Role of Rho GDP dissociation inhibitors in androgen signaling in prostate cancer

Rho GDP 解离抑制剂在前列腺癌雄激素信号传导中的作用

• 批准号: 8259064
• 负责人: Allen C Gao
• 金额: --
• 依托单位: VA NORTHERN CALIFORNIA HEALTH CARE SYS
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8259064
• 关键词: Affect; Amino Acid Sequence; Amino Acids; Androgen Receptor; Androgens; Benign; Biological Assay; Cancer Cell Growth; Cancer Etiology; Castration; Cell Line; Cells; Cessation of life; DNA Binding; Data; Development; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Evolution; Family; Foundations; Gel; Genes; Growth; Guanine Nucleotide Dissociation Inhibitors; Guanosine Triphosphate Phosphohydrolases; Health; Healthcare; Human; IL6 gene; In Vitro; LNCaP; Lead; Malignant - descriptor; Malignant neoplasm of lung; Malignant neoplasm of prostate; MeSH Thesaurus; Messenger RNA; Molecular; N-terminal; Northern Blotting; Nuclear Translocation; Nude Mice; PC3 cell line; Pathway interactions; Patients; Peptide Sequence Determination; Play; Population; Process; Prostate; Prostate-Specific Antigen; Receptor Activation; Receptor Signaling; Relapse; Research; Resistance; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Specificity; Staging; Tissues; Transactivation; United States; Veterans; Western Blotting; Withdrawal; base; cancer cell; cancer diagnosis; cell growth; cell motility; chromatin immunoprecipitation; deprivation; effective intervention; effective therapy; in vivo; jun Oncogene; knock-down; mRNA Stability; male; men; neoplastic cell; novel; overexpression; preclinical study; promoter; protein degradation; protein profiling; receptor expression; research study; response; rho; rhoB p20 GDI; small hairpin RNA; tumor; tumor progression; tumorigenic

DESCRIPTION (provided by applicant): SUMMARY DESCRIPTION OF PROJECT Role of Rho GDP dissociation inhibitors in androgen signaling in prostate cancer KEYWORDS (MeSH terms only; minimum three) Prostate cancer, androgen receptor, RhoGDI, castration-resistance, proliferation BRIEF STATEMENT OF RESEARCH OBJECTIVES (Do not use continuation sheets) Treatment for disseminated prostate cancer (CaP) is the withdrawal of androgens. However, CaP eventually continues to grow in an androgen-independent or castration-resistant state. Great effort has focused on understanding the mechanisms involved in the development and progression of castration-resistant prostate cancer (CRPC). Androgen receptor (AR) appears to play a central role in the development and progression of CRPC. We have identified a novel signaling molecule namely RhoGDI1, using 2-D gel analysis of protein profile combined with protein sequencing, that is downregulated in prostate cancer and its downregulation plays critical role during prostate cancer progression to CRPC. The levels of RhoGDI1 expression were decreased in prostate cancer tissues compared to benign prostate tissues. Overexpression of RhoGDI1 inhibited the growth of castration-resistant prostate cancer cells and caused a reversal to an androgen-sensitive stage, while downregulation of RhoGDI1 enhanced androgen-sensitive prostate cancer cell growth in androgen-deprived conditions. Furthermore, RhoGDI1 suppressed AR expression and AR activation via interaction with AR. Based on these data, we hypothesize that loss of RhoGDI1 expression promotes the development and progression of prostate cancer by activating the AR signaling pathway. In this proposal, we will study the function of RhoGDI1 and elucidate the molecular pathways of RhoGDI1 interaction with androgen signaling during prostate cancer progression to castration-resistance. The specific aims are: I. To examine the effects of RhoGDI1 on androgen responsiveness of prostate cancer cells in vitro We will knockdown RhoGDI1 expression in androgen-responsive LNCaP and LAPC-4 human prostate cancer cell lines, and overexpress RhoGDI1 in androgen-independent C4-2 and LNCaP-IL6+ cells to determine the effects of RhoGDI on cell growth and response to androgens. II. To examine the effects of RhoGDI1 on the development and progression of prostate cancer in vivo We will manipulate the levels of RhoGDI1 in prostate cancer cells and examine the effects of such manipulation on the formation and progression of tumors, as well as on the expression of androgen-inducible genes such as PSA in intact and castrated male athymic mice. III. To determine how RhoGDI1 interacts with AR signaling We will pinpoint the site of AR and RhoGDI1 interaction. We will examine if RhoGDI1 affects AR mRNA transcriptional initiation, protein turnover and nuclear translocation and DNA binding activity of AR. RhoGDI1 recruitment to the promoters of androgen responsive genes will be examined by chromatin immunoprecipitation (ChIP) assays. Potential impact on Veterans health care: Prostate cancer now exceeds lung cancer as the most commonly diagnosed cancer in the United States men, and it is the second leading cause of cancer death in that same population. A very large portion of men with prostate cancer are treated successfully with androgen deprivation therapy. However, virtually all patients will relapse due to acquisition of the growth of castration resistant tumor cells. Unfortunately, there is currently no effective treatment for men with castration resistant prostate cancer. The present proposal directly deals with the mechanisms of this evolution of castration resistant prostate cancer and has identified a critical factor involved in this process. Thus, this project targets castration resistant prostate cancer, a very significant health problem among male veterans. Our important mechanistic and pre-clinical studies will serve as the foundation for development of a mechanism based castration-adjunctive therapy, which may lead to a more effective intervention than castration alone. VA FORM 10-1313-2 Page 2 of VA Form 10-1313 package JUN 1990(R) PUBLIC HEALTH RELEVANCE: Project Narrative Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer death in the United States men. Although prostate cancer initially response to androgen deprivation therapy, virtually all patients will relapse to castration resistant prostate cancer (CRPC). Unfortunately, there is currently no effective treatment for men with CRPC. The present proposal directly deals with the mechanisms of this evolution of CRPC and has identified a novel factor involved in this process. Our hypothesis is that loss of RhoGDI1 expression promotes the development and progression of prostate cancer. In this proposal, we will study the role of RhoGDI1 during prostate cancer progression to castration-resistance. Thus, this project targets CRPC, a very significant health problem among male veterans. Completion of this study will significantly enhance current understanding of the mechanism of CRPC.

