Proj 1 - Targeting Evolving Therapy Resistance

摘要/摘要 神经母细胞瘤(NB)仍然是儿童癌症死亡的主要原因，存活下来的儿童是 留下了长期的副作用，其中许多可能危及生命。在这个治疗更加精确的时代， 目前正在作出相当大的努力来确定最佳目标。而分子靶向的范式 治疗方法大有可为，基因组研究显示，NBS的特点是广泛 肿瘤内遗传异质性，亚克隆性致癌驱动因素通常在标准时间内被选择 放化疗。我们的团队在ALK受体酪氨酸激酶中发现了功能获得突变 家族性NB的病因学，同时与其他几个群体共同发现相同的突变 作为最常见的体细胞单核苷酸变异，导致高达15%的 新诊断的高危病例。我们最近的工作表明，激活ALK-RAS中的突变- MAPK途径在复发NB基因组中高度丰富，为深层次和深层次的Nb提供了动力 这些途径中基因的亚克隆景观的综合表征 治疗的连续性。这是本项目的动力所在，并为双方提供了适应的机会 随着肿瘤的演变，治疗方法也更早地针对亚克隆突变以防止获得 耐化疗的显性克隆。这里要探索的中心假设是，高风险的国家广播公司 其特点是广泛的肿瘤内和间质来源的不均质性，以及先前存在和 获得的亚克隆群体，赋予治疗抗性，可以通过理性选择来利用 目标特工。我们将在三个具体目标中测试我们的中心假设：1)定义频率和临床 亚克隆驱动基因突变的意义；2)确定抑制基因突变所带来的治疗脆弱性 致癌的ALK和/或Ras-MAPK信号；3)靶肿瘤细胞内在和外源性致癌 理性新疗法发展的脆弱性。第一个目标将采用定制的超深 测序平台用于定义诊断和诊断中的克隆和亚克隆体系结构和突变景观 故态复萌的NBS，包括PDX型号。目标2致力于定义可用于治疗的致癌基因 漏洞，重点展示抑制FAK导致ALK中强大的抗肿瘤活性- RAS驱动的NBS用这些通路的抑制剂治疗。最终目标将获得临床前 将联合疗法转移到临床所需的理由，建立在我们广泛的初步数据基础上 我们的致癌基因驱动模型中的药物协同作用。我们认为这个项目意义重大，因为它将 导致新的基于机制的生物标志物定义的治疗策略，最终应该显著 改善高危NB患者的预后。这将解决尽管史无前例的主要未得到满足的需求 在定义NB肿瘤发生的基本机制方面的发现，这一知识尚未转化为 显著改善了高危疾病患者的预后。

SUMMARY/ABSTRACT Neuroblastoma (NB) remains a leading cause of childhood cancer deaths, and the children who do survive are left with long-term side effects, many of which can be life threatening. In this era of more precise therapies, considerable efforts are being made to identify optimal targets. While the paradigm of molecularly targeted therapies holds great promise, genomic studies have revealed that NBs are characterized by extensive intratumor genetic heterogeneity, with subclonal oncogenic drivers often selected for during standard chemoradiotherapy. Our group discovered gain-of-function mutations in the ALK receptor tyrosine kinase as the etiology for familial NB, and at the same time co-discovered with several other groups identical mutations as the most frequent somatic single nucleotide variants leading to a potent oncogenic driver in up to 15% of newly diagnosed high-risk cases. Our more recent work has shown that activating mutations in the ALK-RAS- MAPK pathway are highly enriched in the relapse NB genome, providing the impetus for deep and comprehensive characterization of the subclonal landscape of genes within these pathways across the continuum of therapy. This serves at the motivation for this Project and provides the opportunity to both adapt therapeutic approaches as tumors evolve, and also target subclonal mutations earlier to prevent the acquisition of chemotherapy resistant dominant clones. The central hypothesis to be explored here is that high-risk NBs are characterized by extensive intratumoral and stroma-derived heterogeneity and harbor pre-existing and acquired subclonal populations that confer therapy resistance that can exploited with rationally selected targeted agents. We will test our central hypothesis in three Specific Aims: 1) Define the frequency and clinical significance of subclonal driver mutations; 2) Identify therapeutic vulnerabilities imparted by inhibition of oncogenic ALK and/or RAS-MAPK signaling; 3) Target tumor cell intrinsic and extrinsic oncogenic vulnerabilities for development of rational novel therapeutics. The first Aim will employ a custom ultra-deep sequencing platform to define the clonal and subclonal architecture and mutational landscape in diagnostic and relapse NBs, including PDX models. Aim 2 is devoted to defining therapeutically exploitable oncogenic vulnerabilities with a focus on demonstrating that inhibition of FAK leads to robust anti-tumor activity in ALK- and RAS-driven NBs treated with inhibitors of these pathways. The final Aim will garner the preclinical justification required to move combination therapies to the clinic, building on our extensive preliminary data of synergistic drug interactions in our oncogene-driven models. We consider this project significant because it will result in new mechanism-based biomarker-defined therapeutic strategies that ultimately should significantly improve high-risk NB patient outcomes. This will address the major unmet need that despite unprecedented discoveries in defining the basic mechanisms of NB tumorigenesis, this knowledge has not yet translated into significantly improved outcomes for patients with high-risk disease.