Cross-links At Abasic Sites in Duplex DNA

双链 DNA 中无碱基位点的交联

• 批准号: 8372731
• 负责人: Kent S Gates
• 金额: $ 33.04万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8372731
• 关键词: Adenine; Aging; Alkylating Agents; Antineoplastic Agents; Biological; Biology; Bypass; Cancer Etiology; Cell Death; Cells; Chemical Structure; Chemicals; Chemistry; DNA; DNA Damage; DNA Repair; DNA crosslink; DNA lesion; Defect; Diagnosis; Employee Strikes; Etiology; Family; Functional disorder; Genetic; Genetic Code; Genetic Polymorphism; Genetic Transcription; Genomics; Guanine; Hot Spot; Human; Human Cell Line; In Vitro; Individual; Lead; Left; Lesion; Letters; Malignant Neoplasms; Measures; Methodology; Methods; Molecular; Mutagenesis; Mutation; Nature; Pesticides; Physiological; Process; Reaction; Risk Assessment; Scheme; Shuttle Vectors; Site; Structure; Toxin; Work; anticancer research; cancer cell; carcinogenesis; crosslink; cytotoxic; cytotoxicity; environmental toxicology; novel; nucleobase; prevent; repaired; response; senescence

DESCRIPTION (provided by applicant): Cross-links From Abasic Sites in Duplex DNA. A significant ongoing endeavor in cancer research and environmental toxicology involves the identification of important DNA-damage lesions and characterization of their ability to induce cell death or cancer-causing mutations. The proposed work will characterize a novel family of DNA lesions that are derived from apurinic/abasic (AP) sites in duplex DNA. AP sites are generated by a wide variety of processes and may be the most common type of damage sustained by cellular DNA. This proposal builds upon our recent observations that AP sites can generate interstrand DNA-DNA cross-links via reactions with nucleobases on the opposing strand of the double helix. It is striking that AP sites can generate interstrand cross-links, which generally ar thought to be the most deleterious of all DNA lesions. Cross-links present an exceptional challenge to the DNA-repair machinery in human cells. The repair of cross-links may be error- prone and the resulting mutations in the genetic code could contribute to the etiology of both spontaneous and chemical-induced cancers. Left unrepaired, cross-links may block DNA transcription and replication. The exact nature of the cellular response(s) to these cross-links may be influenced by an individual's genetic makeup, especially with regard to defects or polymorphisms in their DNA damage response and repair machinery. The proposed work is significant because it will characterize how cross-links contribute to the propensity for endogenous or chemically-induced abasic sites to cause mutagenesis, cancer, cell dysfunction, senescence, and aging in humans. Our studies represent the first efforts to characterize the formation and biological consequences of these recently discovered DNA lesions. The proposed work will: (Aims 1 and 2) characterize the formation and chemical structures of two different AP-derived cross-links in duplex DNA, (Aim 3) use mass spectrometric methods to quantitatively measure the formation and repair of AP-derived cross-links in human cells exposed to agents that induce AP sites, including radiolysis and clinically-used alkylating agents and, (Aim 4) assess transcriptional bypass, replication, and repair of the dG-AP cross- link in human cells using a shuttle-vector methodology. PUBLIC HEALTH RELEVANCE: - Cross-links From Abasic Sites in Duplex DNA Abasic sites are generated by the loss of a nucleobase "letter" from the genetic code in cellular DNA. DNA abasic sites occur spontaneously in cells and also can be induced by a variety of natural toxins, industrial chemicals, pesticides, and anticancer drugs. The proposed work will examine the occurrence and repair of a novel family of interstrand DNA cross-links derived from abasic sites in duplex DNA. Cross-links present an exceptional challenge to cells because they prevent separation of the two strands of the double helix. The repair of the abasic-site-derived cross-links may be error prone and the resulting mutations in the genetic code could contribute to the etiology of both spontaneous and chemical-induced cancers. Left unrepaired, these cross-links may block DNA transcription and replication, leading to cell dysfunction, cell death, senescence, and aging. The exact nature of the cellular response(s) to these cross-links may be influenced by an individual's genetic makeup, especially with regard to defects or polymorphisms in their DNA damage response and repair machinery. This work is significant because it will characterize how AP-derived cross-links contribute to the propensity for a very common DNA lesion (the abasic site) to cause mutagenesis, cancer, cell dysfunction, senescence, and aging in humans.

描述（由申请人提供）：双链 DNA 中无碱基位点的交联。 癌症研究和环境毒理学领域正在进行的一项重大工作涉及识别重要的 DNA 损伤病变并表征其诱导细胞的能力 死亡或致癌突变。拟议的工作将描述源自双链 DNA 中的无嘌呤/无碱基 (AP) 位点的新型 DNA 损伤家族。 AP 位点由多种过程产生，可能是细胞 DNA 遭受的最常见的损伤类型。该提议基于我们最近的观察，即 AP 位点可以通过与双螺旋相反链上的核碱基反应产生链间 DNA-DNA 交联。令人惊讶的是，AP 位点可以产生链间交联，这通常被认为是所有 DNA 损伤中最有害的。交联对人类细胞中的 DNA 修复机制提出了特殊的挑战。交联的修复可能容易出错，并且由此产生的遗传密码突变可能导致自发性癌症和化学诱导性癌症的病因学。如果不修复，交联可能会阻碍 DNA 转录和复制。细胞对这些交联反应的确切性质可能会受到个体基因组成的影响，特别是在其 DNA 损伤反应和修复机制中的缺陷或多态性方面。这项拟议的工作意义重大，因为它将描述交联如何促进内源性或化学诱导的脱碱基位点导致人类突变、癌症、细胞功能障碍、衰老和衰老的倾向。我们的研究代表了表征这些最近发现的 DNA 损伤的形成和生物学后果的首次努力。拟议的工作将：（目标 1 和 2）表征双链 DNA 中两种不同的 AP 衍生交联的形成和化学结构，（目标 3）使用质谱方法定量测量 AP 衍生交叉的形成和修复-暴露于诱导 AP 位点的药物（包括放射分解剂和临床使用的烷化剂）的人类细胞中的连接，（目标 4）评估人类细胞中 dG-AP 交联的转录旁路、复制和修复使用穿梭矢量方法。 公共健康相关性： - 双链 DNA 中无碱基位点的交联 无碱基位点是由细胞 DNA 遗传密码中的核碱基“字母”丢失而产生的。 DNA脱碱基位点在细胞中自发出现，也可由多种天然毒素、工业化学品、杀虫剂和抗癌药物诱导。拟议的工作将检查源自双链 DNA 脱碱基位点的新型链间 DNA 交联家族的发生和修复。交联对细胞提出了特殊的挑战，因为它们阻止双螺旋两条链的分离。无碱基位点衍生的交联的修复可能容易出错，并且由此产生的遗传密码突变可能导致自发性癌症和化学诱导性癌症的病因学。如果不修复，这些交联可能会阻碍 DNA 转录和复制，导致细胞功能障碍、细胞死亡、衰老和老化。细胞对这些交联反应的确切性质可能会受到个体基因组成的影响，特别是在其 DNA 损伤反应和修复机制中的缺陷或多态性方面。这项工作意义重大，因为它将描述 AP 衍生的交联如何导致一种非常常见的 DNA 损伤（脱碱基位点）在人类中引起突变、癌症、细胞功能障碍、衰老和衰老的倾向。