ACETYLATION PHARMACOGENETICS--ARYLAMINES AND DNA DAMAGE

描述：拟议研究的目的是确定 N-乙酰转移酶（NAT）多态性，一种遗传代谢特征， 在芳胺的代谢中，影响个体对 芳胺诱导的DNA损伤和致癌作用。 研究发现， 人类中的两种多态性NAT，每一种都有多个等位基因， 研究乙酰化状态在人类中的作用的维度 对外源性化学物质的敏感性。在这项建议中， 细胞培养技术将用于检测 将人NAT导入哺乳动物细胞（COS细胞），然后确定 由此产生的基因型对芳胺诱导的DNA损伤的易感性。 使用乙酰化剂同源物和乙酰化剂，AH-应答者的当前研究 双同源小鼠品系将扩展到其他致癌物， 组织中 进一步的研究将集中在NAT的相互作用 芳胺具有两种交替氧化途径的多晶型现象 致癌物：细胞色素P450 1A亚家族单加氧酶和前列腺素 合成酶（PHS）共氧化。 近交系和同类系小鼠正在被 本实验室开发的一种用于模拟NAT相互作用的 细胞色素P450 1A和NAT与PHS作为人类的决定因素 易患结肠癌和其他肝外癌。 技术 32 P-后标记（以及本研究中先前开发的HPLC方法） 实验室）将用于确定基因型特异性和组织特异性 由碳环芳香胺（例如， 2-氨基芴）和杂环芳族胺（例如IQ）， 熟食 还将构建近交系小鼠模型以确定 PHS及其与NAT联合应用对肝外DNA贡献 由这些芳基和杂环胺引起的损伤。 这一模式也将 可用作研究PHS活动中的药理干预的工具， 它们对预防或减少DNA损伤和致癌作用的影响。

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.