Using Zebrafish to Identify and Analyze Cancer Genes

描述（由申请人提供）：斑马鱼正在成为一种越来越有吸引力的癌症模型，因为几种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。一个插入诱变筛选，以确定所需的基因胚胎发育的斑马鱼已经导致了数百个突变的集合，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，其突变使鱼极易发生一种罕见的肿瘤类型，恶性外周神经鞘瘤。这些基因之一是哺乳动物肿瘤抑制神经纤维瘤病2型（NF 2）的斑马鱼直系同源基因，其突变也可导致神经元起源的肿瘤的发展。令人惊讶的是，其他17个基因都编码核糖体蛋白（RP），分子研究表明，RP基因作为单倍不足的肿瘤抑制基因的功能。对rp突变体的初步分析以及哺乳动物rp的已知作用，提出了两种可能的模型来解释rp的肿瘤抑制功能，即翻译能力和/或p53信号传导的缺陷。该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杂合突变体的翻译性质与其肿瘤抑制活性之间的关系。最后，斑马鱼突变体的面板，并在哺乳动物细胞中的平行分析，将用于建立如何RP有助于调节p53，并确定该途径对肿瘤发生过程的影响。

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.