曲古抑菌素A抑制人脑肿瘤细胞增殖及提高p21和p27蛋白表达  

Trichostatin A Inhibits Proliferation and Induces Expression of p21^(WAF) and p27 in Human Brain Tumor Cell Lines

作　　者：王之敏[1] 胡锦[2] 周岱[1] 许志元 Lawrence C.Panasci 陈忠平[4] 

机构地区：[1]苏州大学附属一院神经外科,江苏苏州215006 [2]上海市第六人民医院神经外科,上海200233 [3]Lady Davis Institute for Medical Research, Sir Mortimer B. Davis -Jewish General Hospital, McGill University, 3755 Cote Ste Catherine, Montreal, Quebec, H3T 1E2, Canada [4]中山大学肿瘤防治中心神经外科,广东广州510060

出　　处：《癌症》2002年第10期1100-1105,共6页Chinese Journal of Cancer

基　　金：CMB-SUMSScholarship项目(NO.98-677)

摘　　要：背景和目的:研究提示组蛋白乙酰化酶抑制剂曲古抑菌素A能诱导细胞凋亡。本研究拟探讨曲古抑菌素A对人脑肿瘤细胞的杀伤作用和机制。材料和方法:选用两种人脑肿瘤细胞株,一株为p53突变型的人胶质瘤细胞株T98G,另一株为p53野生型的人神经母细胞瘤细胞株SKNSH;采用SRB细胞毒测定方法检测TSA作用后肿瘤细胞的增殖状态,用琼脂糖凝胶DNA电泳和流式细胞仪定性和定量分析肿瘤细胞凋亡情况,应用Western印迹分析TSA作用前后,肿瘤细胞中高度乙酰化的组蛋白H3、H4,内源性p53蛋白、乙酰化p53蛋白、以及细胞周期相关蛋白p21、p27的变化。结果:TSA在纳摩尔级浓度即能有效抑制肿瘤细胞增殖,并引起高度乙酰化的组蛋白分子H3和H4集聚;用320nM的TSA作用肿瘤细胞24小时,即发生显著的肿瘤细胞凋亡;TSA刺激肿瘤细胞48小时内,p21和p27蛋白表达显著增强,其中p21蛋白水平在4小时后时即明显升高,8小时达高峰;p27蛋白水平升高发生在8小时后,而内源性p53蛋白水平和乙酰化的p53蛋白水平未发生变化。结论:TSA在体外能有效抑制对传统化疗耐药的人脑肿瘤细胞生长,其抗肿瘤生长机理可能是通过上调p21和p27蛋白水平实现的,而不受内源性p53基因状态和蛋白改变的影响。Background and Objective: The histone deacetylase inhibitor,trichostatin A(TSA),was shown to induce apoptosis in transformed cells at submicromolar concentrations. However, the effect of TSA on brain tumor cells is still unknown. This study was designed to investigate whether TSA posses antitumor activity and if any, its mechanism. Materials and Methods: A p53 mutant human glioma cell line T98G and a p53 wild type human neuroblastoma cell line SKNSH were exposed to TSA. Cell proliferation was assessed by sulforhodamine B (SRB) cytotoxicity assay. Apoptosis was quantified by flow cytometry and confirmed by apoptotic ladder formation. Expression patterns of accumulation of highly acetylated histone H3,H4; p53 and cell cycle associated p21waf,p27 which were induced by TSA were determined by using Western blot analysis. Results: TSA inhibited the proliferation of brain tumor cell lines at nanomolar concentrations and induced accumulation of highly acetylased histone moleculars. Treatment with TSA at 0.33μM for 24h significantly induced cell apoptosis.In addition to the suppression of cell growth, the up regulation of p21waf and p27 expression was observed within 48h after the treatment.p21 protein levels were increased at early time points and reached maximal levels at 8h, while p27 protein levels were increased after 8h. However, there was no significant changes of acetylased p53 and endogenous p53 protein levels were observed. Conclusion:TSA may inhibit brain tumor cell growth in vitro, which is otherwise particularly resistant to chemotherapy. TSA acts as an anti tumor agent could be through co operation between p21 and p27 in growth inhibition, irrespective of endogenous p53 status.

关 键 词：脑肿瘤 组蛋白去乙酰化酶抑制剂 P21 p27 曲古抑菌素A 细胞增殖 蛋白表达 

分 类 号：R739.41[医药卫生—肿瘤]