MiR-182 inhibits the epithelial to mesenchymal transition and metastasis of lung cancer cells by targeting the Met gene

The microRNA miR-182, belonging to the miR-183 family, is one of the most frequently studied cancer-related oncogenic miRNAs that is dysregulated in various cancer tissues, and it plays a crucial role in tumorigenesis and tumor progression. Studies revealed that miR-182 might function as an oncogenic or tumor suppressor miRNA in different tissues. However, the role of miR-182 in the development of lung cancer remains largely unknown. miR-182 expression in tumor samples from 58 patients, normal lung tissue samples, and lung cancer cell lines were evaluated by qRT-PCR. Survival curves were analyzed using the Kaplan-Meier method and compared with a log-rank test. Our study demonstrated that miR-182 is frequently downregulated in metastatic NSCLC cells compared with primary tumor tissues. Over-expression of miR-182 significantly inhibited the migration and invasion of lung cancer cells and promoted the expression of the epithelial marker (E-cadherin) in addition to reducing the levels of Snail in lung cancer cells. Further studies demonstrated that miR-182 negatively regulated Met via direct binding to the Met 3-untranslated region (3-UTR). Furthermore, we found that miR-182 suppressed the phosphorylation of AKT and the nuclear accumulation of Snail, a transcription factor that promotes the epidermal to mesenchymal transition (EMT). Moreover, miR-182 could repress cell migration, invasion, and EMT of lung cancer cells induced by hepatocyte growth factor (HGF). miR-182 might suppress the EMT and metastasis via inactivation of Met/AKT/Snail in non-small cell lung cancer (NSCLC) cells, which implicates miR-182 may be useful as a new therapeutic target in NSCLC.