描述（由申请人提供）： 项目概要Rho GDP解离抑制剂在前列腺癌雄激素信号传导中的作用关键词（仅MeSH术语;最少三个）前列腺癌、雄激素受体、RhoGDI、去势抵抗、增殖研究进展简述（不要使用续页）播散性前列腺癌（CaP）的治疗是雄激素的戒断。然而，CaP最终继续在雄激素非依赖性或去势抵抗状态下生长。大量的努力集中在了解去势抵抗性前列腺癌（CRPC）的发展和进展所涉及的机制。雄激素受体（AR）似乎在CRPC的发生和进展中发挥核心作用。我们已经确定了一种新的信号分子，即RhoGDI 1，使用蛋白质图谱的2-D凝胶分析结合蛋白质测序，在前列腺癌中下调，其下调在前列腺癌进展为CRPC过程中起关键作用。与良性前列腺组织相比，前列腺癌组织中RhoGDI 1的表达水平降低。RhoGDI 1的过表达抑制去势抵抗性前列腺癌细胞的生长，并导致雄激素敏感阶段的逆转，而RhoGDI 1的下调增强雄激素敏感性前列腺癌细胞在雄激素剥夺条件下的生长。此外，RhoGDI 1通过与AR相互作用抑制AR表达和AR活化。基于这些数据，我们假设RhoGDI 1表达的缺失通过激活AR信号通路促进前列腺癌的发展和进展。在这个提议中，我们将研究RhoGDI 1的功能，并阐明RhoGDI 1与雄激素信号转导在前列腺癌进展到去势抵抗过程中相互作用的分子途径。具体目标是：一。为了检测RhoGDI 1在体外对前列腺癌细胞雄激素反应性的影响，我们将在雄激素反应性LNCaP和LAPC-4人前列腺癌细胞系中敲低RhoGDI 1表达，并在雄激素非依赖性C4-2和LNCaP-IL 6+细胞中过表达RhoGDI 1，以确定RhoGDI对细胞生长和对雄激素反应的影响。二.为了检查RhoGDI 1对体内前列腺癌的发展和进展的影响，我们将操纵前列腺癌细胞中RhoGDI 1的水平，并检查这种操纵对肿瘤形成和进展的影响，以及对雄激素诱导基因如PSA在完整和去势雄性无胸腺小鼠中的表达的影响。三.为了确定RhoGDI 1如何与AR信号相互作用，我们将精确定位AR和RhoGDI 1相互作用的位点。我们将研究RhoGDI 1是否影响AR mRNA的转录起始、蛋白质周转和核转位以及AR的DNA结合活性。将通过染色质免疫沉淀（ChIP）试验检查RhoGDI 1向雄激素应答基因启动子的募集。对退伍军人医疗保健的潜在影响：前列腺癌现在超过肺癌，成为美国男性最常见的癌症，也是同一人群中癌症死亡的第二大原因。很大一部分男性前列腺癌患者通过雄激素剥夺疗法得到成功治疗。然而，几乎所有的患者都会由于去势抵抗性肿瘤细胞的生长而复发。不幸的是，目前还没有有效的治疗方法用于去势抵抗性前列腺癌的男性。本提案直接涉及去势抵抗性前列腺癌的这种演变机制，并确定了参与这一过程的关键因素。因此，该项目针对去势抵抗性前列腺癌，这是男性退伍军人中非常重要的健康问题。我们重要的机制和临床前研究将作为开发基于机制的去势治疗的基础，这可能导致比单独去势更有效的干预。VA表格10-1313-2 VA表格10-1313包装第2页1990年6月（R） 公共卫生相关性： 前列腺癌是最常见的癌症，也是美国男性癌症死亡的第二大原因。虽然前列腺癌最初对雄激素剥夺治疗有反应，但几乎所有患者都会复发为去势抵抗性前列腺癌（CRPC）。不幸的是，目前还没有有效的治疗男性CRPC。本提案直接涉及CRPC的这种演变的机制，并确定了一个新的因素参与这一过程。我们的假设是RhoGDI 1表达的缺失促进了前列腺癌的发展和进展。在这项提案中，我们将研究RhoGDI 1在前列腺癌进展到去势抵抗过程中的作用。因此，该项目针对的是CRPC，这是男性退伍军人中一个非常严重的健康问题。这项研究的完成将大大提高目前对CRPC机制的理解。