Integration of epigenomic and transcriptomic profiling uncovers EZH2 target genes linked to cysteine metabolism in hepatocellular carcinoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE237952 | GEO | 2024/10/24
REPOSITORIES: GEO
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Project description:Integration of epigenomic and transcriptomic profiling uncovers EZH2 target genes linked to cysteine metabolism in hepatocellular carcinoma
| PRJNA997288 | ENA
Project description:Epigenetic dysregulation is closely associated with the pathogenesis of hepatocellular carcinoma (HCC). Enhancer of zeste homolog 2 (EZH2) is a key protein involved in the exacerbation of various cancers, including HCC. Despite several clinical trials of epigenetic therapies targeting EZH2, the mechanisms underlying EZH2-mediated gene suppression in HCC are not fully understood. In this study, we investigated EZH2-mediated transcriptional programs under EZH2-selective inhibition through an integrative analysis of epigenomic (ATAC-seq) and transcriptomic (RNA-seq) approaches. To determine the impact of EZH2 dysfunction, we measured the levels of H3K27me3 and EZH2 expression using flow cytometry and reverse transcription quantitative real-time PCR (RT-qPCR), respectively. Notably, we found that higher expression of EZH2 was significantly correlated with poorer survival among HCC patients by reanalyzing transcriptomes in the cancer genome atlas (TCGA). Inhibition of EZH2 with Tazemetostat (EPZ-6438), a selective inhibitor of EZH2, showed that EZH2 regulates genes involved in lipid homeostasis, and cysteine-methionine metabolism. Among the 13 EZH2 target genes identified by transcriptomic and epigenomic profiling, we selected BHMT and CDO1, which were significantly associated with poor survival in HCC patients. When HCC cells were treated with Tazemetostat, the expression levels of the BHMT and CDO1 genes increased, while the expression levels of ferroptosis marker genes, such as FSP1, NFS1, and SLC7A11, decreased. This suggests that inhibiting EZH2 may have potential therapeutic benefits in HCC by regulating the expression of genes involved in important biological processes. Our study suggests that EZH2 epigenetically regulates ferroptosis by controlling cysteine metabolism in HCC.
2024-10-25 | GSE237948 | GEO
Project description:Epigenetic dysregulation is closely associated with the pathogenesis of hepatocellular carcinoma (HCC). Enhancer of zeste homolog 2 (EZH2) is a key protein involved in the exacerbation of various cancers, including HCC. Despite several clinical trials of epigenetic therapies targeting EZH2, the mechanisms underlying EZH2-mediated gene suppression in HCC are not fully understood. In this study, we investigated EZH2-mediated transcriptional programs under EZH2-selective inhibition through an integrative analysis of epigenomic (ATAC-seq) and transcriptomic (RNA-seq) approaches. To determine the impact of EZH2 dysfunction, we measured the levels of H3K27me3 and EZH2 expression using flow cytometry and reverse transcription quantitative real-time PCR (RT-qPCR), respectively. Notably, we found that higher expression of EZH2 was significantly correlated with poorer survival among HCC patients by reanalyzing transcriptomes in the cancer genome atlas (TCGA). Inhibition of EZH2 with Tazemetostat (EPZ-6438), a selective inhibitor of EZH2, showed that EZH2 regulates genes involved in lipid homeostasis, and cysteine-methionine metabolism. Among the 13 EZH2 target genes identified by transcriptomic and epigenomic profiling, we selected BHMT and CDO1, which were significantly associated with poor survival in HCC patients. When HCC cells were treated with Tazemetostat, the expression levels of the BHMT and CDO1 genes increased, while the expression levels of ferroptosis marker genes, such as FSP1, NFS1, and SLC7A11, decreased. This suggests that inhibiting EZH2 may have potential therapeutic benefits in HCC by regulating the expression of genes involved in important biological processes. Our study suggests that EZH2 epigenetically regulates ferroptosis by controlling cysteine metabolism in HCC.
