The landscape of promoter DNA hypomethylation in liver cancer
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Matthew Suderman
PROVIDER: E-GEOD-29722 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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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 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:High frequency of physical aggression is the central feature of severe conduct disorder and is associated with a wide range of social, mental and physical health problems. We have previously tested the hypothesis that differential DNA methylation signatures in peripheral T cells are associated with a chronic aggression trajectory in males. Despite the fact that sex differences appear to play a pivotal role in determining the development, magnitude and frequency of aggression, most of previous studies focused on males, so little is known about female chronic physical aggression. We therefore tested here whether or not there is a signature of physical aggression in female DNA methylation and, if there is, how it relates to the signature observed in males. Genome-wide promoter methylation profiles of T cell DNA from adult females on a Chronic Physical Aggression (CPA, n=5) trajectory during childhood and adolescence were compared to those on normative physical aggression trajectories (NPA, n=14). Two technical replicates were generated for each individual.
2013-12-11 | E-GEOD-53192 | biostudies-arrayexpress
Project description:Early life experience is associated with long-term effects on behavior and epigenetic programming of the NR3C1 (glucocorticoid receptor) gene in the hippocampus of both rats and humans. However, it is unlikely that such effects completely capture the evolutionarily conserved epigenetic mechanisms of early adaptation to environment. Here we present DNA methylation profiles spanning 6.5 million base pairs centered at the NR3C1 gene in the hippocampus of humans who experienced abuse as children and nonabused controls. Hippocampal samples were obtained from the Quebec Suicide Brain Bank and included 10 suicide subjects with histories of severe childhood abuse and 9 controls with validated negative histories of childhood abuse who did not differ in postmortem interval, sex, age at death, or brain pH (all P > 0.05). Using custom-designed microarrays with probes tiling the 6.5 million base pair region of human chromosome 5 centered at the NR3C1 gene at 100 bp spacing, we obtained DNA methylation profiles by MeDIP-chip. Replicates were performed.
2012-05-30 | E-GEOD-38352 | biostudies-arrayexpress
Project description:Animal and human studies suggest that inflammation is associated with behavioral disorders including aggression. We have recently shown that physical aggression of boys during childhood is strongly associated with reduced plasma levels of cytokines IL-1a, IL-4, IL-6, IL-8 and IL-10, later in early adulthood (Provencal et al., unpublished data). This study tests the hypothesis that there is an association between differential DNA methylation regions in cytokine genes in T cells and monocytes DNA in adult subjects and a trajectory of physical aggression from childhood to adolescence. We compared the methylation profiles of the entire genomic loci encompassing the IL-1a, IL-6, IL-4, IL10 and IL8 and three of their regulatory transcription factors (TF) NFkB1, NFAT5 and STAT6 genes in adult males on a chronic physical aggression trajectory (CPA) and males with the same background who followed a normal physical aggression trajectory (control group). We used the method of methylated DNA immunoprecipitation (MeDIP) with comprehensive cytokine gene loci and TF loci microarray hybridization, statistical analysis and false discovery rate correction. We recruited two groups of Caucasian males who were born in families with a low socioeconomic status and were living at the time of the present study within 200km from our laboratory. The first group, composed of 8 subjects, had a history of chronic physical aggression from age 6 to 15 years (chronic physical aggression group, CPA). The second group, composed of 12 subjects, was recruited from the same longitudinal studies but included only those who did not have a history of chronic physical aggression from age 6 to 15 (Control group, CG). Using custom-designed microarrays with 44K probes tiling cytokines IL-1a, IL-6, IL-4, IL10 and IL8 and three of their regulatory transcription factors (TF) NFkB1, NFAT5 and STAT6, we obtained DNA methylation profiles by meDIP-chip. Each profile was generated in triplicate.
2013-05-22 | E-GEOD-47193 | biostudies-arrayexpress
Project description:Maternal care is associated with long-term effects on behavior and epigenetic programming of the NR3C1 (GLUCOCORTICOID RECEPTOR) gene in the hippocampus of both rats and humans. However, epigenetic changes at a single gene promoter are unlikely to account for the range of responses to the early life environment and the persistent change in expression of hundreds of additional genes in adult rats in response to differences in maternal care. Here we show that natural variations in maternal care are associated with coordinate changes in DNA methylation, chromatin, and gene expression spanning over a hundred kilobase pairs in the hippocampus of adult rats. The offspring of high compared to low maternal care mothers show epigenetic changes in promoters, exons, and gene ends and higher transcriptional activity across many genes, suggesting that a broad epigenetic regulation of gene expression may form part of a coordinated response to early maternal care. We obtained hippocampal samples from adult offspring of rat mothers that differed in the frequency of pup licking/grooming in the first week of life. Using custom-designed microarrays with probes tiling the 7 million base pair region of rat chromosome 18 centered at the NR3C1 gene at 100 bp spacing, we obtained DNA methylation and H3K9 acetylation profiles by ChIP-on-chip. Each profile was generated in triplicate, each type of profile from 3 high frequency and 3 low frequency mothers.
