Project description:Revealing Dominant Regulatory MicroRNA-495-3p that Governs Multiple Epigenetic Modifiers in Gastric Carcinogenesis In this study, we identified miR-495-3p targeting multiple epigenetic modifiers through comprehensive miRNA and mRNA profiling analysis with in silico target prediction in GC. Western blotting assay or quantitative real time PCR was performed to confirm the expression of miR-495-3p and targets of it. We applied miRNA mimics to ectopic overexpression in gastric cancer cells and observed tumor suppressive effects of miR-495-3p in the growth and metastasis of cancer. Also, we confirmed the status of CpG islands of miR-495-3p promoter using methylation specific PCR analysis.
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.
