β-谷甾醇对T47D细胞增殖和细胞周期的影响及作用机制探讨

Effect of β-sitosterol on T47D Cell Proliferation and Cell Cycle and Its Mechanisms

目的:观察β-谷甾醇(BSS)对雌激素受体(ER)阳性人乳腺癌T47D细胞的作用,并进一步探讨其可能的作用机制。方法:以ER拮抗剂ICI182 780为工具药,采用MTT细胞增殖实验观察不同浓度BSS对T47D细胞增殖的影响;利用流式细胞术检测其对T47D细胞周期的影响;利用Western-blot和Real-time PCR技术检测其对细胞周期蛋白D1(Cyclin D1)蛋白及m RNA表达的影响。结果:高浓度BSS抑制T47D细胞增殖,使细胞分裂增殖指数降低,且ICI182 780不能完全拮抗其对T47D细胞的增殖抑制作用;低浓度BSS可促进T47D细胞增殖,提高细胞分裂增殖指数,且ICI182 780可完全拮抗其促增殖作用。Western-blot及Real-time PCR结果显示:低浓度BSS可诱导T47D细胞Cyclin D1蛋白和m RNA表达,并且ICI182 780能够抑制此诱导作用。结论:BSS通过ER介导调节Cyclin D1蛋白与m RNA水平的表达,从而影响ER阳性人乳腺癌T47D细胞增殖活性和细胞周期,发挥植物雌激素样作用。

This study was aimed to observe the influence of β-sitosterol （BSS） on estrogen receptor （ER） positive the human breast cancer cell line T47D and to study its mechanisms. ER antagonist ICI182 780 was employed to observe the influence on the proliferation. Proliferations of T47D cells influenced by different concentrations of BSS were analyzed by MTT assay. Cell cycle analyses were examined by flow cytometry. The protein expression of cyclin DI was measured by western blot analysis and cyclin D1 mRNA was quantified by real-time PCR assay. The results showed that BSS in high dose exhibited significant inhibitory effects that were partly antagonized by ICI182 780 and decreased the proliferative index on T47D cells. However, BSS in low dose obviously promoted the proliferation that was completely inhibited by ICI182 780 and increased the proliferative index on T47D cells. The mRNA and protein levels of eyclin D1 were increased in low-dose BSS. The effect was blocked by ICI182 780. It was concluded that BSS in low concentration had phytoestrogenic effect by up-regulating the expression of cyclin D1 via ER pathway.