2024-10-25 | GSE268195 | GEO
Project description:Epigenetic dysregulation is closely associated with the pathogenesis of hepatocellular carcinoma (HCC). Enhancer of zeste homolog 2 (EZH2) is a key protein involved in the exacerbation of various cancers, including HCC. Despite several clinical trials of epigenetic therapies targeting EZH2, the mechanisms underlying EZH2-mediated gene suppression in HCC are not fully understood. In this study, we investigated EZH2-mediated transcriptional programs under EZH2-selective inhibition through an integrative analysis of epigenomic (ATAC-seq) and transcriptomic (RNA-seq) approaches. To determine the impact of EZH2 dysfunction, we measured the levels of H3K27me3 and EZH2 expression using flow cytometry and reverse transcription quantitative real-time PCR (RT-qPCR), respectively. Notably, we found that higher expression of EZH2 was significantly correlated with poorer survival among HCC patients by reanalyzing transcriptomes in the cancer genome atlas (TCGA). Inhibition of EZH2 with Tazemetostat (EPZ-6438), a selective inhibitor of EZH2, showed that EZH2 regulates genes involved in lipid homeostasis, and cysteine-methionine metabolism. Among the 13 EZH2 target genes identified by transcriptomic and epigenomic profiling, we selected BHMT and CDO1, which were significantly associated with poor survival in HCC patients. When HCC cells were treated with Tazemetostat, the expression levels of the BHMT and CDO1 genes increased, while the expression levels of ferroptosis marker genes, such as FSP1, NFS1, and SLC7A11, decreased. This suggests that inhibiting EZH2 may have potential therapeutic benefits in HCC by regulating the expression of genes involved in important biological processes. Our study suggests that EZH2 epigenetically regulates ferroptosis by controlling cysteine metabolism in HCC.
2024-10-25 | GSE237951 | GEO
Project description:The systematic investigation of gene mutation and expression is important to discover novel biomarkers and therapeutic targets in cancers. Here, we integrated genomics, transcriptomics, proteomics, and metabolomics to analyze three hepatocellular carcinoma (HCC) cell lines with differential metastatic potentials. The results revealed the profile of the prometastasis metabolism potentially associated with HCC metastasis. The multiomic analysis identified 12 genes with variations at multiple levels from three metabolic pathways, including glycolysis, starch, and sucrose metabolism, and glutathione metabolism. Furthermore, uridine diphosphate (UDP)-glucose pyrophosphorylase 2 (UGP2), was observed to be persistently up-regulated with increased metastatic potential. UGP2 overexpression promoted cell migration and invasion and enhanced glycogenesis in vitro The role of UGP2 in metastasis was further confirmed using a tumor xenograft mouse model. Taken together, the compendium of multiomic data provides valuable insights in understanding the roles of shifted cellular metabolism in HCC metastasis.
| S-EPMC5880115 | biostudies-literature
Project description:Understanding the intratumoral heterogeneity of hepatocellular carcinoma is instructive for developing personalized therapy and identifying molecular biomarkers. Here we applied whole-exome sequencing to 69 samples from 11 patients to resolve the genetic architecture of subclonal diversification. Spatial genomic diversity was found in all 11 hepatocellular carcinoma cases, with 29% of driver mutations being heterogeneous, including TERT, ARID1A, NOTCH2, and STAG2. Similar with other cancer types, TP53 mutations were always shared between all tumor regions, that is, located on the "trunk" of the evolutionary tree. In addition, we found that variants within several drug targets such as KIT, SYK, and PIK3CA were mutated in a fully clonal manner, indicating their therapeutic potentials for hepatocellular carcinoma. Temporal dissection of mutational signatures suggested that mutagenic processes associated with exposure to aristolochic acid and aflatoxin might play a more important role in early, as opposed to late, stages of hepatocellular carcinoma development. Moreover, we observed extensive intratumoral epigenetic heterogeneity in hepatocellular carcinoma based on multiple independent analytical methods and showed that intratumoral methylation heterogeneity might play important roles in the biology of hepatocellular carcinoma cells. Our results also demonstrated prominent heterogeneity of intratumoral methylation even in a stable hepatocellular carcinoma genome. Together, these findings highlight widespread intratumoral heterogeneity at both the genomic and epigenomic levels in hepatocellular carcinoma and provide an important molecular foundation for better understanding the pathogenesis of this malignancy. Cancer Res; 77(9); 2255-65. ©2017 AACR.
| S-EPMC5413372 | biostudies-literature
Project description:The small molecule erastin inhibits the cystine-glutamate antiporter, system xc-, which leads to intracellular cysteine and glutathione depletion. This can cause ferroptosis, which is an oxidative cell death process characterized by uncontrolled lipid peroxidation. Erastin and other ferroptosis inducers have been shown to affect metabolism but the metabolic effects of these drugs have not been systematically studied. To this end, we investigated how erastin impacts global metabolism in cultured cells and compared this metabolic profile to that caused by the ferroptosis inducer RAS-selective lethal 3 or in vivo cysteine deprivation. Common among the metabolic profiles were alterations in nucleotide and central carbon metabolism. Supplementing nucleosides to cysteine-deprived cells rescued cell proliferation in certain contexts, showing that these alterations to nucleotide metabolism can affect cellular fitness. While inhibition of the glutathione peroxidase GPX4 caused a similar metabolic profile as cysteine deprivation, nucleoside treatment did not rescue cell viability or proliferation under RAS-selective lethal 3 treatment, suggesting that these metabolic changes have varying importance in different scenarios of ferroptosis. Together, our study shows how global metabolism is affected during ferroptosis and points to nucleotide metabolism as an important target of cysteine deprivation.
