Research On Differential Methylation Sites In Gastric Cancer Based On TCGA Database

Purpose: Exploration on the role of methylation in the pathogenesis of gastric carcinoma and screening for potential biomarker genes.Methods: First of all,methylation expression data,gene expression data and sample information related to gastric cancer were downloaded from The Cancer Genome Atlas(TCGA)database;Secondly,CHAMP data packet was used to analyze the methylation expression data for differential methylation sites,and the differential methylation sites were screened;Thirdly,Pearson correlation coefficients of the difference methylation sites and site-related genes were calculated to screen the negative regulatory genes of methylation sites;Fourthly,signaling pathway analysis and protein network analysis of methylation negative regulatory genes in gastric cancer were carried out.Results: 141 methylation microarrays for gastric cancer were downloaded from TCGA database,with 82 gastric cancer samples and 59 paracancerous samples.3442 differential methylation sites were screened out with P < 0.05;151 negative regulatory genes were screened out with P < 0.05,-1.0 < R < =-0.3 as the standard.The main results of signaling pathway analysis related to negative regulatory gene were as follows: oncogene signaling pathway,metabolic signaling pathway,gastric cancer signaling pathway,FoxO signaling pathway,Rap1 signaling pathway,MAPK signaling pathway,PI3K/AKt signaling pathway,cell cycle signaling pathway;the key genes identified by protein network analysis were as follows: FOXA1,PLEKHA1,FGFR2,C3,IHH,etc.Conclusion: 1.The study on differential sites of methylation microarrays is conducive to understand the molecular mechanism of gastric cancer.2.The methylation of gastric cancer may play its role through FoxO signaling pathway and Rap1 signaling pathway,MAPK signaling pathway,PI3K/AKt signaling pathway,etc.3.FOXA1,PLEKHA1,FGFR2,C3,IHH and others may be potential biomarkers of gastric cancer.