ABSTRACT
Aim To investigate the anti-proliferative effect of salinomycin on doxorubicin-resistant human breast cancer MCF-7 /DOX cells.Methods MCF-7 and MCF-7 /DOX cells were treated or untreated with salinomycin.Cell viability was detected by MTS assay. Cell apoptosis was detected by Annexin V-FITC /PI as-say.Reactive oxygen species (ROS)was measured by DCFH-DA staining.Mitochondrial membrane potential was measured by JC-1 assay.The expression of apopto-sis related proteins BAX, BCL-2, caspase-3, and caspase-9 were evaluated by Western blot analysis. Results The cell viability was significantly reduced by salinomycin treatment in a dose-dependent manner. The flow cytometry results showed that salinomycin in-duced MCF-7 /DOX cell apoptosis,increased ROS pro-duction,and decreased mitochondrial membrane poten-tial.Furthermore,salinomycin decreased the expres-sion of BCL-2,and increased the expression of BAX, cleaved caspase-3,and cleaved caspase-9.Moreover, the antioxidant N-acetylcysteine (NAC ) markedly blocked the above effects.Conclusions Our results suggest that salinomycin-induced apoptosis in MCF-7 /DOX is associated with induction of ROS production, and activation of mitochondria apoptosis pathway, which may become a potential chemotherapeutic agent for the therapy of doxorubicin resistant breast cancer.
ABSTRACT
Aim To detect the effects of cetuximab combined with adriamycin on the proliferation and ap-optosis of triple-negative breast cancer cells.Methods Cell viability was evaluated by MTT assay.The cell apoptosis was analyzed by flow cytometry with propidi-um iodide staining.JC-1 staining was used to deter-mine mitochondrial membrane potential.The expres-sions of glucose regulated protein78 (GRP-78),Bcl-2 and Caspase-3 were measured with Western blot.Re-sults MTT assay showed that cetuximab had inhibi-tion effect on the breast cancer cell MDA-MB-231 growth,and the effect was related to concentration of drug.The inhibition effect of adriamycin on MDA-MB-231 had remarkabe relationship with time and concen-tration.When combined with each other,they could re-markably increase inhibition effect.The viability of cells in combination group for 1 2 h,24 h,48 h,sig-nificantly lower than that in cetuximab or adriamycin group (P group (P <0.01 ).JC-1 staining indicated that cetux-imab or adriamycin could reduce the mitochondrial membrane potential,but the reduction effect was more remarkable in the combination group.Western blot re-vealed that cetuximab could reduce the expression of GRP-78 and Bcl-2,and increased the expression of Caspase-3 and its activity.The expressions of Bcl-2, Caspase-3 had no significant change in adriamycin group,but GRP-78 was increased.In combination group,the expression of GRP-78 and Bcl-2 was signifi-cantly decreased,but Caspase-3 was increased nota-blely compared to adriamycin group.Conclusions The combination of cetuximab and adriamycin enhances the inhibition effect on the triple-negative breast cancer MDA-MB-231 cells,and increases cell apoptosis.The mechanism may be that cetuximab reduces the endo-plasmic reticulum stress level,then activates the mito-chondrial pathways by decreasing the expression of Bcl-2,reducing the mitochondrial membrane potential,and promoting cell apoptosis.