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）：双工DNA中无asic位点的交联。 癌症研究和环境毒理学中的一项重大努力涉及鉴定重要的DNA破坏病变，并表征其诱导细胞的能力 死亡或致癌突变。拟议的工作将表征一个新型的DNA病变家族，这些家族来自双链体DNA中的Apurinic/Abasic（AP）位点。 AP位点是由多种过程产生的，可能是细胞DNA承受的最常见损伤类型。该提议建立在我们最近的观察结果上，即AP位点可以通过与双螺旋的相对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，通常认为这是所有DNA病变中最有害的。交联对人类细胞中的DNA修复机制提出了异常挑战。交联的修复可能是错误的 - 容易发生，遗传密码中产生的突变可能导致自发和化学引起的癌症的病因。剩下的未修复的交联可能会阻止DNA转录和复制。细胞反应对这些交联的确切性质可能受个人的基因组成的影响，尤其是在其DNA损伤响应和修复机械中的缺陷或多态性方面。提出的工作很重要，因为它将表征交联如何促进内源或化学诱导的无碱性位点引起诱变，癌症，细胞功能障碍，衰老和人类衰老的倾向。我们的研究是表征这些最近发现的DNA病变的形成和生物学后果的第一批努力。拟议的工作将：（目标1和2）表征双层DNA中两种不同AP衍生的交联的形成和化学结构（目标3）使用质谱方法来定量测量与辐射式良好的Apioldientional-Alkyls Agent Alkyls Ankyls Ankyls Alkyls Aimscript（包括降低辐射型的Appred opectents toss tos tos tos tos tops tosementionally Alkylational of）（包括辐射）（包括），并修复APDERVES的交叉链接（并使用穿梭矢量方法来修复人类细胞中DG-AP跨环节。 公共卫生相关性： - 双链DNA无碱性位点的无asic位点的交联是由细胞DNA中遗传密码的核碱基“字母”丢失而产生的。 DNA无碱性位点自发地发生在细胞中，也可以由多种天然毒素，工业化学物质，农药和抗癌药物诱导。拟议的工作将研究从双链体DNA中无asic位点得出的新型链间DNA交叉链路家族的发生和修复。交联对细胞提出了非凡的挑战，因为它们可以防止双螺旋的两个链分离。无碱性位点衍生的交联的修复可能是错误的，遗传密码的突变可能有助于自发和化学引起的癌症的病因。这些交联未修复，可能会阻止DNA转录和复制，从而导致细胞功能障碍，细胞死亡，衰老和衰老。细胞反应对这些交联的确切性质可能受个人的基因组成的影响，尤其是在其DNA损伤响应和修复机械中的缺陷或多态性方面。这项工作很重要，因为它将表征AP衍生的交联如何促进非常常见的DNA病变（Abasic位点）引起诱变，癌症，细胞功能障碍，衰老和人类衰老的倾向。