中文摘要：

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.

英文摘要：

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.