曲古抑菌素A阻断Stat3信号通路诱导前列腺癌细胞凋亡的实验研究

Trichostatin A inhibits Stat3 signaling pathway and induces apoptosis of prostate cancer cells

目的本实验研究组蛋白去乙酰化酶抑制剂曲古抑菌素A(TSA)对前列腺癌细胞DU145的抑制作用及其对信号传导与转录激活因子3(Stat3)信号通路的影响。方法采用不同浓度的TSA处理DU145不同时间后,四氮甲基唑蓝比色法测定TSA对细胞活力的抑制效应;流式细胞仪分析细胞周期的改变;蛋白印迹实验检测细胞凋亡相关蛋白半胱氨酸蛋白酶(Caspase)家族的Caspase-8、Caspase-9、Caspase-3、二磷酸腺苷核糖多聚酶(PARP)及Stat3信号蛋白活性(phospho-Stat3)的变化。结果 TSA时间和剂量依赖性地抑制DU145细胞的增殖,TSA处理细胞24 h和48 h后,细胞生存率分别是85.7%和68.7%;细胞经TSA处理后,细胞形态和细胞周期均发生明显的变化,细胞周期被阻断在G0/G1期,其细胞百分比从55.6%增加到68.5%;Western blot检测结果显示,TSA作用DU145细胞后,Stat3信号蛋白的磷酸化水平下降,同时IL-6对Stat3的刺激诱导作用也被TSA所阻断;Caspase-8、Caspase-9、Caspase-3、PARP等凋亡蛋白被TSA诱导活化,并发生显著剪切。结论 TSA能够通过抑制Stat3信号通路的活性来诱导DU145细胞凋亡。

Objective To investigate the inhibitory effect of histone deacetylase inhibitor trichostatin A（TSA） on the prostate cancer DU145 cell line and its Stat3 signaling pathway. Methods Cultured DU145 cells were treated with different doses of TSA,and the cell viability was analyzed by MTT assay. The cell cycle was detected using flow cytometry assay. The change of morphology was observed under inverted microscope. The protein levels of phospho-Stat3,Stat3,Caspase-8,Caspase-9,Caspase-3 as well as PARP were determined by western blotting. Results TSA obviously inhibited the proliferation of DU145 cells in a time- and concentration-dependent manner and arrested cell cycle at G0/G1 phase. When DU145 cells were treated with 300 nmol/L TSA for24 h and 48 h,the survival rate was 85.7% and 68.7% respectively. The percentage of cells in G0/G phase elevated from 55.6% to68.5%. The phosphorylated levels of Stat3 as well as the IL-6-induced activation of Stat3 signaling were suppressed by TSA. After treatment of TSA,caspase-8 and caspase-3 as well as its substrate PARP protein were cleaved and the cells were induced to apoptosis. Conclusion TSA suppresses the Stat3 signaling pathway and induces apoptosis in DU145 cell lines.