RAD51 paralog function in cancer predisposition and genome integrity

项目摘要/摘要： DNA损伤的准确修复对遗传稳定性和防止衰老相关的退化至关重要 和癌症。我们正在努力确定调控DNA双链断裂准确修复的关键因素 (DSB)通过无错误的同源重组(HR)途径。引起DSB的原因有很多 包括内源性复制叉损伤、外源性环境毒物或氧化应激 由内源性来源诱导，以及在对毒物损伤的促炎反应期间。我们发现， RAD51对促进HR至关重要，因此对抑制容易出错的修复机制也是至关重要的。完毕 300项研究将人类RAD51基因突变与癌症以及患有乳腺癌或卵巢癌的女性联系起来 现在正在筛查RAD51副对数突变。然而，在很大程度上仍不清楚哪种RAD51并行 突变是致病的，以及这些突变如何使个体对环境诱导的DNA敏感 由于我们缺乏对野生型或突变蛋白的功能分析而造成的损害。我们不知道如何 这些蛋白质是被招募的，它们的功能成分，或者由突变或 RAD51等位基因的多态性。这种知识鸿沟是由于内源信息丰度低造成的。 RAD51类蛋白、重组蛋白的不溶性以及基因敲除中的胚胎致死性 老鼠。因此，我们正在使用遗传、生化和细胞生物学方法来表征RAD51 在接触DSB诱导剂时，PARALLOG功能。我们将使用电离辐射(IR)和博莱霉素作为 环境相关DSB诱导剂的模型代理。使用补充性方法 与高通量基因筛查相结合，我们现在正准备独特地解决RAD51如何 Paralog突变使个体更容易患上人类癌症，从而确定确定 世卫组织在接触环境致癌物时有患癌症的风险。我们的最终目标是 能够为肿瘤携带RAD51的个体患者开发精确的医学策略 Paralog突变特征。

Project Summary/Abstract: Accurate repair of DNA damage is critical for genetic stability, and for preventing aging-related degeneration and cancer. We are working to identify key factors that regulate accurate repair of DNA double-strand breaks (DSBs) through the error-free homologous recombination (HR) pathway. DSBs can arise from many sources including endogenous replication fork damage, exogenous environmental toxicants, or oxidative stresses induced by endogenous sources and during pro-inflammatory responses to toxicant injury. We found that the RAD51 paralogs are critical for promoting HR and hence for suppressing error-prone repair mechanisms. Over 300 studies link mutations in human RAD51 paralogs with cancer, and women with breast or ovarian cancer are now screened for RAD51 paralog mutations. However, it remains largely unknown which RAD51 paralog mutations are pathogenic and how these mutations sensitize individuals to environmentally induced-DNA damage due to our lack of functional analysis of either the wild-type or mutated proteins. We do not know how these proteins are recruited, their functional components, or the disruptions caused by mutations or polymorphisms in the RAD51 paralogs. This knowledge gap results from low abundance of endogenous RAD51 paralog proteins, insolubility of the recombinant proteins, as well as embryonic lethality in knock-out mice. We are therefore using genetic, biochemical, and cell biological approaches to characterize RAD51 paralog function upon exposure to DSB inducing agents. We will use ionizing radiation (IR) and bleomycin as model agents for environmentally relevant DSB-inducing agents. Using complementary approaches in combination with high-throughput genetic screening, we are now uniquely poised to address how RAD51 paralog mutations predispose individuals to human cancer and thus, to identify opportunities for determining who is at risk for cancer development upon exposure to environmental carcinogens. Our ultimate goal is to enable development of precision medicine strategies for individual patients whose tumors harbor a RAD51 paralog mutation profile.