Relationship between microRNA‑29c expression and clinicopathological features of gastric cancer

Objective:To explore the relationship between the expression of miR-29c and clinicopathological characteristics of gastric cancer and predict the biological functions of target genes of miR-29c.Methods:The expression and clinical data of microRNA of gastric cancer were downloaded from The Cancer Genome Atlas(TCGA)to analyze the expression of miR-29c in gastric cancer tissues and normal gastric mucosal tissues.Paraffin specimens of gastric cancer and normal tissues were collected to make tissue microarray.The expression of miR-29c in gastric cancer tissues and normal tissues were detected by miRNAscope technique.The relationship between the expression of miR-29c and clinicopathological characteristics of gastric cancer was analyzed by chi-square test.Target genes of miR-29c were predicted by TargetScan,Pictar,miRTarbase and Starbase databases,and enrichment analysis were performed on potential target genens.Results:TCGA analysis showed that the expression of miR-29c was significantly lower in gastric cancer tissue(n=434)than normal tissues(n=41,P<0.001).miRNAscope analysis showed that the expression of miR-29c was significantly lower in gastric cancer tissue than normal tissues(P<0.001),and was significantly associated with TNM staging,lymph node metastasis and histological type of gastric cancer patients(P<0.05).Database predicted 18 potential target genes that were enriched in DNA methyltransferase activity and cancer-associated miRNA signal pathways.Conclusion:miR-29c was expressed at a low level in gastric cancer tissue and associated with TNM staging,lymph node metastasis and histological type,and could become a potential prognosis marker of gastric cancer and a new target of molecular treatment.