Androgen Receptor-JunD Complex Inhibitors to Prevent Prostate Cancer Progression

雄激素受体-JunD 复合物抑制剂可预防前列腺癌进展

• 批准号: 8315084
• 负责人: Hirak S. Basu
• 金额: $ 30万
• 依托单位: COLBY PHARMACEUTICAL COMPANY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-24 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8315084
• 关键词: Androgen Receptor; Androgens; Animal Model; Animals; Antioxidants; Apoptosis; Basic Science; Binding Sites; Bioavailable; Biological Assay; Cancer Cell Growth; Cancer Etiology; Cancer Patient; Castration; Cell Proliferation; Cessation of life; Chemicals; Clinical; Complex; Computer Assisted; Computer Simulation; Data; Development; Diet; Docking; Dose; Early treatment; Enzymes; Gene Expression; Generations; Growth; Hormones; Human; Hydrogen Peroxide; Hydroxyl Radical; In Situ; Investigation; Ionizing radiation; Lead; Legal patent; Libraries; Luciferases; Malignant Neoplasms; Malignant neoplasm of prostate; Metabolic; Metastatic Prostate Cancer; Modeling; Molecular; NF-kappa B; Nature; Nuclear; Nude Mice; Oxidative Stress; Pathway interactions; Pharmaceutical Preparations; Phase; Preclinical Testing; Process; Production; Prostate; Prostatic; Proteins; Publications; Publishing; Radiation therapy; Radical Prostatectomy; Reactive Oxygen Species; Recurrence; Refractory; Relative (related person); Reporting; Resected; Resistance; Source; Spermidine; Spermine; Staging; Superoxides; Testing; Testosterone; Tissues; Transferase; Transferase Gene; Transgenic Mice; Up-Regulation; Vitamin E; Xenograft procedure; activating transcription factor; analog; autocrine; base; cancer cell; cancer recurrence; cancer therapy; cell growth; deprivation; design; drug candidate; effective therapy; enzyme reconstitution; feeding; follow-up; high throughput screening; inhibitor/antagonist; male; member; men; mouse model; novel; overexpression; oxidation; pre-clinical; prevent; protein expression; protein protein interaction; receptor binding; research clinical testing; small molecule; therapy development; transcription factor; tumor progression

DESCRIPTION (provided by applicant): Most conventional cancer therapies are only modestly effective against CRPCa. Therefore, the development of new and effective therapies to treat early-stage prostate cancer (PCa) to prevent progression of PCa to CRPCa is warranted. Our collaborator Dr. Wilding and his coworkers' basic science investigation of probable mechanism(s) of PCa progression led to a class of natural cancer causative agents, cellular reactive oxygen species (ROS) such as superoxide, hydroxyl radical, hydrogen peroxide, etc. Their published and strong preliminary data show that in human PCa cells, excess cellular ROS activate the transcription factor NF-kappa B that prevents apoptosis and drives PCa cell proliferation in the absence of androgen. It is proposed that targeted inhibitors o PCa specific ROS generation pathway(s) will be more effective than are chemical and/or dietary anti-oxidants in preventing PCa recurrence and progression to CRPCa. Our published data show androgen induces spermidine/spermine acetyl transferase (SSAT) that initiates a spermidine and spermine oxidation pathway to generate copious amounts of ROS specifically in PCa cells that are naturally rich in spermine and spermidine. As JunD protein expression is induced by androgen specifically in PCa cells, it is hypothesized that JunD complexes with the activated androgen receptor (AR) to induce SSAT gene expression and ROS production in PCa cells. We and others have also shown that NF-kappa B can induce SSAT expression, thus setting up a feed-forward loop for SSAT activation, ROS production and PCa progression. Therefore, it is proposed that specific inhibitor(s) of JunD-AR complex should block SSAT induction, ROS production, NF-kappa B activation and stop the autocrine feed-forward loop that helps CRPCa progression. A high-throughput screen using Gaussia luciferase enzyme reconstitution assay for in situ protein-protein interaction, thus far, identified seven inhibitorsthat can block JunD-AR interaction. Two of these compounds blocked androgen-induced ROS generation in androgen-dependent PCa cells and showed growth inhibitory effects against both androgen- dependent and androgen-independent human PCa cells at sub-micromolar to low micromolar levels. Using computer-aided molecular docking to determine the binding site(s) of the inhibitor, we propose to design analogs of the two lead compounds that should more efficiently block androgen-induced ROS generation and cell growth. Our Specific Aims are: 1) To develop models for small molecule interaction with JunD- AR complex using in silico docking and design and synthesize analogs of small molecule inhibitors of JunD- AR interaction; 2) To identify promising agents from their relative abilities to disrupt JunD-AR interaction and their efficacies in reducing intracellular ROS and inhibit cultured human PCa cell growth.; 3) To identify the lead drug candidate from the studies in Aim 2 and test its ability to inhibit human PCa growth in nude mouse xenografts and the same in a transgenic mouse model developing spontaneous PCa. PUBLIC HEALTH RELEVANCE: Advanced hormone refractory metastatic prostate cancer (CRPCa) is the second leading cause of cancer deaths among US men. Most conventional cancer therapies are only modestly effective against CRPCa. Therefore, the development of new and effective therapies to prevent prostate cancer (PCa) recurrence and/or progression to CRPCa is warranted. Our collaborator Dr. Wilding and his coworkers' investigation of probable mechanism(s) of PCa recurrence and progression led to a class of natural cancer causative agents, cellular reactive oxygen species (ROS). ROS levels are generally high in PCa cells as compared to their normal counterpart. Male hormone testosterone induces copious amounts of ROS generation specifically in PCa cells. Recent discoveries show that the main source of the prostatic ROS is oxidation of spermine and spermidine that is found in very high level in the prostate. It has also been demonstrated that activated androgen receptor binds with a protein JunD to induce the spermine/spermidine oxidation. Therefore, it is proposed that specific inhibitor(s) of JunD-AR complex should inhibit spermine/spermidine oxidation and should thus block ROS production in PCa cells and prevent CRPCa proliferation. We used a high throughput screen to identify inhibitors of JunD-AR interaction and identified several compounds that can inhibit JunD-AR interaction. One of these compounds blocked androgen-induced ROS generation in androgen-dependent PCa cells and showed growth inhibitory effects against both androgen-dependent and androgen-independent human PCa cells. Colby has patented these compounds for preclinical and clinical development for treatment of early-stage progressing PCa patients. Using computer-aided molecular design to determine the binding site(s) of the inhibitor, here, we propose to develop new analogs of the lead compound that should more efficiently block androgen-induced ROS generation and cell growth. The most active agent, thus identified, can be further developed for preclinical and clinical testing to prevent progression of early-stage androgen-dependent PCa to CRPCa.

