MicroRNA-3692-3p is overexpressed in lung tumors but may not serve as a prognostic biomarker in lung cancer patients.

Background: We previously reported overexpression of miR-3692-3p in the serum of non-small cell lung cancer patients. However, the expression profile and clinical utility of miR-3692-3p in the tumor tissues of lung cancer patients are not yet reported.

Methods And Results: We quantified the expression levels of miR-3692-3p in the tumors and adjacent normal lung tissues of early-stage (n = 29) and tissue biopsies of locally advanced and metastatic (n = 85) lung cancer patients using TaqMan advanced miRNA assay. We correlated miR-3692-3p expression with survival outcomes, therapeutic response, and other clinicopathological variables. We also predicted the target genes of miR-3692-3p, constructed a protein-protein interaction network, and performed functional enrichment analysis using various in silico tools. We found significant overexpression of miR-3692-3p in the tumors (Log2 fold change = 3.672; p < 0.0001) and tissue biopsies (Log2 fold change = 2.08; p = 0.0001) compared to normal lung tissues of lung cancer patients. The expression of miR-3692-3p did not correlate with overall survival (OS), progression-free survival (PFS), and response to therapy. In multivariate analysis, therapeutic response emerged as an independent prognostic biomarker of OS (HR = 3.47; p = 0.022) and PFS (HR = 19.86; p < 0.001). Our in silico analysis predicted 238 target genes of miR-3692-3p.

Conclusions: Overexpression of miR-3692-3p could contribute to the development of lung cancer. However, mechanistic studies are warranted to shed further light on its role in lung carcinogenesis.