Epigenetic identity in AML is mostly dependent on disruption of non-promoter regulatory elements and reveals potentially antagonistic effects of mutations in epigenetic modifiers
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE98350 | GEO | 2017/04/28
SECONDARY ACCESSION(S): PRJNA384795
REPOSITORIES: GEO
Similar Datasets
Project description:Aberrant DNA methylation of gene promoters is a hallmark of AML. To define how cytosine methylation is redistributed in AML more precisely we performed base-pair resolution methylome sequencing in 119 patients. We find that leukemic DNA methylation patterning is tightly linked to somatic mutations and primarily driven by regulatory elements outside of promoters and by CpG shores as opposed to CpG islands. Active enhancers displayed much stronger focal differential methylation than promoters and were generally aberrantly hypomethylated except in IDH2 mutant and CEBPA silenced AMLs. AMLs with dominant hypermethylation feature greater epigenetic disruption of promoters. Those with dominant hypomethylation, such as DNMT3A mutated AMLs, display greater disruption of distal and intronic regions. IDH mutant AMLs manifest profound hypermethylation whereas DNMT3A mutant AMLs manifest profound hypomethylation of a different set of CpGs. In striking contrast, AMLs with co-occurring IDH1 and DNMT3A mutations exhibited epigenetic antagonism in which most CpGs affected by either mutation alone were no longer affected in the double mutant cases. These patients featured a unique gene expression profile featuring deregulated expression of RAS pathway that was not linked to DNA methylation.
2017-04-19 | GSE86952 | GEO
Project description:Aberrant DNA methylation of gene promoters is a hallmark of AML. To define more precisely how cytosine methylation is redistributed in AML, we performed base-pair resolution methylome sequencing in 119 patients. We find that leukemic DNA methylation patterning is tightly linked to somatic mutations and primarily driven by regulatory elements outside of promoters and by CpG shores as opposed to CpG islands. Active enhancers displayed much stronger focal differential methylation than promoters and were generally aberrantly hypomethylated except in IDH2 mutant and CEBPA silenced AMLs. AMLs with dominant hypermethylation feature greater epigenetic disruption of promoters. Those with dominant hypomethylation, such as DNMT3A mutated AMLs, display greater disruption of distal and intronic regions. IDH mutant AMLs manifest profound hypermethylation whereas DNMT3A mutant AMLs manifest profound hypomethylation of a different set of CpGs. In striking contrast, AMLs with co-occurring IDH1 and DNMT3A mutations exhibited epigenetic antagonism in which most CpGs affected by either mutation alone were no longer affected in the double mutant cases.
2017-04-28 | GSE96744 | GEO
Project description:We performed cytosine methylation sequencing on genetically diverse patients with acute myeloid leukemia (AML) and found leukemic DNA methylation patterning is primarily driven by nonpromoter regulatory elements and CpG shores. Enhancers displayed stronger differential methylation than promoters, consisting predominantly of hypomethylation. AMLs with dominant hypermethylation featured greater epigenetic disruption of promoters, whereas those with dominant hypomethylation displayed greater disruption of distal and intronic regions. Mutations in IDH and DNMT3A had opposing and mutually exclusive effects on the epigenome. Notably, co-occurrence of both mutations resulted in epigenetic antagonism, with most CpGs affected by either mutation alone no longer affected in double-mutant AMLs. Importantly, this epigenetic antagonism precedes malignant transformation and can be observed in preleukemic LSK cells from Idh2R140Q or Dnmt3aR882H single-mutant and Idh2R140Q/Dnmt3aR882H double-mutant mice. Notably, IDH/DNMT3A double-mutant AMLs manifested upregulation of a RAS signaling signature and displayed unique sensitivity to MEK inhibition ex vivo as compared with AMLs with either single mutation.Significance: AML is biologically heterogeneous with subtypes characterized by specific genetic and epigenetic abnormalities. Comprehensive DNA methylation profiling revealed that differential methylation of nonpromoter regulatory elements is a driver of epigenetic identity, that gene mutations can be context-dependent, and that co-occurrence of mutations in epigenetic modifiers can result in epigenetic antagonism. Cancer Discov; 7(8); 868-83. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 783.
| S-EPMC5540802 | biostudies-literature
Project description:Epigenetic identity in AML is mostly dependent on disruption of non-promoter regulatory elements and reveals potentially antagonistic effects of mutations in epigenetic modifiers
| PRJNA384795 | ENA
Project description:Epigenetic identity in AML is mostly dependent on disruption of non-promoter regulatory elements and reveals potentially antagonistic effects of mutations in epigenetic modifiers [mouse]
| PRJNA384797 | ENA
Project description:Although recent observations implicate the importance of telomerase activity in acute myeloid leukaemia (AML), the roles of epigenetic regulations of the TERT gene in leukaemogenesis, drug resistance and clinical prognosis in AML are not fully understood. We developed a quantitative pyrosequencing-based methylation assay covering the TERT proximal promoter and a partial exon 1 (TERTpro/Ex1) region and tested both cell lines and primary leukaemia cells derived from AML and AML with preceding myelodysplastic syndrome (AML/MDS) patients (n = 43). Prognostic impact of methylation status of the upstream TERT promoter region was assessed by the Kaplan-Meier method. The activity of the telomerase inhibitor, imetelstat, was measured using leukaemia cell lines. The TERTpro/Ex1 region was highly methylated in all cell lines and primary leukaemia cells showed diverse methylation profiles. Most cases showed hypermethylated regions at the upstream TERTpro/Ex1 region, which were associated with inferior patient survival. TERTpro/Ex1 methylation status was correlated with the cytotoxicity to imetelstat and its combination with hypomethylating agent enhanced the cytotoxicity of imetelstat. AML cell lines and primary blasts harbour distinct TERTpro/Ex1 methylation profiles that could serve as a prognostic biomarker of AML. However, validation in a large cohort of patients is necessary to confirm our findings.