描述（由申请人提供）：大多数传统的癌症疗法对CRPCa只有适度的疗效。因此，有必要开发新的有效的治疗方法来治疗早期前列腺癌（PCa），以防止PCa向CRPCa发展。我们的合作者Wilding博士和他的同事对PCa进展可能机制的基础科学研究导致了一类天然癌症病原体，细胞活性氧（ROS），如超氧化物，羟基自由基，过氧化氢等。他们发表的强有力的初步数据表明，在人类PCa细胞中，过量的细胞ROS激活转录因子NF-kappa B，该因子可在缺乏雄激素的情况下阻止细胞凋亡并驱动PCa细胞增殖。有人提出，针对PCa特异性ROS生成途径的靶向抑制剂在预防PCa复发和进展为CRPCa方面比化学和/或膳食抗氧化剂更有效。我们发表的数据显示，雄激素诱导亚精胺/精胺乙酰转移酶（SSAT）启动亚精胺和精胺氧化途径，在天然富含精胺和精胺的PCa细胞中特异性地产生大量ROS。由于雄激素在PCa细胞中特异性诱导JunD蛋白表达，因此假设JunD与活化的雄激素受体（AR）复合物诱导PCa细胞中SSAT基因表达和ROS产生。我们和其他人也发现NF-kappa B可以诱导SSAT表达，从而建立了SSAT激活、ROS产生和PCa进展的前馈循环。因此，我们提出jun - ar复合物的特异性抑制剂应该阻断SSAT诱导、ROS产生、NF-kappa B激活，并阻止有助于CRPCa进展的自分泌前馈回路。到目前为止，使用高斯荧光素酶重构法对原位蛋白-蛋白相互作用进行高通量筛选，鉴定出7种可以阻断jun - ar相互作用的抑制剂。其中两种化合物阻断雄激素依赖性PCa细胞中雄激素诱导的ROS生成，并在亚微摩尔到低微摩尔水平上对雄激素依赖性和雄激素非依赖性的人PCa细胞显示出生长抑制作用。利用计算机辅助分子对接来确定抑制剂的结合位点，我们建议设计两种先导化合物的类似物，以更有效地阻断雄激素诱导的ROS生成和细胞生长。我们的具体目标是：1)利用硅对接技术建立与JunD- AR复合物相互作用的小分子模型，设计和合成JunD- AR相互作用的小分子抑制剂类似物；2)从破坏jun - ar相互作用的相对能力、减少细胞内ROS和抑制培养的人PCa细胞生长的功效等方面确定有前景的药物；3)从Aim 2的研究中确定主要候选药物，并测试其在裸鼠异种移植物中抑制人PCa生长的能力，以及在发生自发性PCa的转基因小鼠模型中抑制人PCa生长的能力。