Experimental study on apoptosis of osteosarcoma cell induced by TRAIL combined with IFN-γ

Objective To investigate the synergetic role in inducing apoptosis of osteosarcoma cell(MG-63)when tumor necrosis factor-related apoptosis inducing ligand(TRAIL)combined with interferon(IFN)-γ.to explore the potential mechanism of synergistic antitumor activity,and to observe the toxicity of TRAIL combined with IFN-γin fibroblast.Methods The mor- pholngy was observed with inverted phase contrast microscope and electronic microscope after MC-63 was treated by TRATL, IFN-γ,and TRAIL combined with IFN-γRespectively inhibition rate and apoptosis rate was assessed by methyl thiazolyl tet- razolizm(MTT)assay and flow cytometer(FCM).After MG-63 was intervened by IFN-γ.the expression of TRAIL receptors was detected by Reverse Transcription-Polymerase Chain Reaction(RT-PCR).The toxicity of TRAIL combined with IFN-γin fihro- blast was evaluated by MTT assay.Results The growth activity of MG-63 was weakened after it was intervened by TRAIL com- bined with IFN-γ.When it was treated by IFN-γfor 24 hours,then combined with TRAIL,it showed the lowest activity.The Electronic microscope could reveal the apoptosis characteristic changes.The inhibition rate of MG-63 increased obviously by combi- ning TRAIL and IFN-γ,comparing with administration of TRAIL alone,and the difference was statistically significant(P0.01).The apoptosis rate of MG-63 increased obviously by combining TRAIL and IFN-γ,and the difference was significant(P0.01).The expression of death receptor(DR)4 was increased significantly(P0.01)when MG-63 had been treated with IFN-γfor 24 hours.The toxicity of TRAIL combined with IFN-γin fibroblast was not increased(P0.05).Conclusions IFN-γhad synergetic role in the apoptosis effect induced by TRAIL in MG-63.Up-regulating DR4 might he one of the reasons for synergetic antitumor activity.The risk of toxicity in fibroblast was not raised when TRAIL combined with IFN-γ.