Targeting AR and AR-Variants in Castration-Resistant Prostate Cancer

靶向 AR 和 AR 变异体治疗去势抵抗性前列腺癌

基本信息

批准号：
10400349
负责人：
Chendil Damodaran
金额：
$ 39.51万
依托单位：
TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-01 至 2026-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10400349
关键词：
Acute Androgen Receptor Androgens Binding Binding Sites Bioavailable Biological Assay Body Weight Calorimetry Cancer Patient Cell Death Chemicals Cytosol Development Dose Foundations Goals Growth Histopathology In Vitro Label Lead Maximum Tolerated Dose Mediating Modeling Molecular Mus N-terminal Nuclear Magnetic Resonance Oral Oral Administration Outcome Pattern Phase I Clinical Trials Physiological Pre-Clinical Model Property RNA Splicing Receptor Activation Receptor Signaling Research Resistance Series Signal Transduction Site Solubility Stanolone Stimulus Structure-Activity Relationship Tertiary Protein Structure Testing Titrations Toxic effect Treatment Efficacy Tumor Tissue Ubiquitination Urology V1 Receptors Variant Xenograft procedure abiraterone advanced prostate cancer analog androgen deprivation therapy base biophysical analysis castration resistant prostate cancer chemotherapy design dynamic system effective therapy efficacy evaluation implantation in vivo in vivo Model inhibitor/antagonist next generation novel lead compound patient derived xenograft model pharmacokinetics and pharmacodynamics pro-apoptotic protein prostate cancer cell prostate cancer cell line prostate cancer progression protein expression receptor expression simulation small molecule tumor growth

项目摘要

Project Summary/Abstract Current AR inhibitors (enzalutamide and abiraterone) inhibit either the conversion of androgen to dihydrotestosterone (DHT), block androgen binding to androgen receptor (AR), or AR signaling. Although initially effective, these treatments eventually fail because of factors such as, AR-splice variants (AR-SVs) and AR responding to stimuli other than androgen. An effective way to control the emergence and treatment of castration-resistant prostate cancer (CRPC) is to develop small molecules that either inhibit AR expression or promote its degradation. If there is no AR, there would be no AR signaling, regardless of whether or how much androgen or other stimuli of AR signaling are present in CRPC. Our preliminary studies demonstrated that naturally occurring Urolithin A (UroA) inhibited the AR signaling and selectively suppressed the growth of AR-positive (AR+: IC50 ~35 M) but not AR-negative (AR-: IC50 ~70 µM) CRPC in both in vitro and in vivo models (50 mg/kg/body weight). As higher concentrations of UroA are required to suppress CRPC growth, we aimed to design and develop potent UroA analogs that could selectively inhibit AR activation at lower concentrations (nM), are orally bioavailable and suppress the growth of CRPC. The subsequent development of a series of UroA analogs and structure-activity relationship (SAR) studies led to the identification of two novel lead compounds ASR-600 and ASR-603 (US Provisional 62/941588) which demonstrated better efficacy (nM) than UroA (ASR-600: >40-fold and ASR-603: >12-fold) in inhibiting AR signaling in CRPC cell lines. Molecular studies suggest these two ASRs inhibit both AR and AR-SVs expression via ubiquitination and degradation within the cytosol. Molecular dynamic (MD) system simulation studies, biophysical analysis based on nuclear magnetic resonance (NMR), and thermal shift assays showed that these small molecules bind to the N-terminal domain (NTD) of AR and block the activation of both AR and AR-SV. At physiologically achievable concentrations, ASR-600 abrogated AR+ and AR-SV (C4-2B and 22Rv1) tumor growth in xenografts. Based on our preliminary results, we hypothesized that ‘Rationally designed ASRs will effectively inhibit and/or promote the degradation of both AR and AR-SV expression by directly targeting the AR-NTD and inhibit the growth of CRPC. We will test this hypothesis with the following specific aims. Aim 1. Investigate the mechanism of action of ASRs on AR+ CRPC cells. Aim 2. Determine in vivo signaling mechanism of AR and AR-SVs expression and optimize the dose of ASRs. Aim 3. Determine the therapeutic efficacy of the ASRs to inhibit CRPC growth in orthotopic and patient-derived xenograft (PDX) models. The proposed studies will elucidate the mechanism of action of the ASRs and lead to a better understanding of the chemotherapeutic properties of these compounds against CRPC.

项目概要/摘要目前的 AR 抑制剂（恩杂鲁胺和阿比特龙）抑制雄激素转化为二氢睾酮 (DHT) 阻断雄激素与雄激素受体 (AR) 的结合，或阻断 AR 信号传导。这些治疗最初有效，但由于 AR 剪接变异 (AR-SV) 等因素最终失败 AR对雄激素以外的刺激作出反应是控制出现和治疗的有效方法。去势抵抗性前列腺癌 (CRPC) 的治疗方法是开发抑制 AR 表达的小分子如果没有 AR，无论是否存在或如何，都不会有 AR 信号传导。我们的初步研究表明，CRPC 中存在大量雄激素或 AR 信号传导的其他刺激物。天然存在的尿石素 A (UroA) 抑制 AR 信号传导并选择性抑制体外和体内 CRPC 呈 AR 阳性（AR+：IC50 ~35 µM）但非 AR 阴性（AR-：IC50 ~70 µM）模型（50 mg/kg/体重）由于需要更高浓度的 UroA 来抑制 CRPC 生长，我们的目标是设计和开发有效的 UroA 类似物，可以在较低的条件下选择性抑制 AR 激活浓度（nM），具有口服生物利用度并抑制 CRPC 的生长。一系列 UroA 类似物和构效关系 (SAR) 研究导致鉴定出两种新型先导化合物 ASR-600 和 ASR-603（美国临时 62/941588）表现出更好的性能在 CRPC 细胞中抑制 AR 信号传导的功效（nM）比 UroA（ASR-600：>40 倍和 ASR-603：>12 倍）分子研究表明这两种 ASR 通过泛素化抑制 AR 和 AR-SV 的表达。和细胞质内的降解分子动力学（MD）系统模拟研究、生物物理分析。基于核磁共振（NMR）和热位移分析表明这些小分子与 AR 的 N 末端结构域 (NTD) 结合，并在生理上阻断 AR 和 AR-SV At 的激活。在可达到的浓度下，ASR-600 消除了 AR+ 和 AR-SV（C4-2B 和 22Rv1）肿瘤生长根据我们的初步结果，我们追求“合理设计的 ASR 将有效地” 通过直接靶向 AR-NTD 抑制和/或促进 AR 和 AR-SV 表达的降解我们将通过以下具体目标来检验这一假设。 1. 研究 ASR 对 AR+ CRPC 细胞的作用机制目标 2. 确定体内信号传导。 AR 和 AR-SV 的表达机制并优化 ASR 的剂量。目标 3. 确定治疗方案。 ASR 在原位和患者来源的异种移植 (PDX) 模型中抑制 CRPC 生长的功效。拟议的研究将阐明 ASR 的作用机制，并导致更好地理解这些化合物针对 CRPC 的化疗特性。