MiRNA biomarkers and potential critical genes associated with the prognosis of gastric cancer

Background: Dysregulated expression of miRNAs in gastric cancer (GC) is associated with tumor progression. MiRNA markers are important for the prognosis and therapeutic targeting of GC patients. Methods: To detect differentially expressed miRNAs in GC from the TCGA database and predict their target genes. We downloaded RNA sequencing (RNA-seq), miRNA-seq and clinical data of GC from TCGA. Differential expression analysis of RNA-seq and miRNA-seq data was performed by R 3.6.1. MiRNAs associated with prognosis were evaluated with the Cox model, and differentially expressed miRNAs were assessed by Kaplan–Meier curve analysis. Risk factors were identified in the Cox model. Target genes of differentially expressed miRNAs were searched in three databases. GO enrichment and KEGG pathway analyses were used to evaluate the biological functions of these target genes. Results: Five miRNAs (hsa-miR-135b-3p, hsa-miR-143-5p, hsa-miR-196b-3p, hsa-miR-942-3p, hsa-miR-9-3p) were related to survival. Eight target genes (AKAP12, AR, DZIP1, PCDHA11, PCDHA12, PI15, SH3BGRL and TMEM108) were closely correlated with patient overall survival (OS). Conclusion: Differentially expressed miRNAs and their target genes have an important influence on the diagnosis and prognosis of GC and may be used as tumor biomarkers in further studies and as potential therapeutic targets.