Targeting KDM4B, a novel alternative splicing regulator, in castration-resistant prostate cancer (CRPC)

靶向 KDM4B（一种新型选择性剪接调节因子）治疗去势抵抗性前列腺癌 (CRPC)

• 批准号: 10312132
• 负责人: Jer-Tsong Hsieh
• 金额: $ 40.55万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10312132
• 关键词: 3' Splice Site; Address; Alternative Splicing; Androgen Antagonists; Androgen Receptor; Animal Model; Antineoplastic Agents; Binding; Biological Assay; Biological Availability; Cancer Patient; Characteristics; Chemicals; Chromatin; Chromatin Structure; Clinical; Data; Development; Drug Kinetics; Drug resistance; Enzymes; Epigenetic Process; Exons; FDA approved; Generations; Genes; Genomic approach; Goals; Growth; Hormones; Human; In Vitro; Lead; Ligand Binding Domain; Link; Malignant Neoplasms; Malignant neoplasm of prostate; Metabolic; Metastatic Prostate Cancer; Molecular; Neoplasm Circulating Cells; Oncogenic; Pattern; Pharmaceutical Chemistry; Physiological; Play; Process; Prognosis; Property; Protein Isoforms; Proteins; RNA Binding; RNA Splicing; Refractory; Regulatory Element; Resistance; Role; Spliceosomes; Testing; Therapeutic; Trans-Activators; Transgenic Mice; Treatment Efficacy; Variant; androgen deprivation therapy; base; cancer cell; cancer therapy; castration resistant prostate cancer; chromatin immunoprecipitation; clinical candidate; clinically relevant; comparative; design; drug candidate; effective therapy; enzalutamide; genome-wide; high risk; histone demethylase; in vivo; inhibitor; mRNA Precursor; men; next generation; novel; novel therapeutics; overexpression; pre-clinical; prostate cancer cell; prostate cancer cell line; prostate cancer progression; recruit; standard care; success; targeted treatment; therapy resistant; tumorigenesis; 3' Splice Site; Address; Alternative Splicing; Androgen Antagonists; Androgen Receptor; Animal Model; Antineoplastic Agents; Binding; Biological Assay; Biological Availability; Cancer Patient; Characteristics; Chemicals; Chromatin; Chromatin Structure; Clinical; Data; Development; Drug Kinetics; Drug resistance; Enzymes; Epigenetic Process; Exons; FDA approved; Generations; Genes; Genomic approach; Goals; Growth; Hormones; Human; In Vitro; Lead; Ligand Binding Domain; Link; Malignant Neoplasms; Malignant neoplasm of prostate; Metabolic; Metastatic Prostate Cancer; Molecular; Neoplasm Circulating Cells; Oncogenic; Pattern; Pharmaceutical Chemistry; Physiological; Play; Process; Prognosis; Property; Protein Isoforms; Proteins; RNA Binding; RNA Splicing; Refractory; Regulatory Element; Resistance; Role; Spliceosomes; Testing; Therapeutic; Trans-Activators; Transgenic Mice; Treatment Efficacy; Variant; androgen deprivation therapy; base; cancer cell; cancer therapy; castration resistant prostate cancer; chromatin immunoprecipitation; clinical candidate; clinically relevant; comparative; design; drug candidate; effective therapy; enzalutamide; genome-wide; high risk; histone demethylase; in vivo; inhibitor; mRNA Precursor; men; next generation; novel; novel therapeutics; overexpression; pre-clinical; prostate cancer cell; prostate cancer cell line; prostate cancer progression; recruit; standard care; success; targeted treatment; therapy resistant; tumorigenesis

