ACETYLATION PHARMACOGENETICS--ARYLAMINES AND DNA DAMAGE

描述：拟议研究的目标是确定 N-乙酰转移酶(NAT)多态性，一种涉及的遗传代谢性状 在芳香胺的新陈代谢中，影响个体对 芳胺引起的DNA损伤和致癌。这一发现是有的 人类的两个多态NAT，每个都有多个等位基因，增加了一个新的 人体乙酰化状态作用的研究维度 对外源化学物质的敏感性。在这项建议中，分子生物学 细胞培养技术将被用来转染特定的等位基因 将人NAT导入哺乳动物细胞(COS细胞)，然后确定 由此产生的基因对芳香胺引起的DNA损伤的易感性。 目前使用乙酰化同源基因和乙酰化的研究，啊-响应器 双同基因小鼠品系将扩展到额外的致癌物质和 纸巾。进一步的研究将集中在NAT的相互作用上 芳胺的两条交替氧化途径的多态 致癌物：细胞色素P450 1A亚家族单加氧酶和前列腺素 合酶(PHS)共氧化。近亲交配和同源的小鼠品系 本实验室的开发将用于对NAT的交互进行建模 以细胞色素P4501a和NAT为决定因素 对结肠癌和其他肝外癌症的易感性。这项技术 ~(32)P-后标记(以及在此之前开发的高效液相色谱方法 实验室)将用于确定特定于基因的和特定于组织的 碳环芳胺引起的DNA损伤模式(例如 2-氨基荧烯)和杂环芳胺(如智商) 熟食。还将构建近交系小鼠模型，以确定 PHS及PHS和NAT组合对肝外DNA的贡献 这些芳基胺和杂环胺造成的损害。这款车型还将 被用作研究小灵通活动中的药物干预的工具 它们在预防或减少DNA损伤和致癌方面的作用。

DESCRIPTION: The objective of the proposed study is to determine how the N-acetyltransferase (NAT) polymorphism, a genetic metabolic trait involved in the metabolism of arylamines, influences individual susceptibility to arylamine-induced DNA damage and carcinogenesis. The finding that there are two polymorphic NATs in humans, each with multiple alleles, adds a new dimension to the investigation of the role of acetylator status in human sensitivity to exogenous chemicals.In this proposal, molecular biological and cell culture techniques will be used to transfect specific alleles of human NATs into mammalian cells (COS cells) and then to determine the susceptibility of the resulting genotype to arylamine-induced DNA damage. Current studies using acetylator congenic and acetylator, Ah-responder double congenic mouse lines will be extended to additional carcinogens and tissues. Further studies will focus on the interaction of the NAT polymorphism with two alternative oxidation pathways for arylamine carcinogens: cytochrome P450 1A subfamily monooxygenases and prostaglandin synthase (PHS) co-oxidation. Inbred and congenic mouse lines that are being developing in this laboratory will be used to model the interaction of NAT with cytochrome P450 1A and NAT with PHS as determinants of human susceptibility to colon and other extra-hepatic cancers. The technique of 32P-postlabeling (and the HPLC method previously developed in this laboratory) will be used to determine genotype-specific and tissue-specific patterns of DNA damage resulting from carbocyclic aromatic amines (e.g. 2-aminofluorene) and heterocyclic aromatic amines (e.g. IQ) produced in cooked foods. An inbred mouse model will also be constructed to determine the contribution of PHS and combinations of PHS and NAT to extra-hepatic DNA damage induced by these aryl- and heterocyclic amines. This model will also be used as a tool to study pharmacological interventions in PHS activity and their effects on prevention or reduction of DNA damage and carcinogenesis.