Mir-21-5p and Mir-455-5p as Markers for Diagnosis and Prognosis of Rectal Adenocarcinoma may Reduce Local CD4+ and CD8+ Lymphocyte Infiltration.

Abstract

This study aimed to verify miRNAs and the molecular mechanisms of diagnostic and prognostic biomarkers for rectal adenocarcinoma. Two miRNA datasets of rectal adenocarcinoma were obtained from GEO and TCGA. GEO2R tool, Venn diagram, Kaplan-Meier survival analysis, KEGG pathway analyses, DIANA TOOLS, and Wilcoxon rank-sum test were used for biological information analysis. The diagnostic utility of miRNAs and immune infiltration of tumors in Chinese patients were validated by RTqPCR and immunofluorescence analysis. MiR-21-5P and miR-455-5p were both found to have a significant correlation with poor prognosis and higher expression in rectal adenocarcinoma. Besides, the ability to prognosis was independent of the clinicopathological stage. MiR-21-5P and miR-455-5p were enriched in the TGF-beta, Wnt, MAKP, and PI3K-AKT signaling pathways. Meanwhile, the high expression phenotype of miR-21-5P and miR-455-5p decreased CD4+ and CD8+ T cells. In summary, we found two significant diagnostic and prognostic miRNAs of rectal adenocarcinoma via integrated bioinformatics approach and clinical trials, which might decrease CD4+ and CD8+ T cells.