Abstract
MicroRNA (miRNAs) serve key roles in the progress of various types of cancer. The expression of miRNA (miR)-139-5p is downregulated in several types of tumor and has been recognized as a tumor suppressor. However, the role of miR-139-5p in non-small cell lung cancer (NSCLC) has not been investigated in detail. In the present study, it was demonstrated that miR-139-5p was significantly downregulated in NSCLC cells and tissues, and the overexpression of miR-139-5p in vitro induced apoptosis and significantly inhibited the viability and proliferation of A549 and H1299 cells. In addition, upregulation of miR-139-5p significantly inhibited the migration and invasion of A549 and H1299 cells. Hepatoma-derived growth factor (HDGF) was identified as a direct target of miR-139-5p. Rescue experiments demonstrated that the inhibitory function of miR-139-5p on cell viability, migration and invasion was partially mediated by suppressing HDGF expression. Furthermore, miR-139-5p exhibited efficient inhibition of tumor growth in a xenograft tumor mouse model of A549 cells. In summary, the results from the present study suggested that miR-139-5p may serve an important role in NSCLC by targeting HDGF and causing inhibition of cell viability and metastasis, as well as induction of apoptosis. miR-139-5p may also have the potential to serve as a therapeutic target for the treatment of NSCLC.