Cross-links At Abasic Sites in Duplex DNA

双链 DNA 中无碱基位点的交联

• 批准号: 8867233
• 负责人: Kent S Gates
• 金额: $ 32.16万
• 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 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8867233
• 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 Code; Genetic Polymorphism; Genetic Transcription; Genomic DNA; 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; genetic makeup; 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.

描述(由申请人提供)：来自双链DNA基本站点的交叉链接。在癌症研究和环境毒理学方面正在进行的一项重大努力涉及识别重要的dna损伤损伤并表征其诱导细胞的能力。 死亡或致癌突变。这项拟议的工作将描述一类新的DNA损伤，这些损伤源于双链DNA中的无嘌呤/碱性(AP)位点。AP位点是由多种过程产生的，可能是细胞DNA遭受的最常见类型的损伤。这一建议建立在我们最近观察到的AP位点可以通过与双螺旋相反链上的核苷酸反应产生链间DNA-DNA交联链的基础上。令人惊讶的是，AP位点可以产生链间交叉链接，这通常被认为是所有DNA损伤中最有害的。交联链对人类细胞中的DNA修复机制提出了特殊的挑战。交联链的修复可能容易出错，由此产生的遗传密码突变可能会导致自发性癌症和化学诱导癌症的病因。如果不加以修复，交叉链接可能会阻止DNA转录和复制。细胞对这些交叉连接的反应(S)的确切性质可能会受到个人基因构成的影响，特别是关于他们的DNA损伤反应和修复机制中的缺陷或多态。这项拟议的工作意义重大，因为它将表征交叉链接如何有助于内源性或化学诱导的基本位点在人类中导致突变、癌症、细胞功能障碍、衰老和衰老的倾向。我们的研究是描述这些最近发现的DNA损伤的形成和生物学后果的第一次努力。拟议的工作将：(目标1和2)表征双链DNA中两种不同AP来源的交联链的形成和化学结构，(目标3)使用质谱学方法定量测量在暴露于诱导AP位点的药物(包括辐射和临床使用的烷化剂)的人类细胞中AP来源的交联链的形成和修复，以及(目标4)使用穿梭载体方法评估人类细胞中DG-AP交联链的转录旁路、复制和修复。