Mechanisms of Prostate Cancer Metastasis

联系PD/PI：Freeman，Michael R Project-004(511) 摘要(项目4) 侵袭性前列腺癌(PC)通过一种鲜为人知的过程表现出表型变化，称为 “谱系可塑性(LP)。”LP通常是雄激素受体信号的继发性抵抗的结果 抑制剂(ARSI)治疗，通过不同的组织学和茎、神经内分泌(NE)的出现来确定 上皮-间充质过渡特征。LP可能是基因组和染色体不稳定(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ONECUT2(OC2/HNF6β)是一种 在某些去势抵抗前列腺癌中指定NE转录程序的主调节因子 (CRPC)。OC2抑制雄激素受体(AR)靶基因，并作为生存因子。我们开发了一种 新型小分子OC2抑制剂抑制AR-V7阳性mCRPC的生长和转移 异种移植物。因此，OC2是侵袭性PC中以前未知的LP的驱动因素，可以通过药物靶向- 就像化合物一样。来自基因工程小鼠模型和组织再生模型的证据 证明OC2在产生CIN的条件下上调。在上一个资金周期中，我们使用 模型系统、基因组数据以及人类PC组织和循环肿瘤细胞(CTCs)的组装研究 有证据表明，CIN、OC2激活和核形状不稳定(NSI)是这两种治疗的共同特征- 单纯的转移性PC和mCRPC。这些发现表明，这些是一个或多个攻击性的固有特征 PC类，甚至可能在没有从ARSI中选择的情况下发生。利用这些观察结果作为一种科学 假设OC2、CIN和NSI协同作用，驱动LP和PC的致死性。具体的 目的：目的1.确定CIN在OC2驱动的谱系可塑性中的作用。OC2将于#年在体内实施 人PC组织再生试验确定OC2活性是否依赖于CIN以及OC2是否依赖于CIN 促进LP、CIN或NSI。来自完整和去势小鼠的移植组织将被分析CIN、LP和NSI 采用组织学、免疫组织化学、RNA表达谱和生物信息学等方法。Lp将被诱导 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 这些刺激物是否促进NSI和CIN。目的2.确定NSI促进谱系可塑性的机制。 组织再生试验将被用来确定是否通过沉默核膜而引起NSI 蛋白尿蛋白(EMD)促进CIN、LP和OC2的激活。我们将确定EMD静音是否可以 诱导或与CIN协同促进肿瘤生长、LP和去势抵抗。目标3.调查OC2 在原发和转移性肿瘤细胞群体中，激活、CIN和NSI是平行的。久负盛名的单曲 将使用细胞分析方法来确定CIN、NSI和OC2激活是否在人类PC中共存 从初发转移和mCRPC病例中分离出细胞。 项目摘要/摘要页699 联系PD/PI：Freeman，Michael R Project-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)