MicroRNA-135b promotes proliferation, invasion and migration of osteosarcoma cells by degrading myocardin.

MicroRNA-135b (miR‑135b) functions as an oncogene in malignant tumors suggesting that it might be a target for malignant tumor therapy, but its role in osteosarcoma has not been investigated to date. In this study, we found that myocardin expression is specifically attenuated in MG63 osteosarcoma cells. Silencing miR‑135b restores the expression of myocardin and miR‑135b inhibits the expression of myocardin by targeting its 3'UTR in MG63 osteosarcoma cells. In additional experiments, we found that miR‑135b was highly expressed in osteosarcoma tissues and it promoted MG63 cell proliferation, migration and invasion. Myocardin had the opposite effects of miR‑135b, which suppressed proliferation, migration and invasion in MG63 cells. Thus, it is probably that miR‑135b promotes proliferation, invasion and migration of osteosarcoma cells by degrading myocardin.