Using Zebrafish to Identify and Analyze Cancer Genes

描述(申请人提供)：斑马鱼正在成为一个越来越有吸引力的癌症模型，因为几个癌基因和肿瘤抑制基因似乎在鱼类中具有与哺乳动物相似的特性。为了确定斑马鱼胚胎发育所需的基因，插入突变筛选已经导致了数百个突变的集合，这些突变的基因已经被确定。到目前为止，我们已经确定了18个基因，这些基因的突变使这种鱼非常容易患上一种罕见的肿瘤类型--恶性周围神经鞘瘤。其中一个基因是哺乳动物肿瘤抑制因子神经纤维瘤病2型(NF2)的斑马鱼同源基因，该基因的突变也可能导致神经源性肿瘤的发展。令人惊讶的是，其他17个基因都编码核糖体蛋白(RPS)，分子研究表明RP基因作为单倍体缺陷的肿瘤抑制基因发挥作用。对RP突变体的初步分析，以及哺乳动物RPS的已知作用，提出了两种可能的模型来解释RPS的肿瘤抑制功能，翻译能力缺陷和/或P53信号转导。提案中的实验将测试这些模型。首先，斑马鱼将被用来更好地了解RP杂合突变如何促进肿瘤的发展。其次，将建立RP杂合突变体的翻译特性与其肿瘤抑制活性之间的关系。最后，斑马鱼突变体小组和哺乳动物细胞中的平行分析将被用来确定RPS如何对P53的调节做出贡献，并确定这一途径对肿瘤形成过程的影响。

DESCRIPTION (provided by applicant): The zebrafish is becoming an increasingly attractive cancer model as several oncogenes and tumor suppressor genes appear to have similar properties in fish as they do in mammals. An insertional mutagenesis screen to identify genes required for embryonic development in the zebrafish has led to a collection of hundreds of mutations for which the mutated genes have been identified. To date we have identified 18 genes whose mutation renders the fish highly susceptible to the development of an otherwise rare tumor type, malignant peripheral nerve sheath tumor. One of these genes is a zebrafish ortholog of the mammalian tumor suppressor neurofibromatosis type 2 (NF2), whose mutation can also lead to the development of tumors of neuronal origin. Surprisingly, the other 17 genes all encode ribosomal proteins (RPs), and molecular studies indicate that the rp genes function as haploinsufficient tumor suppressor genes. Preliminary analysis of the rp mutants, and also the known roles of the mammalian RPs, suggests two possible models to account for the rps' tumor suppressor function, defects in translational capacity and/or p53 signaling. Experiments in the proposal will test these models. First, zebrafish will be employed to better understand how the rp heterozygous mutations contribute to the development of tumors. Second, the relationship between the translation properties of the rp heterozygous mutants and their tumor suppressive activity will be established. Finally, the panel of zebrafish mutants, and parallel analysis in mammalian cells, will be used to establish how the RPs contribute to the regulation of p53 and, to determine the impact of this pathway on the tumorigenic process.