乳腺癌细胞共激活因子SRC-1的表达变化与内分泌治疗的关系

Expression changes of SRC-1 in breast cancer cells and its relationship with endocirine therapy

目的:观察三苯氧胺作用前后ERα阳性细胞株T-47D和ERα阴性细胞株MDA-MB-231中共激活因子SRC-1的表达变化,研究共激活因子与内分泌治疗的内在关系。方法:四氮甲唑蓝(MTT)观察两细胞的生存状况,以筛选最佳的药物作用浓度和时间。单细胞凝胶电泳法(Comet法)检测细胞凋亡。细胞免疫组化法观察TAM作用前后细胞中ERα和SRC-1的表达情况。Western blot法检测TAM作用前后细胞中ERα和SRC-1的表达水平变化情况。结果:MTT法测得TAM作用后T-47D和MDA-MB-231的OD值下降,与对照组相比有显著性差异(P<0.05),对T-47D效果更强。0.10mmol/L TAM作用48 h后两种细胞的活力均出现最低值。单细胞凝胶电泳法观察到TAM作用后两组细胞均发生凋亡、染色体断裂现象,尾长、尾DNA%、尾矩、Olive尾矩等指标在给药组与对照组之间有显著性差异,T-47D与MDA-MB-231组相比也有显著性差异(P<0.05)。细胞免疫组化法检测T-47D细胞在TAM作用后ERα阳性细胞减少,SRC-1在作用前后均为阴性;MDA-MB-231细胞SRC-1表达阳性,TAM作用后,SRC-1阳性细胞比例上调,ERα仍为阴性。Western blot结果显示TAM作用后,T-47D细胞ERα表达水平略有下降,SRC-1表达水平未见改变;MDA-MB-231细胞SRC-1表达水平略有升高,ERα表达水平未见改变。结论:在ERα阴性细胞株MDA-MB-231中,共激活因子SRC-1有较高水平表达。0.10mmol/L TAM作用于乳腺癌细胞MDA-MB-231 48 h后SRC-1表达轻微上调,此变化可不依赖于ERα的表达。

Objective：To observe the expression of eo - activator SRC - 1 in the ERa - positive and - negative cell strains before and after using tamoxifen and to study the internal relationship between SRC - 1 and endocrine therapy. Methods： MMT assay was adopted to test OD values of T47D cell strain and MDA - MB -231 cell strain before and after using tamoxifen in order to choose the most appropriate dosage and time of tamoxifen for later re- search. Comet assay was applied to analyze cell apoptosis after tamoxifen administration. Immunohistoehemistry was used to test expression alterations of SRC -1 in T-47D and MDA -MB -231 cell strains with and without tamox- ifen. Expression levels of ERa and SRC - 1 before and after using TAM were evaluated by Western blot. Results： OD values of T-47D and MDA-MB-231 decreased after using tmnoxifen and both had significant differences com-pared to the control group （P 〈0.05） , especially to the Etlot-positive cell strain T47D. The lowest OD value ap-peared after using 0.10 mmol/L tamoxifen for 48 h. Cell apoptosis and DNA fi＇agments were observed by Comet as- say. Tail length, tale DNA% , tail moment and Olive moment had significant differences between tamoxifen group and control group, as well as that between T - 47D group and MDA - MB - 231 group（ P 〈 0.05 ）. The result of immuno-histoeheinistry showd that in T-47D cell strain, after TAM administration, the ratio of ERα positive cells deereaed, and the expression of SRC -1 were both negative. In MDA-MB -231 cell strain, the ratio of SllC -1 positive cells increased slightly, and the expression of ERα were both negative. Western blot indicated that in T -47D cell strain, the expression level of ERa deeresed, and the level of SRC -1 had no change. Meanwhile in MDA-MB-231 cell strain, the expression level of ERa had no moderation, but the level of SRC - 1 increased slightly after TAM affec-tion. Conclusion： In ERa negative MDA - MB -231 cell strain, the eo - activator SRC - 1 had high expression lev-el, after 0.10mmol/L TAM affecting on MDA - MB - 231 cells for 48h, the expression of-SRC - 1 turned from nega-tive to ＋ , which had no relationship with ERα expression.