Targeting androgen receptor nuclear localization in prostate cancer

项目摘要 标题：靶向前列腺癌雄激素受体核定位 前列腺癌（PCa）是最常见的诊断癌症和癌症死亡的第二大原因， 美国男人迫切需要更有效的PCa治疗方法。雄激素受体（AR）是一个关键， PCa的治疗靶点。AR似乎在去势中过表达、稳定和核定位- 耐药PCa（CRPC）。AR核定位是其作为转录因子的功能所必需的。我们有 开发了高通量筛选并鉴定了两种密切相关的吡咯并咪唑，CPPI和EPPI， 其可抑制CRPC中AR的核定位。这些小分子抑制了所有测试的AR阳性 前列腺癌细胞，包括恩杂鲁胺耐药CRPC。进一步的研究表明，这些小 分子可以直接与AR结合，并增强AR在细胞核中的泛素化和降解， 核AR降解器（NARD）。由于CRPC与AR水平和稳定性增加相关，因此抑制或 甚至部分抑制AR水平也可减缓向CRPC的进展。在这里，我们假设NARD 可抑制CRPC和前列腺癌进展为去势抵抗。此外，NARD可以增强 其他AR靶向药物的疗效，因为对AR靶向药物的抗性也与 增加AR表达。为了探索NARD的治疗潜力，提出了3个具体目标。要求1 将确定CPPI抑制CRPC细胞中AR核定位的机制。目标2将 评估CPPI与其他AR靶向方法的潜在协同作用。目标3将综合和 表征CPPI的新类似物，目的是鉴定具有亚微摩尔浓度的新的先导NARD化合物。 对AR阳性PCa细胞具有高特异性。拟议项目的成功可能会导致一项战略， 减缓前列腺癌向去势抵抗的进展，并找到一种替代方法， PROTAC AR降解剂，作为AR阳性CRPC的治疗剂正在积极研究中。 由于NARD的作用机制与PROTAC型AR降解剂不同，NARD可能更容易被降解。 比PROTAC AR降解剂更适合某些患者人群。

Project Summary Title: Targeting androgen receptor nuclear localization in prostate cancer Prostate cancer (PCa) is the most frequently diagnosed cancer and second leading cause of cancer death in American men. More effective therapies for PCa are urgently needed. The androgen receptor (AR) is a key therapeutic target for PCa. AR appears to be overexpressed, stabilized, and nuclear-localized in castration- resistant PCa (CRPC). AR nuclear localization is necessary for its function as a transcription factor. We have developed a high-throughput screen and identified two closely related pyrroloimidazoles, CPPI and EPPI, which can inhibit AR nuclear localization in CRPC. These small molecules inhibited all tested AR-positive prostate cancer cells, including enzalutamide-resistant CRPC. Further studies suggested that these small molecules can directly bind to AR and enhance AR ubiquitination and degradation in the nucleus, acting as nuclear AR degraders (NARDs). Since CRPC is associated with increased AR level and stability, inhibition or even partial inhibition of AR level may slow down the progression to CRPC. Here, we hypothesize that NARD can inhibit CRPC and prostate cancer progression to castration resistance. Also, NARD may enhance the efficacy of other AR targeting agents because resistance to AR targeting agents is also associated with increased AR expression. To explore the therapeutic potential of NARD, 3 specific aims are proposed. Aim 1 will determine the mechanisms by which CPPI inhibits AR nuclear localization in CRPC cells. Aim 2 will evaluate potential synergies of CPPI with other AR-targeting approaches. Aim 3 will synthesize and characterize novel analogues of CPPI with the goal to identify new lead NARD compounds with submicromolar potency and high specificity for AR-positive PCa cells. Success of the proposed project may lead a strategy to slow down the progression of prostate cancer to castration resistance and to an alternative approach to PROTAC AR degraders, which are being actively investigated as a therapeutic agent for AR-positive CRPC. Since the mechanisms of NARD action are different from PROTAC-type AR degraders, NARD may be more suitable than PROTAC AR degraders in certain patient populations.