Studies on Lineage Plasticity in Prostate Cancer

项目摘要 尽管靶向癌症治疗取得了显着的成功，但某些癌症，包括肺癌，乳腺癌， 前列腺癌和黑色素瘤总是对治疗产生抗性。一种次级机制 当细胞转变为攻击性状态时，抵抗性-谱系可塑性-就会出现，在前列腺的情况下， 癌症，获得神经内分泌组织学。这导致了一个快速下坡过程的一个子集，所谓的 去势抵抗性前列腺癌（CRPC）患者。从本质上讲，这不仅构成了临床挑战， 也让我们面对一个开放的生物学问题--血统的分子基础是什么 可塑性，重要的是，这个过程可以逆转吗？我们最近的研究表明， JAK/STAT和FGFR信号通路的激活促进谱系可塑性，并导致对 雄激素受体信号传导抑制剂（ARSI）[*Chan，*Zaidi，等，科学，2022，PMID：35981096，*co- 第一作者）。重要的是，我们发现FDA批准的JAK/STAT（鲁索利替尼）和FGFR抑制剂 （erdafitinib）协同逆转谱系可塑性并恢复ARSI敏感性。因此，我们假设， JAK/STAT和FGFR下游的信号，包括新的转录因子，相互作用以促进谱系 可塑性，和他们的定时扰动可以逆转可塑性和ARSI不敏感性。在具体目标1中， 为了研究FGFR信号如何与JAK/STAT协同作用以赋予可塑性，我们将使用化学抑制剂， CRISPR-Cas9删除TP 53/RB 1缺失小鼠和人类肿瘤类器官中的特定分子。具体 Aim 2将专注于通过无偏的单克隆抗体来进一步解卷积谱系可塑性的分子复杂性。 细胞配对RNA和ATAC（多组）测序。我们希望找到新的转录 因素，并研究其DNA可及性后TP 53/RB 1删除整个谱系可塑性的演变， 并且不使用鲁索利替尼和/或埃达非替尼。在具体目标3中，在体内研究的概念验证中，我们将检查 鲁索替尼加埃达非替尼联合治疗逆转谱系可塑性和恢复 ARSI灵敏度。为此，将在NOD SCID小鼠中研究ruxolitinib+erdafitinib联合给药， 与TP 53/RB 1-无效鼠类器官原位接触，或与人类肿瘤MSK-PCA 3皮下接触。 这些研究不仅将为未来的治疗策略提供信息，以颠覆CRPC患者的耐药性， 也应该为我的培训目标提供一个独特的平台。在我的主要导师的指导下，博士。 查尔斯·索耶和我的顾问委员会，我希望提高我在高级计算方面的能力， 癌症建模和基因编辑，以及床边翻译。加上丰富的科学环境， 在MSKCC的大量资源，我的研究和培训应该定位我实现我的目标，成为 一个独立资助的泌尿生殖肿瘤学的医生调查员在此补助期结束。

PROJECT SUMMARY Despite the remarkable successes of targeted cancer therapies, certain cancers, including lung, breast, and prostate cancer and melanoma, invariably become resistant to therapy. One mechanism of secondary resistance—lineage plasticity—arises when cells transition into aggressive states, and, in the case of prostate cancer, acquire a neuroendocrine histology. This results in a rapid downhill course for a subset of the so–termed castrate–resistant prostate cancer (CRPC) patients. This, in essence, not only poses a clinical challenge, but also confronts us with a wide–open biological question—what are the molecular underpinnings of lineage plasticity, and importantly, can the process be reversed? We have very recently documented that the activation of JAK/STAT and FGFR signaling pathways promote lineage plasticity and result in complete insensitivity to androgen receptor signaling inhibitors (ARSIs) [*Chan, *Zaidi, et al., Science, 2022, PMID: 35981096, *co– first authors]. Importantly, we found that FDA–approved inhibitors of JAK/STAT (ruxolitinib) and FGFR (erdafitinib) synergize to reverse lineage plasticity and restore ARSI sensitivity. We therefore hypothesize that signals downstream of JAK/STAT and FGFR, including novel transcription factors, interact to promote lineage plasticity, and their timed perturbation can reverse plasticity and ARSI insensitivity. Thus, in Specific Aim 1, to study how FGFR signals synergize with JAK/STAT to impart plasticity, we will use chemical inhibitors and CRISPR–Cas9 to delete specific molecules in TP53/RB1–null mouse and human tumor organoids. Specific Aim 2 will focus on further deconvoluting the molecular complexity of lineage plasticity through unbiased single cell paired RNA and ATAC (multiome) sequencing in murine organoids. We expect to identify novel transcription factors and study their DNA accessibility post–TP53/RB1 deletion across the evolution of lineage plasticity, with and without ruxolitinib and/or erdafitinib. In Specific Aim 3, in proof–of–concept in vivo studies, we will examine the efficacy of combined treatment with ruxolitinib plus erdafitinib in reversing lineage plasticity and restoring ARSI sensitivity. For this, the ruxolitinib+erdafitinib combination will be studied in NOD SCID mice grafted either with TP53/RB1–null murine organoids, orthotopically, or with the human tumoroid MSK–PCA3, subcutaneously. These studies will not only inform future therapeutic strategies to subvert drug resistance in CRPC patients but should also provide a unique platform for my Training Aims. Under the tutelage of my primary mentor, Dr. Charles Sawyers, and my Advisory Committee, I expect to enhance my competencies in advanced computation, cancer modeling and genetic editing, and bedside translation. Together with the rich scientific environment and vast array of resources at MSKCC, my research and training should position me to achieve my goal of becoming an independently funded physician–investigator in genitourinary oncology by the end of this grant period.