Targeting Oncogenic ALK Signaling in Neuroblastoma

描述(申请人提供)：神经母细胞瘤是一种重要的儿科癌症，因为它与儿童疾病相关的发病率和死亡率不成比例。我们最近发现，间变性淋巴瘤激酶(ALK)基因的胚系突变可以解释大多数遗传性神经母细胞瘤，激活突变也可以通过躯体获得。这个项目将扩展我们的工作，重点放在ALK是一个关键的神经母细胞瘤癌基因以及这种细胞表面激酶的激活是一个容易处理的治疗靶点这一压倒一切的假设上。我们提出了三个具体目标来验证这一假设，并将这一工作扩展到临床上的新治疗策略。首先，我们将使用一组完全注释的1500个散发性神经母细胞瘤肿瘤来表征导致ALK激活的生殖系和体细胞DNA改变(突变、扩增、易位)的全谱和频率，所有这些肿瘤都具有可用的配对的生殖系DNA，以及大量的人类神经母细胞瘤来源的细胞系。其次，我们将确定与神经母细胞瘤致癌表型相关的功能相关的ALK突变，并研究这些突变如何不同地激活下游信号通路。我们将通过强制将ALK突变体过度表达到神经脊来源的视网膜色素上皮细胞(RPE1)来确定AIM 1中确认的所有突变的恶性转化特性。为了了解恶性转化的机制，我们将调查ALK突变型和野生型细胞中激活的下游信号通路。最后，我们将确定不同ALK突变对药物抑制的不同敏感性，这项工作将为临床上开发旨在抑制ALK介导的信号转导的治疗策略提供动力。抗肿瘤疗效的临床前评估将被设计为迅速发展必要的理论基础，将该项目中的发现转移到神经母细胞瘤儿童的早期临床试验中。公共卫生相关性：神经母细胞瘤仍然是一个具有挑战性的儿童健康问题，因为我们试图治愈更多患者的努力只导致治愈率只有很小的改善，但伴随着幸存者广泛发病率的相关成本。我们的工作发现了人类神经母细胞瘤的遗传病因学，为ALK通过激活域的突变致癌激活提供了第一个证据。该项目将导致在开发合理的治疗策略方面向前迈出重要的一步，旨在抑制ALK介导的信号传递，以治疗这种经常具有破坏性的儿童癌症。

DESCRIPTION (provided by applicant): Neuroblastoma is an important pediatric cancer as it contributes disproportionately to childhood disease-related morbidity and mortality. We have recently discovered that germline mutations in the anaplastic lymphoma kinase (ALK) gene explain most hereditary neuroblastomas, and that activating mutations can also be somatically acquired. This project will extend our work focused on the overriding hypothesis that ALK is a critical neuroblastoma oncogene and that activation of this cell surface kinase is a tractable therapeutic target. We propose three Specific Aims to validate this hypothesis and extend this work towards new therapeutic strategies in the clinic. First, we will characterize the full spectrum and frequency of germline and somatic DNA alterations (mutation, amplification, translocation) leading to ALK activation using a fully annotated set of 1500 sporadic neuroblastoma tumors obtained at diagnosis, all with available matched germline DNA, and a large set of human neuroblastoma derived cell lines. Second, we will identify the functionally relevant ALK mutations that contribute to the neuroblastoma oncogenic phenotype and examine how these mutations differentially activate downstream signaling pathways. We will determine the malignant transforming properties of all mutations identified in Aim 1 by forcibly over expressing ALK mutants to neural crest-derived retinal pigment epithelial cells (RPE1). To understand the mechanism for malignant transformation, we will survey the downstream signaling pathways activated in ALK mutant and wild-type cells. Finally, we will determine the varying sensitivity of different ALK mutations to pharmacologic inhibition, work that should provide the impetus for developing therapeutic strategies aimed at inhibiting ALK-mediated signaling in the clinic. Preclinical evaluations of anti-tumor efficacy will be designed to quickly develop the rationale necessary to move discoveries in this project to early Phase clinical trials in children with neuroblastoma. PUBLIC HEALTH RELEVANCE: Neuroblastoma remains a challenging childhood health problem as our attempts to cure more patients has resulted in only very modest improvements in cure rates, but with the associated cost of extensive morbidity in survivors. Our work discovering the genetic etiology of human neuroblastoma provides the first evidence for oncogenic activation of ALK via mutation of the kinase domain. This project will result in important steps forward in developing rational therapeutic strategies aimed at inhibiting ALK- mediated signaling for this often-devastating childhood cancer.