Estrogen Signaling in Normal and Transformed Cell Growth

正常和转化细胞生长中的雌激素信号传导

• 批准号: 7104684
• 负责人: ZHAO-YI WANG
• 金额: $ 29.42万
• 依托单位: CREIGHTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-03-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7104684
• 关键词: MCF7 cell; biological signal transduction; brca gene; breast neoplasms; chromatin immunoprecipitation; estrogen receptors; estrogens; gel mobility shift assay; gene targeting; mammary gland; microarray technology; mitogen activated protein kinase; neoplastic cell; neoplastic growth; neoplastic transformation; protein structure function; receptor expression; reproductive development; small interfering RNA

DESCRIPTION (provided by applicant): 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.

描述(申请人提供)：这项研究计划的长期目标是阐明雌激素信号在乳腺正常发育和乳腺肿瘤发生的生物学中的作用和潜在机制。在我们的初步研究中，我们鉴定和克隆了一个36 kDa的雌激素受体(ER)-a的新变体(ER-A36)，它介导了膜启动的雌激素和抗雌激素信号。它抑制ER-a和-(3)介导的基因组雌激素信号。ER-A36在所检测的60%的乳腺癌标本中表达，甚至在79%的ER阴性乳腺癌中表达。我们还发现乳腺癌易感基因1(BRCA1)负调控ER-A36的表达。我们将通过以下实验方法进一步进行这些初步研究。1.我们将利用体外和体内细胞生长和转化实验，结合siRNA敲除方法，研究ER-cc36在已建立的ER阴性乳腺癌细胞膜启动的雌激素和抗雌激素信号转导中的作用，以及在BRCA1功能障碍引起的乳腺转化中的作用。2.利用表达不同水平ER-A36的MCF7细胞株，研究ER-CC36在ER阳性乳腺癌恶性生长和抗雌激素耐药形成中的作用。我们还将利用基因芯片和生化方法研究ER-A36在雌激素/抗雌激素信号转导中的作用机制。3.利用生化、凝胶漂移、芯片和荧光素酶等方法研究ER-A36调控ER-a表达和功能的机制。我们还将通过DNA-蛋白质结合分析和荧光素酶实验分析ER-A36启动子的结构和功能，研究ER-a、Mark通路和BRCA1调控ER-A36表达的分子机制。这些研究的意义在于，它们将为雌激素信号在正常和转化细胞生长中发挥作用的分子机制提供重要而新颖的信息。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。