论文部分内容阅读
Aim:To determine whether interferon-α(IFNα) can enhance doxorubicinsensitivity in osteosarcoma cells and its molecular mechanism.Methods:Cellviability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay.Apoptosis was studied using Flow cytometry analysis,Hoechst33258 staining,DNA fragmentation assay,as well as the activation ofcaspase-3 and poly (ADP-ribose) polymerase.Protein expression was detectedby Western blotting.The dependence of p53 was determined using p53-siRNAtransfection.Results:IFNα increased doxorubicin-induced cytotoxicity to a muchgreater degree through apoptosis in human osteosarcoma p53-wild U2OS cells,but not p53-mutant MG63 cells.IFNα markedly upregulated p53,Bax,Mdm2,andp21,downregulated Bcl-2,and activated caspase-3 and PARP cleavage in re-sponse to doxorubicin in U2OS cells.Moreover,the siRNA-mediated silencing ofp53 significantly reduced the IFNα/doxorubicin combination-induced cytotoxic-ity and PARP cleavage.Conclusion:IFNα enhances the sensitivity of humanosteosarcoma U2OS cells to doxorubicin by p53-dependent apoptosis.The propercombination with IFNα and conventional chemotherapeutic agents may be a ra-tional strategy for improving the treatment of osteosarcoma with functional p53.
Aim: To determine whether interferon-α (IFNα) can enhance doxorubicinsensitivity in osteosarcoma cells and its molecular mechanism. Methods: Cell virylation was evaluated using 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolumbromide assay. was studied using Flow cytometry analysis, Hoechst 33258 staining, DNA fragmentation assay, as well as the activation of caspase-3 and poly (ADP-ribose) polymerase. Protein expression was detected by Western blotting. The dependence of p53 was determined using p53-siRNA transfection. Results : IFNα increased doxorubicin-induced cytotoxicity to a muchgreater degree through apoptosis in human osteosarcoma p53-wild U2OS cells, but not p53-mutant MG63 cells. IFNα markedly upregulated p53, Bax, Mdm2, andp21, downregulated Bcl- 2, and activated caspase- 3 and PARP cleavage in re-sponse to doxorubicin in U2OS cells. More over the siRNA-mediated silencing of p53 significantly reduced the IFNα / doxorubicin combination-induced cytotoxic-ity and PARP cleavage. Conlusion: IFN α enhances the sensitivity of humanosteosarcoma U2OS cells to doxorubicin by p53-dependent apoptosis. The propercombination with IFNα and conventional chemotherapeutic agents may be a ra tional strategy for improving the treatment of osteosarcoma with functional p53.