Augereau P, Miralles F, Cavaillès V, Gaudelet C, Parker M, Rochefort H
Unité Hormones et Cancer (U 148) INSERM, Faculté de Médecine, Montpellier, France.
Mol Endocrinol. 1994 Jun;8(6):693-703. doi: 10.1210/mend.8.6.7935485.
Cathepsin D, a lysosomal proteinase, is induced by estrogens in mammary cancer cells where its concentration is correlated with a higher risk of metastasis. Its gene expression is stimulated by estrogens in MCF7 cells, and we have shown that a short proximal promoter fragment from -365 to -122 is required for this induction. We now characterize, at -261, a nonconsensus estrogen-responsive element (ERE) (E2) with two differences in the distal half of its palindrome, which confers estradiol responsiveness to the heterologous Herpes simplex virus thymidine kinase promoter in transient transfection experiments. This ERE is located in a 21-base pair sequence: 5'GGGCCGGGCTGACCCCGC GGG3', containing a GC-rich region in its 3'-part, which is almost perfectly repeated at -362 (the E1 site). The E2 site was necessary but not sufficient to mediate an estrogen response and required cooperation with the homologous E1 element and/or with general transcription sites located downstream. In vitro, the E2 site but not the E1 site was protected by estrogen receptor (ER) against DNAse I digestion, and gel shift experiments suggested an interaction with the ER as a dimer. Moreover, we showed in vivo that ER DNA binding domain was required to mediate estrogen induction from the cathepsin D ERE. We conclude that estradiol induction of cathepsin D is mediated by interaction of the ER with a nonconsensus ERE that requires synergy with other elements located upstream and/or downstream of this central ERE.
组织蛋白酶D是一种溶酶体蛋白酶，在乳腺癌细胞中由雌激素诱导产生，其浓度与转移风险较高相关。在MCF7细胞中，其基因表达受雌激素刺激，并且我们已经表明，-365至-122的短近端启动子片段是这种诱导所必需的。我们现在在-261处鉴定了一个非典型雌激素反应元件（ERE）（E2），其回文结构的后半部分有两个差异，在瞬时转染实验中，该元件赋予单纯疱疹病毒胸苷激酶异源启动子雌二醇反应性。这个ERE位于一个21个碱基对的序列中：5'GGGCCGGGCTGACCCCGC GGG3'，在其3'部分含有一个富含GC的区域，该区域在-362（E1位点）几乎完美重复。E2位点对于介导雌激素反应是必要的，但不是充分的，需要与同源E1元件和/或下游的一般转录位点协同作用。在体外，E2位点而非E1位点受到雌激素受体（ER）的保护而免受DNA酶I消化，凝胶迁移实验表明其与二聚体形式的ER相互作用。此外，我们在体内表明，ER DNA结合结构域是介导组织蛋白酶D ERE雌激素诱导所必需的。我们得出结论，组织蛋白酶D的雌二醇诱导是由ER与一个非典型ERE相互作用介导的，该ERE需要与位于这个中心ERE上游和/或下游的其他元件协同作用。
