细胞外调节蛋白激酶与端粒酶对肝癌细胞SMMC-7721凋亡的调控作用

Regulative function of extracelluar regulated protein kinases and telomerase in apoptosis of hepatocarcinomatous cellSMMC-7721

目的 研究3种化疗药物抑制肝癌SMMC-7721细胞增殖、促进细胞凋亡过程中端粒酶活性及细胞外调节蛋白激酶（ERK）磷酸化蛋白表达水平的变化,探讨端粒酶与ERK在肝癌细胞凋亡过程中的调节作用及相互之间的关系。方法 用MTT法、流式细胞术检测法、端粒重复序列扩增法（TRAP法）、生物发光分析法及western blot检测法。结果3种化疗药物使肝癌细胞增殖受抑（抑制率分别为:028％±0.08％、0.25％±0.16％和0.24％±0.11％）并诱发凋亡（凋亡率分别为21.12％、28.83％和12.30％）的同时,端粒酶活性也有不同程度减低（分别为对照组的46％、65％和98％）;处于活化状态的磷酸化ERK1/2蛋白表达水平下降。结论ERK通路可能是化疗药物下调端粒酶活性,进而促进细胞凋亡的机制之一。

Objective To study the changes of telomerase activity and protein expression of phosphorylated( activated) extracel-luar regulated protein kinases (ERK1 and ERK2) in the course of inhibiting hepatocarcinomatous cell proliferation and inducing cell apop-tosis by three kinds of chemotherapy drugs: Harringtonine (HRT), Vincristine (VCR), and Etoposide (Vpl6). To discuss the regulative function to hepatocarcinomatous cell apoptosis and interrelation of telomerase and ERK. Methods Cytotoxicity assay, flow cytometry analysis, telomerase repeat amplification protocol assay (TRAP), bioluminescence analysis, and western blot were used in this experiment. Results HRT, VCR, and Vpl6 could inhibit cell proliferation inhibition ratios are 0.28% ±0.08%, 0.25%±0.16% and 0.24%±0.11% respectively, induce apoptosis (21.12%, 28.83% and 12.30%), inhibit telomerase activity (46%, 65% and 98% of control group), and down-regulate the protein expression of phosphorylated ERK. Conclusions It might be through ERK signal transduction pathways that chemotherapy drags down-regulate telomerase activity and induce apoptosis.