Large-Scale Atlas of Mutant IDH1-Dependent Chromatin State Reprogramming, Reversibility, and Persistence
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE85942 | GEO | 2017/08/23
SECONDARY ACCESSION(S): PRJNA339790
REPOSITORIES: GEO
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Project description:Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations drive the development of gliomas and other human malignancies. Significant efforts are already underway to attempt to target mutant IDH in clinical trials. However, how mutation of IDH leads to tumorigenesis is poorly understood. Mutant IDH1 promotes epigenetic changes that promote tumorigenesis but the scale of these changes throughout the epigenome and the reversibility of these changes are unknown. Here, using both human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant IDH1-induced epigenomic reprogramming. We characterize the changes in the histone code landscape, DNA methylome, chromatin state, and transcriptional reprogramming that occur following IDH1 mutation and characterize the kinetics and reversibility of these alterations over time. We discover coordinate changes in the localization and intensity of multiple histone marks and chromatin states throughout the genome. These alterations result in systematic chromatin states changes, which result in widespread gene expression changes involving oncogenic pathways. Specifically, mutant IDH1 drives alterations in differentiation state and establishes a CD24+ population that features enhanced self-renewal and other stem-like properties. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented molecular portraits of mutant IDH1-dependent epigenomic reprogramming at high resolution. These findings have significant implications for our understanding the mechanisms underlying mutant IDH function and for optimizing therapeutic approaches to targeting IDH mutant tumors.
2017-08-23 | GSE85938 | GEO
Project description:Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations drive the development of gliomas and other human malignancies. Significant efforts are already underway to attempt to target mutant IDH in clinical trials. However, how mutation of IDH leads to tumorigenesis is poorly understood. Mutant IDH1 promotes epigenetic changes that promote tumorigenesis but the scale of these changes throughout the epigenome and the reversibility of these changes are unknown. Here, using both human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant IDH1-induced epigenomic reprogramming. We characterize the changes in the histone code landscape, DNA methylome, chromatin state, and transcriptional reprogramming that occur following IDH1 mutation and characterize the kinetics and reversibility of these alterations over time. We discover coordinate changes in the localization and intensity of multiple histone marks and chromatin states throughout the genome. These alterations result in systematic chromatin states changes, which result in widespread gene expression changes involving oncogenic pathways. Specifically, mutant IDH1 drives alterations in differentiation state and establishes a CD24+ population that features enhanced self-renewal and other stem-like properties. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented molecular portraits of mutant IDH1-dependent epigenomic reprogramming at high resolution. These findings have significant implications for our understanding the mechanisms underlying mutant IDH function and for optimizing therapeutic approaches to targeting IDH mutant tumors.
2017-08-23 | GSE85941 | GEO
Project description:Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations drive the development of gliomas and other human malignancies. Significant efforts are already underway to attempt to target mutant IDH in clinical trials. However, how mutation of IDH leads to tumorigenesis is poorly understood. Mutant IDH1 promotes epigenetic changes that promote tumorigenesis but the scale of these changes throughout the epigenome and the reversibility of these changes are unknown. Here, using both human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant IDH1-induced epigenomic reprogramming. We characterize the changes in the histone code landscape, DNA methylome, chromatin state, and transcriptional reprogramming that occur following IDH1 mutation and characterize the kinetics and reversibility of these alterations over time. We discover coordinate changes in the localization and intensity of multiple histone marks and chromatin states throughout the genome. These alterations result in systematic chromatin states changes, which result in widespread gene expression changes involving oncogenic pathways. Specifically, mutant IDH1 drives alterations in differentiation state and establishes a CD24+ population that features enhanced self-renewal and other stem-like properties. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented molecular portraits of mutant IDH1-dependent epigenomic reprogramming at high resolution. These findings have significant implications for our understanding the mechanisms underlying mutant IDH function and for optimizing therapeutic approaches to targeting IDH mutant tumors.
2017-08-23 | GSE85940 | GEO
Project description:Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations drive the development of gliomas and other human malignancies. Significant efforts are already underway to attempt to target mutant IDH in clinical trials. However, how mutation of IDH leads to tumorigenesis is poorly understood. Mutant IDH1 promotes epigenetic changes that promote tumorigenesis but the scale of these changes throughout the epigenome and the reversibility of these changes are unknown. Here, using both human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant IDH1-induced epigenomic reprogramming. We characterize the changes in the histone code landscape, DNA methylome, chromatin state, and transcriptional reprogramming that occur following IDH1 mutation and characterize the kinetics and reversibility of these alterations over time. We discover coordinate changes in the localization and intensity of multiple histone marks and chromatin states throughout the genome. These alterations result in systematic chromatin states changes, which result in widespread gene expression changes involving oncogenic pathways. Specifically, mutant IDH1 drives alterations in differentiation state and establishes a CD24+ population that features enhanced self-renewal and other stem-like properties. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented molecular portraits of mutant IDH1-dependent epigenomic reprogramming at high resolution. These findings have significant implications for our understanding the mechanisms underlying mutant IDH function and for optimizing therapeutic approaches to targeting IDH mutant tumors.
