New models and therapeutic approaches in alveolar rhabdomyosarcoma

项目概要（30行） 腺泡状横纹肌肉瘤（ARMS）是一种常见的侵袭性肌肉癌， 每年在美国的孩子。ARMS与致癌性染色体易位有关 PAX基因和叉头转录因子（FOXO 1）之间的关系。然而，PAX 3/7- FOXO 1转录因子调节肿瘤细胞的起源，以及肿瘤细胞中出现的治疗脆弱性。 ARMS细胞仍然不清楚，主要是由于缺乏精确的动物模型，准确地概括了相同的 在人类ARMS中发现的易位融合事件。我们工作的长期目标是从治疗上揭示 推动ARMS增长的相关途径。本申请的总体目标是开发斑马鱼 ARMS的模型，以确定可以在临床上利用的治疗漏洞。我们的核心假设是 PAX 3-FOXO 1 + ARMS中更差的生存结果反映在细胞来源的差异， 分子定义的肿瘤增殖细胞（TPC）的数量和转移倾向。可行性 我们的方法得到了我们使用斑马鱼来模拟各种人类癌症的工作的支持， 优化Crispr/CAS9方法，使用CRE/Lox创建患者特异性易位，以及我们的 成功的高内涵成像筛选方法，以确定FDA批准的药物， 其他RMS亚型的生长。我们研究的基本原理是很少有好的实验动物 精确模拟人类ARMS潜在遗传学的模型，排除了我们定义如何 特定的致癌融合驱动癌症生长。这项工作是有意义的，因为它将揭示不同的 解释PAX 3/7-FOXO 1 + ARMS临床表现差异的细胞机制， 确定治疗ARMS的新疗法，并为易位+癌症提供新的建模方法， PA-16-251中概述的明确目标得到了癌症登月计划的支持。目标1将描述 PAX 3/7-FOXO 1诱导的ARMS的差异，使用创新的斑马鱼模型，测试我们的假设， 融合+ ARMS在增殖和细胞来源方面具有固有差异。目标2将评估PAX 3/7-FRKH 对于调节转移和肿瘤增殖潜力的不同作用，检验我们的假设， PAX 3-FOXO 1 + ARMS在临床上表现更差，因为它们具有升高的TPC数量和转移能力。 Aim 3将使用创新的高内容成像屏幕来识别FDA批准的杀死TPC的药物， 抑制人类手臂的生长。关于结果，我们的研究将发展急需的精确性， ARMS的动物模型，并确定PAX 3/7-FOXO 1 + ARMS的关键差异，包括 来源细胞、TPC和转移能力，解释了PAX 3-FOXO 1 + ARMS为什么表现更差 临床上我们的工作还将确定新的疗法来杀死人类患者来源的异种移植物（PDX）中的TPC。 这项工作预计将通过证明以下药物的临床前疗效产生积极的转化影响： 靶向人类ARMS中的TPC，并确定治疗这种毁灭性癌症的新疗法。

PROJECT SUMMARY (30 lines) Alveolar rhabdomyosarcoma (ARMS) is a common and aggressive muscle cancer that affects hundreds of children annually in the United States. ARMS are pathognomonic with oncogenic chromosomal translocations between the PAX genes and the fork-head transcription factor (FOXO1). Yet, the pathways that the PAX3/7- FOXO1 transcription factors modulate, the tumor cells of origin, and the therapeutic vulnerabilities that arise in ARMS cells is still unclear, largely due to lack of precision animal models that accurately recapitulate the same translocation fusion events found in human ARMS. The long-term goal of our work is to uncover therapeutically relevant pathways that drive ARMS growth. The overall objective of this application is to develop zebrafish models of ARMS to identify therapeutic vulnerabilities that can be exploited clinically. Our central hypothesis is that worse survival outcomes in PAX3-FOXO1+ ARMS are reflected in differences in cells of origin, elevated numbers of molecular defined tumor-propagating cells (TPCs), and predisposition to metastasis. The feasibility of our approach is supported by our work in using zebrafish to model a wide range of human cancers, recent optimization of Crispr/CAS9 approaches to create patient-specific translocations using CRE/Lox, and our successful high-content imaging screening approach to identify FDA approved drugs with efficacy in curbing growth of other RMS subtypes. The rationale for our research is that there are few good experimental animal models that accurately mimic the underlying genetics of human ARMS, obviating our ability to define how specific oncogenic fusions drive cancer growth. This work is significant because it will uncover divergent cellular mechanisms that account for differences in the clinical manifestation of PAX3/7-FOXO1+ ARMS, identify new therapies to treat ARMS, and provide new modeling approaches for translocation+ cancers, all expressed goals outlined in PA-16-251 supported by the Cancer Moonshot Initiative. Aim 1 will characterize differences in PAX3/7-FOXO1-induced ARMS using innovative zebrafish models, testing our hypothesis that fusion+ ARMS have inherent differences in proliferation and cell(s)-of-origin. Aim 2 will assess PAX3/7-FRKH for differential effects on modulating metastasis and tumor propagating potential, testing our hypothesis that PAX3-FOXO1+ ARMS do worse clinically because they have elevated TPC numbers and metastatic capacity. Aim 3 will use an innovative high-content imaging screen to identify FDA-approved drugs that kill TPCs and suppress growth of human ARMS. With respect to outcomes, our research will develop much-needed precision animals models of ARMS and identify key differences in PAX3/7-FOXO1+ ARMS including likely differences in cell-of-origin, TPCs, and metastatic capacity, providing explanation of why PAX3-FOXO1+ ARMS do worse clinically. Our work will also identify novel therapies to kill TPCs in human patient derived xenografts (PDX). This work is expected to have a positive translational impact by demonstrating the pre-clinical efficacy of targeting TPCs in human ARMS and identifying new therapies for the treatment of this devastating cancer.