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: 7209790
• 负责人: ZHAO-YI WANG
• 金额: $ 28.56万
• 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/7209790
• 关键词: Estrogen; Signaling; Normal; Transformed; Cell

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（由申请人提供）：本研究计划的长期目标是阐明雌激素信号传导在乳腺正常发育和乳腺肿瘤发生生物学中的功能和潜在机制。在我们的初步研究中，我们鉴定并克隆了雌激素受体（ER）-a（ER-a36）的36 kDa新变体，其介导膜起始的雌激素和抗雌激素信号传导。它抑制由ER-α和-β介导的基因组雌激素信号传导。ER-α 36在60%的乳腺癌标本中表达，甚至在79%的ER阴性乳腺癌肿瘤中表达。我们还发现，乳腺癌易感基因1（BRCA 1）负调控ER-α 36的表达。我们将通过以下实验方法进一步开展这些初步研究。1.我们将研究ER-cc 36在膜启动的雌激素和抗雌激素信号传导中的功能，这些信号传导在已建立的ER阴性乳腺癌细胞中观察到，并且在乳腺转化中使用体外和体内细胞生长和转化测定结合siRNA敲低方法由BRCA 1功能障碍引起。2.我们将使用表达不同水平ER-α 36的MCF 7细胞变体研究ER-α 36在ER阳性乳腺癌中恶性生长和抗雌激素抗性发展中的功能。我们还将研究ER-α 36在雌激素/抗雌激素信号转导中的作用机制，使用微阵列方法和生物化学测定。3.我们将使用生物化学、凝胶迁移、ChIP和荧光素酶测定来研究ER-α 36调节ER-α表达和功能的机制。我们还将通过使用DNA-蛋白质结合测定和荧光素酶测定对ER-α 36启动子的结构和功能分析来研究ER-α 36表达受ER-α、MARK通路和BRCA 1调节的分子机制。这些研究的意义在于，它们将提供关于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的重要和新颖的信息。这些知识将大大推动我们在预防和治疗人类乳腺癌方面的进展。