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

描述（由申请人提供）：去势抵抗性前列腺癌（CRPC）是一种无法治愈的疾病，急需新型有效的治疗方法。CRPC仍然依赖于雄激素受体（AR）的转录活性，以继续生长和存活。CRPC的当前和研究性疗法直接或间接靶向AR的配体结合结构域（LBD），但反式激活和DNA结合结构域（分别为BBD和DBD）尚未被用作治疗靶点。为了鉴定新型AR转录抑制剂，我们设计了高通量酵母单杂交药物筛选（Aim 1），其中报告基因表达依赖于缺乏功能性LBD的AR缺失突变体的组成性转录活性。在这个系统中， 报告基因活性指示干扰和/或DBD功能的推定AR转录抑制剂。因此，我们的测定将有利于鉴定靶向卵巢癌和/或DBD的所需化合物组，并提供克服去势抗性的希望。已经建立了我们的酵母单杂交筛选测定的稳健性（Z' > 0.5），并且已经设计了反筛选以排除非特异性抑制报道基因活性的化合物。在我们的酵母单杂交筛选中鉴定的化合物的AR抑制特性将在多个AR依赖性哺乳动物系统中进行测试（目的2）。接下来，将评价化合物的体外抗肿瘤活性（目的3）。最具活性的药物将进行结构活性关系（SAR）分析，然后在重复过程中重复测试生物化学和体外生物活性，其目标将是鉴定两种用于评估体内抗肿瘤生物活性的先导优化化合物。 AR依赖性CRPC小鼠模型（目的3）。然后，我们将评估在AR依赖性CRPC模型中表现出选择性体内抗肿瘤活性的化合物的抗AR作用的潜在机制（目的4）。在成功执行拟议工作后，我们的目标是选择一种领先的优化AR转录抑制剂，用于快速翻译至转移性CRPC患者的早期人体试验。

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.