Identification of Inhibitors of the N-Terminal Region of the Androgen Receptor

说明(申请人提供)：耐阉割前列腺癌(CRPC)是一种无法治愈的疾病，迫切需要新的有效的治疗方法。CRPC的持续生长和存活依赖于雄激素受体(AR)的转录活性。目前和研究中的CRPC治疗直接或间接针对AR的配体结合域(LBD)，而反式激活和DNA结合域(分别为TAD和DBD)尚未被用作治疗靶点。为了寻找新的AR转录抑制因子，我们设计了一种高通量酵母单杂交药物筛选(AIM 1)，其中报告基因的表达依赖于AR缺失突变体的结构性转录活性，该突变体缺乏功能LBD。在这个系统中，抑制 报告基因的活性表明可能存在AR转录抑制因子，干扰TAD和/或DBD功能。因此，我们的试验将有利于鉴定一组针对TAD和/或DBD的所需化合物，并提供克服去势抵抗的前景。我们的酵母单杂交筛选试验的稳健性已经建立(Z‘&gt；0.5)，并且反筛选已经被设计来排除非特异性抑制报告基因活性的化合物。在我们的酵母单杂交筛选中确定的化合物的AR抑制特性将在多个依赖AR的哺乳动物系统中进行测试(AIM 2)。接下来，将评估化合物的体外抗肿瘤活性(目标3)。最有效的药物将进行结构活性关系(SAR)分析，然后重复进行生化和体外生物活性测试，其目标将是确定两个先导优化的化合物，用于评估在体内的抗肿瘤生物活性。 AR依赖的CRPC小鼠模型(AIM 3)。然后，我们将在依赖AR的CRPC模型中评估具有选择性体内抗肿瘤活性的化合物的抗AR作用的潜在机制(目标4)。我们的目标是在成功执行建议的工作后，选择一种先导优化的AR转录抑制物，用于在转移性CRPC患者中快速翻译到早期PHA人类试验。

DESCRIPTION (provided by applicant): Castration resistant prostate cancer (CRPC) is an incurable disease for which novel and effective therapies are critically needed. CRPCs remain dependent upon androgen receptor (AR) transcriptional activity for continued growth and survival. Current and investigational therapies for CRPC directly or indirectly target the ligand binding domain (LBD) of the AR, yet the transactivation and DNA binding domains (TAD and DBD, respectively) have not been exploited as therapeutic targets. To identify novel AR transcriptional inhibitors, we have designed a high throughput yeast one-hybrid drug screen (Aim 1), in which reporter gene expression is dependent upon the constitutive transcriptional activity of a deletion mutant of the AR that lacks a functional LBD. In this system, suppression of reporter gene activity is indicative of a putative AR transcriptional inhibitor that interferes wit TAD and/or DBD function. Thus, our assay will favor the identification of a desired group of compounds that target the TAD and/or DBD and offer the promise of overcoming castration resistance. The robustness of our yeast one-hybrid screening assay has been established (Z' > 0.5), and counter-screens have been designed to exclude compounds that non-specifically inhibit reporter gene activity. The AR inhibitory properties of compounds identified in our yeast one-hybrid screen will be tested in multiple AR-dependent mammalian systems (Aim 2). Next, compounds will be evaluated for in vitro anti-tumor activity (Aim 3). The most active drugs will undergo structure activity relationship (SAR) analysis followed by repeated testing of biochemical and in vitro biologic activity in a reiterative process, the goal of which will be to identify two lead optimized compounds for assessing anti- neoplastic biological activity in vivo in AR-dependent CRPC mouse models (Aim 3). We will then evaluate the underlying mechanism of anti-AR action of compounds that exhibit selective in vivo anti- tumor activity in AR-dependent CRPC models (Aim 4). Our objective subsequent to the successful execution of the proposed work is to select a lead optimized AR transcriptional inhibitor for rapid translation to early phas human trials in patients with metastatic CRPC.