MicroRNA-211-5p promotes the apoptosis and inhibits the migration of osteosarcoma cells by targeting proline-rich protein PRR11.

Osteosarcoma remains fatal in adolescents and young adults, with a 5-year survival rate of less than 20%. However, the detailed mechanism that regulates osteosarcoma metastasis is poorly understood. We analyzed the expression levels of miR-211-5p in clinical osteosarcoma samples and cell lines, which revealed that miR-211-5p expression was reduced in osteosarcoma. Moreover, induction of miR-211-5p in several osteosarcoma cell lines dramatically inhibited their migration and invasion capacity. Furthermore, miR-211-5p overexpression led to a significant increase of osteosarcoma cell apoptosis. Importantly, our in vivo xenograft experiments showed that miR-211-5p strongly inhibits tumorigenesis. Additionally, functional experiments demonstrated that miR-211-5p suppresses the expression of proline-rich protein 11 (PRR11) by directly binding to the 3' region of PRR11 mRNA. Moreover, we showed that PRR11 overexpression attenuated the increase of apoptosis and decreased migration and invasion when the upstream miR-211-5p was overexpressed. Our data provide new insights into the mechanisms that regulate osteosarcoma metastasis and novel potential pharmaceutical targets for personalized medicine.