Chemistry and Biology of Oxidized Purine Lesions in DNA

DNA 中氧化嘌呤损伤的化学和生物学

• 批准号: 8103243
• 负责人: Cynthia J Burrows
• 金额: $ 27.72万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-04 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8103243
• 关键词: 8-hydroxyguanosine; Address; Affect; Affinity; Aging; Allantoin; Amines; Attention; Base Excision Repairs; Binding; Biochemical; Biochemistry; Biological; Biological Assay; Biology; Catalysis; Cells; Chemical Structure; Chemicals; Chemistry; Coupled; Crystallography; DNA; DNA Damage; DNA Repair; DNA Repair Enzymes; DNA lesion; DNA-Directed DNA Polymerase; Electrons; Enzymes; Excision; Exposure to; Family; Fapy-dG; Fluorescence; Goals; Guanine; Guanosine; Heart Diseases; Human Development; Hydantoins; Hydrogen Bonding; In Vitro; Infection; Inflammatory Response; Injury; Knockout Mice; Laboratories; Lead; Lesion; Liquid substance; Malignant Neoplasms; Mass Spectrum Analysis; Methods; Modification; Monitor; Mutagenesis; Mutation; Nucleosides; Nucleotide Excision Repair; Oxidants; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Peroxonitrite; Play; Procedures; Process; Proteins; Purines; Relative (related person); Research; Roentgen Rays; Role; Site; Source; Structure; Surface; Testing; Toxic Environmental Substances; Vermont; Work; adduct; aptamer; base; carcinogenesis; design; guanidinohydantoin; human DNA; in vivo; innovation; member; nervous system disorder; novel; oxidation; public health relevance; purine; repaired; spiroiminodihydantoin; stereochemistry; tumor

DESCRIPTION (provided by applicant): A causative role has been established between compromised DNA repair and the development of human cancers. DNA bases are subject to oxidative stress undergoing chemical modification of guanine and other bases as a result of endogenous oxidants, inflammatory responses to infection and injury, and exposure to redox-active environmental toxins. While much attention has been focused on G to T mutations as a result of the oxidized guanine lesion 8-oxoguanine (OG), this project investigates the hyperoxidized guanine lesions resulting from further oxidation of OG. These lesions constitute a family of highly mutagenic hydantoin structures including spiroiminodihydantoin (Sp) and guanidinohydantoin (Gh) that appear to cause G to C in addition to G to T mutations. In the present work, related members of this class of compounds will be studied to further explore the relationship between oxidation pathway, product structure, and activity with DNA processing enzymes including base excision repair and nucleotide excision repair mechanisms. The new structures to be studied include amine adducts of oxidized guanosine. Novel pathways are proposed that might explain additional observations in the mutagenic spectrum of oxidative stress, including the formation of double-stranded tandem lesions. The specific aims of this work are to: (1) resolve structural questions surrounding the formation of hydantoin lesions in duplex DNA through the use of synthetic lesion-containing oligodeoxynucleotides, mass spectrometry, and x-ray crystallography, (2) understand the roles of base excision repair vs. nucleotide excision repair for hydantoin lesions via in vitro and in vivo biochemical assays with a particular focus on the role of the Nei-like (hNEIL1) and Fpg glycosylases, and (3) develop innovative assays to detect hydantoin products in cell lysates by generating aptamers to DNA lesions coupled to fluorescent readouts. PUBLIC HEALTH RELEVANCE: Oxidative stress plays a significant role in the damaging DNA creating lesions that underlie cancer, aging, neurological and cardiac disorders. This project will help define how specific oxidized DNA bases and base adducts lead to mutations related to cancer. In addition, methods will be developed to monitor the formation and excision of these damaged bases from DNA, revealing new information about the relationship between DNA damage and cancer.

描述（由申请人提供）：已确定 DNA 修复受损与人类癌症的发生之间存在因果关系。由于内源性氧化剂、对感染和损伤的炎症反应以及暴露于具有氧化还原活性的环境毒素，DNA碱基会受到氧化应激，导致鸟嘌呤和其他碱基发生化学修饰。虽然氧化鸟嘌呤损伤 8-氧代鸟嘌呤 (OG) 导致的 G 到 T 突变受到广泛关注，但本项目研究了 OG 进一步氧化导致的超氧化鸟嘌呤损伤。这些病变构成了一系列高度诱变的乙内酰脲结构，包括螺亚氨基二乙内酰脲 (Sp) 和胍基乙内酰脲 (Gh)，除了 G 到 T 突变外，它们似乎还导致 G 到 C 突变。在本工作中，将研究此类化合物的相关成员，以进一步探讨氧化途径、产物结构和活性与DNA加工酶（包括碱基切除修复和核苷酸切除修复机制）之间的关系。待研究的新结构包括氧化鸟苷的胺加合物。提出的新途径可能可以解释氧化应激诱变谱中的其他观察结果，包括双链串联损伤的形成。这项工作的具体目标是：(1) 通过使用合成的含有损伤的寡脱氧核苷酸、质谱分析和 X 射线晶体学，解决双链 DNA 中乙内酰脲损伤形成的结构问题，(2) 了解通过体外和体内生化测定，特别关注 Nei 样 (hNEIL1) 和 Fpg 的作用，比较乙内酰脲损伤的碱基切除修复与核苷酸切除修复(3) 开发创新的检测方法，通过生成 DNA 损伤适体并结合荧光读数来检测细胞裂解物中的乙内酰脲产物。 公众健康相关性：氧化应激在 DNA 损伤、癌症、衰老、神经系统疾病和心脏病等病变中发挥着重要作用。该项目将帮助确定特定的氧化 DNA 碱基和碱基加合物如何导致与癌症相关的突变。此外，还将开发方法来监测DNA中这些受损碱基的形成和切除，揭示有关DNA损伤与癌症之间关系的新信息。