delta-Catenin and Cell-Cell Adhesion in Prostate Cancer

描述（由申请人提供）：前列腺癌（CaP）是美国男性最常见的恶性肿瘤，也是癌症死亡率的第二大原因。为了降低显著的发病率和死亡率，CaP预防和治疗的新策略取决于确定与该疾病有关的特定分子机制。？catenin是一种独特的armadillo （ARM）结构域蛋白，具有神经特异性，主要在大脑中表达。然而,?-catenin在前列腺腺癌中的表达增加，使E-cadherin/p120ctn从细胞-细胞交界处重新分布，促进CaP细胞的生长和侵袭。为了研究癌症外周组织中神经元连环蛋白基因表达这一很大程度上未被探索的领域，该项目的总体目标是验证以下假设：-catenin通过与多种细胞机制相互作用促进CaP的形成和进展，包括细胞-细胞和细胞-基质粘附、细胞生长/存活和侵袭。这项建议有三个具体目标。具体目标1将决定如何？-catenin在CWR22肿瘤异种移植物及其衍生细胞系对肝细胞生长因子和/或雄激素的反应中促进细胞生长/存活和运动。我们将广泛筛选和分析？-catenin诱导信号分子改变的阵列技术这些研究将确定癌症的特定途径？-catenin参与并将研究它们与？-catenin用蛋白共免疫沉淀和酵母双杂交分析。具体目标2将决定如何？-catenin与Rho家族小GTPases相互作用，破坏粘附体连接，促进CaP细胞生长/存活和侵袭。我们将首先确定？-catenin序列负责这个动作。那么，对？-catenin RNAi或其在Rac-1或E-cadherin结合中存在缺陷的突变体将决定GTP-Rac-1/IQGAP-1和E-cadherin/p120ctn途径之间的相互作用，以揭示细胞-细胞粘附和细胞生长/存活和侵袭的可能差异调节。我们还将确定？的细胞质积累和核信号传导。-catenin由IQGAP-1从e -钙粘蛋白复合体中释放。特异性Aim 3将使用Y311（一种独特的（去磷酸化特异性）单克隆抗体）和定点诱变来确定如何？-catenin修饰会发生，它们在CaP中的作用是什么。我们还将研究？-连环蛋白水解片段及其作为DNA结合蛋白和基因表达核信号的潜力。最后，我们将产生具有前列腺组织特异性的转基因小鼠。-catenin的表达来在动物水平上解决这些问题。这些研究将会发生什么？-catenin在与CaP相关的生长因子和激酶信号机制的广泛背景下的研究。-连环蛋白的功能将解开机制，通过什么？-catenin调节基因表达，促进体内CaP。

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.