Effect Of XIAP-siRNA On Osteosarcoma MG-63 Cell Biological Characteristics

Objective: Osteosarcoma is the most frequent malignant bone tumor, with a peak incidence in teenagers. XIAP is expressed in some normal tissues and overexpressed in many carcinoma tissues. It is a member of the inhibitor of apoptosis(IAP) protein gene family which can block apoptosis and inhibit caspases family. It directly inhibits both the initiation and execution phase of the caspase cascade which is crucial to mediate the controlled demise of malignant tumors. RNA interference(RNAi) is known as double-stranded RNA-mediated post-transcriptional silencing. In this study, we constructed two kinds of ready to- use, synthetic XIAP-si RNA to study their influence on osteosarcoma MG-63 cells and provided a target theoretical basis to osteosarcoma.Methods:1 Specific synthetic XIAP-si RNA were transfected into MG-63 cells by Lipofectamine TM 2000. We used XIAP-si RNA to block XIAP expression while evaluating the effect of XIAP-si RNA on cell proliferation and cell apoptosis and the combined effect with ADM in osteosarcoma cells. The IAP protein level and the cell cycle and apoptosis rate of MG-63 cells transfected with si RNAs were analyzed by FCM.2 Statistical methodsThe results were anaylized with t-test, ANOVA and q-test using SPSS13.0 software. Significance were defined as a p valuve of <0.05.Results :1 XIAP-si RNA inhibted cell proliferation and made cell cycle arrested at G0/G1 stage and induced cell apoptosis.2 XIAP-si RNA effectively decrease the expression of XIAP.3 The treatment with XIAP-si RNA in combination with ADM enhanced chemosensitivity for osteosarcoma cell line.Conclusions:1 Specific synthetic XIAP-si RNA can effectively inhibit the expression of XIAP gene and proliferation and differentiation of osteosarcoma MG-63 cells and arrest cell cycle at G0/1 stage and induce cell apoptosis.2 Simultaneously specific synthetic XIAP-si RNA enhances the chemosensitivity of MG-63 cells to ADM, and improves the effect of chemotherapy. RNAi is a powerful tool on inhibiting tumor gene expression and a novel therapeutic strategy for osteosarcoma.