Project description:Time-series comprehensive DNA methylation analysis after EBV infection in the immortalised normal gastric epithelial cell line, GES1, and low methylation gastric cancer cell line, MKN7. Infinium HumanMethylation450 BeadChip was used to obtain DNA methylation profiles across 485,577 CpG sites. Samples included 9 GES1 with and without EBV infection, 5 MKN7 with and without EBV infection, EBV+ gastric cancer cell and xenograft, SNU719 and KT, 2 normal gastric mucosae, 2 low-methylation gastric cancer cases, and 2 high-methylation gastric cancer cases.
Project description:Genome wide DNA methylation profiling of normal gastric epuithelial cells and gastric cancer cell lines. The Illumina Infinium 450k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 450,000 CpGs. Samples included 2 normal gastric epithelial cells and 14 gastric cancer cells.
Project description:Extensive DNA methylation in promoter regions is observed in gastric cancer with Epstein-barr virus (EBV) infection and EBV infection is the cause to induce this extensive hypermethylaiton phenotype in gastric epithelial cells. From transcriptome analysis, we found that TET2, one of the demethylase enzymes, was downregulated by EBV infection in gastric epithelial cell line MKN7. TET2 was overexpressed in a gastric epithelial cell line, GES1, to see its function and the hydroxymethylation, a byproduct of DNA demethylation, acquired genes by TET2 overexpression and methylation acquired genes by EBV infection were significantly overlapped. These suggested that hydroxymethylation by TET2 could function to keep unmethylated status of genes before EBV infection, and TET2 depression could contribute to methylation acquisition of these target genes after EBV infection.
Project description:Clopidogrel is associated with a series of gastrointestinal side effects, such as bleeding complications and recurrent gastric ulcer; however, their mechanisms are largely unclear. In this study, human gene expression microarray and gene ontology analysis were utilized to evaluate the effects of clopidogrel on gene expression in human gastric epithelial cells (GES-1) Keywords: Clopidogrel; Gastric injury; GES-1 cell line
Project description:This SuperSeries is composed of the following subset Series: GSE31787: Aberrant DNA methylation epigenotype expanding to non-polycomb target genes, induced by Epstein-Barr virus infection in human gastric cancer [Affymetrix Expression] GSE31788: Aberrant DNA methylation epigenotype expanding to non-polycomb target genes, induced by Epstein-Barr virus infection in human gastric cancer [Illumina Methylation] Refer to individual Series
Project description:Persistent colonization of the gastric mucosa by Helicobacter pylori (Hp) elicits chronic inflammation and aberrant epithelial cell proliferation, which increases the risk of gastric cancer. We examined the ability of microRNAs to modulate gastric cell proliferation in response to persistent Hp infection and found that epigenetic silencing of miR-210 plays a key role in gastric disease progression. Importantly, DNA methylation of the miR-210 gene was increased in Hp-positive human gastric biopsies as compared to Hp-negative controls. Moreover silencing of miR-210 in gastric epithelial cells promoted proliferation. We identified STMN1 and DIMT1 as miR-210 target genes and demonstrated that inhibition of miR-210 expression augmented cell proliferation by activating STMN1 and DIMT1. Together, our results highlight inflammation-induced epigenetic silencing of miR-210 as a mechanism of induction of chronic gastric diseases, including cancer, during Hp infection. To identify miR-210 targets in gastric cells, whole transcriptome analysis of AGS and MKN45 cells transfected with pre-miR-210 was conducted using Affymetrix GeneChip Human Genome U133 Plus 2.0 Array.
Project description:Gene expression changes specific for healthy undifferentiated and differentiated human gastric primary epithelial cells of different regions of the stomach were here determined in order to describe the transcriptomic profile of these cells in correlation to their DNA methylation pattern. In addition, gene expression changes upon 5-aza-2'-deoxycytidine treatment of antral gastric primary cells compared to mock-treated cells were deterimend.
Project description:DNA methylation changes specific for healthy undifferentiated and differentiated human gastric primary epithelial cells of different regions of the stomach were here determined in order to describe the epigenetic profile of these cells in correlation to their gene expression pattern.
