Caspase-8 dependent osteosarcoma cell apoptosis induced by proteasome inhibitor MG132 / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effects of proteasome inhibitor Z-LLL-CHO(MG132) on human osteosarcoma cell line MG-63 and its possibly mechanism.METHODS: After treated with different concentration of MG132,the morphological change,ultrastructral morphology,cell viability,cell apoptosis,gene transcription and protein expression in MG-63 cells were accessed by fluorescence microscope,electron microscope,MTT assay,agrose gel electrophoresis,FCM,RT-PCR and Western blotting.RESULTS: Proteasome inhibitor MG132 was an effective inducer of apoptosis in human osteosarcoma MG-63 cells.Not only apoptotic changes,but also cell arrest at G2-M-phase,the accumulation of p27kip1,the accumulation of activated caspase-8 and increased ratio of Bax∶Bcl-2 were observed.However,to normal human diploid fibroblast cells,MG132 did not show apoptosis-inducing effect.CONCLUSION: Apoptosis induced by MG132 may be caspase-8,p27kip1and bcl-2-related.