Expression, Clinical Significance, Immune Infiltration, and Regulation Network of miR-3940-5p in Lung Adenocarcinoma Based on Bioinformatic Analysis and Experimental Validation.

Abstract

BackgroundBased on bioinformatics analysis and experimental validation, we investigated the expression, clinical significance, immune infiltration, and potential signaling pathways of miR-3940-5p in lung adenocarcinoma (LUAD).Methods521 LUAD tissue samples and 46 normal lung tissue samples from The Cancer Genome Atlas (TCGA) database. We evaluated the relationship between clinical features and miR-3940-5p expression using Kruskal–Wallis, Wilcoxon sign-rank, and logistic regression, explored the relationship between miR-3940-5p expression and the prognosis of LUAD patients using Kaplan–Meier survival curve analysis. Several databases were used to identify miRNA targets. MiR-3940-5p target genes were analyzed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The significant role of miR-3940-5p in function was evaluated using immune infiltration analysis. LUAD cell lines were tested for miR-3940-5p expression using QRT-PCR.ResultsThere was a significant association between high miR-3940-5p expression in LUAD and T stage (P=0.005), pathologic stage (P=0.047), race (White vs Asian & Black or African American) (P=0.041), residual tumor (P=0.043), and anatomic neoplasm subdivision2 (P=0.030). MiR-3940-5p expression predicted poor overall survival (HR: 1.35; 95% CI: 1.01–1.81; P=0.045), disease-specific survival (HR: 1.53; 95% CI: 1.05–2.23; P=0.026), and progression-free survival (HR: 1.35; 95% CI: 1.03–1.77; P=0.032). BAP1, BBS1, CCR2, KCNE3, PEBP1, and RABL2A were all associated with poor OS in LUAD patients with low miR-3940-5p expression levels. According to GO and KEGG analyses, miR-3940-5p may play a role in LUAD development by regulating pathways such as measles, PI3K-Akt signaling pathway, and p53 signaling pathway. There was a correlation between the expression level of miR-3940-5p and immune infiltration. LUAD cell lines showed significantly higher levels of miR-3940-5p than Beas-2B cells.ConclusionA high expression of miR-3940-5p is significantly associated with a poor prognosis in patients with LUAD, suggesting that it could be used as a prognostic biomarker.