膜雌激素受体在乳腺癌中的表达及对表皮生长因子水平的影响

Membrane estrogen receptor expression in breast cancer and its effect on epidermal growth factor

目的:探讨了乳腺癌细胞中膜雌激素受体(membraneestrogenreceptor,m ER)表达情况以及对表皮生长因子水平的影响。方法:采用q RT-PCR和Western blot分析乳腺癌细胞乳腺癌细胞系-7(michigan cancer foundation-7,MCF-7)、MDA-MB-231和MDA-MB-435中膜雌激素受体m ER m RNA和蛋白质的表达水平。并选取中等表达的细胞采用慢病毒介导的m ER sh RNA建立m ER Knowdown的稳定细胞系,并分析膜雌激素白蛋白-E2(membrane estrogen-2,m E2)和传统的雌激素(estrogen-2,E2)分别对乳腺癌细胞(ERα+和ERα-)的生长影响及其对EGFR和EGF表达水平的影响。结果:3种乳腺癌细胞系中m ER均有表达,其中MCF-7细胞表达水平最高,MDA-MB-231和MDA-MB-435细胞表达水平相当。采用慢病毒介导m ER sh RNA建立的MCF-7稳定细胞系(MCF-7/ERα-)其m ER m RNA和蛋白质水平较正常MCF-7均明显下调(P<0.05)。传统E2均能促进MCF-7和MCF-7/ERα-细胞的增殖,无统计学意义(P>0.05),但m E2作用后,MCF-7/ERα-生长速度明显低于MCF-7细胞(P<0.05)。传统E2刺激MCF-7和MCF-7/ERα-细胞后,细胞EGF m RNA和蛋白质水平无差异(P>0.05),而m E2刺激MCF-7和MCF-7/ERα-细胞后,MCF-7/ERα-细胞EGF m RNA和蛋白质水平较MCF-7细胞水平明显下降(P<0.05)。结论:本研究有望为乳腺癌的治疗提供更新的分子治疗靶点,更精确的临床内分泌治疗预测指标。

Objective：To investigate the expression of estrogen receptor in breast cancer cell and its effect on epidermal growth factor. Methods：The membrane estrogen receptor（mER） expression at mRNA and protein levels in haman breast cancer cell line MCF-7, MDA-MB-231 and MDA-MB-435 were detected by real time fluorescent quantitative PCR and Western blot. Stable mER knowdown cell lines were constructed by lentiviral mediated mER shRNA. The effect of membrane estrogen （mE2） and traditional estrogen on growth of （ERα＋ and ERα-） as well as on expression of epithelial growth factor receptor（EGFR） and epidermal growth factor（EGF） were analyzed by MTI＇. Results：mER was expressed in MCF-7,MDA-MB-231 and MDA-MB-435 cell lines,with MCF-7 cell having the highest expression, mER mRNA and protein levels in knowdown stable cells by lentiviral mediated shRNA were signif- icantly lower than those of MCF-7 cells（P〈0.05）. Estrogen can promote proliferation of MCF-7 and MCF-7/ER- cell and there was not statistical significance among three lines（P〉0.05）. But after treatment by mE2, the proliferation of MCF-7/ER- was significantly lower than that of MCF-7 cells（P〈O.05）. After MCF-7 and MCF-7/ER alpha cells being stimulated by estrogen, there was no statis- tical difference in EGF mRNA and protein levels between MCF-7/ER- cells and MCF-7（P〉0.05）. But after being stimulated by mER, EGF mRNA and protein levels was significantly decreased in MCF-7/ER- cells than in MCF-7 （P〈0.05）. Conclusion ：This study is expected to provide a molecular therapeutic targeting for the treatment of breast cancer.