Decreased microRNA-132 and its function in human non-small cell lung cancer

MicroRNA‑132 (miR‑132) has been shown to be dysregulated in certain types of human malignancies and is associated with tumor progression. However, its function in non‑small cell lung cancer (NSCLC) and whether it is differentially expressed in this disease, remain unclear. Thus, the aim of the present study was to investigate the effects of miR‑132 on NSCLC tumorigenesis and progression. Using reverse transcription‑quantitative polymerase chain reaction, miR‑132 expression was detected in NSCLC cell lines and primary tumor tissues. The association between miR‑132 expression, and clinicopathological factors and prognosis was assessed using statistical analysis. An MTT assay, flow cytometry, Transwell invasion assays and scratch migration assays were conducted in order to examine the proliferation, apoptosis, invasion and migration of NSCLC cells that had been transfected with miR‑132 mimics or inhibitors. The results showed that miR‑132 expression levels were significantly downregulated in NSCLC cells compared with that in corresponding non‑cancerous lung tissues (P<0.001). In addition, reduced miR‑132 expression was significantly associated with lymph node metastasis (P=0.003), an advanced tumor‑node‑metastasis stage (P<0.001) and shorter overall survival (P<0.001). Multivariate regression analysis confirmed that downregulation of miR‑132 was an independent predictor of prognosis. Furthermore, transfection of miR‑132 mimics into the NSCLC cells reduced cell proliferation, invasion and migration, and promoted cell apoptosis. These findings indicate that miR‑132 may be a novel diagnostic and prognostic marker, as well as a potential target for molecular therapy in NSCLC.