摘要
目的:探讨组蛋白去乙酰化酶抑制剂曲古抑菌素A(trichostatin A,TSA)诱导尤文肉瘤细胞株WE-68和VH-64凋亡及作用机制。方法:四甲基偶氮唑蓝法(MTT法)测定细胞增殖抑制率。流式细胞计数法测量TSA给药后细胞周期中sub-G1含量的变化。免疫印迹法(Western-blot)检测细胞中活化型多聚ADP核糖多聚酶(cleaved-PARP),p53-lys382残基乙酰化和p53蛋白总量的表达。实时定量PCR和siRNA转染技术测定p53多个下游基因的mRNA水平改变和p53表达下调对TSA诱导凋亡的影响。结果:TSA抑制了尤文肉瘤细胞的增殖,诱导细胞周期中sub-G1含量和凋亡终产物cleaved-PARP蛋白表达的增加。TSA给药后,p53-lys382残基乙酰化表达量呈浓度依存性增加,同时上调p53下游因子p21,mdm2,Bax和PUMA的mRNA水平。另一方面,p53蛋白表达的下调明显削弱了TSA介导的p21表达的上调和cleaved-PARP的产生。结论:组蛋白去乙酰化酶抑制剂TSA能够通过激活p53高乙酰化表达来恢复p53转录功能,从而诱导尤文肉瘤细胞株产生凋亡。
Objective：To investigate the inhibitory effects of histone deacetylase inhibitor （TSA）on the prolifera- tion of human Ewing Sarcoma WE - 68 and 1H - 64 cell lines and the apoptotic mechanism. Methods ： The prolifera- tion of WE - 68 and VH - 64 cells was determined by using MTY method. The content of sub - G1 in cell cycle pro- gression was determined by flow cytometry. The expression of cleaved - PARP, p53 - lys382 and p53 total protein was detected by western blot. The mRNA levels of p53 target genes were measured by real - time PCR and the expression of p21 and cleaved - PARP induced by TSA was detected by western blot after the knockdown of p53 using siRNA transfection. Results： After exposure to TSA, the growth of WE - 68 and VH - 64 cells were inhibited. The content of sub - G1 and the expression amount of cleaved - PARP were higher than that of control group. Moreover, the ratio of acetylation expression of p53 at lys - 382 to the amount of its total protein increased in a dose - dependent manner to- gether with upregulation of p21, mdm2, Bax and PUMA. On the other hand, expression of p21 and cleaved -PARP in- duced by TSA was impaired after the knockdown of p53 expression. Conclusion：A HDAC inhibitor, TSA can induce p53 -dependent transactivation and apoptosis by hyperacetylation in Ewing Sarcoma cells.
出处
《现代肿瘤医学》
CAS
2013年第10期2151-2154,共4页
Journal of Modern Oncology
基金
国家自然科学基金面上项目(编号:30973021
81272946)