2011-03-09 | E-GEOD-20714 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-12-11 | E-GEOD-53193 | biostudies-arrayexpress
Project description:Methylated DNA binding protein 2 (MBD2) has been shown to bind specific methylated promoters and suppress transcription. Here we systematically investigate MBD2 suppression by overexpressing MBD2 in MCF-10A cells and generating genome-wide promoter methylation profiles in order to identify methylation changes likely to affect gene expression levels. MCF-10A cells were infected with MBD2 lentivirus in order to increase MBD2 expression. DNA was extracted from both infected and non-infected cells and enriched for methylated DNA through the method of methylated DNA immunoprecipitation (MeDIP). Enriched and total DNA was hybridized in different channels to 244K custom microarrays (Agilent Technologies) that contained probes covering at 100bp-spacing all transcription start sites from -800bp to 200bp (human, Ensembl v44) and all microRNAs in miRBase from 250bp before to 250bp after the microRNA. Three technical replicates were hybridized for infected and non-infected cells.
2013-06-13 | E-GEOD-47857 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE20714: Broad epigenetic signature of maternal care in the brain of adult rats (DNA methylation and H3K9 acetylation profiles) GSE20717: Broad epigenetic signature of maternal care in the brain of adult rats (expression) Refer to individual Series
2011-03-09 | E-GEOD-20840 | biostudies-arrayexpress
Project description:Chronic physical aggression (CPA) is characterized by frequent use of physical aggression from early childhood to adolescence. Observed in approximately 5% of males, it is associated with early childhood adverse environments. DNA methylation, a covalent modification of DNA, regulates genome function and has been associated with early childhood adverse environments. We analyzed T cell DNA genome-wide promoter methylation profiles from two groups of adult males assessed annually for frequency of physical aggression between 6 and 15 years of age: a group with CPA and a control group. Whole genome methylation analysis was performed using MeDIP followed by hybridization to microarrays. We mapped the promoter regions of 20 000 genes and 400 microRNAs. The subjects were recruited from participants in two longitudinal studies of child development9,47. We recruited two groups of Caucasian males who were born in families with a low socioeconomic status and were living at the time of the present study within 200km from our laboratory. The first group had a history of high physical aggression from age 6 to 15 years (chronic physical aggression group, CPA). The second group was recruited from the same longitudinal studies but included only those who did not have a history of high physical aggression from age 6 to 15 (Control group). A total of 65 eligible subjects agreed to participate (8 CPA and 57 controls). Using custom-designed microarrays with 244K probes tiling the promoter regions of 20000 genes and 400 microRNAs, we obtained DNA methylation profiles by meDIP-chip. Each profile was generated in triplicate.
2013-09-30 | E-GEOD-50674 | biostudies-arrayexpress
Project description:As a non-invasive blood testing, the detection of cell-free DNA (cfDNA) methylation in plasma is raising increasing interest due to its diagnostic and biology applications. Although extensively used in cfDNA methylation analysis, bisulfite sequencing is less cost-effective. Through enriching methylated cfDNA fragments with MeDIP followed by deep sequencing, we aimed to characterize cfDNA methylome in cancer patients. In this study, we investigated the cfDNA methylation patterns in lung cancer patients by MeDIP-seq. MEDIPS package was used for the identification of differentially methylated regions (DMRs) between patients and normal ones. Overall, we identified 330 differentially methylated regions (DMRs) in gene promoter regions, 33 hypermethylation and 297 hypomethylation respectively, by comparing lung cancer patients and healthy individuals as controls. The 33 hypermethylation regions represent 32 genes. Some of the genes had been previously reported to be associated with lung cancers, such as GAS7, AQP10, HLF, CHRNA9 and HOPX. Taken together, our study provided an alternative method of cfDNA methylation analysis in lung cancer patients with potential clinical applications.
2019-03-31 | E-MTAB-7163 | biostudies-arrayexpress