Screening And Identifition Of PRSS1-related CircRNAs

Objective:Gastric cancer is one of the most common malignant tumors in China,which causes serious harm to human health.Gastric cancer-related protein serine proteinase-1(PRSS1)has been screened and identified in our previous study,but the regulation mechanism of its expression in gastric cancer remains unclear.In this study,circRNA microarray was used to screen and identify circRNAs related to the regulation of PRSS1 expression,so as to further explore its role in gastric cancer and the regulation mechanism of its expression.Methods: 1.Three cases of gastric adenocarcinoma with high expression of PRSS1 protein expression(2 moderately differentiated adenocarcinoma and 1 poorly differentiated adenocarcinoma)and paracancerous noncancerous tissues with low expression of PRSS1 confirmed by immunohistoc hemical staining were collected.2.Arraystar circRNA microarray was used to screen differentially expressed circRNAs(containing 13615 genes)in three pairs of gastric adenocarcinoma and paracancerous tissues,and Fold Change(FC)>1.5,P<0.05 was used for screening.3.The circRNAs associated with PRSS1 expression was analyzed by bioinformatics combined with microarray results.4.In addition,we collected 20 cases of gastric adenocarcinoma and adjacent non-cancerous tissues,used qRTPCR method to verify the expression of related circRNAs,and analyzed the relationship between its expression and clinicopathological factors of the patients.5.In order to further analyze the biological function of objective circRNAs,GO and KEGG Pathway enrichment analysis of objective circRNAs were carried out.Results: 1.A total of 197 differentially expressed circRN As,were found in circRNA microarray,including 107 up-regulated circRNAs and 90 down-regulated.2.Through bioinformatics analysis and prediction,combine d with the results of circRNA microarray,we screened out PRSS1expression-related circRNAs hsa＿circRNA＿405133 and hsa＿circRNA＿405815,in which hsa＿circRNA＿405133 expression was up-regulated and hsa＿circRNA＿405815 expression was down-regulated.3.The expression of hsa＿circRNA＿405133 was up-regulated in 20 cases of gastric cancer by qRT-PCR(P > 0.05);the expression of hsa＿circRNA＿405815 was down-regulated in gastric cancer,and the expression level was negatively correlated with TNM stage and lymph node metastasis of gastric cancer(P < 0.05).4.The GO analysis results showed that the molecular functions of the target genes regulated by hsa＿circRNA＿405815 mainly focused on binding proteins and regulating enzyme activities.In terms of cellular components,they are mainly located in intracellular and intracellular organelles.In terms of biological process,it mainly focuses on the aspects of cell metabolism and so on.KEGG pathway enrichment analysis showed that hsa＿circRNA＿405815 may be involved in three signaling pathways,including Th17 cell differentiation,inflammatory bowel disease,and glutathione metabolism.Conclusion: 1.The circRNAs expression profile of gastric cancerassociated protein PRSS1 was established(including 107 up-regulated circRNAs and 90 down-regulated).2.hsa＿circRNA＿405815 was low expressed in gastric cancer tissues and negatively correlated with tumor TNM staging and lymph node metastasis.