TEL-AML1 Transgenic Zebrafish Model of Human Leukemia

描述（由申请人提供）：近期目标：建立TEL-AML 1转基因斑马鱼模型，并研究加重白血病发展的次级遗传事件。职业发展目标：在白血病研究中发展独立的职业生涯。研究项目：t（12;染色体易位，产生TEL-AML 1融合基因，是儿童癌症中最常见的结构遗传异常，并且仅与前体B细胞急性淋巴细胞白血病（ALL）相关。有证据表明，TEL-AML 1易位通常发生在胎儿造血过程中的子宫内，并构成了白血病发展所必需但不充分的起始或首发突变。 该提案的目的是确定TEL-AML 1诱导的白血病发展所需的次级遗传事件。本研究旨在验证TEL-AML 1融合蛋白需要次级遗传事件才能诱导白血病转化的中心假设，具体目标有两个：1）获得稳定表达TEL-AML 1融合蛋白的转基因斑马鱼品系，并评价转基因表达对斑马鱼造血和白血病发生的影响; 2）通过研究正常斑马鱼TEL的表达和组蛋白乙酰转移酶活性的改变，在TEL-AML 1转基因斑马鱼中开发“二次打击”模型，两者都涉及TEL-AML 1白血病的发展，并且平行地，通过在转基因斑马鱼中启动逆转录病毒插入诱变筛选，旨在鉴定在ALL发展中与TEL-AML 1融合蛋白协同作用的癌症基因。可用于实现这些目标的资源包括我们建立的TEL-AML 1转基因创始人及其后代，组蛋白乙酰转移酶的斑马鱼突变体，以及表达斑马鱼特异性报告基因的逆转录病毒。 斑马鱼系统是唯一适合于这些实验，因为它提出了一种脊椎动物模型，具有多功能的生物学，遗传灵活性，保守的造血发育，并有机会进行转基因和随后的诱变。进行大规模表型驱动的突变筛选以鉴定在染色体融合蛋白存在下加速白血病发展的协同事件的能力代表了该模型的独特优势。在这些研究中，白血病通路中关键基因的鉴定可能为白血病特异性治疗确定新的靶点。 虽然这个应用程序是一个K22职业发展奖，没有一个机构的隶属关系，我相信，有一个博士后奖学金在国家癌症研究所三年准备我发展一个独立的癌症研究生涯，而这个应用程序的良好反应将大大促进这一过渡。我的长期目标是确定与儿童白血病发展相关的遗传事件，能够进行拟议的研究是实现这一重要目标的一步。

DESCRIPTION (provided by applicant): Immediate Goal: To generate TEL-AML1 transgenic zebrafish model and investigate the secondary genetic events that accentuate leukemia development. Career Development Goal: To develop an independent career in leukemia research. Research Project: The t(12;21) chromosomal translocation, which generates the TEL-AML1 fusion gene, is the most frequent structural genetic abnormality in childhood cancer, and is exclusively associated with precursor B-cell acute lymphoblastic leukemia (ALL). Evidence suggests that the TEL-AML1 translocation usually occurs In Utero during fetal hematopoiesis and constitutes an initiating or first-hit mutation that is necessary but insufficient for leukemia development. The aim of this proposal is to identify the secondary genetic events required for the development of TEL-AML1-induced leukemia. The two specific aims designed to test the central hypothesis that TEL-AML1 fusion protein requires secondary genetic events to induce leukemic transformation are: 1) To generate stable transgenic zebrafish lines expressing the TEL-AML1 fusion protein, and evaluate the effects of transgene expression on zebrafish hematopoiesis and leukemic development; 2) To develop a "second-hit" model in TEL-AML1 transgenic zebrafish by investigating the altered expression of the normal zebrafish TEL and histone acetyltransferase activity, both implicated in TEL-AML1 leukemic development, and in parallel, by initiating a retroviral insertional mutagenesis screen in transgenic zebrafish aimed at identifying cancer genes that synergize with the TEL-AML1 fusion protein in ALL development. Resources available to carry out these aims include our established TEL-AML1 transgenic founders and their progeny, a zebrafish mutant for histone acetyltransferase, and a retrovirus expressing zebrafish-specific reporter gene. The zebrafish system is uniquely suitable for these experiments in that it presents a vertebrate model with a versatile biology, genetic flexibility, conserved hematopoietic development, and the opportunity to conduct transgenesis and subsequent mutagenesis. The ability to perform a large-scale phenotype-driven mutational screen to identify cooperating events that accelerate leukemic development in the presence of chromosomal fusion proteins represents the unique advantage of this model. The identification of crucial genes in the leukemic pathway in these studies may identify novel targets for leukemia specific therapies. Although this application is for a K22 career development award, without an institutional affiliation, I believe that having a postdoctoral fellowship at the National Cancer Institute for three years prepared me to develop an independent cancer research career, and that the favorable response to this application would significantly facilitate this transition. My long-term goal is to identify the genetic events associated with the development of leukemia in children, and the ability to perform the proposed studies is one step towards this vital goal.