The Role of N1-Inosine Adducts in Butadiene Mutagenesis

N1-肌苷加合物在丁二烯诱变中的作用

• 批准号: 6740324
• 负责人: Gunnar Boysen
• 金额: $ 4.16万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-11-16 至 2005-11-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6740324
• 关键词: DNA damage; adduct; adenine; animal data; animal tissue; biohazard detection; chemical carcinogen; chemical synthesis; inosine; mass spectrometry; method development; mutagens; pharmacokinetics; point mutation; postdoctoral investigator; thymine; tissue /cell culture

DESCRIPTION (provided by applicant): 1,3-butadiene (BD) is a known rodent and human carcinogen. However, the DNA adducts responsible for base pair mutations have not been identified. We hypothesize that N1- (hydroxybutene)-deoxyinosine (N1-HB-dI) and N1-trihydroxybutane-deoxyinosine (N1-THB-dl) adducts are responsible of the mutations at A:T base pairs. This hypothesis is based on studies showing that N1-HB-dl adducts are highly mutagenic in site directed mutation studies in E. coli and COS cells. There is no information on the formation, persistence or repair of these adducts in vitro or in vivo. Therefore, in the proposed studies we will synthesize the N1-HB-dl and N1-THB-dl adduct standards and develop a method for their detection and analysis by LC-ESI-MS. The developed methods will then be applied to DNA samples from human TK6 cells, exposed to 1,2-epoxy-3-butene (EB) or 1,2;3,4-diepoxybutane (DFB). Additionally, these methods will be used to analyze N1-inosine adducts in mice and rats exposed to different concentrations of BD, EB or DEB to evaluate the dosimetry of adduct formation in vivo. Further, tissues from mice and rats treated with BD for 10 days and sacrificed 2h, 1, 3 or 6 days post exposure will be analyzed to calculate the adduct half-lives and give insight on the rate of repair. Finally, the number of N1-inosine adducts will be compared with previously analyzed amounts of N7-gunaine adducts (N7-HB-gunaine and N7-THB-gunine) and the hprt mutations in mice and in TK6 cells. Addressing this hypothesis is essential for determining the sources of BD mutations and will ultimately increase our ability to accurately assess the risk of BD to humans.

描述（由申请人提供）：1,3-丁二烯（BD）是一种已知的啮齿动物和人类致癌物。 然而，导致碱基对突变的 DNA 加合物尚未确定。 我们假设 N1-(羟基丁烯)-脱氧肌苷 (N1-HB-dI) 和 N1-三羟基丁烷-脱氧肌苷 (N1-THB-dl) 加合物是 A:T 碱基对突变的原因。 该假设基于研究表明，在大肠杆菌和 COS 细胞的定点突变研究中，N1-HB-dl 加合物具有高度诱变性。 没有关于这些加合物在体外或体内的形成、持久性或修复的信息。 因此，在拟议的研究中，我们将合成 N1-HB-dl 和 N1-THB-dl 加合物标准品，并开发一种通过 LC-ESI-MS 检测和分析它们的方法。 然后，所开发的方法将应用于来自人类 TK6 细胞的 DNA 样本，这些样本暴露于 1,2-环氧-3-丁烯 (EB) 或 1,2;3,4-二环氧丁烷 (DFB)。 此外，这些方法将用于分析暴露于不同浓度 BD、EB 或 DEB 的小鼠和大鼠的 N1-肌苷加合物，以评估体内加合物形成的剂量测定。 此外，将分析用 BD 处理 10 天并在暴露后 2 小时、1、3 或 6 天处死的小鼠和大鼠的组织，以计算加合物半衰期并深入了解修复率。 最后，将 N1-肌苷加合物的数量与先前分析的 N7-古奈碱加合物（N7-HB-古奈碱和 N7-THB-古奈碱）的量以及小鼠和 TK6 细胞中的 hprt 突变进行比较。 解决这一假设对于确定双相情感障碍突变的来源至关重要，并将最终提高我们准确评估双相情感障碍对人类风险的能力。