Abstract: Objective The aim of this study was to investigate the effect of miR-129 on the proliferative activity and apoptosis of osteosarcoma MG-63 cells.Methods Thirty cases of osteosarcoma and its adjacent paracancerous tissues were collected.RT-PCR was used to detect the expressions of miR-129 mRNA and SEPHS1 mRNA.Western blot was used to detect the protein level of SEPHS1.After MiR-129 was over-expressed and knocked down,the cell proliferation was detected in MG-63 cells by CCK-8,and apoptosis was detected in MG-63 cells by Westerm blot and hoechest staining.Results In this study,the expression of miR-129 in osteosarcoma tissues was significantly higher than that in para-cancerous tissues(P＜0.05).Through the established model in vitro of miR-129 overexpression or knockdown,it was determined that the miR-129 mimetic and inhibitor concentrations were optimal for overexpression and knockdown at 50nM and 200nM,respectively.The possibility of binding between miR-129 and SEPHS1 was predicted by software,and the luciferase reporter assay further confirmed the binding relationship between miR-129 and SEPHS1.Knockdown of miR-129 significantly inhibited the proliferation of MG-63 cells and accelerated the apoptosis of MG-63 cells.Conclusion miR-129 plays a key role in regulating the proliferation and apoptosis of osteosarcoma cells by binding to SEPHS1.

Key words: Osteosarcoma, MG-63 cells, miR-129, SEPHS1