miR-206 inhibits non small cell lung cancer cell proliferation and invasion by targeting SOX9

Background: MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been suggested to play an essential role in tumorigenesis. miR-206 functions as a tumor suppressor in several cancers. However, its role in non small cell lung cancer (NSCLC) remains unclear. Methods: Expression levels of miR-206 in NSCLC tissues and cell lines were determined by quantitative real-time PCR (qRT-PCR). Then, we investigated the role of miR-206 on NSCLC cell proliferation, migration and invasion. Furthermore, luciferase reporter assay was performed to confirm the target gene of miR-206 and the results were validated in NSCLC cells. Results: In the present study, our results showed that miR-206 was decreased in NSCLC tissues compared with adjacent non-tumor tissues. Forced overexpression of miR-206 significantly inhibited cell proliferation, migration and invasion of NSCLC cells. SOX9 was found to be a target of miR-206. Furthermore, down-regulation of SOX9 by shRNA performed similar effects with overexpression of miR-206. Conclusions: Our study suggested that miR-206 acts as tumor suppressor in NSCLC partially via targeting SOX9.