| S-EPMC10074211 | biostudies-literature
Project description:The fundamental cause of transcription dysregulation in hepatocellular carcinoma (HCC) remains elusive. To investigate the underlying mechanisms, comprehensive 3D-epigenomic analyses are performed in cellular models of THLE2 (a normal hepatocytes cell line) and HepG2 (a hepatocellular carcinoma cell line) using integrative approaches for chromatin topology, genomic and epigenomic variation, and transcriptional output. Comparing the 3D-epigenomes in THLE2 and HepG2 reveal that most HCC-associated genes are organized in complex chromatin interactions mediated by RNA polymerase II (RNAPII). Incorporation of genome-wide association studies (GWAS) data enables the identification of non-coding genetic variants that are enriched in distal enhancers connecting to the promoters of HCC-associated genes via long-range chromatin interactions, highlighting their functional roles. Interestingly, CTCF binding and looping proximal to HCC-associated genes appear to form chromatin architectures that overarch RNAPII-mediated chromatin interactions. It is further demonstrated that epigenetic variants by DNA hypomethylation at a subset of CTCF motifs proximal to HCC-associated genes can modify chromatin topological configuration, which in turn alter RNAPII-mediated chromatin interactions and lead to dysregulation of transcription. Together, the 3D-epigenomic analyses provide novel insights of multifaceted interplays involving genetics, epigenetics, and chromatin topology in HCC cells.
| S-EPMC9993472 | biostudies-literature
Project description:Chromodomain helicase DNA binding protein 5 (CHD5) acts as a tumor suppressor in many cancers. In the present study, we demonstrated that reduced levels of CHD5 in hepatocellular carcinoma (HCC) tissues were significantly associated with metastasis and poor prognosis. Gain-of-function assays revealed that CHD5 suppressed motility and invasion of HCC cells. Subsequent investigations showed that CHD5 was epigenetically silenced by polycomb repressive complex 2 (PRC2)-mediated the trimethylation of histone H3 at lysine 27 (H3K27me3) in HCC cells. Furthermore, overexpression of CHD5 repressed enhancer of zeste homolog 2 (EZH2) and activated PRC2 target genes, such as p16 and p21. Chromatin immunoprecipitation and luciferase reporter assays also showed that CHD5 and EZH2 bind to each other's promoters and inhibit transcription. These findings uncovered, for the first time, a mutual suppression regulation between CHD5 and EZH2, which may provide new insights into their potential therapeutic significance for HCC.
| S-EPMC4747380 | biostudies-literature
Project description:BACKGROUND:Accumulating studies suggest that targeting epigenetic modifications could improve the efficacy of tumor immunotherapy; however, the mechanisms underlying this phenomenon remain largely unknown. Here, we investigated the ability of the epigenetic modifier, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), to regulate the expression of immune checkpoint inhibitor, programmed death-1 ligand 1 (PD-L1) in hepatocellular carcinoma (HCC). METHODS:Immunohistochemistry and multiplex immunofluorescence staining were performed to analyze the expression and correlation of EZH2 and PD-L1 in HCC tissues. Immunoblotting, quantitative real-time PCR, flow cytometry, chromatin immunoprecipitation, and dual-luciferase reporter gene assays were performed to evaluate the regulatory roles of EZH2 on PD-L1 expression. RESULTS:In vitro cell experiments revealed that EZH2 negatively regulated the PD-L1 expression of hepatoma cell lines in IFNγ-dependent manner. Mechanistic studies demonstrated that EZH2 could suppress PD-L1 expression by upregulating the H3K27me3 levels on the promoters of CD274 (encoding PD-L1) and interferon regulatory factor 1 (IRF1), an essential transcription factor for PD-L1 expression, without affecting the activation of the IFNγ-signal transducer and activator of transcription 1 (STAT1) pathway. Clinical samples from HCC patients with immune-activated microenvironments showed negative correlations between EZH2 and PD-L1 expression in hepatoma cells. Multivariate Cox analysis demonstrated that the combination of EZH2 and PD-L1 was an independent prognostic factor for both OS and RFS for patients with HCC. CONCLUSIONS:The epigenetic modificator EZH2 can suppress the expression of immune checkpoint inhibitor PD-L1 by directly upregulating the promoter H3K27me3 levels of CD274 and IRF1 in hepatoma cells, and might serve as a potential therapeutic target for combination of immunotherapy for immune-activated HCC.
| S-EPMC6854886 | biostudies-literature