【摘要】 目的研究在不同处理因子作用下,外源基因ERβ的表达对MCF-7乳腺癌细胞系生长特性的影响。方法利用lipofectamine2000将ERβ真核表达载体pCDNA3-ERβ导入MCF-7乳腺癌细胞系。采用含雌激素应答元件(ERE)的荧光素酶报告基因及Western blot方法,检测转染细胞中ERβ的转录活性和蛋白表达水平,筛选阳性克隆。以亲本细胞MCF-7及转染空载体质粒pCDNA3的MCF-7细胞为对照,在雌激素E2和雌激素受体拮抗剂4-OHT作用下观察细胞的生长特点。结果在转染ERβ基因的MCF-7细胞系中,ERβ的转录激活活性明显升高;Western blot检测证实,ERβ的蛋白表达水平显著增高。在无处理因子情况下,外源基因ERβ在MCF-7细胞系中的表达对细胞的形态及生长速度无明显影响。与亲本细胞MCF-7及转染空载体质粒的MCF-7细胞相比,稳定转染ERβ的MCF-7细胞对雌激素的敏感性下降,但对4-OHT处理的敏感性无明显减少。结论外源性ERβ基因在MCF-7乳腺癌细胞中的稳定表达不增加对4-OHT的耐药性,但使之对雌激素的敏感性下降。更多还原

【Abstract】 Objective To study the effects of exogenous ER β on the growth of breast cancer MCF-7 cells under different treatment. Methods An eukaryotic expression vector containing 1.6 kb of human entire coding sequence of ER β (pCDNA3-ER β) was transfected into human breast cancer MCF-7 cells using lipofectamine 2000. The biological activity of ER β was detected with the luciferase reporter containing estrogen responsive element (ERE) and the expression of ER β protein by Western blot. The growth properties of MCF-7, pCDNA 3-transfected MCF-7 and pCDNA 3-ER β-transfected MCF-7 cells under different treatment, including E2 (17beta-estradiol) and 4-OHT (4-hydroxytamoxifen), were observed. Results A stronger activation of the reporter by ER β in the presence of E2 was observed in the pCDNA 3-ER β-transfected MCF-7 cells than in the pCDNA 3-transfected MCF-7 and in MCF-7 cells. Western blot analysis showed that the protein level of ER β in the pCDNA 3-ER β-transfected MCF-7 cells was markedly increased. Exogenous ER β expression did not change the growth properties and the morphology of MCF-7 cells under normal condition. The pCDNA 3-ER β-transfected MCF-7 cells proliferated at the same rate as naive cells in the presence of 4-OHT, whereas a strong inhibition of the proliferation of the pCDNA 3-ER β-transfected MCF-7 cells in the presence of E2 was observed.Conclusion Exogenous ER β expression does not increase the resistance to 4-OHT, and a strong inhibition of the proliferation may occurre in the presence of E2.更多还原