Estrogen-induced activation of Erk-1 and Erk-2 requires the G protein-coupled receptor homolog, GPR30, and occurs via trans-activation of the epidermal growth factor receptor through release of HB-EGF.
Estrogen-induced activation of Erk-1 and Erk-2 requires the G protein-coupled receptor homolog, GPR30, and occurs via trans-activation of the epidermal growth factor receptor through release of HB-EGF.
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DOI：
10.1210/mend.14.10.0532
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发表时间：
2000-10
影响因子：
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通讯作者：
E. Filardo;Jeffrey A. Quinn;K. Bland;A. Frackelton;Roger Williams
中科院分区：
文献类型：
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作者：
E. Filardo;Jeffrey A. Quinn;K. Bland;A. Frackelton;Roger Williams
雌激素通过一种未知的机制迅速激活丝裂原激活的蛋白激酶Erk-1和Erk-2。在这里，有证据表明，雌激素诱导的Erk-1/-2激活独立于已知的雌激素受体，但需要G蛋白偶联受体同源物GPR30的表达。我们发现，17β-雌二醇不仅在同时表达雌激素受体α(ERα)和ERβ的MCF-7细胞中激活ERK-1/-2，而且在SKBR3乳腺癌细胞中也激活ERK-1/-2，而SKBR3乳腺癌细胞不表达这两种受体。使用GPR30多肽抗体的免疫印迹分析表明，这种雌激素反应与这些细胞中GPR30蛋白的存在有关。MDA-MB-231乳腺癌细胞(ERα-、ERβ+)缺乏GPR30，对17β-雌二醇激活ERK-1/-2不敏感。将GPR30互补DNA导入MDA-MB-231细胞，可导致GPR30蛋白过表达，并转化为雌激素反应表型。此外，依赖GPR30的Erk-1/-2的激活可由ER拮抗剂，包括ICI 182,780触发，而不是由17α-雌二醇或孕酮触发。与通过G蛋白偶联受体的作用一致，雌激素对Erk-1/-2的信号是通过Gbetagma依赖的、百日咳毒素敏感的途径发生的，该途径需要与Src相关的酪氨酸激酶活性和Shc接头蛋白的酪氨酸317的酪氨酸磷酸化。强化这一观点的是，雌激素对ERK-1/-2的信号依赖于通过释放肝素结合的表皮生长因子(HB-EGF)而反式激活表皮生长因子(EGF)受体。雌激素对ERK-1/-2的信号转导可通过以下方式被阻断：1)抑制EGF受体酪氨酸激酶活性，2)用抗体中和HB-EGF，或3)白喉毒素突变体CRM-197下调细胞表面HB-EGF的表达。我们的数据暗示，继续表达GPR30的ER阴性乳腺肿瘤可能会使用雌激素来驱动生长因子依赖的细胞反应。
Estrogen rapidly activates the mitogen-activated protein kinases, Erk-1 and Erk-2, via an as yet unknown mechanism. Here, evidence is provided that estrogen-induced Erk-1/-2 activation occurs independently of known estrogen receptors, but requires the expression of the G protein-coupled receptor homolog, GPR30. We show that 17beta-estradiol activates Erk-1/-2 not only in MCF-7 cells, which express both estrogen receptor alpha (ER alpha) and ER beta, but also in SKBR3 breast cancer cells, which fail to express either receptor. Immunoblot analysis using GPR30 peptide antibodies showed that this estrogen response was associated with the presence of GPR30 protein in these cells. MDA-MB-231 breast cancer cells (ER alpha-, ER beta+) are GPR30 deficient and insensitive to Erk-1/-2 activation by 17beta-estradiol. Transfection of MDA-MB-231 cells with a GPR30 complementary DNA resulted in overexpression of GPR30 protein and conversion to an estrogen-responsive phenotype. In addition, GPR30-dependent Erk-1/-2 activation was triggered by ER antagonists, including ICI 182,780, yet not by 17alpha-estradiol or progesterone. Consistent with acting through a G protein-coupled receptor, estradiol signaling to Erk-1/-2 occurred via a Gbetagamma-dependent, pertussis toxin-sensitive pathway that required Src-related tyrosine kinase activity and tyrosine phosphorylation of tyrosine 317 of the Shc adapter protein. Reinforcing this idea, estradiol signaling to Erk-1/-2 was dependent upon trans-activation of the epidermal growth factor (EGF) receptor via release of heparan-bound EGF (HB-EGF). Estradiol signaling to Erk-1/-2 could be blocked by: 1) inhibiting EGF-receptor tyrosine kinase activity, 2) neutralizing HB-EGF with antibodies, or 3) down-modulating HB-EGF from the cell surface with the diphtheria toxin mutant, CRM-197. Our data imply that ER-negative breast tumors that continue to express GPR30 may use estrogen to drive growth factor-dependent cellular responses.