Alternative splicing of pre-mRNA is a fundamental mechanism to generate protein diversity that is often deregulated in cancer cells, producing aberrant proteins that promote growth and survival. Growth of prostate cancer (PCa) is driven by the androgen receptor (AR) activities. The standard care for metastatic PCa is androgen-deprivation therapy (ADT). However, ADT inevitably leads to castration-resistant PCa (CRPC) that, while still relies on the AR activities, is no longer hormone-sensitive. Among the many mechanisms underlying CRPC, is the generation of constitutively active AR variants (AR-Vs) through alternative splicing. Of note is AR- V7, which may play a causal role in PCa progression and treatment resistance. Until now, no FDA-approved agent can target these AR-Vs. Recently, we identified a pro-oncogenic role for histone demethylase KDM4B in PCa and several chemical inhibitors of KDM4B. In our preliminary studies, we found that KDM4B is necessary and sufficient to promote AR-V7 expression. KDM4B binds RNA and interacts with many trans-acting factors and may regulate alternative splicing of AR at both the pre-mRNA and chromatin levels. In addition, KDM4B may have other genome-wide alternatively spliced targets that are hallmarks of cancer. High KDM4B expression in human PCa patients predicts poor prognosis and correlates with elevated AR-V7 expression. Based on these scientific premises, we hypothesize that KDM4B may be a gene-specific alternative splicing regulator that dictates an oncogenic splicing pattern in CRPC and that targeting this enzyme could inhibit CRPC and re-sensitize CRPC to current ADT. We propose three specific aims to test this hypothesis. Aim 1: To determine the molecular mechanisms by which KDM4B regulates alternative splicing of AR-Vs. KDM4B may promote alternative splicing by recruiting the spliceosome to the 3'-splice site of alternative exons via binding to splicing regulatory elements (SREs) and by changing the chromatin structures around alternatively spliced exons. We will identify these SREs and determine the chromatin landscape around alternatively spliced exons. Aim 2. To identify KDM4B-regulated genome-wide splice variants. Preliminary studies indicated that KDM4B may have additional alternatively spliced variants that are specific for PCa tumorigenesis. We will test this hypothesis by comparative profiling genome-wide KDM4B-targeted splice variants, their associated SREs and chromatin landscapes in both hormone-sensitive and refractory PCa cells. Aim 3. To generate a clinical candidate(s) through optimization of KDM4B inhibitors. Our data indicated that the KDM4B inhibitor B3 may serve as a strong lead compound for further optimization to generate a clinical candidate agent. We will optimize B3 through iterative rounds of medicinal chemistry design, synthesis and testing. The notion that KDM4B is an oncogenic regulator of alternative splicing is novel. Understanding mechanism of action of KDM4B and identifying potent KDM4B inhibitors with in vivo efficacy will have significant clinical impact on the development of new therapies for CRPC with active oncogenic alternatively spliced variants.

前MRNA的替代剪接是产生蛋白质多样性的基本机制 在癌细胞中失调，产生异常的蛋白质，促进生长和生存。前列腺的生长 癌症（PCA）由雄激素受体（AR）活性驱动。转移性PCA的标准护理是 雄激素剥夺疗法（ADT）。但是，ADT不可避免地会导致耐custatration-PCA（CRPC），该PCA（CRPC） 尽管仍然依靠AR活动，但不再对激素敏感。在众多机制中 CRPC是通过替代剪接生成组成型活性AR变体（AR-VS）。值得注意的是 V7，可能在PCA进展和治疗耐药性中起因果作用。到目前为止，没有FDA批准 代理可以针对这些AR-VS。最近，我们确定了组蛋白脱甲基酶KDM4B的促核作用 PCA和KDM4B的几种化学抑制剂。在我们的初步研究中，我们发现KDM4B是必要的 足以促进AR-V7表达。 KDM4B结合RNA并与许多跨作用因子相互作用 并可能调节AR在前MRNA和染色质水平上的替代剪接。此外，KDM4B 可能具有其他全基因组的剪接靶标，这是癌症的标志。高kdm4b 人类PCA患者的表达预测预后不良，并且与AR-V7表达升高相关。 基于这些科学的前提，我们假设KDM4B可能是基因特异性的替代剪接 指示CRPC中的致癌剪接模式的调节剂，靶向这种酶可以抑制 CRPC并将CRPC重新敏感到当前ADT。我们提出了三个特定的目的来检验这一假设。目标1： 确定KDM4B调节AR-VS替代剪接的分子机制。 KDM4B 通过将剪接体招募到替代外显子的3'splice位点，可以通过 与剪接调节元件（SRE）结合，并通过更改染色质结构。 剪接外显子。我们将识别这些SRE，并确定周围剪接的染色质景观 外显子。目标2。确定KDM4B调节的全基因组剪接变体。初步研究表明 KDM4B可能具有其他针对PCA肿瘤发生的剪接变体。我们将测试 通过比较分析基因组范围KDM4B靶向剪接变体的假设，其相关的SRE 激素敏感和难治性PCA细胞中的染色质景观。目标3。生成临床 通过优化KDM4B抑制剂来候选。我们的数据表明KDM4B抑制剂B3可能 用作强大的铅化合物，以进一步优化生成临床候选剂。我们将 通过迭代循环的药物化学设计，合成和测试来优化B3。那个概念 KDM4B是替代剪接的致癌调节剂是新颖的。了解行动机制 KDM4B并确定具有体内功效的有效KDM4B抑制剂将对该抑制作用产生重大临床影响 具有主动致癌性变种的CRPC的新疗法的开发。