Nuclear Factor I/B Action in Castrate Resistant Prostate Cancer

 描述(申请人提供)：候选人背景：我在密歇根大学获得博士学位，与Mark L.Day博士进行论文研究，重点是通过EGFR在良性前列腺增生症和前列腺癌(PCa)中的可溶性E-钙粘素信号。我正在与范德比尔特大学的Robert J.Matusik博士一起继续我的PCA研究，担任博士后研究员，重点研究雄激素受体(AR)辅助因子如何支持进展为去势抵抗性PCa(CRPCa)和治疗获得性神经内分泌PCa(NEPCa)。职业目标和目的：我的职业目标是成为一名独立的、终身教职的教员，在一家高素质的研究机构工作，与一个跨学科团队合作，专注于寻找CRPCA的新疗法。实现我的职业目标需要通过K99/R00额外的指导时间。职业发展和培训活动：我的培训计划围绕着导师、授课培训和受保护的研究时间，以支持我向独立的过渡。马图西克博士将担任我的主要导师；他将培训我畜牧业、老鼠模型人物塑造和人事管理。泌尿外科肿瘤学家彼得·克拉克博士将担任我的临床导师，西蒙·海沃德博士将提供肿瘤微环境方面的导师。我还将完成生物统计学课程和ASPIRE模块，参加免疫学研讨会，并继续进行负责任的研究行为(RCR)培训。研究策略：意义和创新：这个项目意义重大，因为它研究了NFIB如何驱动致命性CRPCa，并支持从神经内分泌分化(NED)到治疗获得性NEPCa的进展。这个项目具有创新性，因为它探索了NFIB如何通过与AR和AR剪接变体(AR-V)的相互作用来提高对雄激素剥夺治疗的抵抗力(去势抵抗力)，以及诱导支持非ED的IL-1β。它还探索了NFIB如何调节不同的CRPCa肿瘤细胞之间的通信。方法：晚期前列腺癌患者在雄激素剥夺治疗后不可避免地进展为CRPCA。CRPCa的进展可通过多种机制实现，包括AR-V和NED的表达。AR-V缺乏全长AR的配体结合域，因此具有结构性活性，对阻断AR活性的治疗无效。AR在NED或治疗后获得的NEPCA区域完全丢失。NED是一种局灶性改变，PCa开始失去AR的表达，而获得神经内分泌标志物的表达。40%-100%的CRPCA样本出现局灶性NED，在腺癌中观察到NED区域是很常见的。重要的是，这些区域的分泌物可以支持腺癌的去势抵抗。NED也可以是进展性的，接受下一代雄激素剥夺治疗的CRPCA患者中有25%将通过NED发展为治疗诱导性NEPCA。因此，CRPCA的成功治疗需要针对AR活性的治疗，而不是依赖于配体结合域。我发现核因子I/B(NFIB)是AR作用的有力调节剂。CRPCA样本强烈表达NFIB，NED诱导的PCa细胞NFIB表达上调。值得注意的是，在体外，NFIB的敲除可以预防NED。NFIB似乎也是IL-1β表达的关键，IL-1在体外与NED有关。基于这些观察，我假设NFIB是CRPCA的主要驱动因素，通过支持AR靶基因的表达和驱动促肿瘤细胞因子的表达。具体目标1：研究NFIB如何与AR/FOXA1复合体相互作用以驱动CRPCA。1A)确定NFIB、FOXA1、AR和AR-V在PCa细胞系中是否相互作用。1b)研究NFIB基因敲除对CRPCa细胞系AR和AR-V作用的影响。1c)探讨NFIB过表达对能够进行NED的PCa细胞株AR和AR-V活动的影响。具体目标2：确定是否需要NFIB表达才能进展为CRPCa和/或NEPCa。2a)在CRPCa小鼠模型中表征NFIB丢失的后果。2b)在CRPCa进展为NEPCa的小鼠模型中确定NFIB丢失的后果。特异目的3：研究NFIB的表达如何通过分泌IL-1β来支持NED。3A)探讨IL-1β在NFIB调控下的变化。3b)确定IL-1β的变化如何推动抗去势生长。3C)评估分泌的IL-1β是否驱动CRPCA。这些研究的成功完成将决定NFIB在CRPCA中表达的后果。这些研究将作为我在三年级结束时提交的NCI R01申请的基础。过渡到独立：我将过渡到独立，在K99阶段申请教员职位，并接受一家新机构的终身教职跟踪职位，以完成R00阶段。我独立于马图西克博士设计了这些目标，他不会在PCA中从事与NFIB相关的项目。

 DESCRIPTION (provided by applicant): Candidate Background: I received my Ph.D. from the University of Michigan for my dissertation studies with Dr. Mark L. Day, focusing on soluble E-cadherin signaling through EGFR in benign prostatic hyperplasia and prostate cancer (PCa). I am continuing my PCa research studies with Dr. Robert J. Matusik at Vanderbilt University as a postdoctoral research fellow by focusing on how androgen receptor (AR) cofactors can support progression to castrate resistant PCa (CRPCa) and therapy acquired neuroendocrine PCa (NEPCa). Career Goals and Objectives: My career goal is to become an independent, tenure-track faculty member at a high-caliber research institution, working with an interdisciplinary team, and focusing on identifying new therapies for CRPCa. Achievement of my career goals requires additional mentored time through the K99/R00. Career Development and Training Activities: My training plan revolves around mentorship, didactic training, and protected research time to support my transition to independence. Dr. Matusik will serve as my primary mentor; he will train me in animal husbandry, mouse model characterization, and personnel management. Dr. Peter Clark, a urologic oncologist, will serve as my clinical mentor, and Dr. Simon Hayward will provide mentorship in tumor microenvironment. I will also complete a biostatistics course and ASPIRE modules, attend immunology seminars, and continue responsible conduct in research (RCR) training. Research Strategy: Significance and Innovation: This project is significant because it examines how NFIB drives lethal CRPCa and supports