Mouse Models to Elucidate p53 Regulatory Mechanisms

阐明 p53 调节机制的小鼠模型

• 批准号: 6881681
• 负责人: Geoffrey Myles Wahl
• 金额: $ 47.56万
• 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/6881681
• 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肿瘤抑制剂是一种转录因子，该因子在DNA损害剂，缺氧，癌基因，端粒异常和其他影响肿瘤生长和生存的疾病中激活的途径中起作用。在大多数人类肿瘤中，该途径被灭活，使肿瘤细胞能够因损害的基因组而循环，或者在诱导基因组不稳定的条件下循环。细胞培养模型引起了p53调节的优雅机制，也引起了其在体内相关性的重大争议。拟议的研究使用胚胎干细胞中的同源重组来产生假定的p53调节结构域中突变的小鼠，以研究其对正常p53表达条件下不同组织中遗传定义的天花板中p53调节和功能的影响。具体而言，提出了实验来继续对我们最近产生的小鼠进行分析，并删除了N末端推定的蛋白质相互作用结构域，据报道会影响细胞凋亡，但不影响细胞周期停滞。我们建议在C末端结构域中产生具有突变的小鼠，从而影响p53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，凋亡和衰老的影响将由激活应力（例如上述应激）确定，因为它们与肿瘤起始，进展和化学疗法反应最相关。我们还将研究自发性肿瘤发生，以及多种癌基因诱导的肿瘤性模型，以评估这些突变对p53依赖性肿瘤抑制的影响。提出的模型将在N末端调节结构域中对蛋白质 - 蛋白质相互作用的贡献进行评估，以及稳定和翻译后修饰对p53途径的转录和生物产量的重要性。这些研究对于在生理相关的条件下对不同细胞类型的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靶向的疗法具有相关性，并且为转录因子如何将复杂输入转化为不同的调节决策提供了范式。