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: 8397517
• 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 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8397517
• 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; castration resistant prostate cancer; 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; prostate cancer cell; 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)

描述（由申请人提供）： 项目概要描述 Rho GDP 解离抑制剂在前列腺癌雄激素信号转导中的作用 关键词（仅限 MeSH 术语；至少三个） 前列腺癌、雄激素受体、RhoGDI、去势抵抗、增殖 研究目的简要说明（不使用续页） 播散性前列腺癌 (CaP) 的治疗是停用雄激素。然而，CaP 最终会在雄激素非依赖性或去势抵抗状态下继续生长。人们付出了很大的努力来了解去势抵抗性前列腺癌（CRPC）发生和进展的机制。雄激素受体 (AR) 似乎在 CRPC 的发生和进展中发挥着核心作用。我们利用蛋白质谱的二维凝胶分析结合蛋白质测序，鉴定出一种新型信号分子，即 RhoGDI1，该分子在前列腺癌中下调，并且其下调在前列腺癌进展为 CRPC 过程中发挥着关键作用。与良性前列腺组织相比，前列腺癌组织中 RhoGDI1 表达水平降低。 RhoGDI1的过表达抑制了去势抵抗性前列腺癌细胞的生长，并引起雄激素敏感期的逆转，而RhoGDI1的下调则增强了雄激素剥夺条件下雄激素敏感型前列腺癌细胞的生长。此外，RhoGDI1 通过与 AR 相互作用抑制 AR 表达和 AR 激活。基于这些数据，我们假设 RhoGDI1 表达缺失通过激活 AR 信号通路促进前列腺癌的发生和进展。在本提案中，我们将研究 RhoGDI1 的功能，并阐明在前列腺癌进展为去势抵抗过程中 RhoGDI1 与雄激素信号相互作用的分子途径。具体目的是： 一、体外研究RhoGDI1对前列腺癌细胞雄激素反应性的影响 我们将敲低雄激素反应性LNCaP和LAPC-4人前列腺癌细胞系中RhoGDI1的表达，并在雄激素非依赖性C4-2和LNCaP-IL6+细胞中过表达RhoGDI1，以确定RhoGDI对细胞生长和对雄激素反应的影响。 雄激素。二.体内检查RhoGDI1对前列腺癌发生和进展的影响我们将操纵前列腺癌细胞中RhoGDI1的水平，并检查这种操纵对肿瘤形成和进展的影响，以及对完整和去势雄性无胸腺小鼠中雄激素诱导基因（例如PSA）表达的影响。三．为了确定 RhoGDI1 如何与 AR 信号传导相互作用，我们将查明 AR 和 RhoGDI1 相互作用的位点。我们将检查 RhoGDI1 是否影响 AR mRNA 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) 检测检查 RhoGDI1 招募到雄激素反应基因启动子的情况。对退伍军人医疗保健的潜在影响：前列腺癌现已超过肺癌，成为美国男性中最常诊断出的癌症，并且是同一人群中癌症死亡的第二大原因。很大一部分患有前列腺癌的男性通过雄激素剥夺疗法得到了成功治疗。然而，几乎所有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，目前还没有针对患有去势抵抗性前列腺癌的男性的有效治疗方法。本提案直接涉及去势抵抗性前列腺癌的这种演变机制，并确定了参与该过程的关键因素。因此，该项目针对的是去势抵抗性前列腺癌，这是男性退伍军人中一个非常严重的健康问题。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辅助疗法的基础，这可能会导致比单独去势更有效的干预。 VA 表格 10-1313-2 VA 表格 10-1313 包的第 2 页 1990 年 6 月(R)