delta-Catenin and Cell-Cell Adhesion in Prostate Cancer

前列腺癌中的 δ-连环蛋白和细胞间粘附

• 批准号: 7035153
• 负责人: QUN LU
• 金额: $ 18.95万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7035153
• 关键词: cadherins; cell adhesion; neoplasm /cancer; prostate neoplasms

DESCRIPTION (provided by applicant): Prostate cancer (CaP) is the most common malignancy in men in US and the second leading cause of cancer mortality. To reduce the significant morbidity and mortality, new strategies for CaP prevention and treatment depend on the determination of specific molecular mechanisms involved in this disease. ?-Catenin is a unique armadillo (ARM) domain-containing protein in that it is neural specific and primarily expresses in the brain. However, ?-catenin expression increases in prostatic adenocarcinomas, redistributes E-cadherin/p120ctn from the cell-cell junction, and promotes CaP cell growth and invasion. To investigate this largely unexplored area of neuronal catenin gene expression in peripheral tissues of cancers, the overall goal of this project is to test the hypothesis that ?-catenin promotes CaP formation and progression by interacting with multiple cellular machineries, including cell-cell and cell-matrix adhesion, cell growth/survival, and invasion. There are three specific aims in this proposal. Specific Aim 1 will determine how ?-catenin promotes cell growth/survival and motility in response to the hepatocyte growth factor and/or androgen using CWR22 tumor xenografts and their derived cell lines. We will broadly screen and profile the ?-catenin induced alteration of signaling molecules by array technology. These studies will identify cancer specific pathways that ?-catenin is involved in and will investigate their interactions with ?-catenin using protein co-immunoprecipitation and yeast two-hybrid analyses. Specific Aim 2 will determine how ?-catenin interacts with Rho family small GTPases to disrupt adherens junction and promote CaP cell growth/survival and invasion. We will first identify the ?-catenin sequence responsible for this action. Then, the analyses of ?-catenin RNAi or its mutants that are defective in Rac-1 or E-cadherin binding will determine the interactions between GTP-Rac-1/IQGAP-1 and E-cadherin/p120ctn pathways to reveal possible differential modulations on cell-cell adhesion and cell growth/survival and invasion. We will also determine the cytoplasmic accumulation and nuclear signaling of ?-catenin that is released from E-cadherin complexes by IQGAP-1. Specific Aim 3 will apply Y311, a unique (dePhospho-specific) monoclonal antibody, and site-directed mutagenesis to determine how ?-catenin modifications occur and what are their roles in CaP. We will also investigate ?-catenin proteolytic fragments and their potentials as DNA binding proteins and nuclear signaling for gene expression. Finally, we will generate transgenic mice displaying prostate tissue specific ?-catenin expression to approach these questions at the animal level. These studies will place ?-catenin into the broad context of growth factor and kinase signaling machineries relevant to CaP. Understanding the posttranslational modifications that control ?-catenin functions will unravel mechanisms by which ?-catenin modulates gene expression and promotes CaP in vivo.

描述(申请人提供)：前列腺癌(CAP)是美国男性最常见的恶性肿瘤，是癌症死亡的第二大原因。为了减少严重的发病率和死亡率，预防和治疗CAP的新策略取决于对这种疾病所涉及的特定分子机制的确定。？-连环蛋白是一种独特的含有手臂结构域的蛋白质，因为它是神经特异性的，主要在大脑中表达。然而，β-catenin在前列腺癌中的表达增加，使E-cadherin/p120ctn从细胞-细胞连接处重新分布，并促进帽细胞的生长和侵袭。为了研究肿瘤外周组织中神经元连环蛋白基因表达的这一未知区域，本项目的总体目标是检验这一假说，即？-连环蛋白通过与多种细胞机制相互作用促进帽子的形成和进展，包括细胞-细胞和细胞-基质黏附、细胞生长/存活和侵袭。这项提议有三个具体目标。具体目标1将通过使用CWR22肿瘤移植瘤及其衍生细胞系来确定？-连环蛋白如何在肝细胞生长因子和/或雄激素的反应中促进细胞的生长/存活和运动。我们将利用阵列技术对β-连环蛋白诱导的信号分子改变进行广泛的筛选和分析。这些研究将确定？-catenin参与的癌症特定途径，并将使用蛋白质免疫共沉淀和酵母双杂交分析来研究它们与？-catenin的相互作用。特异性目标2将确定？-catenin如何与Rho家族小GTP酶相互作用，破坏粘着连接，促进帽细胞的生长/存活和侵袭。我们将首先确定负责这一作用的？-连环蛋白序列。然后，对Rac-1或E-cadherin结合缺陷的β-catenin RNAi及其突变体的分析将确定GTP-Rac-1/IQGAP-1与E-cadherin/p120ctn通路之间的相互作用，以揭示可能对细胞间黏附和细胞生长/存活和侵袭的差异调控。我们还将测定IQGAP-1从E-钙粘附素复合体释放出来的β-连环蛋白的胞质积累和核信号转导。特殊目标3将应用Y311，一种独特的(脱磷特异的)单抗，和定点突变来确定？-连环蛋白修饰是如何发生的，以及它们在CAP中的作用。我们还将研究β-连环蛋白的蛋白分解片段及其作为DNA结合蛋白和核信号表达基因的潜力。最后，我们将产生显示前列腺组织特异性连环蛋白表达的转基因小鼠，以在动物水平上探讨这些问题。这些研究将把β-连环蛋白放入与CAP相关的生长因子和激酶信号机制的广泛背景中。了解控制？-catenin功能的翻译后修饰将揭开？-catenin在体内调节基因表达和促进CAP的机制。