MicroRNA-98-5p inhibits proliferation and metastasis in non-small cell lung cancer by targeting TGFBR1

MicroRNAs (miRNAs or miRs) have recently emerged as key regulators of various types of cancer, including non-small cell lung cancer (NSCLC). The disrupted expression of miRNAs is associated with tumorigenesis and metastasis; however, the underlying mechanisms remain unclear. In this study, we demonstrate that miR-98-5p is downregulated in NSCLC and that miR-98-5p deficiency is associated with an advanced clinical stage and metastasis. A dual-luciferase reporter assay was performed to confirm that transforming growth factor beta receptor 1 (TGFBR1), a key stimulator of tumor proliferation and metastasis, was a direct target of miR-98-5p. miR-98-5p overexpression resulted in the downregulation of TGFBR1 and the suppression of the viability, proliferation, migration and invasion of A549 and H1299 cells. Furthermore, miR-98-5p was demonstrated to be an efficient suppressor of tumor growth in an A549 subcutaneous xenograft tumor mouse model. Finally, miR-98-5p overexpression exerted a significant anti-metastatic effect in a mouse model of pulmonary metastasis. On the whole, the results of the present study suggest that miR-98-5p/TGFBR1 may serve as promising targets for NSCLC therapy.