Growth factors change nuclear distribution of estrogen receptor-alpha via mitogen-activated protein kinase or phosphatidylinositol 3-kinase cascade in a human breast cancer cell line.
Growth factors change nuclear distribution of estrogen receptor-alpha via mitogen-activated protein kinase or phosphatidylinositol 3-kinase cascade in a human breast cancer cell line.
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DOI：
10.1210/en.2005-0302
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发表时间：
2005-09
期刊：
影响因子：
4.8
通讯作者：
Toshifumi Takahashi;M. Ohmichi;J. Kawagoe;Chika Ohshima;M. Doshida;T. Ohta;M. Saitoh;Akiko Mori-Abe;Botao Du;H. Igarashi;Kazuhiro Takahashi;H. Kurachi
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文献类型：
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作者：
Toshifumi Takahashi;M. Ohmichi;J. Kawagoe;Chika Ohshima;M. Doshida;T. Ohta;M. Saitoh;Akiko Mori-Abe;Botao Du;H. Igarashi;Kazuhiro Takahashi;H. Kurachi
在本研究中，检查的动态变化，在本地化的核雌激素受体（ER）α生长因子诱导，我们使用延时共聚焦显微镜直接可视化ER α融合绿色荧光蛋白（GFP-ER α）在单个活细胞与表皮生长因子（EGF）或IGF-I处理。我们观察到，17 β-雌二醇（E2）改变了正常弥漫分布的GFP-ER α在整个核质的hyperspeckled分布在10分钟内。EGF和IGF-I也改变了GFP-ER α的核分布，类似于E2治疗。但EGF或IGF-I诱导的GFP-ER α核内分布的时程与E2诱导的不同。在EGF处理的细胞中，在30 min时观察到GFP-ER α核的重新分布，并在60 min时达到最大值，而在IGF-I处理的细胞中，在60 min时观察到GFP-ER α核的重新分布，并在90 min时达到最大值。而用磷脂酰肌醇3-激酶抑制剂LY 294002预处理可阻断IGF-I诱导的GFP-ER α再分布。使用GFP-ER α的激活功能-2结构域缺失突变体的分析表明，E2、EGF或IGF-I处理不诱导GFP-ER α分布的变化。这些数据表明，MAPK和磷脂酰肌醇3-激酶级联分别参与了EGF和IGF-I对ER α的核再分布，并且ER α的激活功能-2域可能是ER α核再分布所必需的。
In the present study, to examine the dynamic changes in the localization of nuclear estrogen receptor (ER)alpha induced by growth factors, we used time-lapse confocal microscopy to directly visualized ERalpha fused with green fluorescent protein (GFP-ERalpha) in single living cells treated with epidermal growth factor (EGF) or IGF-I. We observed that 17beta-estradiol (E2) changed the normally diffuse distribution of GFP-ERalpha throughout the nucleoplasm to a hyperspeckled distribution within 10 min. Both EGF and IGF-I also changed the nuclear distribution of GFP-ERalpha, similarly to E2 treatment. However, the time courses of the nuclear redistribution of GFP-ERalpha induced by EGF or IGF-I were different from that induced by E2 treatment. In the EGF-treated cells, the GFP-ERalpha nuclear redistribution was observed at 30 min and reached a maximum at 60 min, whereas in the IGF-I-treated cells, the GFP-ERalpha nuclear redistribution was observed at 60 min and reached a maximum at 90 min. The EGF-induced redistribution of GFP-ERalpha was blocked by pretreatment with a MAPK cascade inhibitor, PD98059, whereas the IGF-I-induced redistribution of GFP-ERalpha was blocked by pretreatment with a phosphatidylinositol 3-kinase inhibitor, LY294002. Analysis using an activation function-2 domain deletion mutant of GFP-ERalpha showed that the change in the distribution of GFP-ERalpha was not induced by E2, EGF, or IGF-I treatment. These data suggest that MAPK and phosphatidylinositol 3-kinase cascades are involved in the nuclear redistribution of ERalpha by EGF and IGF-I, respectively, and that the activation function-2 domain of ERalpha may be needed for the nuclear redistribution of ERalpha.