Estrogen Signaling in Normal and Transformed Cell Growth

这项研究计划的长期目标是阐明其功能和潜在机制。 雌激素信号在乳腺和乳腺正常发育生物学中的作用 肿瘤发生学。 在我们的初步研究中，我们鉴定并克隆了一个36 kDa的雌激素受体(ER)-a的新变体。 (ER-A36)，介导膜启动的雌激素和抗雌激素信号。它能抑制基因组 ER-a和-(3.ER-A36在60%的乳腺癌组织中表达 检查，甚至79%的肿瘤特征为ER阴性的乳腺癌。我们还发现， 乳腺癌易感基因1(BRCA1)负调控ER-A36的表达。我们将致力于实现这些目标 通过以下实验方法进一步进行初步研究。 1.研究ER-CC36在膜启动的雌激素和抗雌激素信号转导中的作用 在已建立的ER阴性的乳腺癌细胞中观察到 BRCA1功能障碍的体外和体内细胞生长和转化试验 SiRNA敲除方法。 2.研究ER-CC36在抗雌激素药物恶性生长发育中的作用 使用表达不同水平ER-A36的MCF7细胞变异体研究ER阳性乳腺癌的耐药性。 我们还将研究ER-A36在雌激素/抗雌激素信号转导中的作用机制 微阵列方法和生化分析。 3.我们将研究ER-A36调节ER-a表达和功能的机制 生化、凝胶漂移、芯片和荧光素酶分析。我们还将通过以下方式研究分子机制 ER-a、Mark通路和BRCA1通过结构和蛋白途径调节ER-A36的表达 用DNA-蛋白结合实验和荧光素酶实验分析ER-A36启动子的功能。 这些研究的意义在于它们将提供重要和新颖的信息 雌激素信号在正常和转化细胞生长中作用的分子机制。 这些知识将极大地推动我们在预防和治疗人类乳腺癌方面的进步。

The long-term goals of this research program are to elucidate the functions and underlying mechanisms of estrogen signaling in the biology of normal development of mammary glands and mammary tumorigenesis. In our preliminary studies, we identified and cloned a 36-kDa novel variant of Estrogen Receptor (ER)-a (ER-a36) that mediates membrane-initiated estrogen-and antiestrogen-signaling. It inhibits genomic estrogen signaling mediated by ER-a and-(3. ER-a36 is expressed in 60% breast cancer specimens examined, and even in 79% tumors characterized as ER-negative breast cancers. We also found that breast cancer susceptibility gene 1 (BRCA1) negatively regulates ER-a36 expression. We will pursue these preliminary studies further through the following experimental approaches. 1. We will study the functions of ER-cc36 in membrane-initiated estrogen- and antiestrogen-signaling observed in established ER-negative breast cancer cells and in mammary transformation resulted from BRCA1 dysfunction using in vitro and in vivo cell growth and transformation assays combined with the siRNA knockdown approach. 2. We will study the functions of ER-cc36 in malignant growth and development of antiestrogen resistance in ER-positive breast cancer using MCF7 cell variants that express different levels of ER-a36. We will also study the mechanisms by which ER-a36 functions in estrogen/antiestrogen signaling using the microarray approach and biochemistry assays. 3. We will study the mechanisms by which ER-a36 regulates ER-a expression and function using biochemistry, the gel shift, ChIP and luciferase assays. We will also study the molecular mechanisms by which ER-a36 expression is regulated by ER-a, the MARK pathway and BRCA1 through structure and function analysis of the ER-a36 promoter using DNA-protein binding assays and the luciferase assay. The significance of these studies resides in the fact that they will provide important and novel information on the molecular mechanisms by which estrogen signaling functions in normal and transformed cell growth. Such knowledge will greatly advance our progress in prevention and treatment of human breast cancer.