Altered chromosomal topology drives oncogenic programs in SDH-deficient GISTs
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA420090 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Epigenetic aberrations are widespread in cancer, yet the underlying mechanisms and causality remain poorly understood. A subset of gastrointestinal stromal tumors (GISTs) lack canonical kinase mutations but instead have succinate dehydrogenase (SDH)-deficiency and global DNA hyper-methylation. Here we associate this hyper-methylation with changes in genome topology that activate oncogenic programs. To investigate epigenetic alterations systematically, we mapped DNA methylation, CTCF insulators, enhancers, and chromosome topology in KIT-mutant, PDGFRA-mutant, and SDH-deficient GISTs. Although these respective subtypes shared similar enhancer landscapes, we identified hundreds of putative insulators where DNA methylation replaced CTCF binding in SDH-deficient GISTs. We focused on a disrupted insulator that normally partitions a core GIST super-enhancer from the FGF4 oncogene. Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs, allowing aberrant physical interaction between enhancer and oncogene. CRISPR-mediated excision of the corresponding CTCF motifs in an SDH-intact GIST model disrupted the boundary and strongly up-regulated FGF4 expression. We also identified a second recurrent insulator loss event near the KIT oncogene, which is also highly expressed across SDH-deficient GISTs. Finally, we established a patient-derived xenograft (PDX) from an SDH-deficient GIST that faithfully maintains the epigenetic state of the parental tumor, including hyper-methylation and insulator defects. This PDX model is highly sensitive to FGF receptor (FGFR) inhibitor, and more so to combined FGFR and KIT inhibition, validating the functional significance of the underlying epigenetic lesions. Our study reveals how epigenetic alterations can drive oncogenic programs in the absence of canonical kinase mutations, with implications for mechanistic targeting of aberrant pathways in cancers.
2019-10-16 | GSE107447 | GEO
Project description:<p>Metabolic lesions with pleiotropic effects on epigenetic regulation and other cellular processes are widely implicated in cancer, yet their oncogenic mechanisms remain poorly understood. Succinate dehydrogenase (SDH) deficiency causes a subset of gastrointestinal stromal tumors (GISTs) with DNA hyper-methylation. Here we associate this hyper-methylation with changes in chromosome topology that activate oncogenic programs. To investigate epigenetic alterations in this disease, we systematically mapped DNA methylation, CTCF insulators, enhancers and chromosome topology in KIT-mutant, PDGFRA-mutant and SDH-deficient GISTs. Although these respective subtypes share similar enhancer landscapes, we identified hundreds of putative insulators where DNA methylation replaced CTCF binding in SDH-deficient GISTs. We focused on disrupted insulators that partitions super-enhancers from FGF3, FGF4 and the KIT oncogene. Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs, allowing aberrant physical interaction between enhancers and oncogenes. CRISPR-mediated excision of the corresponding CTCF motif in an SDH-intact model disrupted the boundary and up-regulated FGFs and KIT expression. Our findings reveal how a metabolic lesion destabilizes chromatin structure to facilitate the initiation and selection of epigenetic alterations that drive oncogenic programs in the absence of canonical mutations.</p>
| phs001906 | dbGaP
Project description: Not available
| S-EPMC6913936 | biostudies-literature
Project description:KIT, PDGFRA, NF1, and SDH mutations are alternate initiating events, fostering hyperplasia in gastrointestinal stromal tumors (GISTs), and additional genetic alterations are required for progression to malignancy. The most frequent secondary alteration, demonstrated in ~70% of GISTs, is chromosome 14q deletion. Here we report hemizygous or homozygous inactivating mutations of the chromosome 14q MAX gene in 16 of 76 GISTs (21%). We find MAX mutations in 17% and 50% of sporadic and NF1-syndromic GISTs, respectively, and we find loss of MAX protein expression in 48% and 90% of sporadic and NF1-syndromic GISTs, and in 3 of 8 micro GISTs, which are early GISTs. MAX genomic inactivation is associated with p16 silencing in the absence of p16 coding sequence deletion, and MAX induction restores p16 expression and inhibits GIST proliferation. Hence, MAX inactivation is a common event in GIST progression, fostering cell cycle activity in early GISTs.
2017-02-03 | GSE93077 | GEO
Project description:Extrachromosomal, circular DNA (ecDNA) is emerging as a prevalent yet less characterized oncogenic alteration in cancer genomes. We leverage ChIA-PET and ChIA-Drop chromatin interaction assays to characterize genome-wide ecDNA-mediated chromatin contacts that impact transcriptional programs in cancers. ecDNAs in glioblastoma patient-derived neurosphere and prostate cancer cell cultures are marked by widespread intra-ecDNA and genome-wide chromosomal interactions. ecDNA-chromatin contact foci are characterized by broad and high-level H3K27ac signals converging predominantly on chromosomal genes of increased expression levels. Prostate cancer cells harboring synthetic ecDNA circles composed of characterized enhancers result in the genome-wide activation of chromosomal gene transcription. Deciphering the chromosomal targets of ecDNAs at single-molecule resolution reveals an association with actively expressed oncogenes spatially clustered within ecDNA-directed interaction networks. Our results suggest that ecDNA can function as mobile transcriptional enhancers to promote tumor progression and manifest a potential synthetic aneuploidy mechanism of transcription control in cancer.