| S-EPMC5245983 | biostudies-literature
Project description:The use of low dose hypomethylating agents for patients with myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (AML) has had made a significant impact. In the past, therapies for these diseases were limited and patients who elected to receive treatment were subject to highly toxic, inpatient chemotherapeutics, which were often ineffective. In the era of hypomethylating agents (azacitidine and decitabine), a patient with high grade MDS or AML with multilineage dysplasia can be offered the alternative of outpatient, relatively low-toxicity therapy. Despite the fact that CR (CR) rates to such agents remain relatively low at 15-20%, a much larger percentage of patients will have clinically significant improvements in hemoglobin, platelet, and neutrophil counts while maintaining good outpatient quality of life. As our clinical experience with azanucleotides expands, questions regarding patient selection, optimal dosing strategy, latency to best response and optimal duration of therapy following disease progression remain, but there is no question that for some patients these agents offer, for a time, an almost miraculous clinical benefit. Ongoing clinical trials in combination and in sequence with conventional therapeutics, with other epigenetically active agents, or in conjunction with bone marrow transplantation continue to provide promise for optimization of these agents for patients with myeloid disease. Although the mechanism(s) responsible for the proven efficacy of these agents remain a matter of some controversy, activity is thought to stem from induction of DNA hypomethylation, direct DNA damage, or possibly even immune modulation; there is no question that they have become a permanent part of the armamentarium against myeloid neoplasms.
| S-EPMC4086806 | biostudies-other
Project description:Alcoholic liver disease (ALD), a disorder caused by excessive alcohol consumption is a global health issue. More than two billion people consume alcohol in the world and about 75 million are classified as having alcohol disorders. ALD embraces a wide spectrum of hepatic lesions including steatosis, alcoholic steatohepatitis (ASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). ALD is a complex disease where environmental, genetic, and epigenetic factors contribute to its pathogenesis and progression. The severity of alcohol-induced liver disease depends on the amount, method of usage and duration of alcohol consumption as well as on age, gender, presence of obesity, and genetic susceptibility. Genome-wide association studies and candidate gene studies have identified genetic modifiers of ALD that can be exploited as non-invasive biomarkers, but which do not completely explain the phenotypic variability. Indeed, ALD development and progression is also modulated by epigenetic factors. The premise of this review is to discuss the role of genetic variants and epigenetic modifications, with particular attention being paid to microRNAs, as pathogenic markers, risk predictors, and therapeutic targets in ALD.
| S-EPMC6320903 | biostudies-literature
Project description:We systematically studied the expression of more than fifty histone and DNA (de)methylating enzymes in lymphoma and healthy controls. As a main result, we found that the expression levels of nearly all enzymes become markedly disturbed in lymphoma, suggesting deregulation of large parts of the epigenetic machinery. We discuss the effect of DNA promoter methylation and of transcriptional activity in the context of mutated epigenetic modifiers such as EZH2 and MLL2. As another mechanism, we studied the coupling between the energy metabolism and epigenetics via metabolites that act as cofactors of JmjC-type demethylases. Our study results suggest that Burkitt's lymphoma and diffuse large B-cell Lymphoma differ by an imbalance of repressive and poised promoters, which is governed predominantly by the activity of methyltransferases and the underrepresentation of demethylases in this regulation. The data further suggest that coupling of epigenetics with the energy metabolism can also be an important factor in lymphomagenesis in the absence of direct mutations of genes in metabolic pathways. Understanding of epigenetic deregulation in lymphoma and possibly in cancers in general must go beyond simple schemes using only a few modes of regulation.
| S-EPMC4690029 | biostudies-literature
Project description:Cancer cells are under the surveillance of the host immune system. Nevertheless, a number of immunosuppressive mechanisms allow tumors to escape protective responses and impose immune tolerance. Epigenetic alterations are central to cancer cell biology and cancer immune evasion. Accordingly, epigenetic modulating agents (EMAs) are being exploited as anti-neoplastic and immunomodulatory agents to restore immunological fitness. By simultaneously acting on cancer cells, e.g. by changing expression of tumor antigens, immune checkpoints, chemokines or innate defense pathways, and on immune cells, e.g. by remodeling the tumor stroma or enhancing effector cell functionality, EMAs can indeed overcome peripheral tolerance to transformed cells. Therefore, combinations of EMAs with chemo- or immunotherapy have become interesting strategies to fight cancer. Here we review several examples of epigenetic changes critical for immune cell functions and tumor-immune evasion and of the use of EMAs in promoting anti-tumor immunity. Finally, we provide our perspective on how EMAs could represent a game changer for combinatorial therapies and the clinical management of cancer.
| S-EPMC8042276 | biostudies-literature