Role of PALB2 in the DNA Damage Response and Cancer Suppression

项目摘要/摘要 PALB2是一种肿瘤抑制蛋白，它在物理和功能上连接BRCA1和BRCA2这两个主要的 乳腺癌抑制物，在DNA损伤反应和肿瘤抑制中发挥作用。这3种蛋白质在一种 BRCA1-PALB2-BRCA2轴在基于同源重组(HR)的DNA加倍中发挥重要作用 DNA损伤后的链断裂修复(DSBR)和细胞周期检查点控制。这些功能是至关重要的 用于维持基因组的稳定性和抑制肿瘤的发生。近年来，很多事情都发生了 了解了PALB2在HR-DSBR中的作用机制，但PALB2与 BRCA2和BRCA1促进细胞周期检查点反应仍然难以捉摸，以及PALB2突变如何正常 细胞在体内存活和增殖，并进化成癌细胞，人们对此知之甚少。在这项提案中，我们将 采用最先进的体外和体内方法相结合来回答上述悬而未决的问题。在……里面 目的1，我们将利用磷酸蛋白质组学、靶向蛋白质组学和功能研究来确定关键因子和 PALB2介导的G2/M检查点调控机制在目标2中，我们将建立在我们最近发现的 核因子κB在PALB2突变小鼠中的激活，并结合使用系统敲除，条件基因敲除， 用于确定PALB2相关乳腺肿瘤发生机制的谱系追踪和器官模型 以及核因子κB在这一过程中的作用。在目标3中，我们将确定我们新生的 通过检测PALB2和BRCA1在乳腺肿瘤发生发展中的互补关系 RAD52和RNF168在各自模型中的作用。

Project Summary/Abstract PALB2 is tumor suppressor protein that physically and functionally links BRCA1 and BRCA2, the two major breast cancer suppressors, in the DNA damage response and tumor suppression. The 3 proteins function in a BRCA1-PALB2-BRCA2 axis to play essential roles in in homologous recombination (HR)-based DNA double strand break repair (DSBR) and cell cycle checkpoint control after DNA damage. These functions are critical for the maintenance of genome stability and suppressing tumorigenesis. In recent years, much has been learned about the mechanisms of PALB2 in HR-DSBR, but the mechanisms by which PALB2 functions with BRCA2 and BRCA1 to promote cell cycle checkpoint response remain elusive, and how normal PALB2 mutant cells survive and proliferate in vivo and evolve into cancer cells is poorly understood. In this proposal, we will deploy a combination of state-of-the-art in vitro and in vivo approaches to answer the above open questions. In Aim 1, we will use phosphoproteomics, targeted proteomics and functional studies to identify key factors and mechanisms of PALB2-mediated G2/M checkpoint control. In Aim 2, we will build upon our recent discovery of NFκB activation in Palb2 mutant mice and use a combination of systemic knockin, conditional knockout, lineage tracing and organoid models to define the mechanisms of PALB2-associated mammary tumorigenesis and the role of NFκB in the process. In Aim 3, we will determine the genetic mechanisms of our newly discovered complementary relationship of PALB2 and BRCA1 in mammary tumor development by testing the roles of RAD52 and RNF168 in the respective models.