Norcantharidin Induces Human Melanoma A375-S2 Cell Apoptosis through Mitochondrial and Caspase Pathways

Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris. To examine the pathway of NCTD-induced A375-S2 cell death, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide (MTT) assay, photomicroscopical observation, DNA agarose gel electrophoresis, caspase activity assay and Western blot analysis were carried out. A375-S2 cells treated with NCTD exhibited several typical characteristics of apoptosis. The inhibitory effect of NCTD on human melanoma, A375-S2 cells, was partially reversed by the inhibitors of pan-caspase, caspase-3 and caspase-9. The activities of caspase-3 and -9 were significantly increased after treatment with NCTD at different time. The expression of inhibitor of caspase-activated DNase was decreased in a time-dependent manner, simultaneously, the ratio of Bcl-2/Bax or Bcl-xL/Bax was decreased and the expression ratio of proteins could be reversed by caspase-3 inhibitor. The expression of cytochrome c in cytosol was increased after NCTD treatment and caspase- 3 inhibitor had no significant effect on the up-regulation of cytochrom c. These results suggest that NCTD induced A375-S2 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of NCTD-induced A375-S2 cell apoptosis.

Human interleukin-1? induces A375-S2 human melanoma apoptosis through caspase pathway / 中国病理生理杂志

AIM: To study the molecular biological mechanism and signal transduction pathway of interleukin-1? (IL-1?)-induced apoptosis in A375-S2 melanoma cells. METHODS: Photomicrocropy showed typical apoptotic changes. The cytotoxic effect of IL-1? in vitro and influences of caspases in this effect were measured by MTT assay. The cytotoxicity of cells was assessed by LDH-based assay. Degradation of DNA was detected by agarose gel electrophoresis. RESULTS: The inhibitory effect of IL-1? on A375-S2 cell growth was in a dose and time-dependent manner, and cell death rate reached more than 90% at 72 h after treatment with 10~(-9)mol/L IL-1?. The inhibitors of caspase-family, -1, -3, -8, -9, and -10, partially blocked cell death at early stage. LDH assay showed that major IL-1?-induced cell death was apoptosis, and in a dose and time-dependent manner. Typical apoptotic DNA ladder was observed in agarose gel electrophoresis. CONCLUSION: IL-1? induced apoptosis in melanoma A375-S2 cells by activating caspase pathway. [