Targeting Drug-Resistant Castration Resistant Prostate Cancer via LIMK2

通过 LIMK2 靶向耐药去势前列腺癌

• 批准号: 10349560
• 负责人: Kavita Shah
• 金额: --
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10349560
• 关键词: Androgen Receptor; Androgens; Automobile Driving; Biogenesis; Cancer Etiology; Cancer Patient; Castration; Cell Line; Cells; Cessation of life; Chemicals; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Critical Pathways; Data; Disease; Disease Progression; Drug Targeting; Drug resistance; Engineering; Feedback; Genetic; Goals; Knock-out; Lead; Legal patent; Link; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; Molecular; Mus; Neoplasm Metastasis; Nuclear Translocation; Null Lymphocytes; PTEN gene; Pathogenesis; Pathway interactions; Patients; Phosphorylation; Phosphotransferases; Prostate; Prostate Cancer therapy; Prostatic Neoplasms; Protein Isoforms; Proteins; Publishing; RNA Splicing; Receptor Signaling; Research; Resistance; Ribosomes; Role; Signal Transduction; Specimen; Testing; Therapeutic Index; Tissues; Toxic effect; Up-Regulation; Validation; Variant; androgen deprivation therapy; base; castration resistant prostate cancer; cohort; drug candidate; enzalutamide; improved; in vivo; inhibitor; innovation; knock-down; men; molecular targeted therapies; mouse model; novel; patient derived xenograft model; pre-clinical; predictive marker; prevent; prostate cancer cell; prostate cancer cell line; prostate cancer progression; receptor; response; small molecule inhibitor; therapeutic target; therapy design; tool; tumorigenesis; ubiquitin-protein ligase

Abstract Prostate cancer (PCa) is the second most common cause of cancer-related death in men in the US, primarily due to the emergence of castration resistant prostate cancer (CRPC). Our long-term goal is to identify effective drug targets and develop small molecule inhibitors for CRPC. Our objective here is to determine the potential of LIMK2 kinase as a clinical target, and LI-11 (a highly potent and specific LIMK2 inhibitor) as a drug candidate for enzalutamide-resistant CRPC. The central hypothesis is that LIMK2 is a disease-specific target that is upregulated upon castration and promotes CRPC emergence, progression and enzalutamide resistance via upregulation of AR, ARV7 and PI3K pathways. We show that LIMK2 is highly expressed in CRPC tissues, but minimally expressed in normal prostates. Inducible knockdown or specific inhibition of LIMK2 fully reverses CRPC tumorigenesis in vivo, strongly supporting LIMK2 as a potential clinical target. Equally importantly, LI-11 synergistically enhances the efficacy of enzalutamide in CRPC cells. At a molecular level, LI-11 simultaneously depletes AR and ARV7, and inhibits PI3K signaling. Thus, LIMK2 targets three critical nodes driving CRPC progression including enzalutamide-resistance in tandem. We propose the following three specific aims: (1) Dissect the molecular mechanisms by which LIMK2 activates AR signaling in CRPC. (2) Investigate the molecular mechanism of LIMK2-mediated activation of PI3K pathway in CRPC. (3) Determine the potential of LIMK2 as a clinical target in enzalutamide-resistant CRPC and PDX models using LI-11 in vivo. Innovation: LIMK2 is a potential clinical target for PCa. The hypothesis was formulated based on an innovative chemical screen, which led to the discovery of several direct substrates of LIMK2. These LIMK2 substrates unlocked a powerful mechanism for therapeutic targeting of AR, ARV7 and PI3K pathways in tandem in CRPC. We have developed a highly potent and specific LIMK2 inhibitor (LI-11) that fully reverses tumorigenesis in vivo with no detectable toxicity. LI-11 will be used for preclinical validation of LIMK2 as a therapeutic target in cells and in vivo. LuCaP PDX models with variable LIMK2 levels will be used to determine whether LIMK2 levels correlate with LI-11 and enzalutamide sensitivity in vivo. Several CRISPR engineered cell lines will be utilized for genetic interrogation of LIMK2’s role in CRPC pathogenesis. Significance: Successful completion of the proposed studies will provide a new strategy to simultaneously inhibit three critical pathways via LIMK2, which lead to CRPC progression and enzalutamide-resistance. In vivo studies will reveal the potential of LIMK2 as a clinical target and LI-11 as a candidate drug. PDX mouse models with different LIMK2 levels will further uncover whether LIMK2 levels can serve as a novel predictive marker for determining the efficacy of CRPC therapy. The data further indicate that targeting LIMK2 could prevent the emergence of CRPC following androgen deprivation therapy. Finally, the validation of LIMK2 as a therapeutic target in CRPC may improve the odds of treating other aggressive cancers, where LIMK2 is upregulated.

