A novel functional genomic pipeline for target identification in sarcoma

描述（由申请人提供）：这项工作的长期目标是改善尤因肉瘤的结局，尤因肉瘤是儿童最致命的骨肿瘤。尤文肉瘤家族肿瘤（ESFT）是第二常见的骨和软组织癌症，困扰儿童，青少年和年轻人。ESFT的特征在于染色体易位，导致EWS与转录因子ETS家族成员（最常见的是FLI 1）融合。ESFT通过强化化疗，放疗和手术治疗，但超过一半的患者在诊断后五年内死于疾病，而幸存者往往遭受长期的有害影响。迫切需要开发有效且具有降低毒性的靶向疗法。不幸的是，我们仍然有一个有限的 对ESFT肿瘤发生的分子机制的理解，这极大地阻碍了改进疗法的鉴定。我们的初步数据表明，在尤文肉瘤中发生染色体获得和丢失的复发区域，这表明在这些复发区域中的协作基因的扩增或缺失促进了EWS-FLI 1的细胞转化。这些合作基因的鉴定和验证对于开发新疗法至关重要，因为靶向EWS-FLI 1本身的策略迄今尚未成功。我们以前开发了一种ESFT的斑马鱼模型，该模型概括了人类疾病的关键特征。我们现在将使用鱼模型进行高通量功能基因组测定，以验证从我们对人ESFT的高分辨率基因组分析中出现的有希望的候选EWS-FLI 1效应基因。我们将通过进行小分子筛选来进一步利用该测定，以鉴定作为EWS-FLI 1介导的细胞转化的抑制剂的先导化合物。为了实现这一目标，我们将1）通过肿瘤的高分辨率基因组分析来鉴定关键的EWS-FLI 1效应子; 2）使用EWS-FLI 1活性的斑马鱼体内模型来验证在基因组拷贝数分析中鉴定的候选ESFT效应子;和3）鉴定能够在斑马鱼模型中抑制EWS-FLI 1功能的小分子在本研究完成时，我们将证明一种新的基因组管道用于发现和功能分析易位阳性肉瘤中的协作基因的有效性。这一新的管道将利用我们在使用斑马鱼模型进行拷贝数分析和比较肿瘤学方面的综合专业知识。这种新的管道及其新方法将导致快速测试和引入新的肉瘤治疗药物，肉瘤是儿童和成人最致命的癌症之一。

DESCRIPTION (provided by applicant): The long-term goal of this work is to improve outcomes in Ewing Sarcoma, the most lethal bone tumor of children. Ewing Sarcoma Family Tumors (ESFT) are the second most common bone and soft tissue cancer afflicting children, adolescents, and young adults. ESFT are characterized by a chromosomal translocation resulting in a fusion between EWS and a member of the ETS family of transcription factors, most commonly FLI1. ESFT are treated with intensive chemotherapy, radiation, and surgery, yet more than half of patients die of disease within five years of diagnosis, while survivors often suffer long-term deleterious effects of treatment. An immediate need exists for the development of effective and targeted therapies with decreased toxicity. Unfortunately, we still have a limited understanding of the molecular mechanisms of ESFT tumorigenesis, which has greatly impeded the identification of improved therapies. Our preliminary data indicate that recurrent areas of chromosomal gain and loss occur in Ewing Sarcoma, suggesting that amplification or deletion of cooperating genes in these recurring regions facilitate cell transformation by EWS-FLI1. Identification and validation of these cooperating genes is essential for the development of new therapies, because strategies to target EWS-FLI1 itself have not to date been successful. We previously developed a zebrafish model of ESFT that recapitulates key features of the human disease. We will now use the fish model for high-throughput functional genomic assays to validate promising candidate EWS-FLI1 effector genes emerging from our high- resolution genomic analyses of human ESFT. We will further capitalize on this assay by conducting small- molecule screens to identify lead compounds that act as inhibitors of EWS-FLI1-mediated cellular transformation. To achieve this goal we will 1) identify critical EWS-FLI1 effectors though high-resolution genomic analysis of tumors; 2) use zebrafish in vivo models of EWS-FLI1 activity to validate candidate ESFT effectors identified in genomic copy number analyses; and 3) identify small molecules capable of inhibiting EWS-FLI1 function in the zebrafish model At the completion of this study, we will have demonstrated the effectiveness of a novel genomic pipeline for discovery and functional analysis of cooperating genes in translocation positive sarcomas. This novel pipeline will take advantage of our combined expertise in copy number analysis and comparative oncology using zebrafish models. This new pipeline and its novel approach will lead to the rapid testing and introduction of new therapeutic agents for sarcomas, one of the most deadly types of cancer in children and adults.