Clonal expansion and epigenetic reprogramming following deletion or amplification of mutant IDH
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PROVIDER: EGAS00001002618 | EGA |
REPOSITORIES: EGA
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Project description:IDH1 mutation is the earliest genetic alteration in low-grade gliomas (LGGs), but its role in tumor recurrence is unclear. Mutant IDH1 drives overproduction of the oncometabolite D-2-hydroxyglutarate (2HG) and a CpG island (CGI) hypermethylation phenotype (G-CIMP). To investigate the role of mutant IDH1 at recurrence, we performed a longitudinal analysis of 50 IDH1 mutant LGGs. We discovered six cases with copy number alterations (CNAs) at the IDH1 locus at recurrence. Deletion or amplification of IDH1 was followed by clonal expansion and recurrence at a higher grade. Successful cultures derived from IDH1 mutant, but not IDH1 wild-type, gliomas systematically deleted IDH1 in vitro and in vivo, further suggestive of selection against the heterozygous mutant state as tumors progress. Tumors and cultures with IDH1 CNA had decreased 2HG, maintenance of G-CIMP, and DNA methylation reprogramming outside CGI. Thus, while IDH1 mutation initiates gliomagenesis, in some patients, mutant IDH1 and 2HG are not required for later clonal expansions.
| EGAS00001001854 | EGA
Project description:IDH1 mutation is the earliest genetic alteration in low-grade gliomas (LGGs), but its role in tumor recurrence is unclear. Mutant IDH1 drives overproduction of the oncometabolite d-2-hydroxyglutarate (2HG) and a CpG island (CGI) hypermethylation phenotype (G-CIMP). To investigate the role of mutant IDH1 at recurrence, we performed a longitudinal analysis of 50 IDH1 mutant LGGs. We discovered six cases with copy number alterations (CNAs) at the IDH1 locus at recurrence. Deletion or amplification of IDH1 was followed by clonal expansion and recurrence at a higher grade. Successful cultures derived from IDH1 mutant, but not IDH1 wild type, gliomas systematically deleted IDH1 in vitro and in vivo, further suggestive of selection against the heterozygous mutant state as tumors progress. Tumors and cultures with IDH1 CNA had decreased 2HG, maintenance of G-CIMP, and DNA methylation reprogramming outside CGI. Thus, while IDH1 mutation initiates gliomagenesis, in some patients mutant IDH1 and 2HG are not required for later clonal expansions.
| S-EPMC5635900 | biostudies-literature
Project description:Ollier disease and Maffucci syndrome are non-hereditary skeletal disorders characterized by multiple enchondromas (Ollier) combined with spindle cell hemangiomas (Maffucci). We found somatic heterozygous IDH1 mutations (R132C and R132H) in 83% of enchondromas, benign cartilage tumors, as well as in 40% of spindle cell hemangiomas, benign vascular lesions. In total, 33 of 42 (78%) patients with Ollier disease and 7 of 13 (54%) patients with Maffucci syndrome carried a mutation in at least one of their tumors. Twelve patients with multiple tumors at different locations displayed identical mutations in separate lesions. Immunohistochemical staining for the R132H IDH1 mutant protein suggested intraneoplastic as well as somatic mosaicism. IDH1 mutations were less frequent (63%) in high grade malignant cartilage tumors in Ollier disease, suggesting that IDH1 is less important for malignant transformation. IDH1 and IDH2 mutations were found in 36% of sporadic cartilage tumors and in four cell lines derived from sporadic chondrosarcomas. 16 samples were analyzed in two color experiment, using normal male or female as a reference sample (gender mismatched)
2011-11-05 | E-GEOD-30354 | biostudies-arrayexpress
Project description:Gene expression of mouse hepatoblasts (HBs) expressing IDH1 WT, IDH1 R132C, IDH2 WT, R172K and empty vector controls (N=2 cultures for each condition) grown on collagen-coated plates and IDH1 R132C and empty vector controls on uncoated plates were evaluated using Affymetrix Mouse 430Av2 DNA microarrays that were processed at the Dana-Farber Cancer Institute core facility (http://macf-web.dfci.harvard.edu/) using their standard protocol. Mutations in Isocitrate dehydrogenase 1 (IDH1) and IDH2 are among the most common genetic alterations in intrahepatic cholangiocarcinoma (IHCC), a deadly primary liver cancer. Mutant IDH proteins in IHCC and other malignancies acquire an abnormal enzymatic activity allowing them to convert alphaketoglutarate (aKG) to 2-hydroxyglutarate (2HG), which inhibits the activity of multiple aKG-dependent dioxygenases, and results in alterations in cell differentiation, survival, and extracellular matrix maturation. However, the molecular pathways by which IDH mutations lead to tumour formation remain unclear. Here we show that mutant IDH blocks primary liver progenitor cells from undergoing hepatocyte differentiation through the production of 2HG and suppression of HNF4a, a master regulator of hepatocyte identity and quiescence. Correspondingly, genetically engineered mouse models (GEMMs) expressing mutant IDH in the adult liver show aberrant response to hepatic injury, characterized by HNF4a silencing, impaired hepatocyte differentiation and markedly elevated levels of cell proliferation. Moreover, mutant IDH and activated Kras, genetic alterations that co-exist in a subset of human IHCCs, cooperate to drive the expansion of liver progenitor cells, development of premalignant biliary lesions, and progression to metastatic IHCC. These studies provide a functional link between IDH mutations, hepatic cell fate, and IHCC pathogenesis and present a novel GEMM of IDH-driven malignancy. Gene expression of HBs expressing IDH1 WT, IDH1 R132C, IDH2 WT, R172K and empty vector controls under a doxycycline-inducible system (N=2 cultures for each condition) grown on collagen-coated plates and IDH1 R132C and empty vector controls on uncoated plates were evaluated using Affymetrix Mouse 430Av2 DNA microarrays.
