Mouse Models to Elucidate p53 Regulatory Mechanisms

阐明 p53 调节机制的小鼠模型

• 批准号: 6604838
• 负责人: Geoffrey Myles Wahl
• 金额: $ 46.18万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6604838
• 关键词: aging; apoptosis; biological signal transduction; cell cycle; embryonic stem cell; gene expression; gene mutation; gene targeting; genetic models; genetic regulation; laboratory mouse; model design /development; neoplastic transformation; oncogenes; p53 gene /protein; posttranslational modifications; proline; protein protein interaction; telomere

DESCRIPTION (provided by applicant): The p53 tumor suppressor is a transcription factor functioning in a pathway activated by DNA damaging agents, hypoxia, oncogenes, telomere abnormalities and other conditions that impact on tumor growth and survival. This pathway is inactivated in most human neoplasms, enabling tumor cells to cycle with damaged genomes, or under conditions that induce genomic instability. Cell culture models elicited both elegant mechanisms of p53 regulation and significant controversy over their relevance in vivo. The proposed studies use homologous recombination in embryonic stem cells to generate mice with mutations in putative p53 regulatory domains to study their effects on p53 regulation and function in genetically defined ceils in different tissues under conditions of normal p53 expression. Specifically, experiments are proposed to continue analysis of mice we recently generated with a deletion of an N-terminal putative protein interaction domain reported to affect apoptosis but not cell cycle arrest. We propose to generate mice with mutations in a C-terminal domain that impacts on p53 stability and transcriptional regulation. The impact of these mutations on p53 stability, target gene binding, cell cycle arrest, apoptosis, and aging will be determined in response to activating stresses such as those described above as they are most relevant to tumor initiation, progression and chemotherapy response. We will also study spontaneous tumorigenesis, as well as several models of oncogene induced tumorigencity to assess the impact of these mutations on p53 dependent tumor suppression. The models proposed will enable in rive assessments of the contribution of protein-protein interactions in the N- terminal regulatory domain, and importance of stabilization and post-translational modifications on the transcriptional and biological output of the p53 pathway. These studies are essential for unambiguous conclusions about p53 regulation in different cell types under physiologically relevant conditions. The data obtained and systems developed have relevance for p53-targeted therapies, and they provide a paradigm for how transcription factors convert complex inputs into distinct regulatory decisions.

描述（由申请人提供）：p53 肿瘤抑制因子是一种转录因子，在 DNA 损伤剂、缺氧、癌基因、端粒异常和其他影响肿瘤生长和存活的条件激活的途径中发挥作用。该途径在大多数人类肿瘤中失活，使肿瘤细胞能够在基因组受损的情况下或在诱导基因组不稳定的条件下循环。细胞培养模型引发了 p53 调节的优雅机制以及其体内相关性的重大争议。拟议的研究利用胚胎干细胞中的同源重组来产生假定 p53 调控域发生突变的小鼠，以研究它们在正常 p53 表达条件下对不同组织中基因定义的细胞中 p53 调控和功能的影响。具体来说，建议进行实验来继续分析我们最近生成的小鼠，该小鼠删除了 N 端推定的蛋白质相互作用结构域，据报道该结构域会影响细胞凋亡，但不会影响细胞周期停滞。我们建议培育 C 端结构域发生突变的小鼠，这些突变会影响 p53 的稳定性和转录调控。这些突变对 p53 稳定性、靶基因结合、细胞周期停滞、细胞凋亡和衰老的影响将根据对激活应激（例如上述那些）的响应来确定，因为它们与肿瘤发生、进展和化疗反应最相关。我们还将研究自发性肿瘤发生，以及癌基因诱导的肿瘤发生的几种模型，以评估这些突变对 p53 依赖性肿瘤抑制的影响。所提出的模型将能够实时评估 N 端调控域中蛋白质-蛋白质相互作用的贡献，以及稳定和翻译后修饰对 p53 途径转录和生物输出的重要性。这些研究对于在生理相关条件下不同细胞类型中 p53 调节的明确结论至关重要。获得的数据和开发的系统与 p53 靶向疗法相关，它们为转录因子如何将复杂的输入转化为不同的监管决策提供了范例。