2017-08-23 | GSE85939 | GEO
Project description:Mutations in IDH1 and IDH2 (encoding isocitrate dehydrogenase 1 and 2) drive the development of gliomas and other human malignancies. Mutant IDH1 induces epigenetic changes that promote tumorigenesis, but the scale and reversibility of these changes are unknown. Here, using human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant-IDH1-induced epigenomic reprogramming. We characterize the reversibility of the alterations in DNA methylation, the histone landscape, and transcriptional reprogramming that occur following IDH1 mutation. We discover genome-wide coordinate changes in the localization and intensity of multiple histone marks and chromatin states. Mutant IDH1 establishes a CD24+ population with a proliferative advantage and stem-like transcriptional features. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented high-resolution molecular portraits of mutant-IDH1-dependent epigenomic reprogramming. These findings have substantial implications for understanding of mutant IDH function and for optimizing therapeutic approaches to targeting IDH-mutant tumors.
| S-EPMC5769471 | biostudies-literature
Project description:Large-Scale Atlas of Mutant IDH1-Dependent Chromatin State Reprogramming, Reversibility, and Persistence
| PRJNA339790 | ENA
Project description:BackgroundMutations in isocitrate dehydrogenase (IDH) 1 have been reported in over 70% of low-grade gliomas and secondary glioblastomas. IDH1 is the enzyme that catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate while mutant IDH1 catalyzes the conversion of α-ketoglutarate into 2-hydroxyglutarate. These mutations are associated with the accumulation of 2-hydroxyglutarate within the tumor and are believed to be one of the earliest events in the development of low-grade gliomas. The goal of this work was to determine whether the IDH1 mutation leads to additional magnetic resonance spectroscopy (MRS)-detectable changes in the cellular metabolome.MethodsTwo genetically engineered cell models were investigated, a U87-based model and an E6/E7/hTERT immortalized normal human astrocyte (NHA)-based model. For both models, wild-type IDH1 cells were generated by transduction with a lentiviral vector coding for the wild-type IDH1 gene while mutant IDH1 cells were generated by transduction with a lentiviral vector coding for the R132H IDH1 mutant gene. Metabolites were extracted from the cells using the dual-phase extraction method and analyzed by 1H-MRS. Principal Component Analysis was used to analyze the MRS data.ResultsPrincipal Component Analysis clearly discriminated between wild-type and mutant IDH1 cells. Analysis of the loading plots revealed significant metabolic changes associated with the IDH1 mutation. Specifically, a significant drop in the concentration of glutamate, lactate and phosphocholine as well as the expected elevation in 2-hydroxyglutarate were observed in mutant IDH1 cells when compared to their wild-type counterparts.ConclusionThe IDH1 mutation leads to several, potentially translatable MRS-detectable metabolic changes beyond the production of 2-hydroxyglutarate.
| S-EPMC4338038 | biostudies-literature
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-other
Project description:That channels and transporters can influence the membrane morphology is increasingly recognized. Less appreciated is that the extent and free-energy cost of these deformations likely varies among different functional states of a protein, and thus, that they might contribute significantly to defining its mechanism. We consider the trimeric Na+-aspartate symporter GltPh, a homolog of an important class of neurotransmitter transporters, whose mechanism entails one of the most drastic structural changes known. Molecular simulations indicate that when the protomers become inward-facing, they cause deep, long-ranged, and yet mutually-independent membrane deformations. Using a novel simulation methodology, we estimate that the free-energy cost of this membrane perturbation is in the order of 6-7 kcal/mol per protomer. Compensating free-energy contributions within the protein or its environment must thus stabilize this inward-facing conformation for the transporter to function. We discuss these striking results in the context of existing experimental observations for this and other transporters.
| S-EPMC6957315 | biostudies-literature
Project description:Mutant isocitrate dehydrogenase 1 (IDH1-R132H; mIDH1) is a hallmark of adult gliomas. Lower grade mIDH1 gliomas are classified into 2 molecular subgroups: 1p/19q codeletion/TERT-promoter mutations or inactivating mutations in α-thalassemia/mental retardation syndrome X-linked (ATRX) and TP53. This work focuses on glioma subtypes harboring mIDH1, TP53, and ATRX inactivation. IDH1-R132H is a gain-of-function mutation that converts α-ketoglutarate into 2-hydroxyglutarate (D-2HG). The role of D-2HG within the tumor microenvironment of mIDH1/mATRX/mTP53 gliomas remains unexplored. Inhibition of D-2HG, when used as monotherapy or in combination with radiation and temozolomide (IR/TMZ), led to increased median survival (MS) of mIDH1 glioma-bearing mice. Also, D-2HG inhibition elicited anti-mIDH1 glioma immunological memory. In response to D-2HG inhibition, PD-L1 expression levels on mIDH1-glioma cells increased to similar levels as observed in WT-IDH gliomas. Thus, we combined D-2HG inhibition/IR/TMZ with anti-PDL1 immune checkpoint blockade and observed complete tumor regression in 60% of mIDH1 glioma-bearing mice. This combination strategy reduced T cell exhaustion and favored the generation of memory CD8+ T cells. Our findings demonstrate that metabolic reprogramming elicits anti-mIDH1 glioma immunity, leading to increased MS and immunological memory. Our preclinical data support the testing of IDH-R132H inhibitors in combination with IR/TMZ and anti-PDL1 as targeted therapy for mIDH1/mATRX/mTP53 glioma patients.
| S-EPMC7880418 | biostudies-literature