Understanding and Targeting the DNA Repair Network in Cancer

描述(申请人提供)：基因组不稳定是癌细胞的特征。同源重组(HR)介导的DNA修复代表了一种无错误的修复机制，以保持基因组的完整性并确保遗传信息的高保真传递。我的长期目标是建立一个成功和可持续的独立研究项目，在使用基因组和蛋白质组方法研究HR修复方面具有核心竞争力。在我的独立职业生涯中，我希望从事(1)了解HR介导的DNA修复及其在肿瘤发生中的功能障碍的基础研究，以及(2)基于机制的翻译研究，将HR修复的根本性突破转化为癌症预防、诊断、预后和治疗的临床应用。 我提出的研究的总体目标是了解人Ago2在HR修复和基因组维护中的新核功能。这项研究将为我的独立研究生涯奠定基础。根据我的初步数据，我假设在DNA损伤反应的背景下，通过翻译后修饰的微调调节机制，潜在地通过ATM/ATR激酶依赖的磷酸化，人核Ago2通过蛋白质-蛋白质相互作用在损伤部位招募DNA修复蛋白来调节双链断裂的HR修复。我将通过一个机制和功能研究相结合的综合平台，通过追求三个具体目标来验证这一假设：(1)确定Ago2作为一种新的调节因子在HR修复中的功能。(2)研究HR修复过程中DNA损伤对Ago2翻译后修饰的影响。(3)确定Ago2在防止基因组不稳定性和肿瘤发生中的核功能。这项拟议的研究意义重大，因为它挑战了目前的研究范式，即人类Ago2主要在细胞质中发挥作用。本研究将阐明两种进化上保守的基因组防御机制，即小调节RNA通路和DNA损伤反应通路，如何通过Ago2蛋白的功能参与在HR修复过程中汇聚到DNA损伤处。 公共卫生相关性：拟议中的Ago2在HR修复中的研究将拓宽我们对这一复杂过程的了解，并提高我们对HR修复功能障碍如何促进肿瘤发生的理解。阐明Ago2在HR修复和肿瘤发生中的作用也可能为扩大PARP抑制剂在BRCA1/BRCA2缺陷的肿瘤中的应用提供分子基础。

DESCRIPTION (provided by applicant): Genomic instability is a characteristic of cancer cells. Homologous recombination (HR)-mediated DNA repair represents an error-free repairing mechanism to maintain genomic integrity and ensure high-fidelity transmission of genetic information. My long-term goal is to establish a successful and sustainable independent research program with a core competency in the study of HR repair using genomic and proteomic approaches. In my independent career, I wish to pursue (1) fundamental studies to understand HR-mediated DNA repair and its dysfunction in tumorigenesis and (2) mechanism-based translational studies to translate fundamental breakthroughs in HR repair into clinical applications in cancer prevention, diagnosis, prognostication, and therapy. The overall objective of my proposed research, which will lay the foundation for my independent research career, is to understand the novel nuclear function of human Ago2, a core protein in RNA interference pathways, in HR repair and genome maintenance. Based on my preliminary data, I hypothesize that in the context of DNA damage response, via fine-tuned regulatory mechanisms by posttranslational modifications, potentially through ATM/ATR kinase-dependent phosphorylation, human nuclear Ago2 regulates HR repair of double-strand breaks by recruiting DNA repair proteins at damage sites via protein-protein interactions. I will test this hypothesis by pursuing 3 specific aims through an integrated platform that combines mechanistic and functional studies: (1) Determine the function of Ago2 as a novel regulator in HR repair. (2) Characterize posttranslational modifications of Ago2 induced by DNA damage in HR repair. (3) Determine the nuclear function of Ago2 in preventing genomic instability and tumorigenesis. The proposed research is significant because it challenges the current research paradigm that human Ago2 functions predominantly in the cytoplasm. This study will shed light on how 2 evolutionarily conserved genome defense mechanisms, the small regulatory RNA pathways and DNA damage response pathway, converge at DNA lesions in the process of HR repair via the functional involvement of Ago2 protein. PUBLIC HEALTH RELEVANCE: The proposed studies of Ago2 in HR repair will broaden our knowledge of this complex process and improve our understanding of how dysfunction of HR repair contributes to tumorigenesis. Elucidating the role of Ago2 in HR repair and tumorigenesis also may provide a molecular basis to expand the use of PARP inhibitors against tumors beyond BRCA1/BRCA2-deficient tumors.