Background: 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.
Objective: 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.
Methods: 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.
Results: 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.
Conclusions: 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.
Keywords: MicroRNA-519a; non-small cell lung cancer; prognosis; progression.