他莫昔芬对ER^-GPER^+乳腺癌细胞上皮间质转化的影响及机制

The effect of tamoxifen on ER-GPER+breast cancer cell EMT and its mechanism

目的:探讨他莫昔芬(TAM)对雌激素受体(ER)阴性、G蛋白偶联雌激素受体(GPER)阳性乳腺癌细胞上皮间质转化(EMT)的影响。方法:以ER阴性(ER-)、GPER阳性(GPER+)乳腺癌MDA-MB-468细胞为研究对象,用TAM处理细胞,GPER特异性抑制剂G15抑制胞内GPER活性,si RNA干扰GPER蛋白表达,侵袭小室实验检测细胞侵袭能力,Western blot检测ERα、GPER、Vimentin、E-cadherin及N-cadherin蛋白表达变化。结果:TAM(5μmol/L)可明显增强MDA-MB-468细胞的侵袭能力(P<0.01);G15(10μmol/L)预处理能显著抑制TAM诱导的细胞侵袭活动(P<0.01);GPER-si RNA可明显干扰MDA-MB-468细胞GPER蛋白表达(P<0.01);干扰GPER蛋白表达能有效抑制TAM诱导的细胞侵袭活动(P<0.01)。TAM处理明显诱导Vimentin和N-cadherin蛋白表达上调(P<0.01),E-cadherin蛋白表达下调(P<0.01);G15预处理或干扰GPER蛋白表达均能抑制TAM的上述诱导作用(均P<0.05)。结论:TAM能诱导ER-GPER+乳腺癌MDA-MB-468细胞EMT,其作用与其激活GPER有关。

Objective:To investigate the effect of TAM on EMT in ER-GPER+breast cancer cells and to discuss its signaling mechanism.Methods:ER-GPER+breast cancer MDA-MB-468 cells were researched object.Cells were treated by TAM,intracellular GPER activity were inhibited by GPER specific inhibitor G15,GPER protein expression was interfered by siRNA,cell invasion ability was detected by invasion chamber experiment and western blot experiment was used to detect ERα,GPER,Vimentin,E-cadherin and N-cadherin protein expression changes.Results:TAM(5μmol/L)could significantly enhance the invasion ability of MDA-MB-468 cells(P<0.01),and G15(10μmol/L)pretreatment could significantly inhibit TAM-induced cell invasion(P<0.01).GPER-siRNA could significantly interfere with the expression of GPER protein in MDA-MB-468 cells(P<0.01),and interference with GPER protein expression could effectively inhibit TAM-induced cell invasion(P<0.01).TAM treatment significantly induced up-regulation of Vimentin and N-cadherin protein expression(P<0.01)and down-regulation of E-cadherin protein expression(P<0.01).G15 pretreatment or interference with GPER protein expression could inhibit the above induction of TAM(P<0.05).Conclusion:TAM can induce EMT in ER-GPER+breast cancer MDA-MB-468 cells,which is related to the activation of GPER.