The landscape of promoter DNA hypomethylation in liver cancer (expression data)
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE29721 | GEO | 2011/06/04
SECONDARY ACCESSION(S): PRJNA153863
REPOSITORIES: GEO
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Project description:Extensive loss of DNA methylation is a hallmark of cancer. The role of hypomethylation in altering gene expression in cancer cells has been poorly understood. Hepatic cellular carcinoma (HCC) is one of the most common human cancers. We use HCC as a model to investigate hypomethylation in cancer by a combination of methylated DNA immunoprecipitation and hybridization with comprehensive promoter arrays. We identify approximately 2,800 promoters that are hypomethylated in tumor samples. The hypomethylated promoters appear in clusters across the genome suggesting a high-level organization behind the epigenomic changes in cancer. The genes whose promoters are demethylated are mainly involved in cell growth, cell adhesion and communication, signal transduction, mobility and invasion; functions that are essential for cancer progression and metastasis. Previous studies suggested that MBD2 was involved in demethylation of uPA and MMP2 genes in human breast and prostate cancer cell lines. We extend these results here showing that whereas MBD2 depletion in normal liver cells has little or no effect, its depletion in the human hepatocellular carcinoma cell line HepG2 and the adenocarcinoma cell line SkHep1 results in suppression of cell growth, anchorage-independent growth and invasiveness, as well as an increase in promoter methylation and silencing of several of the genes that are hypomethylated in tumors. Our studies establish for the first time the rules governing hypomethylation of promoters in liver cancer and define the potential functional role of hypomethylation in cancer. Cancerous and normal adjacent tissue samples were obtained from 11 patients with HCC from the Chinese National Human Genome Center at Shanghai, China (Dr. Ze-Guang Han). For three patients, the cancer samples were dissected using the laser capture microdissection technique. Gene expression profiles for these patients were generated using Affymetrix expression microarrays.
2011-06-04 | E-GEOD-29721 | biostudies-arrayexpress
Project description:Extensive loss of DNA methylation is a hallmark of cancer. The role of hypomethylation in altering gene expression in cancer cells has been poorly understood. Hepatic cellular carcinoma (HCC) is one of the most common human cancers. We use HCC as a model to investigate hypomethylation in cancer by a combination of methylated DNA immunoprecipitation and hybridization with comprehensive promoter arrays. We identify approximately 2,800 promoters that are hypomethylated in tumor samples. The hypomethylated promoters appear in clusters across the genome suggesting a high-level organization behind the epigenomic changes in cancer. The genes whose promoters are demethylated are mainly involved in cell growth, cell adhesion and communication, signal transduction, mobility and invasion; functions that are essential for cancer progression and metastasis. Previous studies suggested that MBD2 was involved in demethylation of uPA and MMP2 genes in human breast and prostate cancer cell lines. We extend these results here showing that whereas MBD2 depletion in normal liver cells has little or no effect, its depletion in the human hepatocellular carcinoma cell line HepG2 and the adenocarcinoma cell line SkHep1 results in suppression of cell growth, anchorage-independent growth and invasiveness, as well as an increase in promoter methylation and silencing of several of the genes that are hypomethylated in tumors. Our studies establish for the first time the rules governing hypomethylation of promoters in liver cancer and define the potential functional role of hypomethylation in cancer.
2011-06-04 | GSE29720 | GEO
Project description:Extensive loss of DNA methylation is a hallmark of cancer. The role of hypomethylation in altering gene expression in cancer cells has been poorly understood. Hepatic cellular carcinoma (HCC) is one of the most common human cancers. We use HCC as a model to investigate hypomethylation in cancer by a combination of methylated DNA immunoprecipitation and hybridization with comprehensive promoter arrays. We identify approximately 2,800 promoters that are hypomethylated in tumor samples. The hypomethylated promoters appear in clusters across the genome suggesting a high-level organization behind the epigenomic changes in cancer. The genes whose promoters are demethylated are mainly involved in cell growth, cell adhesion and communication, signal transduction, mobility and invasion; functions that are essential for cancer progression and metastasis. Previous studies suggested that MBD2 was involved in demethylation of uPA and MMP2 genes in human breast and prostate cancer cell lines. We extend these results here showing that whereas MBD2 depletion in normal liver cells has little or no effect, its depletion in the human hepatocellular carcinoma cell line HepG2 and the adenocarcinoma cell line SkHep1 results in suppression of cell growth, anchorage-independent growth and invasiveness, as well as an increase in promoter methylation and silencing of several of the genes that are hypomethylated in tumors. Our studies establish for the first time the rules governing hypomethylation of promoters in liver cancer and define the potential functional role of hypomethylation in cancer. Cancerous and normal adjacent tissue samples were obtained from 11 patients with HCC from the Chinese National Human Genome Center at Shanghai, China (Dr. Ze-Guang Han). For three patients, the cancer samples were dissected using laser capture microdissection technique. All patients provided written informed consent, and the Ethics Committee from the Chinese National Human Genome Center at Shanghai approved all aspects of this study. Human HCC HepG2 cells and adenocarcinoma SkHep1 cells were purchased from ATCC (HB8065 and HTB52, respectively, USA), whereas human untransformed hepatocytes (normal hepatocytes, NorHep) were obtained from Celprogen (33003-02, USA). Purified DNA from cancerous samples and normal adjacent samples, as well as HepG2 and NorHep cells, was enriched for methylated DNA using the MeDIP protocol developed by Cedar's group (PMID 16444255). The labeled input and bound DNA samples were hybridized to a custom-designed 244K promoter tiling array that contained probes covering all transcription start sites at intervals from 800 bp upstream to 200 bp downstream of all genes described in Ensembl (version 44) and within 250 bp of the ~400 microRNAs from miRBase, all at 100 bp-spacing.
