FK228阻断细胞生存信号通路诱导前列腺癌细胞凋亡

FK228 blocks cells survival signal pathways and induces apoptosis of prostate cancer DU145 cells

目的：研究组蛋白去乙酰化酶(HDAC)抑制剂FK228诱导前列腺癌细胞系DU145凋亡的作用机制。方法：MTT比色法测定FK228抑制DU145细胞增殖及其对细胞的杀伤效应；瑞氏-姬姆萨染色观察细胞形态的变化；流式细胞术分析细胞周期的改变；蛋白印迹实验检测细胞内蛋白表达水平的变化。结果：FK228明显抑制DU145细胞体外增殖,并介导细胞死亡；12．5 ng/ml FK228作用细胞48 h后,细胞存活率降至63．7%；伴有细胞形态改变及细胞周期阻滞于G_0/G_1期；细胞内多种重要的激酶蛋白,包括EGFR、Her2、RM-1、Sic、Cdk4、Akt及凋亡抑制蛋白Survivin均发生了不同程度的降解,细胞内两条重要的生存信号通路Raf-MEK-ERK及PI3K/Akt被阻断,细胞发生凋亡。结论：FK228可以通过清除细胞内重要信号蛋白、阻断细胞生存信号通路来诱导DU145细胞发生凋亡。

Objective： To investigate the underlying mechanism of histone deacetylase （HDAC） inhibitor FK228-induced apoptosis of the prostate cancer cell line DU145. Methods： The inhibitory effect of FK228 on DU145 cell growth and its cytotoxicity were determined by MTT assay; cell cycle arrest was detected by flow cytometry assay; morphological change was observed by Giemsa staining; and defined kinase protein levels were determined by Western blot analysis. Resuits： FK228 obviously inhibited DU145 cells growth , arrested cell cycle at Go/G, phase, induced ceils morphological changes and degraded several kinase proteins, including EGFR, Her2, Raf-1, Src, Cdk4 and IAP member Survivin. The degradation of these kinases blocked Raf-Mek-Erk and PI3K/Akt survival signal pathways, inducing apoptosis. Conclusion： FK228 may induce DU145 cell apoptosis through depletion of multiple kinase proteins and blockade of survival signal pathways of DU145 cells.