蛋白激酶C在吴茱萸碱诱导A375-S2细胞死亡中的作用

目的研究蛋白激酶C(protein kinase C，PKC)在吴茱萸碱(evodiamine)诱导的A375-S2细胞死亡过程中的作用。方法TUNEL法检测吴茱萸碱诱导细胞凋亡的比例。MTT法测定药物对A375-S2细胞的细胞毒作用。Western blotting法分析药物作用后对ERK及其磷酸化蛋白和Bcl-2家族蛋白的影响。结果吴茱萸碱诱导A375-S2细胞的死亡在24 h以前以凋亡为主。PKC抑制剂staurosporine和ERK抑制剂PD98059均能促进吴茱萸碱诱导的A375-S2细胞死亡。吴茱萸碱能够抑制PKC的活力，下调ERK及其磷酸化蛋白的表达水平，并使Bax/Bcl-2表达比例上升。而staurosporine对吴茱萸碱抑制PKC活力，降低ERK及其磷酸化蛋白和Bcl-2的表达有进一步增强的作用。结论在吴茱萸碱诱导的A375-S2细胞死亡中，PKC位于ERK和Bcl-2的上游发挥其调节作用。

Effect of protein kinase C on human melanoma A375-S2 cell death induced by evodiamine

Aim To study the role of PKC in evodiamine-induced A375-S2 cell death. Methods Ratio of apoptosis induced by evodiamine was determined by TUNEL assay. MTT assay was carried out to assess cytotoxic effect of evodiamine. The influence on expression of ERK, phospho-ERK and Bcl-2 was detected by Western blotting analysis. Results TUNEL assay indicated that apoptosis was the type of A375-S2 cell death induced by evodiamine treatment for 24 h. Both staurosporine (inhibitor of PKC) and PD98059 (inhibitor of ERK) cooperated with evodiamine to further induce A375-S2 cell death. Evodiamine inhibited PKC activity, down-regulated the expression of ERK, phospho-ERK and Bcl-2, and staurosporine was capable of augmenting these effects induced by evodiamine. Conclusion PKC lies upstream and exhibits regulatory effect on ERK and Bcl-2 in evodiamine-induced cell death.