抽象的 前列腺癌 (PCa) 是美国男性癌症相关死亡的第二大常见原因，主要是 由于去势抵抗性前列腺癌（CRPC）的出现。我们的长期目标是找到有效的 药物靶向并开发 CRPC 的小分子抑制剂。我们的目标是确定潜力 LIMK2 激酶作为临床靶点，LI-11（一种高效且特异性的 LIMK2 抑制剂）作为药物 恩杂鲁胺耐药 CRPC 的候选者。中心假设是 LIMK2 是疾病特异性靶点 去势后上调，促进 CRPC 的出现、进展和恩杂鲁胺耐药 通过 AR、ARV7 和 PI3K 途径的上调。我们发现 LIMK2 在 CRPC 组织中高表达， 但在正常前列腺中表达极少。 LIMK2 的诱导敲低或特异性抑制完全逆转 CRPC 体内肿瘤发生，有力支持 LIMK2 作为潜在的临床靶点。同样重要的是，LI-11 协同增强恩杂鲁胺在 CRPC 细胞中的功效。在分子水平上，LI-11同时 消耗 AR 和 ARV7，并抑制 PI3K 信号传导。因此，LIMK2 针对驱动 CRPC 的三个关键节点 进展包括串联的恩杂鲁胺耐药性。我们提出以下三个具体目标：（1） 剖析 LIMK2 激活 CRPC 中 AR 信号传导的分子机制。 (2) 调查 CRPC 中 LIMK2 介导的 PI3K 通路激活的分子机制。 (3) 确定潜力 LIMK2 作为体内使用 LI-11 的恩杂鲁胺耐药 CRPC 和 PDX 模型的临床靶点。 创新：LIMK2是前列腺癌的潜在临床靶点。该假设是基于创新性的 化学筛选，导致 LIMK2 的几种直接底物的发现。这些 LIMK2 底物 解锁了 CRPC 中 AR、ARV7 和 PI3K 通路串联治疗靶向的强大机制。 我们开发了一种高效且特异性的 LIMK2 抑制剂 (LI-11)，可在体内完全逆转肿瘤发生 没有可检测到的毒性。 LI-11将用于LIMK2作为细胞治疗靶点的临床前验证 和体内。具有可变 LIMK2 水平的 LuCaP PDX 模型将用于确定 LIMK2 水平是否 与体内 LI-11 和恩杂鲁胺敏感性相关。将使用多种 CRISPR 工程细胞系 用于对 LIMK2 在 CRPC 发病机制中的作用进行基因研究。 意义：成功完成拟议的研究将为同时 通过 LIMK2 抑制三个关键途径，从而导致 CRPC 进展和恩杂鲁胺耐药。体内 研究将揭示 LIMK2 作为临床靶点和 LI-11 作为候选药物的潜力。 PDX小鼠模型 不同 LIMK2 水平的研究将进一步揭示 LIMK2 水平是否可以作为新的预测标记物 确定 CRPC 治疗的疗效。数据进一步表明，靶向 LIMK2 可以阻止 雄激素剥夺治疗后出现 CRPC。最后，验证 LIMK2 作为治疗药物 CRPC 中的靶点可能会提高治疗 LIMK2 上调的其他侵袭性癌症的几率。