Role of JMJD1A modifications in castration resistance of prostate cancer

项目总结/摘要 去势抵抗性前列腺癌（CRPC）和神经内分泌前列腺癌（NEPC）是主要的前列腺癌。 前列腺癌（PCa）治疗的挑战。雄激素受体（AR）通路的激活是主要的 CRPC进展的潜在机制。NEPC的发生也与去势有关 NEPC的已知驱动因子之一是N-Myc癌蛋白。我们发现组蛋白 脱甲基酶JMJD 1A在CRPC和NEPC组织中上调; JMJD 1A通过以下途径支持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，JMJD 1A的选择性抑制剂还不可用。 我们已经确定了一个新的途径，调节JMJD 1A的稳定性和染色质募集。我们 初步数据显示，JMJD 1A是泛素化的目标，随后被泛素降解， 连接酶STUB 1，而被乙酰转移酶p300乙酰化的JMJD 1A逃避STUB诱导的降解。 我们观察到Enzalutamide耐药CRPC细胞或VCaP CRPC中JMJD 1A乙酰化水平升高， 模型;更高水平的JMJD 1A乙酰化与前列腺癌更快的复发相关 新辅助激素治疗后，表明JMJD 1A乙酰化在JMJD 1A稳定性中的关键作用， CRPC进展。我们有证据表明乙酰化的JMJD 1A的稳定性需要BET家族蛋白BRD 4， 其结合乙酰化赖氨酸并作为CRPC治疗的有希望的靶点。有趣的是， 使用p300抑制剂或BET抑制剂的JMJD 1A乙酰化诱导JMJD 1A降解并抑制CRPC 或体外NEPC细胞生长。 我们将检验JMJD 1A通过泛素化和乙酰化修饰调节 JMJD 1A活性，可能作为潜在的CRPC和NEPC治疗的靶点。目标1表征生化 JMJD 1A乙酰化通过BRD 4调节JMJD 1A募集到AR靶点的机制。目标2将 确定操纵STUB 1-JMJD 1A轴后CRPC细胞中AR靶基因的整体调节 或使用RNA-seq和ChIP-seq研究的JMJD 1A乙酰化。目标3将评估CRPC或NEPC的增长 STUB 1-JMJD 1A轴或JMJD 1A乙酰化操作后或处理后的异种移植物 p300抑制剂或BET抑制剂。最后，在目的4中，我们将评估JMJD 1A敲除在小鼠中的作用。 PTEN或Hi-Myc PCa模型的进展和去势敏感性。我们还将进行染色， 乙酰化的JMJD 1A和STUB 1在一个大的PCa组织微阵列（TMA）的集合，以评估他们如何 表达与JMJD 1A水平、各种类型的前列腺癌及其临床相关性相关。在 总之，我们提出的研究可以确定新的机制，目标和战略有用的潜力， 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.