Role of JMJD1A modifications in castration resistance of prostate cancer

项目摘要/摘要 耐去势前列腺癌(CRPC)和神经内分泌前列腺癌(NEPC)是主要的 前列腺癌(PCA)治疗面临的挑战。雄激素受体(AR)途径的激活是主要的 CRPC进展的机制。NEPC的发展也与去势有关 耐药，N-Myc癌蛋白是NEPC的已知驱动因素之一。我们发现组蛋白 去甲基酶JMJD1A在CRPC和NEPC组织中上调；JMJD1A通过以下方式支持CRPC细胞的生长 促进AR活性和c-Myc水平，同时通过增加N-Myc水平支持NEPC细胞生长。 然而，目前还没有JMJD1A的选择性抑制剂。 我们已经发现了一条调控JMJD1A稳定性和染色质募集的新途径。我们的 初步数据显示，JMJD1A的目标是泛素化和随之而来的泛素降解 连接酶STUB1，而被乙酰转移酶p300乙酰化的JMJD1A则避免了存根诱导的降解。 我们观察到苯扎鲁胺耐药的CRPC细胞或VCaP CRPC细胞中JMJD1A乙酰化水平升高 模型：更高水平的JMJD1A乙酰化与前列腺癌更快的复发相关 在新辅助激素治疗后，表明JMJD1A乙酰化在JMJD1A稳定性和 CRPC进展。我们有证据表明，乙酰化JMJD1A的稳定性需要BET家族蛋白BRD4， 它与乙酰化赖氨酸结合，是CRPC治疗的有希望的靶点。有趣的是，目标是 使用p300抑制剂或BET抑制剂的JMJD1A乙酰化诱导JMJD1A降解并抑制CRPC 或NEPC细胞在体外生长。 我们将测试JMJD1A通过泛素化和乙酰化修饰调节的假设 JMJD1A的活性，可作为潜在的CRPC和NEPC治疗的靶点。目标1：生化特性 JMJD1A乙酰化调节JMJD1A通过BRD4向AR靶点募集的机制目标2将 确定操纵STUB1-JMJD1A轴对CRPC细胞中AR靶基因的整体调控 或使用RNA-SEQ和CHIP-SEQ研究的JMJD1A乙酰化。AIM 3将评估CRPC或NEPC的增长 在操纵STUB1-JMJD1A轴或JMJD1A乙酰化后或在治疗后的异种移植 使用p300抑制剂或BET抑制剂。最后，在目标4中，我们将评估JMJD1A基因敲除在 PTEN或Hi-Myc PCA模型的进展和去势敏感性。我们还会进行染色检查 在一大组PCA组织微阵列(TMA)中乙酰化JMJD1A和STUB1，以评估其 其表达与JMJD1A水平、前列腺癌的不同类型及其临床相关性有关。在……里面 综上所述，我们拟议研究可以确定新的机制、目标和战略，作为潜在的 CRPC和NEPC的治疗。

PROJECT SUMMARY/ABSTRACT Castration-resistant prostate cancer (CRPC) and neuroendocrine prostate cancer (NEPC) are major challenges in prostate cancer (PCa) therapy. Activation of the androgen receptor (AR) pathway is the main mechanism underlying CRPC progression. Development of NEPC is also associated with castration resistance, and one of known drivers of NEPC is N-Myc oncoprotein. We have found that the histone demethylase JMJD1A is upregulated in CRPC and NEPC tissues; JMJD1A supports growth of CRPC cells by promoting AR activity and c-Myc levels, while it supports NEPC cell growth by increasing N-Myc levels. However, selective inhibitors of JMJD1A are not yet available. We have identified a new pathway that regulates JMJD1A stability and chromatin recruitment. Our preliminary data shows that JMJD1A is targeted for ubiquitination and consequent degradation by the ubiquitin ligase STUB1, whereas JMJD1A acetylated by acetyltransferase p300 escapes STUB-induced degradation. We observed elevation of JMJD1A acetylation levels in enzalutamide-resistant CRPC cells or in a VCaP CRPC model; higher levels of JMJD1A acetylation were associated with more rapid recurrence of prostate cancer after neoadjuvant hormone therapy, indicating a key role for JMJD1A acetylation in JMJD1A stability and CRPC progression. We have evidence that stability of acetylated JMJD1A requires BET family protein BRD4, which binds acetylated lysine and serves as promising targets for CRPC therapy. Interestingly, targeting JMJD1A acetylation using a p300 inhibitor or a BET inhibitor induces JMJD1A degradation and inhibits CRPC or NEPC cell growth in vitro. We will test the hypothesis that JMJD1A modifications by ubiquitination and acetylation regulate JMJD1A activity and may be targeted as potential CRPC and NEPC therapy. Aim 1 characterizes biochemical mechanisms of JMJD1A acetylation in regulating JMJD1A recruitment to AR targets via BRD4. Aim 2 will determine global regulation of AR target genes in CRPC cells upon manipulation of the STUB1-JMJD1A axis or JMJD1A acetylation using RNA-seq and ChIP-seq studies. Aim 3 will evaluate growth of CRPC or NEPC xenografts following manipulation of the STUB1-JMJD1A axis or JMJD1A acetylation, or following treatment with a p300 inhibitor or a BET inhibitor. Finally, in Aim 4, we will evaluate effect of JMJD1A knockout in the progression and castration sensitivity of PTEN or Hi-Myc PCa models. We will also perform staining for acetylated JMJD1A and STUB1 in a large set of PCa tissue microarrays (TMAs) to evaluate how their expression correlates with JMJD1A levels, various types of prostate cancer and their clinical relevance. In summary, our proposed studies could identify novel mechanisms, targets and strategies useful as potential therapy for CRPC and NEPC.