Role of E6-AP in the Development of Prostate Cancer

E6-AP 在前列腺癌发展中的作用

• 批准号: 6645332
• 负责人: Zafar Nawaz
• 金额: $ 20.18万
• 依托单位: CREIGHTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6645332
• 关键词: androgen receptor; carcinogenesis; disease /disorder model; gene expression; gene mutation; genetically modified animals; histogenesis; laboratory mouse; model design /development; molecular oncology; p53 gene /protein; prostate; prostate neoplasms; transcription factor

DESCRIPTION (Provided by the applicant) Androgens are important regulators of cell growth and prostate gland development. Androgens exert their biological effects on target tissues through an intracellular receptor protein named androgen receptor (AR). Recent evidence suggests that transcriptional regulation by AR require a diverse group of proteins termed coactivators. Coactivators portray a growing class of proteins that interact with receptors in a hormone dependent manner and are required for maximal gene activation by the receptors. It is the general belief that coactivators enhance receptor function by acting as a bridge between the DNA-bound receptor and basal transcription factors of the preinitiation complex and also by providing histone acetyl transferase activity, HAT, which disrupts the local repressive chromatin structure and contributes to increase transcriptional activity. Recently, our laboratory has cloned, E6-associated protein (E6-AP), as a coactivator of steroid receptors including that of AR. E6-AP possesses ubiquitin-protein ligase activity, instead of HAT activity. Our preliminary observation suggests that E6-AP act as a coactivator of AR and is overexpressed both in mouse and human prostate tumors. The initial data from E6-AP knockout mice also suggest that E6-AP play a major role in the normal development of prostate gland. The prostate glands of the E6-AP knockout mice are smaller and weigh less compare to that of wild-type normal littermates. Furthermore, p53 levels are elevated in E6-AP knockout prostate glands. Additionally, the AR expression is down in E6-AP knockout prostate. Based on these initial findings, we hypothesize that E6-AP, an important modulator of prostate gland, androgen receptor-mediated signal transduction pathway and cell cycle control, is functionally significant in the development of normal prostate gland and prostate cancer. In order to understand the exact role of E6-AP in the development of normal prostate gland and in the development of prostate tumors, we propose the following three specific aims: A) Development and analysis of animal models for the overexpression of wild type E6-AP, C833S mutant E6-AP (an E3 ubiquitin-protein ligase defective mutant) and loss of E6-AP (E6-AP knockout) in the prostate gland, B), Design and development of stable in vitro models for the overexpression of wild-type and C833S mutant E6-AP proteins in the prostate cancer cell lines, and C) Expression analyses of endogenous E6-AP, p53 and AR in prostate tumor biopsy samples.

描述（由申请人提供） 雄激素是细胞生长和前列腺的重要调节剂 发展。雄激素通过以下方式对靶组织发挥生物学作用： 一种称为雄激素受体（AR）的细胞内受体蛋白。最近的证据 表明 AR 的转录调控需要不同的组 称为共激活剂的蛋白质。共激活剂描绘了越来越多的蛋白质类别 以激素依赖性方式与受体相互作用，并且是 受体的最大基因激活。人们普遍认为 共激活剂通过充当受体之间的桥梁来增强受体功能 DNA 结合受体和预起始复合物的基础转录因子 还通过提供组蛋白乙酰转移酶活性 HAT，它会破坏 局部抑制染色质结构并有助于增加 转录活性。最近，我们实验室克隆了E6相关的 蛋白 (E6-AP)，作为类固醇受体（包括 AR 受体）的共激活剂。 E6-AP 具有泛素蛋白连接酶活性，而不是 HAT 活性。我们的 初步观察表明 E6-AP 作为 AR 的共激活剂，并且是 在小鼠和人类前列腺肿瘤中过度表达。初始数据来自 E6-AP 敲除小鼠也表明 E6-AP 在正常细胞中发挥着重要作用。 前列腺的发育。 E6-AP 敲除小鼠的前列腺 与野生型正常同窝仔猪相比，它们体形更小，体重也更轻。 此外，E6-AP 敲除的前列腺中 p53 水平升高。 此外，E6-AP 敲除前列腺中 AR 表达下降。基于 根据这些初步发现，我们假设 E6-AP 是一种重要的调节剂 前列腺、雄激素受体介导的信号转导途径和细胞 周期控制，在正常发育中具有重要功能 前列腺和前列腺癌。为了了解其具体作用 E6-AP 在正常前列腺发育和前列腺发育中的作用 前列腺肿瘤，我们提出以下三个具体目标： A) 发展 野生型E6-AP、C833S过表达的动物模型及分析 突变体 E6-AP（E3 泛素蛋白连接酶缺陷突变体）和缺失 前列腺中的 E6-AP（E6-AP 敲除），B)，设计和开发 野生型和 C833S 突变体过表达的稳定体外模型 前列腺癌细胞系中的 E6-AP 蛋白，以及 C) 的表达分析 前列腺肿瘤活检样本中的内源性 E6-AP、p53 和 AR。