MicroRNA-16 suppressed the invasion and migration of osteosarcoma by directly inhibiting RAB23.

OBJECTIVE: Osteosarcoma is the most frequent primary bone malignancy that affects young adults and adolescents around the world. Increasing evidence suggests that dysfunctions of microRNAs (miRNAs) used to play an important role in human cancers. We aimed at evaluating the potential function of miR-16 and verify its influence on the function of RAB23 in osteosarcoma. PATIENTS AND METHODS: miR-16 expressions in osteosarcoma tissues and cell lines were examined using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Transwell chambers were conducted to detect the miR-16 effects on osteosarcoma cells migration and invasion. Meanwhile, Western blot and luciferase assays were performed to validate RAB23 as miR-16 targets. RESULTS: miR-16 was down-regulated in osteosarcoma cell lines (MG63, SAOS-2, U2OS, and SOSP-9607) and osteosarcoma specimens, while RAB23 expression was higher in tumor tissues. Ectopic over-expression of miR-216 in osteosarcoma cells could inhibit cells migration and invasion. RAB23 was confirmed as a direct target of miR-16 and the inverse relationship between them was also observed. Over-expression of RAB23 ablates the inhibitory effects of miR-16. CONCLUSIONS: miR-16 inhibited cancer migration and invasion, and promoted the RAB23 expression in osteosarcoma. This newly identified miR-16/RAB23 axis may provide new insight into the pathogenesis and represents a potential therapeutic target for osteosarcoma.