β-谷甾醇对子宫颈癌细胞微管系统的影响  

Effects of β-sitosterol on microtubular systems in cervical cancer cells

作　　者：王莉 杨永杰[1] 陈松华[1] 葛锡锐[1] 徐丛剑 归绥琪 

机构地区：[1]上海生命科学研究院细胞资源中心

出　　处：《中华医学杂志》2006年第39期2771-2775,共5页National Medical Journal of China

基　　金：美国国立卫生研究院(NIH)基金中医和妇女健康中心(1 R21 AT001957-01)

摘　　要：目的探讨β-谷甾醇对子宫颈癌细胞 SiHa 的生长抑制作用及对细胞内微管系统的影响。方法采用四甲基偶氮唑蓝(MTT)法测定β-谷甾醇对 SiHa 细胞的增殖抑制作用,并用流式细胞技术分析β-谷甾醇作用前后细胞周期的变化,应用激光共聚焦显微技术观察β-谷甾醇处理的 SiHa细胞内微管和微管相关蛋白2的表达、分布,采用蛋白免疫印迹法检测微管蛋白、微管相关蛋白2的表达,及聚合和未聚合微管蛋白含量的变化。结果 20 μmol/L 的β-谷甾醇能明显抑制 SiHa 细胞的增殖,并显著促进 S 期细胞的集聚。激光共聚焦分析表明,β-谷甾醇作用5d 的 SiHa 细胞微管网络异常,微管相关蛋白2表达显著下调,蛋白免疫印迹结果进一步证实β-谷甾醇能抑制微管蛋白α和微管相关蛋白2的表达,同时β-谷甾醇能抑制 SiHa 细胞内微管蛋白的聚合,并随着作用时间的延长而逐渐增强。结论β-谷甾醇能降低 SiHa 细胞微管蛋白α和微管相关蛋白2的表达,并抑制 SiHa 细胞内微管的聚合,提示β-谷甾醇具有一定的抗微管作用,这一作用可能是造成 SiHa 细胞生长抑制的重要原因。Objective To investigate β-sitosterol＇s inhibitory effects on SiHa cells＇ growth, and the effects on microtubular system in SiHa cell. Methods Proliferation inhibition of SiHa cell line was evaluated by MTT assay. Cell cycle of SiHa cells treated with β-sitosterol was analyzed by flow cytometry. The expression and distribution of microtubule and microtubule associated protein 2 in SiHa cells were investigated by confocal microscopy. Immunoblotting analysis was used to determine tubulin or, microtubule associated protein 2, and the proportion of polymerization of tubulin. Results β-sitosterol could obviously inhibit the proliferation of SiHa cells, and induce the accumulation of cells in S phase （rather than the G2/ M phase） and mitotic arrest in the cell cycle. Confocal microscopy showed an abnormal microtubular network in SiHa cell treated with β-sitosterol for 5 days, and the expression of microtubule associated protein 2 was marked down-regulated. Further analysis by immunoblotting confirmed the down-regulation of β-sitosterol on the expression for both microtubule associated protein 2 and tubulin α. Moreover, β-sitosterol reduced the proportion of polymerization of microtubule in a time-dependent manner. Conclusion β-sitosterol could down-regulate the expression of tubulin ot and microtubule associated protein 2 in SiHa cells, and inhibit the microtubular polymerization. Our results suggested an anti-microtubule characteristic of β-sitosterol which might contribute to the proliferation inhibition of SiHa cells.

关 键 词：Β-谷甾醇 子宫颈癌 微管 微管相关蛋白2 微管聚合 

分 类 号：R737.33[医药卫生—肿瘤]