MiR-519a functions as a tumor suppressor and is negatively associated with poor prognosis of non-small cell lung cancer.

Abstract

Non-small cell lung cancer (NSCLC) is the major type of lung cancer. MicroRNAs (miRNAs) are currently considered as novel targets and tools in cancer therapy. The aim of this study was to investigate the expression level and functional role of miR-519a in NSCLC, as well as its clinical values. One hundred and two patients with NSCLC were recruited. Quantitative real-time PCR (qRT-PCR) was used for the measurement of the expression level of miR-519a. Kaplan-Meier survival and Cox regression analyses were conducted to explore the prognostic significance of miR-519a in NSCLC. MTT and Transwell assays were used to detect the effect of miR-519a on NSCLC cell proliferation, migration, and invasion. MiR-519a was significantly downregulated in NSCLC tissues, as well as NSCLC cell lines. The expression level of miR-519a was prominently associated with lymph node metastasis and TNM stage. Kaplan-Meier analysis suggested that low miR-519a expression was closely associated with shorter overall survival. Multivariate Cox regression analysis demonstrated that miR-519a expression level and TNM stage were two independent prognostic factors for 5-year overall survival in NSCLC patients. In vitro study, miR-519a significantly inhibited the proliferation, migration, and invasion of NSCLC cells. STAT3 was proved to be the target gene of miR-519a. MiR-519a functions as a tumor suppressor and inhibits tumor progression of NSCLC via targeting STAT3. MiR-519a may act as a prognostic biomarker and therapeutic target for NSCLC.