is composed of the following subset Series: GSE32079: Mutations in IDH1 and IDH2 are associated with DNA hypermethylation in intrahepatic cholangiocarcinomas GSE32283: Mutations in IDH1 are associated with DNA hypermethylation in glioblastomas Refer to individual Series
Project description:We compared the DNA methylation profiles of 12 intrahepatic cholangiocarcinomas harboring mutations in the genes encoding isocitrate dehydrogenase, IDH1 and IDH2, with 28 intrahepatic cholangiocarcinomas without these mutations. We profiled these samples with the Illumina HumanMethylation450 BeadChip, and characterized over 2,000 genes that were hypermethylated in tumors with mutations in IDH1 or IDH2.
Project description:We compared the DNA methylation profiles of 12 intrahepatic cholangiocarcinomas harboring mutations in the genes encoding isocitrate dehydrogenase, IDH1 and IDH2, with 28 intrahepatic cholangiocarcinomas without these mutations. We profiled these samples with the Illumina HumanMethylation450 BeadChip, and characterized over 2,000 genes that were hypermethylated in tumors with mutations in IDH1 or IDH2. Genomic DNA from fresh frozen tumors was bisulfite converted with the Zymo Research EZ DNA Methylation kit, then hybridized to the Illumina HumanMethylation450 Beadchip.
Project description:More than 50% of patients with chondrosarcomas exhibit gain-of-function mutations in either isocitrate dehydrogenase 1 (IDH1) or IDH2. In this study, we performed genome-wide CpG methylation sequencing of chondrosarcoma biopsies and found that IDH mutations were associated with DNA hypermethylation at CpG islands but not other genomic regions. Regions of CpG island hypermethylation were enriched for genes implicated in stem cell maintenance/differentiation and lineage specification. In murine 10T1/2 mesenchymal 20 progenitor cells, expression of mutant IDH2 led to DNA hypermethylation and an impairment in differentiation that could be reversed by treatment with DNA-hypomethylating agents. Introduction of mutant IDH2 also induced loss of contact inhibition and generated undifferentiated sarcomas in vivo. The oncogenic potential of mutant IDH2 correlated with the ability to produce 2-hydroxyglutarate. Together, these data demonstrate that neomorphic IDH2 mutations can be oncogenic in mesenchymal cells.. RRBS sequencing of (1) IDH wild type and mutant human chondrosarcomas, (2) isogenic cell lines expressing wild-type or mutant IDH.
Project description:Mutations of isocitrate dehydrogenase (IDH) 1 or 2 occur in 10-30% of intrahepatic cholangiocarcinomas (ICCs). However, their functional roles in biliary carcinogenesis are still unknown. We used microarrays to investigate how mutant IDH1 affect the gene expression of intrahepatic biliary organoids generated from normal murine liver.
Project description:More than 50% of patients with chondrosarcomas exhibit gain-of-function mutations in either isocitrate dehydrogenase 1 (IDH1) or IDH2. In this study, we performed genome-wide CpG methylation sequencing of chondrosarcoma biopsies and found that IDH mutations were associated with DNA hypermethylation at CpG islands but not other genomic regions. Regions of CpG island hypermethylation were enriched for genes implicated in stem cell maintenance/differentiation and lineage specification. In murine 10T1/2 mesenchymal 20 progenitor cells, expression of mutant IDH2 led to DNA hypermethylation and an impairment in differentiation that could be reversed by treatment with DNA-hypomethylating agents. Introduction of mutant IDH2 also induced loss of contact inhibition and generated undifferentiated sarcomas in vivo. The oncogenic potential of mutant IDH2 correlated with the ability to produce 2-hydroxyglutarate. Together, these data demonstrate that neomorphic IDH2 mutations can be oncogenic in mesenchymal cells..
2013-10-21 | GSE50539 | GEO
Project description:DNA hypermethylation in intrahepatic cholangiocarcinomas and glioblastomas
Project description:Through exomic sequencing of 32 intrahepatic cholangiocarcinomas, we discovered frequent inactivating mutations in multiple chromatin remodeling genes (including BAP1, ARID1A, and PBRM1) – mutation in one of these genes occurred in almost half of the carcinomas sequenced. We also identified frequent mutations at previously reported hotspots in genes encoding the metabolic enzymes IDH1 and IDH2 in intrahepatic cholangiocarcinomas. In contrast, TP53 was the most frequently altered gene in a series of nine gallbladder carcinomas. These studies highlight the importance of dysregulation of chromatin remodeling in intrahepatic cholangiocarcinomas.
Project description:Mutations of IDH1 (R132) and IDH2 (R172 and R140), which produce an oncometabolite 2-hydroxyglutarate (2HG), have been identified in several tumors including acute myeloid leukemia (AML). Recent studies have shown that expression of the IDH mutant enzymes results in high levels of 2HG and a block in cellular differentiation that can be reversed with IDH-mutant specific small molecule inhibitors. To further understand the role of IDH mutations in cancer, we conducted mechanistic studies in the TF-1/IDH2 R140Q erythroleukemia model system and found that IDH2 mutant expression caused both histone and genomic DNA methylation changes that can be reversed when IDH2 mutant activity is inhibited. Specifically, histone hypermethylation is rapidly reversed within days whereas reversal of DNA hypermethylation proceeds in a progressive manner over the course of weeks. Pathway enrichment analysis revealed several pathways involved in tumorigenesis of leukemia and lymphoma, indicating a selective modulation of relevant cancer genes by IDH mutations. As methylation of DNA and histones is closely linked to mRNA expression and differentiation, these results indicate that IDH2 mutant inhibition may function as a cancer therapy via short-term histone demethylation and long-term DNA demethylation at genes involved in differentiation and tumorigenesis. TF-1 cells with and without IDH2/R140Q expression were treated with DMSO or AGI-6780, an inhibitor of IDH2/R140Q for 7 to 28 days. Genomic DNA was extracted and analyzed by the Illumina 450k Methylation array.