Investigating DNA double-strand break repair mechanisms in mammalian cells

研究哺乳动物细胞中 DNA 双链断裂修复机制

基本信息

批准号：
10810445
负责人：
Xiaohua Wu
金额：
$ 1.36万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-01 至 2026-01-31
项目状态：
未结题

项目摘要

Principal Investigator: Wu, Xiaohua Project Summary Gross chromosomal rearrangement (GCR) is a hallmark of cancer cells and the cause of structural variant formation in genetic disorders. DNA double-strand breaks (DSBs) are a major source to induce GCR, but the details on how the DSB repair process leads to genome instability in cancers and other genetic disorders remains elusive. Microhomologies are prevalent at chromosomal break junctions in cancer and other human diseases, suggesting that microhomology-mediated end joining (MMEJ) is one major player to mediate GCRs. Repetitive sequences are abundant, constituting about half of the human genome, which raises the question of how recombination between repetitive sequences is suppressed to prevent genome instability. In this proposal, we aim to investigate the mechanisms underlying MMEJ and repeat-mediated recombination in mammalian cells. We have established multiple EGFP-based DSB repair reporter systems, which enable us to study different DSB repair pathways in mammalian cells. By using newly established MMEJ reporters, we identified new players in the MMEJ pathway. We will investigate how these MMEJ players regulate MMEJ to balance its usage and its mutagenic consequences. We will also study the biological role of MMEJ in repairing replication- associated DSBs and in coping with replication and oncogenic stress, and address how MMEJ contributes to genome instability and the oncogenic process. Additionally, we will determine the mechanisms of repeat-mediated recombination in causing deletions and translocations, and study the role of heteroduplex rejection in preventing recombination among divergent repeats. These studies will generate much-needed new knowledge to fill the gap in our understanding of DSB repair mechanisms and the cause of genome instability that is associated with the oncogenic process and other genetic disorders.

首席研究员：吴晓华项目概要染色体总重排（GCR）是癌细胞的一个标志，遗传性疾病中结构变异形成的原因。 DNA 双链断裂 (DSB) 是诱发 GCR 的主要来源，但 DSB 修复过程如何导致的详细信息癌症和其他遗传性疾病中的基因组不稳定性仍然难以捉摸。微同源性在癌症和其他疾病的染色体断裂连接处普遍存在人类疾病，表明微同源介导的末端连接（MMEJ）是一种主要的疾病玩家调解 GCR。重复序列非常丰富，约占序列的一半人类基因组，这提出了重复基因之间如何重组的问题序列被抑制以防止基因组不稳定。在本提案中，我们的目标是研究 MMEJ 和重复介导的重组的潜在机制哺乳动物细胞。我们建立了多个基于EGFP的DSB修复报告系统，使我们能够研究哺乳动物细胞中不同的 DSB 修复途径。通过使用新建立 MMEJ 记者后，我们确定了 MMEJ 途径中的新参与者。我们将研究这些 MMEJ 参与者如何调节 MMEJ 以平衡其使用和诱变结果。我们还将研究 MMEJ 在修复复制中的生物学作用—— 相关的 DSB 并应对复制和致癌应激，并解决如何 MMEJ 导致基因组不稳定和致癌过程。此外，我们将确定重复介导的重组导致缺失的机制易位，并研究异源双链体排斥在防止重组中的作用在不同的重复之间。这些研究将产生急需的新知识来填补我们对 DSB 修复机制和基因组原因的理解存在差距与致癌过程和其他遗传性疾病相关的不稳定性。