2021-04-08 | GSE124769 | GEO
Project description:Gastrointestinal stromal tumors (GISTs) are the most important mesenchymal tumors of the gastrointestinal tract. The vast majority of GISTs exhibit activating mutations of KIT or PDGFRA, but epigenetic alteration of GISTs is largely unknown. In this study, we aimed to clarify the involvement of DNA methylation in GIST malignancy. A total of 25 GIST specimens were studied using Human Genome CGH Microarray Kit 105A (G4412A, Agilent). Levels of LINE-1 methylation were analyzed using bisulfite-pyrosequencing. LINE-1 hypomethylation was correlated with risk grade, and high-risk GISTs exhibited lower levels of LINE-1 methylation than low- or intermediate-risk GISTs. Array CGH analysis revealed a significant correlation between LINE-1 hypomethylation and chromosomal aberrations. Our data suggest that LINE-1 hypomethylation correlates with the aggressiveness of GISTs. Hypomethylation may increase the malignant potential of GISTs by inducing accumulation of chromosomal aberrations.
2010-06-20 | GSE22185 | GEO
Project description:Chimeric proteins resulting from chromosomal translocations play a major role as driver oncogenes in cancer. Among them, fusions between EWSR1 and a set of transcription factors (TFs) generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs. However, specific EWSR1 fusion proteins have been implicated in distinct tumor types, suggesting an enhancement of their functional properties by permissive precursor cells. Here we combined functional epigenomics with nuclear topology mapping to define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma (CCS), one of the most aggressive forms of human cancer, driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 display a distinctive binding pattern that depends on the EWSR1 prion-like domain, and is divergent from wild type ATF1, despite the physical interaction between wt and EWSR1-ATF1 proteins. This cooperativity promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures shared with primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of a new set of connections controlling neural crest-related developmental programs. Accordingly, interrogation of more than 160’000 single cell expression profiles from the human skin atlas reveals loss of EWSR1-ATF1 expression to induce a more differentiated tumor cell state. Taken together, our study uncovers the cooperativity network of EWSR1-ATF1, delineates the molecular underpinnings of its epigenetic function in CCS, and points to precursor cells along the Schwann cell-melanocytic axis as a candidate origin for these tumors.
2022-03-04 | GSE180194 | GEO
Project description:Chimeric proteins resulting from chromosomal translocations play a major role as driver oncogenes in cancer. Among them, fusions between EWSR1 and a set of transcription factors (TFs) generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs. However, specific EWSR1 fusion proteins have been implicated in distinct tumor types, suggesting an enhancement of their functional properties by permissive precursor cells. Here we combined functional epigenomics with nuclear topology mapping to define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma (CCS), one of the most aggressive forms of human cancer, driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 display a distinctive binding pattern that depends on the EWSR1 prion-like domain, and is divergent from wild type ATF1, despite the physical interaction between wt and EWSR1-ATF1 proteins. This cooperativity promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures shared with primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of a new set of connections controlling neural crest-related developmental programs. Accordingly, interrogation of more than 160,000 single cell expression profiles from the human skin atlas reveals loss of EWSR1-ATF1 expression to induce a more differentiated tumor cell state. Taken together, our study uncovers the cooperativity network of EWSR1-ATF1, delineates the molecular underpinnings of its epigenetic function in CCS, and points to precursor cells along the Schwann cell-melanocytic axis as a candidate origin for these tumors.
2022-03-04 | GSE180187 | GEO
Project description:Chimeric proteins resulting from chromosomal translocations play a major role as driver oncogenes in cancer. Among them, fusions between EWSR1 and a set of transcription factors (TFs) generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs. However, specific EWSR1 fusion proteins have been implicated in distinct tumor types, suggesting an enhancement of their functional properties by permissive precursor cells. Here we combined functional epigenomics with nuclear topology mapping to define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma (CCS), one of the most aggressive forms of human cancer, driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 display a distinctive binding pattern that depends on the EWSR1 prion-like domain, and is divergent from wild type ATF1, despite the physical interaction between wt and EWSR1-ATF1 proteins. This cooperativity promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures shared with primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of a new set of connections controlling neural crest-related developmental programs. Accordingly, interrogation of more than 160,000 single cell expression profiles from the human skin atlas reveals loss of EWSR1-ATF1 expression to induce a more differentiated tumor cell state. Taken together, our study uncovers the cooperativity network of EWSR1-ATF1, delineates the molecular underpinnings of its epigenetic function in CCS, and points to precursor cells along the Schwann cell-melanocytic axis as a candidate origin for these tumors.
2022-03-04 | GSE180183 | GEO
Project description:Chimeric proteins resulting from chromosomal translocations play a major role as driver oncogenes in cancer. Among them, fusions between EWSR1 and a set of transcription factors (TFs) generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs. However, specific EWSR1 fusion proteins have been implicated in distinct tumor types, suggesting an enhancement of their functional properties by permissive precursor cells. Here we combined functional epigenomics with nuclear topology mapping to define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma (CCS), one of the most aggressive forms of human cancer, driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 display a distinctive binding pattern that depends on the EWSR1 prion-like domain, and is divergent from wild type ATF1, despite the physical interaction between wt and EWSR1-ATF1 proteins. This cooperativity promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures shared with primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of a new set of connections controlling neural crest-related developmental programs. Accordingly, interrogation of more than 160,000 single cell expression profiles from the human skin atlas reveals loss of EWSR1-ATF1 expression to induce a more differentiated tumor cell state. Taken together, our study uncovers the cooperativity network of EWSR1-ATF1, delineates the molecular underpinnings of its epigenetic function in CCS, and points to precursor cells along the Schwann cell-melanocytic axis as a candidate origin for these tumors.
2022-03-04 | GSE180196 | GEO