NIH resubmission Deyu Li - Etheno adductome and repair pathways

NIH 重新提交 Deyu Li - 乙烯加合组和修复途径

• 批准号: 10659931
• 负责人: Sarah Delaney
• 金额: $ 38.91万
• 依托单位: UNIVERSITY OF RHODE ISLAND
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-10 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10659931
• 关键词: Affect; Alkylation; Amino Acid Sequence; Base Excision Repairs; Carcinogens; Cells; Chromatin; Chronic; Clip; Complex; Core Protein; Data; Dealkylation; Development; Dioxygenases; Discipline; Disease; Enzymes; Epigenetic Process; Eukaryotic Cell; Excision Repair; Family; Fingerprint; Future; Genetic; Genomic Instability; Goals; Health; Histones; Human; Hydroxyl Radical; Infection; Inflammation; Inflammatory; Knowledge; Large Intestine Carcinoma; Lesion; Link; Lipid Peroxidation; Lung Adenocarcinoma; Malignant Neoplasms; Methods; Molecular; Mutation; N-terminal; Neoplastic Cell Transformation; Nucleosome Core Particle; Organism; Oxidative Stress; Pathway interactions; Pattern; Poisson Distribution; Population; Positioning Attribute; Process; Productivity; Proteins; Proteolytic Processing; Reaction; Reporting; Research; Research Project Grants; Site; Tail; Techniques; Testing; Therapeutic; United States National Institutes of Health; Universities; Variant; Vinyl Chloride; Work; adduct; alpha ketoglutarate; base; cancer risk; carcinogenesis; carcinogenicity; chronic infection; clinically relevant; cytotoxic; ds-DNA; epigenetic marker; experimental study; flexibility; genome integrity; improved; in vivo; innovation; member; next generation; novel; repair enzyme; repaired; response; translational potential; translational study

PROJECT SUMMARY Chronic inflammation and persistent infection conditions have long been associated with increased risk of cancer. Growing evidence suggests that cancer-associated inflammatory processes, such as lipid peroxidation, cause genomic instability that can be linked to the development of carcinogenesis. Reactive species from lipid peroxidation are known to damage DNA and form etheno-type adducts. Previously, four etheno DNA adducts have been reported: 1,N6-ethenoadenine (εA), 3,N4-ethenocytosine (εC), 1,N2-ethenoguanine (1,N2-εG), and N2,3-ethenoguanine (N2,3-εG). These etheno lesions are also generated by metabolites of the human carcinogen vinyl chloride. Recently, a new etheno adduct, 3,N4-etheno-5-methylcytosine (ε5mC), was identified. It bears the etheno damage on 5-methylcytosine, an important epigenetic marker in humans. Thus far, no information on the repair and mutagenicity of ε5mC has been reported. Replication of the etheno lesions is known to cause mutations and may constitute a critical step in the pathway leading to neoplastic transformation. Importantly for cells, DNA repair pathways are the guardians of genomic integrity and function to return damaged DNA to its canonical state. This research project focuses on two key repair pathways: base excision repair (BER) and direct reversal repair (DRR). Most of the experiments that give rise to our current understanding of BER and DRR were conducted using DNA oligomers. There is a fundamental gap in knowledge of how repair occurs in the context of chromatin, where eukaryotic DNA is compacted in a complex hierarchy of DNA-protein interactions. At the most fundamental level of chromatin organization, the nucleosome core particle (NCP) is the basic packaging unit that is comprised of ds-DNA wrapped around a histone protein core. The overarching goal of the proposed research is to understand how DNA sequence context and the packaging of DNA into chromatin influence repair of the etheno adductome. The central hypothesis of this proposal is that BER and DRR enzymes repair etheno lesions with different efficiencies, and these distinctive repair profiles are the result of 1) sequence context of the lesion and interactions with the enzyme and 2) modulation of repair by the protein component of chromatin, the histones. Guided by this novel hypothesis, strong preliminary data, and innovative techniques, the proposal investigates three aims that: (1) define the sequence context effects (by considering the 5’ and 3’ neighboring bases) of BER and DRR enzymes in unpackaged DNA oligomers; (2) characterize the repair profiles of the five etheno adducts in NCPs; and (3) determine the extent to which tailless and variant histone proteins provide a mechanism of modulating repair in chromatin. The proposed research is significant because it will reveal key mechanisms and critical differences that influence repair of the etheno adductome and how cells minimize the harmful consequences of these lesions. The results obtained in this work will explain in vivo observations of alkylation damage profiles and contribute to our understanding of mutational hotspots and mutational signatures. Therefore, the research has considerable translational potential to enhance our understanding of DNA repair and the results can assist in the development of future therapeutic treatments that improve cellular defenses against genomic instability.

项目摘要 慢性感染和持续感染状况长期以来一直与癌症风险增加有关。 越来越多的证据表明，与癌症相关的炎症过程（例如脂质过氧化）导致 基因组不稳定性可以与癌变发展有关。脂质的反应性物种 已知过氧化会损害DNA并形成乙诺型加合物。以前，四个Etheno DNA加合物 已经报道了：1，N6-乙烯基腺苷（εa），3，N4-乙烯基细胞苷（εc），1，N2-乙诺甲氨酸（1，N2-乙烯氧基）和 N2,3-甲氧烷（N2,3-εg）。这些埃塞那诺病变也由人致癌的代谢产生 乙烯基氯化物。最近，确定了一种新的Etheno加合物，3，N4-乙烯-5-甲基环霉素（ε5MC）。它带有 5-甲基胞嘧啶的乙诺损伤，这是人类的重要表观遗传标记。那远，没有关于 据报道，ε5MC的修复和诱变。已知埃塞那诺病变的复制会导致 突变并可能构成导致肿瘤转化的途径的关键步骤。重要的是 细胞，DNA修复途径是基因组完整性的监护人和功能，可将受损的DNA返回其 规范状态。该研究项目侧重于两个关键的维修途径：基本惊喜维修（BER）和直接 逆转维修（DRR）。引起我们当前对BER和DRR的理解的大多数实验是 使用DNA低聚物进行。关于维修如何在上下文中进行的知识存在根本的差距 染色质，其中真核DNA在DNA蛋白相互作用的复杂层次结构中被压缩。在 染色质组织的大多数基本水平，核小体核心粒子（NCP）是基本包装 围绕组蛋白核心包裹的DS-DNA完成的单元。拟议的总体目标 研究是了解DNA序列环境和将DNA包装成染色质修复的方式 Etheno addome的。该提议的中心假设是BER和DRR酶修复Etheno 具有不同效率的病变，这些独特的修复轮廓是1）序列上下文的结果 病变和与酶的相互作用和2）通过染色质的蛋白质成分调节修复， 希腊。在这个新颖的假设，强大的初步数据和创新技术的指导下，该提案 研究三个目的，即：（1）定义序列上下文效应（通过考虑5'和3'相邻 在未包装的DNA低聚物中的BER和DRR酶的碱； （2）表征五个的维修轮廓 NCPS中的Etheno加合物； （3）确定尾鼠和变体组蛋白提供的程度 调节染色质修复的机制。拟议的研究很重要，因为它将揭示关键 影响乙诺纳添加剂修复的机制和临界差异以及细胞如何最小化 这些病变的有害后果。这项工作中获得的结果将解释体内观察 烷基化损伤曲线并有助于我们对突变热点和突变特征的理解。 因此，该研究考虑了翻译潜力，以增强我们对DNA修复的理解 结果可以帮助开发未来的治疗疗法，以改善细胞防御能力 反对基因组不稳定。