progression from neuroendocrine differentiation (NED) to therapy acquired NEPCa. This project is innovative because it explores how NFIB can drive resistance to androgen deprivation therapy (castrate resistance) through interactions with AR and AR splice variants (AR-V), as well as induce IL-1β, which supports NED. It also explores how NFIB mediates communication between distinct CRPCa tumor cells. Approach: Patients with advanced PCa inevitably progress to CRPCa following androgen deprivation therapy. Progression to CRPCa can be achieved through multiple mechanisms, including expression of AR-V and NED. AR-V lack the ligand binding domain of full length AR and are therefore constitutively active and unresponsive to therapies which block AR activity. AR is lost altogether in areas of NED or therapy-acquired NEPCa. NED is a focal change whereby PCa begins to lose AR expression, and gains neuroendocrine marker expression. Focal NED occurs in 40-100% of CRPCa samples, and it is common to observe areas of NED within adenocarcinomas. Importantly, secretions from these areas can support castrate resistance of the adenocarcinoma. NED can also be progressive, and 25% of CRPCa patients treated with next generation androgen deprivation therapy will develop therapy-induced NEPCa through NED. Successful treatment of CRPCa, therefore, requires therapies targeting AR action independently of the ligand binding domain. I have discovered that nuclear factor I/B (NFIB) is a potent modulator of AR action. CRPCa samples strongly express NFIB, and NFIB is upregulated in PCa cells which have become castrate resistant through NED. Significantly, knockdown of NFIB prevents NED in vitro. NFIB also appears to be critical for expression of IL-1β which has been implicated in NED in vitro. Based on these observations, I hypothesize that NFIB is a major driver of CRPCa by supporting AR-target gene expression and driving expression of pro-tumorigenic cytokines. Specific Aim 1: Examine how NFIB interacts with the AR/FOXA1 complex to drive CRPCa. 1a) Determine whether NFIB, FOXA1, AR and AR-V interact in PCa cell lines. 1b) Examine the consequences of NFIB knockout on AR and AR-V action in CRPCa cell lines. 1c) Explore the consequences of NFIB overexpression on AR and AR-V action in PCa cell lines capable of undergoing NED. Specific Aim 2: Determine whether NFIB expression is required for progression to CRPCa and/or NEPCa. 2a) Characterize the consequences of NFIB loss in a mouse model of CRPCa. 2b) Determine the consequence of NFIB loss in a mouse model of CRPCa progression to NEPCa. Specific Aim 3: Characterize how NFIB expression supports NED through IL-1β secretion. 3a) Explore changes in IL-1β in response to NFIB modulation. 3b) Determine how changes in IL-1β drive castrate resistant growth. 3c) Evaluate whether secreted IL-1β drives CRPCa. Successful completion of these studies will determine the consequences of NFIB expression in CRPCa. These studies will serve as the basis for an NCI R01 application to be submitted during the end of my third year. Transition to Independence: I will transition to independence by applying to faculty positions during the K99 phase and accepting a tenure track position at a new institution to complete the R00 phase. I have designed these aims independent of Dr. Matusik, and he will not pursue projects relating to NFIB in PCa.