Objective To investigate the role of microRNA-10b (miR-10b) in the proliferation and invasion potential of osteosarcoma cell lines MG63 and the exact underlying mechanism. Methods The expression level of miR-10b in human osteosarcoma tissue samples and adjacent normal bone tissues were detected by relative quantitative real-time PCR (qRT-PCR). miR-10b mimic and siRNA against Twist (Twist siRNA) were transfected into human osteosarcoma cell lines MG-63 respectively using lipofactamine 2000

and RT-PCR was used to detect the mRNA expression levels of miR-10b and Twist

and Twist protein expression level was detected by Western blot.The effect of miR10b mimic and Twist siRNA on proliferation of MG-63 were detected by MTT［3-(4

5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium］. The invitro cell invasion ability was determined by Transwell invasion assays after upregulating miR10b or knocking down of Twist. Results The expression levels of miR10b was higher in human osteosarcoma tissue samples compared with adjacent normal bone tissues

the differences were extremely statistical significance(P<0.01). miR-10b directly up regulated the mRNA and protein expression levels of Twist

the differences were significant(P＜0.05). In addition

miR-10b had enhanced the cell invasion and the proliferation(P＜0.05)

whereas the proliferation and invasion ability of MG63 which transfected by both miR-10b mimic and Twist-siRNA were significantly reduced than that transfected by miR10b mimic(P＜0.05). Conclusion miR-10b in MG-63 promotes the proliferation and invasion potential of human osteosarcoma cell lines MG-63

at least partly through the upregulation of Twist gene.