Overexpression of ubiquitin E3 ligase WWP1 as an oncogenic factor in the prostate

泛素 E3 连接酶 WWP1 过度表达作为前列腺致癌因子

• 批准号: 7094733
• 负责人: JIN-TANG DONG
• 金额: $ 24.74万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-18 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7094733
• 关键词: chromosome deletion; clinical research; genetic library; human genetic material tag; human tissue; loss of heterozygosity; male; molecular cloning; neoplasm /cancer genetics; prostate neoplasms; tumor suppressor genes

DESCRIPTION (provided by applicant): The goals of the previous funding period were to map, clone, and characterize a tumor suppressor gene at 13q21 in prostate cancer. In 9 papers including 7 published and 2 submitted, we identified the transcription factor KLF5 as a strong candidate for the 13q21 gene, and demonstrated three mechanisms that inactivate KLF5 in cancer cells, including genomic deletion, transcriptional downregulation, and excessive protein degradation. In addition, we found that KLF5 is an indispensable component of the TGFbeta signaling pathway; and that a ubiquitin E3 ligase that ubiquitinates and degrades KLF5, WWP1, is often overexpressed via copy number gain at 8q21 in prostate cancer, which is responsible for excessive degradation of KLF5 in cancer cells. Furthermore, it has been shown that VWVP1 negatively regulates the TGFbeta signaling pathway by inducing the degradation of Smad2, Smad4, and TGFbeta receptor type I. We therefore hypothesize that overexpression of the E3 ligase WWP1 in epithelial cells causes excessive protein degradation of KLF5 and other components of the TGFbeta signaling pathway, and thus makes cells resistant to the inhibitory effect of TGFbeta in cell proliferation. As a result, cells become more susceptible to other factor-induced carcinogenesis. We will further test and validate this hypothesis in three specific aims. 1) To assess molecular alterations of WWP1 and related molecules in human prostate cancer, clinical cancer specimens will be examined for copy number gain, overexpression, and mutations of WWP1 and for expression change in KLF5 and other components of the TGFbeta pathway. The alterations will be correlated with clinicopathological features of prostate cancer. 2) To examine the function of WWP1 in cell growth in the context of KLF5 and TGFbeta, cells expressing different levels of WWP1 will be examined for growth, cell cycle progression, tumorigenesis, and gene expression changes. 3) To test the role of WWP1 overexpression in carcinogenesis using genetically modified mice, WWP1 will be specifically overexpressed in the prostates of mice. Such mice will be crossed with NKX3.1 and PTEN knockout mice. Phenotypic and molecular alterations will be analyzed in these mice. Completion of these studies will likely show WWP1 to be a molecule useful for developing biomarkers and therapeutic targets as well as for understanding prostate cancer biology.

描述（由申请人提供）：上一个融资期的目标是在前列腺癌中13q21绘制，克隆和表征肿瘤抑制基因。在9篇论文中，包括已发布的7篇论文和2项提交的论文，我们将转录因子KLF5确定为13q21基因的强候选者，并证明了三种机制，这些机制使癌细胞中的KLF5失活，包括基因组缺失，转录下调下调和过量蛋白质蛋白质。此外，我们发现KLF5是TGFBETA信号通路的必不可少的组成部分。而且，泛素E3连接酶泛素化并降解KLF5，WWP1，通常通过在前列腺癌中的拷贝数增长到8q21的拷贝数增长过表达，这是癌细胞中KLF5过度降解的。此外，已经表明，VWVP1通过诱导SMAD2，SMAD4和TGFBETA受体的降解来负调节TGFBETA信号通路。途径，从而使细胞抗TGFBETA在细胞增殖中的抑制作用。结果，细胞变得更容易受到其他因子诱导的癌变的影响。我们将进一步检验并验证这一假设的三个特定目标。 1）为了评估人类前列腺癌中WWP1和相关分子的分子改变，将检查临床癌标本的​​拷贝数增益，过表达和WWP1突变以及KLF5和TGFBETA途径的其他成分的表达变化。这些改变将与前列腺癌的临床病理特征相关。 2）为了检查WWP1在KLF5和TGFBETA背景下的细胞生长中的功能，将检查表达不同水平WWP1的细胞的生长，细胞周期进展，肿瘤发生和基因表达变化。 3）为了测试WWP1过表达在使用基因修饰的小鼠使用癌变中的作用，WWP1将在小鼠的前列腺中特别表达。这样的小鼠将与NKX3.1和PTEN敲除小鼠交叉。这些小鼠将分析表型和分子改变。这些研究的完成可能会表明WWP1是一种可用于开发生物标志物和治疗靶标以及了解前列腺癌生物学的分子。