p53对大肠癌中Numb/Notch信号通路调控的分子机制研究

项目名称： p53对大肠癌中Numb/Notch信号通路调控的分子机制研究

项目编号： No.30872470

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 王杉

作者单位： 北京大学

项目金额： 31万元

中文摘要： 我们前期研究首次发现结直肠癌中p53与Numb在体内能够相互结合，为进一步分析p53如何参与调控Numb和Notch之间相互作用关系，我们在结直肠癌组织标本中检测p53的突变情况（测序），分析其突变与Numb：Notch1的表达模式的关系；检测Numb基因启动子区甲基化状况，明确了其与结直肠癌病理性特征的关系；采用GST-pull down及CoIP技术体外明确了p53和Numb蛋白的直接相互作用及作用结构域，用基因过表达（Transfection）和RNA干扰分析p53与Numb的结合如何导致Numb 、Notch1蛋白功能的变化（稳定性、修饰等），明确了对其下游靶基因的影响以及在肿瘤细胞的增殖与凋亡过程中发挥的作用。同时我们检测了p53的翻译后修饰（泛素化 、磷酸化以及乙酰化）在Numb/Notch通路的调控中的作用机制，揭示了大肠癌p53调控Numb/Notch信号通路的分子机制，明确其不同的突变或修饰方式与Numb/Notch的相互作用的因果关系，阐明了Notch通路在结直肠癌发生发展中的作用。

中文关键词： Numb; 受体;Notch; 信号通路; p53; 结直肠肿瘤

英文摘要： The biological antagonism between Notch and Numb controls the proliferative/differentiative balance in development and homeostasis. Although deregulation of Notch is thought to play a key role in the development of several human cancers, evidence for a substantial involvement of Numb/Notch pathway in human colorectal cancer has remained elusive. As an important tumor supressor, p53 is whether involved in regulation of Numb/Notch pathway in colorectal cancer. Firstly we evaluate the correlation between the expression pattern of Numb/Notch1 and clinical outcome in a series of patients with colorectal carcinomas (CRCs) and to define the association of p53 mutation with the expression pattern of Numb and Notch1. Secondly we confirmed that Numb is able to interact with p53 in vivo and in vitro with GST-pull down and CoIP. The structural domain of two proteins interaction was identified. The interaction between two proteins whether leads to up-regulating Numb expression and further study understands p53 and its post-translation modification effect on stability of Numb protein and Notch pathway. Thirdly To establish p53-mediated Numb/Notch pathway whether correlated with colon carcinoma cells proliferation and apoptosis. This is the first study to establish p53 acts as a key regulator of Numb-Notch1 pathway in colorectal cancer to and a significant correlation of Numb/Notch1 expression with the clinicopathological parameters of colorectal cance.

英文关键词： Numb; Receptor;Notch; Signal Pathway; p53; colorectal carcinomas