曲古抑菌素A通过雌激素受体α依赖和非依赖方式抑制乳腺癌细胞中细胞周期素D1的表达  

Trichostatin A induces cyclin D1 down-regulation through both ER-α-dependent and ER-α- independent mechanisms in human breast carcinoma cell fines

作　　者：徐周敏[1] 梅琪[1] 陈坚[1] 杜佳[1] 韩亮[1] 徐迎春[1] 魏燕[1] 

机构地区：[1]武警上海总队医院肿瘤科,201103

出　　处：《中华普通外科杂志》2007年第8期605-608,共4页Chinese Journal of General Surgery

摘　　要：目的探讨曲古抑菌素A（TSA）对ER—α阳性和ER—α阴性乳腺癌细胞系的作用机制。方法以含不同浓度TSA的培养液培养MCF-7（ER—α阳性）和MDA—MB-231细胞（ER—α阴性）；采用四甲基亚噻唑蓝（MTT）法检测TSA作用后肿瘤细胞的增殖状态；用流式细胞仪定量分析肿瘤细胞增殖周期的改变；用半定量RT—PCR法测定ER—α和cyclinD1mRNA的表达。Western blot检测ER—α、p21和细胞周期素cyclinD1的蛋白表达水平。结果ER—α阳性的MCF-7细胞对TSA的敏感性明显高于ER—α阴性的MDA—MB-231细胞，TSA作用48h时前者的IC50约为40．6nmol／L，后者的IC50约为272．4nmol／L。在MCF-7细胞系中，TSA能有效抑制ER—α和cyclinD1 mRNA的表达，并增强cyclinD1蛋白通过泛素-蛋白酶体通路降解，使肿瘤细胞主要阻滞在G0／G1和G2／M期。在MDA—MB-231细胞系中，TSA对cyclinD1蛋白通过泛素-蛋白酶体通路降解作用增强，但对其mRNA转录本表达无明显影响。结论TSA不仅可以通过依赖ER—α途径抑制cyclinD1 mRNA的表达，也可通过增强泛素-蛋白酶体通路降解cyclinD1蛋白而不依赖于雌激素途径。Objective To study the mechanism by which trichostatin A, a histone deacetylase inhibitor, effects an growth inhibition on both estrogen receptor α （ER—α）-positive breast cancer cell lines （MCF-7） and ER—α-negative cell lines （MDA-MB-231）. Methods The ER—α-positive MCF-7 cell line and the ER—α-negative MDA-MB-231 cell line were treated in vitro with various concentrations of trichostatin A （TSA） . The inhibitory effect of TSA on the growth of the cells was measured by MTT assay. Induction of cell cycle arrest was studied by flow cytometry. Changes in gene expression of ER—α and cyclin D1 mRNA were studied by semiquantitative RT-PCR. The protein levels of ER—α, p21 and cyclin D1 were determined by Western blot analysis. Results The ER—α-positive MCF-7 cell line was highly sensitive to the action of TSA （IC50, 40.6 nmol/L） compared with the ER—α-negative MDA-MB-231 cell line （IC50, 272. 4 nmol/L）. In the ER—α-positive MCF-7 cell line,TSA repressed ER—α and cyclin D1 transcription and induced ubiquitin dependent proteasomal degradation of cyclin D1 , leading primarily to G0/G1 and G2/M phase cell cycle arrest. By contrast,cyclin D1 degradation was enhanced but its transcription unaffected by TSA in the ER—α-negative MDA-MB-231 cell line,which was arrested in G2/M phase. Conclusion TSA effectively induces cyclin D1 down-regulation through both ER—α-dependent and ER—α-independent mechanisms.

关 键 词：乳腺肿瘤 雌激素受体Α 曲古抑菌素A 细胞周期素D1 

分 类 号：R686[医药卫生—骨科学]