曲古菌素A调节NB4细胞组蛋白乙酰化和p21WAF1/CIP1表达

目的研究去乙酰化酶抑制剂曲古菌素A(trichostatinA，TSA)对人急性早幼粒细胞白血病细胞NB4组蛋白H3乙酰化水平的调节作用及对细胞周期素依赖性激酶抑制剂p21^WAF1/CIP1。表达的影响。方法应用300、150、75、37．5、18．75nmol／L浓度的TSA分别作用NB4细胞4、8、12、24、48h，提取细胞的总mRNA和总蛋白，采用RT-PCR技术检测p21^WAF1/CIP1表达情况，并用免疫印迹技术(Western blot)观察组蛋白H3的乙酰化水平变化及p21^WAF1/CIP1蛋白的表达水平。结果TSA对组蛋白H3乙酰化作用随时间改变而变化；在低浓度时就可引起组蛋白H3的乙酰化。TSA对p21^WAF1/CIP1 p21^WAF1/CIP1蛋白表达的影响呈时间和剂量依赖性。结论TSA能够明显上调NB4细胞组蛋白H3的乙酰化水平，促进细胞周期依赖性激酶抑制剂p21^WAF1/CIP1的表达。

Regulation of Histone Acetylation and the Expression ofp21WAF1/CIP1 by Trichostatin A in NB4 Cells

Objective To investigate the regulation of histone H3 acetylation and the expression of p21 WAF1/CIP1 by trichostatin A(TSA) in NB4 cells. Methods Total proteins and mRNA were extracted from NB4 cells treated with or without TSA with different doses (300,150,75,37.5,18.75 nmol/L) at various time points ( 4,8,12,24,48 h). By using Western blot,the levels of acetylated histone H3 and p21 WAF1/CIP1 protein expression were assayed. RT-PCR was used to detect the expression level of p21 WAF1/CIP1 mRNA. Results Histone H3 acetylation was obviously increased by TSA at a time-dependent manner and promoted by TSA at a low dose. The expression levels of p21 WAF1/CIP1 mRNA and protein were up-regulated at a time- and dose-dependent manner. Conclusion The level of acetylated histone H3 were up-regulated by TSA,and the expression of p21 WAF1/CIP1 was increased at the same time.