MDM2 regulates estrogen receptor α and estrogen responsiveness in breast cancer cells
MDM2 regulates estrogen receptor α and estrogen responsiveness in breast cancer cells
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DOI：
10.1677/jme-10-0110
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发表时间：
2011-04-01
影响因子：
3.5
通讯作者：
Safe, Stephen
中科院分区：
文献类型：
--
作者：
Kim, Kyounghyun;Burghardt, Robert;Safe, Stephen
小鼠双分钟克隆2 （MDM2）是一种调节核受体介导的转激活的多功能蛋白。在本研究中，我们发现MDM2显著增强了MCF-7和ZR-75乳腺癌细胞中雌激素受体α (ER α)和ER α /特异性蛋白介导的转激活。通过RNA干扰MDM2过表达和敲低实验证实了这一点。ER α与野生型MDM2以及含有1-342 （c端缺失）和134-490 （n端缺失）氨基酸的MDM2缺失突变体相互作用，但与134-342不相互作用。相比之下，只有野生型MDM2而不是突变型MDM2增强了ER α介导的交互激活。体外蛋白-蛋白相互作用是17 β -雌二醇（E-2）独立的，而活细胞荧光共振能量转移实验表明，E-2增强ER α - mdm2相互作用。随后的RNA干扰和哺乳动物双杂交实验表明，MDM2不直接与内源性共激活因子（如类固醇受体共激活因子）相互作用，而是通过与ER α相互作用增强ER α介导的基因表达和雌激素反应。分子内分泌杂志（2011）46,67 -79
Murine double minute clone 2 (MDM2) is a multifunctional protein, which modulates nuclear receptor-mediated transactivation. In this study, we show that MDM2 significantly enhanced estrogen receptor alpha (ER alpha) and ER alpha/specificity protein-mediated transactivation in MCF-7 and ZR-75 breast cancer cells. This was demonstrated by both MDM2 overexpression and knockdown experiments by RNA interference. ER alpha interacted with wild-type MDM2 and deletion mutants of MDM2 containing amino acids 1-342 (C-terminal deletion) and 134-490 (N-terminal deletion), but not 134-342. In contrast, only wild-type but not mutant MDM2 enhanced ER alpha-mediated transactivation. Protein-protein interactions in vitro were 17 beta-estradiol (E-2) independent, whereas fluorescent resonance energy transfer experiments in living cells showed that E-2 enhanced ER alpha-MDM2 interactions. Subsequent RNA interference and mammalian two-hybrid experiments suggested that MDM2 did not directly interact with endogenous coactivators such as the steroid receptor coactivators but played a role in enhancing ER alpha-mediating gene expression and estrogen responsiveness through interactions with ER alpha. Journal of Molecular Endocrinology (2011) 46, 67-79