Objectives:Cisplatin(CDDP)therapy for glioblastoma(GBM)is linked with several limitations,which include poor penetration of the blood-brain barrier(BBB),systemic toxicity,and the development of drug resistance mechani...Objectives:Cisplatin(CDDP)therapy for glioblastoma(GBM)is linked with several limitations,which include poor penetration of the blood-brain barrier(BBB),systemic toxicity,and the development of drug resistance mechanisms implicating oxidative stress dysregulation and compromised apoptotic pathways.This study evaluates C-Phycocyanin(C-PC)as a potential adjuvant to enhance CDDP efficacy by modulating redox balance and apoptosis.Methods:GBM cells(U87 and U87-EGFRvIII)were treated with CDDP,C-PC,or their combination.Cell viability was assessed by MTT assay;apoptosis was evaluated by DAPI staining andWestern blot analysis of cleaved Caspase-3 and poly(ADP-ribose)polymerase(PARP).Both intracellular and extracellular reactive oxygen species(ROS)were measured using 2′,7′-dichlorodihydrofluorescein diacetate(DCF-DA)fluorescence and lucigenin chemiluminescence,respectively.Catalase activity was quantified via hydrogen peroxide(H2O2)decomposition assay,and manganese superoxide dismutase(MnSOD)expression byWestern blot.Results:C-PCselectively decreased U87GBMcell viability while sparing normal cells.C-PC enhanced CDDP cytotoxicity,reducing viability to 26.5%vs.53.2%for CDDP alone.This effect correlated with increased apoptosis,evidenced by DNA fragmentation and higher cleaved caspase-3 and PARP levels.Combined treatment lowered ROS below survival thresholds while upregulating MnSOD and catalase activity.In U87-EGFRvIII cells,CDDP reduced viability modestly(85.2%),C-PC alone decreased viability significantly(51.5%)and induced cell death,but the combination did not further increase apoptosis.Here,C-PC’s pro-apoptotic effects,alone or with CDDP,were also associated with reduced oxidative stress in cells.Conclusion:We demonstrate that C-PC enhances CDDP cytotoxicity in sensitive U87 cells by promoting apoptosis and modulating ROS,suggesting potential for improved therapeutic efficacy with reduced systemic toxicity.Compared to the combination,C-PC monotherapy achieves superior cytotoxicity in CDDP-resistant U87-EGFRvIII cells,underscoring its potential as a standalone therapeutic approach for chemotherapy-resistant glioblastoma subtypes.展开更多
文摘Objectives:Cisplatin(CDDP)therapy for glioblastoma(GBM)is linked with several limitations,which include poor penetration of the blood-brain barrier(BBB),systemic toxicity,and the development of drug resistance mechanisms implicating oxidative stress dysregulation and compromised apoptotic pathways.This study evaluates C-Phycocyanin(C-PC)as a potential adjuvant to enhance CDDP efficacy by modulating redox balance and apoptosis.Methods:GBM cells(U87 and U87-EGFRvIII)were treated with CDDP,C-PC,or their combination.Cell viability was assessed by MTT assay;apoptosis was evaluated by DAPI staining andWestern blot analysis of cleaved Caspase-3 and poly(ADP-ribose)polymerase(PARP).Both intracellular and extracellular reactive oxygen species(ROS)were measured using 2′,7′-dichlorodihydrofluorescein diacetate(DCF-DA)fluorescence and lucigenin chemiluminescence,respectively.Catalase activity was quantified via hydrogen peroxide(H2O2)decomposition assay,and manganese superoxide dismutase(MnSOD)expression byWestern blot.Results:C-PCselectively decreased U87GBMcell viability while sparing normal cells.C-PC enhanced CDDP cytotoxicity,reducing viability to 26.5%vs.53.2%for CDDP alone.This effect correlated with increased apoptosis,evidenced by DNA fragmentation and higher cleaved caspase-3 and PARP levels.Combined treatment lowered ROS below survival thresholds while upregulating MnSOD and catalase activity.In U87-EGFRvIII cells,CDDP reduced viability modestly(85.2%),C-PC alone decreased viability significantly(51.5%)and induced cell death,but the combination did not further increase apoptosis.Here,C-PC’s pro-apoptotic effects,alone or with CDDP,were also associated with reduced oxidative stress in cells.Conclusion:We demonstrate that C-PC enhances CDDP cytotoxicity in sensitive U87 cells by promoting apoptosis and modulating ROS,suggesting potential for improved therapeutic efficacy with reduced systemic toxicity.Compared to the combination,C-PC monotherapy achieves superior cytotoxicity in CDDP-resistant U87-EGFRvIII cells,underscoring its potential as a standalone therapeutic approach for chemotherapy-resistant glioblastoma subtypes.
