MiR-195 Suppresses Cervical Cancer Migration and Invasion Through Targeting Smad3

Objective: MicroRNAs (miRNAs) play crucial roles in cervical cancer development and progression. The purposes of this study were to investigate the role of miR-195 in cervical cancer and clarify the regulation of Smad3 by miR-195. Methods: Quantitative real-time polymerase chain reaction was used to examine miR-195 expression in cervical cancer tissues and cell lines. The clinicopathological significance of miR-195 down-regulation was further analyzed. Transwell migration and invasion assays were performed. A luciferase reporter assay was conducted to confirm the target gene of miR-195, and the results were validated in cervical cancer tissues and cell lines. Results: MiR-195 was significantly decreased in clinical tissues and cervical cancer cell lines. The low miR-195 level was significantly correlated with higher International Federation of Gynecology and Obstetrics stage, node metastasis, and deep stromal invasion. Up-regulation of miR-195 suppressed cell migration and invasion in vitro. Smad3 was verified as a direct target of miR-195, which was further confirmed by the inverse expression of miR-195 and Smad3 in patients' specimens. Conclusions: The newly identified miR-195/Smad3 pathway provides an insight into cervical cancer metastasis and may represent a novel therapeutic target.