2014-04-30 | E-GEOD-57002 | biostudies-arrayexpress
Project description:Mutations in the genes encoding isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a variety of tumor types, resulting in production of the proposed oncometabolite, 2-hydroxyglutarate (2-HG). How mutant IDH and 2-HG alter signaling pathways to promote cancer, though, remains unclear. Additionally, there exist relatively few cell lines with IDH mutations. To examine the effect of endogenous IDH mutations and 2-HG, we created a panel of isogenic epithelial cell lines with either wild-type IDH1/2 or clinically relevant IDH1/2 mutations. Differences were noted in the ability of IDH mutations to cause robust 2-HG accumulation. IDH1/2 mutants that produce high levels of 2-HG cause an epithelial-mesenchymal transition (EMT)-like phenotype, characterized by changes in EMT-related gene expression and cellular morphology. 2-HG is sufficient to recapitulate aspects of this phenotype in the absence of an IDH mutation. In the cells types examined, mutant IDH-induced EMT is dependent on upregulation of the transcription factor ZEB1 and downregulation of the mir-200 family of microRNAs. Furthermore, sustained knockdown of IDH1 in IDH1 R132H mutant cells is sufficient to reverse many characteristics of EMT, demonstrating that continued expression of mutant IDH is required to maintain this phenotype. These results suggest mutant IDH proteins can reversibly deregulate discrete signaling pathways that contribute to tumorigenesis 9 HCT116 isogenic clones with wild-type or IDH1/2 mutations. Samples were analyzed in duplicate.
2012-10-25 | E-GEOD-41802 | biostudies-arrayexpress
Project description:Ollier disease and Maffucci syndrome are non-hereditary skeletal disorders characterized by multiple enchondromas (Ollier) combined with spindle cell hemangiomas (Maffucci). We found somatic heterozygous IDH1 mutations (R132C and R132H) in 83% of enchondromas, benign cartilage tumors, as well as in 40% of spindle cell hemangiomas, benign vascular lesions. In total, 33 of 42 (78%) patients with Ollier disease and 7 of 13 (54%) patients with Maffucci syndrome carried a mutation in at least one of their tumors. Twelve patients with multiple tumors at different locations displayed identical mutations in separate lesions. Immunohistochemical staining for the R132H IDH1 mutant protein suggested intraneoplastic as well as somatic mosaicism. IDH1 mutations were less frequent (63%) in high grade malignant cartilage tumors in Ollier disease, suggesting that IDH1 is less important for malignant transformation. IDH1 and IDH2 mutations were found in 36% of sporadic cartilage tumors and in four cell lines derived from sporadic chondrosarcomas.
2011-11-05 | GSE30354 | GEO
Project description:BackgroundWe aimed to evaluate the clinical outcomes of molecular glioblastoma (mGBM) as compared to histological GBM (hGBM) and to determine the prognostic impact of TERT mutation, EGFR amplification, and CDKN2A/B deletion on isocitrate dehydrogenase (IDH)-wildtype GBM.MethodsIDH-wildtype GBM patients treated with radiation therapy (RT) between 2012 and 2019 were retrospectively analyzed. mGBM was defined as grade II-III IDH-wildtype astrocytoma without histological features of GBM but with one of the following molecular alterations: TERT mutation, EGFR amplification, or combination of whole chromosome 7 gain and whole chromosome 10 loss. Overall survival (OS) and progression-free survival (PFS) were calculated from RT and analyzed using the Kaplan-Meier method. Multivariable analysis (MVA) was performed using Cox regression to identify independent predictors of OS and PFS.ResultsOf the 367 eligible patients, the median follow-up was 11.7 months. mGBM and hGBM did not have significantly different OS (median: 16.6 vs 13.5 months, respectively, P = .16), nor PFS (median: 11.7 vs 7.3 months, respectively, P = .08). However, mGBM was associated with better OS (hazard ratio [HR] 0.50, 95% CI 0.29-0.88) and PFS (HR 0.43, 95% CI 0.26-0.72) than hGBM after adjusting for known prognostic factors on MVA. CDKN2A/B deletion was associated with worse OS (HR 1.57, 95% CI 1.003-2.46) and PFS (HR 1.57, 95% CI 1.04-2.36) on MVA, but TERT mutation and EGFR amplification were not.ConclusionCriteria for mGBM may require further refinement and validation. CDKN2A/B deletion, but not TERT mutation or EGFR amplification, may be an independent prognostic biomarker for IDH-wildtype GBM patients.
| S-EPMC7668466 | biostudies-literature
Project description:Immortalized human astrocytes were stably transfected to express IDH1 R132H. These cells were treated with 1uM ATRA
2021-04-15 | GSE172055 | GEO
Project description:Immortalized human astrocytes were stably transfected to express IDH1 R132H. These cells were treated with 1uM ATRA
2024-04-01 | GSE252527 | GEO
Project description:Long-term complications such as radiation-induced second malignancies occur in a subset of patients following radiation-therapy, particularly relevant in pediatric patients due to the long follow-up period in case of survival. Radiation-induced gliomas (RIGs) have been reported in patients after treatment with cranial irradiation for various primary malignancies such as acute lymphoblastic leukemia (ALL) and medulloblastoma (MB). We perform comprehensive (epi-) genetic and expression profiling of RIGs arising after cranial irradiation for MB (n=23) and ALL (n=9). Our study reveals a unifying molecular signature for the majority of RIGs, with recurrent PDGFRA amplification and loss of CDKN2A/B and an absence of somatic hotspot mutations in genes encoding histone 3 variants or IDH1/2, uncovering diagnostic markers and potentially actionable targets.
2021-03-23 | GSE168457 | GEO