2011-06-04 | E-GEOD-29720 | biostudies-arrayexpress
Project description:Perpose:We examined here whether SAM, which alters DNA methylation dynamics, interferes with the activity of Methyl-CpG Binding Domain Protein 2(Mbd2). Methods: mRNA of MBD2 knocked down of Skhep1 and HepG2 cells were generated by deep sequencing using Illumina GAIIx. DNA enriched by our designed microarray of MBD2 knocked down Skhep1 and HepG2 cells were also generated by deep sequencing using Illumina GAIIx. ChIP (Chromatin immunoprecipitation) was performed using ChIP-IT Express Kit with MBD2 antibody of SAM treated Skhep1, HepG2 and NorHep cells. concluds: SAM treatment results in reduction and redistribution of Mbd2 binding across genomic features in liver cancer cells, which is different from the response in untransformed liver cells. There is significant overlap between genes whose Mbd2 binding, DNA methylation and transcription are altered by Mbd2 depletion or SAM treatment. These data suggest that Mbd2 has a cancer specific footprint in binding, DNA methylation and transcription in liver cancer cells that is altered by SAM treatment. SAM selective impact on liver cancer cells is partially mediated by altering cancer specific Mbd2 binding. These data provide a molecular rationale for using either SAM or other Mbd2 modulators for treating/preventing liver cancer.
2021-02-10 | GSE166416 | GEO
Project description:Cancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in â??rewritingâ?? the cancer methylome at specific regulatory regions. LNCaP prostate cancer cell line clones with reduced MBD2 expression were establised by using shRNA to MBD2 and scrambled control clones were established with scrambled control shRNA. To interrogate methylation changes induced by MBD2 knock-down we profiled three stably transfected scrambled control clones and three MBD2 knockdown clones on Illumina HumanMethylation450K arrays. Differential methylation analysis was carried out to identified CpG sites hypo-/hyper-methylated as a result of MBD2 knockdown.
2016-08-24 | E-GEOD-77201 | biostudies-arrayexpress
Project description:Cancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in ârewritingâ the cancer methylome at specific regulatory regions. LNCaP prostate cancer cell line clones with reduced MBD2 expression were establised by using shRNA to MBD2 and scrambled control clones were established with scrambled control shRNA. To interrogate expression changes induced by MBD2 knock-down we profiled three stably transfected scrambled control clones and three MBD2 knockdown clones on Affymetrix HuGene 1.0ST expression arrays. Differential expression analysis was carried out to identified genes up-/down-regulated by MBD2 knockdown.
2016-08-24 | E-GEOD-77187 | biostudies-arrayexpress
Project description:Cancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in “rewriting” the cancer methylome at specific regulatory regions.
2016-08-24 | GSE77201 | GEO
Project description:Cancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in “rewriting” the cancer methylome at specific regulatory regions.
2016-08-24 | GSE77187 | GEO
Project description:We show that in vivo MBD2 is mainly recruited to CpG island promoters that are highly methylated. We also report that MBD2 binds to a subset of CpG island promoters that are characterized by the presence of active histone marks and RNA polymerase II (Pol2). At such sites, MBD2 binds downstream of the transcription start site. Active promoters bound by MBD2 show low to medium gene expression levels and H3K36me3 deposition suggesting a putative role for MBD2 in blocking polymerase II (Pol2) elongation at these promoters.
2014-07-03 | GSE54693 | GEO
Project description:We show that in vivo MBD2 is mainly recruited to CpG island promoters that are highly methylated. We also report that MBD2 binds to a subset of CpG island promoters that are characterized by the presence of active histone marks and RNA polymerase II (Pol2). At such sites, MBD2 binds downstream of the transcription start site. Active promoters bound by MBD2 show low to medium gene expression levels and H3K36me3 deposition suggesting a putative role for MBD2 in blocking polymerase II (Pol2) elongation at these promoters. To gain further insight into the function of and epigenetic regulation by MBD2 we generated a tagged version of the protein and stably expressed it in the MCF-7 cell line. We mapped genome wide binding of MBD2 by ChIP sequencing (ChIP-seq) and together with base resolution whole genome bisulfite sequencing (WGBS) we were able to determine the methylation content and the role of methylation density at MBD2 enriched regions. We further dissected MBD2 binding properties, taking advantage of a large set of ChIP-seq data including active histone marks, RNA polymerase II (POL2) and strand specific RNA-seq.
2014-07-03 | E-GEOD-54693 | biostudies-arrayexpress