MicroRNA-361-5p inhibits papillary thyroid carcinoma progression by targeting ROCK1.

MicroRNAs function as key regulators in various human cancers, including papillary thyroid cancer (PTC). MiR-361-5p has been proved to be a tumor suppressor in multiple cancers. However, the function of miR-361-5p in PTC remains unknown. In this study, we aimed to determine the function of miR-361-5p in PTC progression, and elaborate the mechanism by which miR-361-5p acts in PTC. Here, we report that miR-361-5p expression levels were significantly downregulated in PTC tissues and cell lines, as detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR) analysis. Functional analysis revealed that overexpression of miR-361-5p significantly inhibited cell proliferation, migration, invasion in vitro, as well as suppressed tumor growth in vivo. Bioinformatic analysis showed that Rho-associated coiled-coil kinase 1 (ROCK1) was a predicted target of miR-361-5p, which was further validated by the dual-luciferase reporter assay, qRT-PCR, and western blot analysis. In addition, an inverse expression pattern was also observed between miR-361-5p and ROCK1 in a cohort of PTC tissues. Rescue experiments showed that restoration of ROCK1 expression significantly reversed the suppressive effect of miR-361-5p on cell proliferation, migration, and invasion in PTC cells. Taken together, these findings suggest that miR-361-5p is a novel potential therapeutic target for thyroid cancer.