miR-218 expression in osteosarcoma tissues and its effect on cell growth in osteosarcoma cells

Objective: To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells. Methods: miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis. Results: The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (chi(2)=5.380, P=0.020), clinical stage (chi(2)=6.692, P=0.010) and distant metastasis (chi(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells. Conclusions: The low expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.