PMEPA1 Function and Expression in Prostate Cancer

PMEPA1 在前列腺癌中的功能和表达

• 批准号: 7250261
• 负责人: SHIV SRIVASTAVA
• 金额: $ 15.31万
• 依托单位: HENRY M. JACKSON FDN FOR THE ADV MIL/MED
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7250261
• 关键词: Age; Androgen Receptor; Androgens; Animal Model; Back; Benign; Binding; Binding Proteins; Biological Assay; Biological Markers; Biology; Cancer Biology; Cancer Cell Growth; Cells; Characteristics; Chromatin; Code; Cultured Cells; Data; Development; Diagnostic Neoplasm Staging; Disease-Free Survival; Doctor of Philosophy; Down-Regulation; Environment; Epithelial Cells; Epithelium; Expression Feature; Feedback; Frozen Sections; Gene Expression Profile; Genes; Genetic Transcription; Genome; Goals; Growth; Immunohistochemistry; In Vitro; Indium; Knowledge; LNCaP; Laboratories; Lasers; Luciferases; Malignant - descriptor; Malignant neoplasm of prostate; Mediating; Methylation; Molecular Profiling; Mus; Mutation; Outcome Study; Pathologic; Pathway interactions; Patients; Play; Polymerase Chain Reaction; Property; Prostate; Prostatic; Prostatic Neoplasms; Protein Overexpression; Proteins; Regulation; Research; Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Pathway; Signal Transduction; Specimen; Staging; Time; Tumor Biology; Tumor stage; Ubiquitin; Ubiquitination; cancer cell; cell growth; feeding; hormone regulation; multicatalytic endopeptidase complex; neoplastic cell; novel; prognostic; programs; promoter; receptor; receptor expression; receptor function; response; serial analysis of gene expression; serum PSA; size; therapeutic target; transcription factor; tumor progression; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The objective of this proposal is to define the functions of novel and critical components of the androgen regulated transcriptome in the patho-biology of prostate gland. Specifically, we will establish expression characteristics and functions of PMEPA1, a novel androgen responsive gene (ARG) discovered in our laboratory by Serial Analysis of Gene Expression in androgen treated LNCaP cells. Background: PMEPA1 expression is prostate-abundant and is restricted to prostatic epithelial cells. PMEPA1 binds to NEDD4 protein (ubiquitin E3 ligase) involved in the ubiquitin-proteasome pathway. PMEPA1 overexpression down-regulates AR protein in LNCaP cells and PMEPA1 negatively regulates prostate cancer cell growth. PMEPA1 also binds to AR. Loss or reduced PMEPA 1 expression is noted in 65% of primary CaP specimens. Our central hypothesis is that PMEPA1, as an androgen responsive-NEDD4 binding protein, down regulates the Androgen Receptor (AR) protein by a feed back loop between PMEPA1 and AR, which plays a critical role in maintaining the AR levels and prostatic epithelial cell growth. We propose to define PMEPA 1 functions and expression in prostate cancer cells by following specific aims: (1) Mechanisms of regulation of PMEPA1 expression by AR: The androgen responsive elements in PMEPA1 promoter will be defined by ChiP assays and PMEPA1 promoter-luciferase assays. Binding of AR to PMEPA1 promoter will also be analyzed in the genome of benign and malignant prostate epithelium; (2) PMEPA1 functions in negative regulation of AR and prostate cancer cell growth: PMEPA1 mediated regulation of AR and the AR-PMEPA1-NEDD4 connection will be established. Ubiquitination of PMEPA1 and AR will be analyzed. Cell growth inhibitory properties of PMEPA1 will be characterized in the AR and NEDD4 context using cell culture and animal models; and (3) PMEPA1 and AR expression features in human prostate pathobiology and their biomarker potential: PMEPA1 and AR expression in prostate cancer cells will be analyzed by real time PCR and IHC and will be correlated with clinico-pathologic features and evaluated for prognostic value. Relevance: PMEPA1 is a prostate abundant novel ARG and is a NEDD4 binding protein that inhibits CaP cell growth in vitro. Characterization of the functions and expression profiles of PMEPA 1 will enhance our knowledge of this gene in prostate tumor biology and in androgen signaling pathways. These goals are highly relevant in research defining prostate cancer biology and in the development of potentially new biomarkers and therapeutic targets for CaP.

描述（由申请人提供）：本提案的目的是定义雄激素调节转录组的新颖且关键的成分在前列腺病理生物学中的功能。具体来说，我们将建立 PMEPA1 的表达特征和功能，PMEPA1 是我们实验室通过雄激素处理的 LNCaP 细胞基因表达的系列分析发现的一种新型雄激素反应基因 (ARG)。背景：PMEPA1 表达在前列腺中大量表达，并且仅限于前列腺上皮细胞。 PMEPA1 与参与泛素-蛋白酶体途径的 NEDD4 蛋白（泛素 E3 连接酶）结合。 PMEPA1 过表达会下调 LNCaP 细胞中的 AR 蛋白，并且 PMEPA1 会负向调节前列腺癌细胞的生长。 PMEPA1 也与 AR 结合。 65% 的原代 CaP 样本中发现 PMEPA 1 表达缺失或减少。我们的中心假设是，PMEPA1 作为雄激素反应性 NEDD4 结合蛋白，通过 PMEPA1 和 AR 之间的反馈环路下调雄激素受体 (AR) 蛋白，这在维持 AR 水平和前列腺上皮细胞生长中发挥着关键作用。我们建议通过以下具体目标来定义 PMEPA 1 在前列腺癌细胞中的功能和表达： (1) AR 调节 PMEPA1 表达的机制：PMEPA1 启动子中的雄激素反应元件将通过 ChiP 测定和 PMEPA1 启动子-荧光素酶测定来定义。还将在良性和恶性前列腺上皮基因组中分析 AR 与 PMEPA1 启动子的结合； (2)PMEPA1在AR和前列腺癌细胞生长的负调节中发挥作用：PMEPA1介导的AR调节和AR-PMEPA1-NEDD4连接将建立。将分析 PMEPA1 和 AR 的泛素化。 PMEPA1 的细胞生长抑制特性将使用细胞培养和动物模型在 AR 和 NEDD4 背景下进行表征； (3) 人类前列腺病理学中的 PMEPA1 和 AR 表达特征及其生物标志物潜力：将通过实时 PCR 和 IHC 分析前列腺癌细胞中的 PMEPA1 和 AR 表达，并将其与临床病理特征相关并评估预后价值。 相关性：PMEPA1 是一种前列腺丰富的新型 ARG，也是一种 NEDD4 结合蛋白，可在体外抑制 CaP 细胞生长。 PMEPA 1 的功能和表达谱的表征将增强我们对该基因在前列腺肿瘤生物学和雄激素信号通路中的了解。这些目标与定义前列腺癌生物学的研究以及开发潜在的 CaP 新生物标志物和治疗靶点高度相关。