Mechanisms of Prostate Cancer Metastasis

联系PD/PI：Freeman，Michael R项目-004（511） 摘要（项目4） 侵袭性前列腺癌（PC）通过一个不太清楚的过程表现出表型变化， 谱系可塑性（LP）。LP通常是由于雄激素受体信号传导的继发性抵抗而发生的 抑制剂（ARSI）治疗，并通过不同的组织学和干性，神经内分泌（NE） 和上皮-间质转化特征。LP可以是基因组和染色体不稳定性（CIN）的驱动因素。 在之前的P01周期中，我们首次报道了转录因子ONECUT 2（OC 2/HNF 6 β）是一个转录因子， 在某些去势抵抗性前列腺癌中指定NE转录程序的主调节因子 （CRPC）。OC 2抑制雄激素受体（AR）靶基因，并作为一种生存因子。我们开发了一个 抑制AR-V7阳性mCRPC生长和转移的新型小分子OC 2抑制剂 异种移植因此，OC 2是侵袭性PC中以前未知的LP驱动因子，可以用药物靶向- 类似化合物。来自基因工程小鼠模型和组织再生模型的证据 表明OC 2在产生CIN的条件下上调。在上一个融资周期中， 模型系统，基因组学数据，以及人类PC组织和循环肿瘤细胞（CTC）的研究， 有证据表明CIN、OC 2激活和核形状不稳定性（NSI）是两种治疗的共同特征- 初治原发性转移性PC和mCRPC。这些发现表明，这些是一个或多个侵略性 PC类，甚至可能发生在没有选择从ARSI。利用这些观察结果作为科学 在此前提下，我们假设OC 2、CIN和NSI协同作用以驱动LP和PC致死率。具体 目标：目标1。确定CIN在OC 2驱动的谱系可塑性中的作用。OC 2将在体内实施， 人PC组织再生测定以确定OC 2活性是否依赖于CIN以及OC 2是否 促进LP、CIN或NSI。将分析来自完整和去势小鼠的移植物组织的CIN、LP和NSI 利用组织学、免疫组织化学、RNA表达谱和生物信息学方法。将诱导LP 在人mCRPC 2D和3D人体模型中通过缺氧和骨髓基质分泌来确定 这些刺激是否促进NSI和CIN。目标二。确定NSI促进谱系可塑性的机制。 将使用组织再生测定来确定NSI是否通过沉默核膜而诱导。 蛋白质Emerin（EMD）促进CIN、LP和OC 2活化。我们将确定EMD沉默是否可以 诱发或协同CIN以驱动肿瘤生长、LP和去势抵抗。目标3。调查OC 2 在原发性和转移性肿瘤细胞群中，对活化、CIN和NSI进行平行测定。已建立的单一 细胞分析方法将用于确定CIN、NSI和OC 2活化是否在人PC中共存 从新发转移性和mCRPC病例中分离的细胞。 项目摘要/摘要第699页 联系PD/PI：Freeman，Michael R项目-004（511）

Contact PD/PI: Freeman, Michael R Project-004 (511) ABSTRACT (PROJECT 4) Aggressive prostate cancers (PC) exhibit phenotypic changes through a poorly-understood process termed “lineage plasticity (LP).” LP typically occurs as a result of secondary resistance to androgen receptor signaling inhibitor (ARSI) therapy and is identified by variant histology and emergence of stemness, neuroendocrine (NE) and epithelial-mesenchymal transition features. LP can be a driver of genome and chromosome instability (CIN). In the previous P01 cycle we were the first to report that the transcription factor ONECUT2 (OC2/HNF6β) is a master regulator that specifies an NE transcriptional program in certain castration-resistant prostate cancers (CRPC). OC2 suppresses androgen receptor (AR) target genes and acts as a survival factor. We developed a novel class of small molecule OC2 inhibitors that inhibit growth and metastasis of AR-V7-positive mCRPC xenografts. OC2 is thus a previously unknown driver of LP in aggressive PC that can be targeted with a drug- like compound. Evidence from genetically engineered mouse models and tissue regeneration models demonstrate that OC2 is upregulated under conditions that produce CIN. In the previous funding cycle we used model systems, genomics data, and studies of human PC tissues and circulating tumor cells (CTCs) to assemble evidence that CIN, OC2 activation, and nuclear shape instability (NSI) are shared features of both treatment- naïve de novo metastatic PC and mCRPC. These findings suggest these are inherent to one or more aggressive PC classes and may even occur in the absence of selection from ARSI. Using these observations as a scientific premise, we hypothesize that OC2, CIN, and NSI act coordinately to drive LP and PC lethality. The Specific Aims are: Aim 1. Determine the role of CIN in OC2-driven lineage plasticity. OC2 will be enforced in vivo in human PC tissue regeneration assays to determine whether OC2 activity is dependent on CIN and whether OC2 promotes LP, CIN or NSI. Graft tissues from intact and castrated mice will be analyzed for CIN, LP, and NSI using histologic, immunohistochemical, RNA expression profiling and bioinformatics methods. LP will be induced in human mCRPC 2D and 3D human models by hypoxia and bone marrow stromal secretions to determine whether these stimuli promote NSI and CIN. Aim 2. Identify mechanisms of NSI that promote lineage plasticity. Tissue regeneration assays will be used to determine whether NSI induced by silencing the nuclear membrane protein emerin (EMD) promotes CIN, LP, and OC2 activation. We will determine whether EMD silencing can elicit or cooperate with CIN to drive tumor growth, LP and castration resistance. Aim 3. Investigate OC2 activation, CIN and NSI in parallel across primary and metastatic tumor cell populations. An established single cell analysis approach will be used to determine whether CIN, NSI and OC2 activation co-exist in human PC cells isolated from de novo metastatic and mCRPC cases. Project Summary/Abstract Page 699 Contact PD/PI: Freeman, Michael R Project-004 (511)