N ACETYLTRANSFERASES--GENOTYPES AND GENOTOXICITY

N 乙酰转移酶——基因型和基因毒性

基本信息

批准号：
6382328
负责人：
Charlene A McQueen
金额：
$ 21.68万
依托单位：
UNIVERSITY OF ARIZONA
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-09-01 至 2003-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6382328
关键词：
acyltransferase adduct amines bladder neoplasm chemical carcinogenesis enzyme activity gene environment interaction gene expression gene targeting genetic polymorphism genetic promoter element genetic susceptibility genetically modified animals genotype laboratory mouse molecular pathology tobacco

项目摘要

DESCRIPTION: (Adapted from the Investigator's Abstract) Arylamine N-acetyltransferases (Nats) catalyze the acetylation of the extracyclic nitrogen of hydrazines and aromatic amines including the tobacco smoke carcinogen 4-aminobiphenyl (4AB). Two genes NAT I and NAT 2 each exhibit polymorphisms that result in variations in enzyme activities. Associations of NAT genes and susceptibility to smoking-related urinary bladder cancer have been reported. However, the involvement of one or both NAT genes, interactions between the two genes and genetic-environmental interactions are not fully understood. The overall goal is to investigate these relationships in genetically-defined mice. The hypothesis to be tested is that susceptibility to aromatic amine genotoxicity is associated with tissue specific expression of specific combinations of NAT I and NAT 2 genotypes. The specific aims are 1) to identify variants of mouse Nat 1; 2) to create a controllable knockout of Nat I and Nat 2; 3) to over-express Nat I and/or Nat 2 in a particular tissue using tissue specific promoters in transgenic mice; 4) to evaluate Nat 1 and Nat 2 expression in transgenic and knockout mice and 5) to detect 4AB-DNA adducts in mice genetically defined at Nat I and/or Nat 2. The controllable knockout without hepatic Nat genes will be achieved using the Cre-loxP system to knockout the gene then crossing the mice with the "floxed" knockout to albumin promoter Cre transgenic mice. Transgenic animals over-expressing either or both Nat genes will also be developed. An albumin promoter will allow targeting of over-expression to liver. Mice differing in Nat genes will be exposed to 4AB and DNA adducts measured in target and non-target tissue using a monoclonal antibody and immunohistochemistry. These studies will show whether 4AB genotoxicity is modulated by Nat expression. The results will provide insight into genetic regulation of susceptibility to a carcinogen found in tobacco smoke.

描述：（改编自研究者摘要）芳胺 N-乙酰转移酶 (Nats) 催化环外乙酰化肼和芳香胺的氮，包括烟草烟雾致癌物质4-氨基联苯(4AB)。两个基因 NAT I 和 NAT 2 各表现出多态性导致酶活性的变化。协会 NAT 基因和吸烟相关膀胱癌的易感性被举报。然而，一个或两个 NAT 基因的参与、相互作用两个基因之间以及遗传-环境相互作用并不完全明白了。总体目标是调查这些关系基因定义的小鼠。要检验的假设是对芳香胺的遗传毒性与组织特异性表达有关 NAT I 和 NAT 2 基因型的特定组合。具体目标是 1) 鉴定小鼠 Nat 1 的变体； 2）创建一个可控敲除 Nat I 和 Nat 2； 3) 过度表达 Nat I 和/或 Nat 2 在转基因小鼠中使用组织特异性启动子在特定组织中； 4）评估转基因和基因敲除小鼠中的 Nat 1 和 Nat 2 表达以及 5) 检测 Nat I 和/或 Nat 2 基因定义的小鼠中的 4AB-DNA 加合物。利用以下方法实现无肝Nat基因的可控敲除 Cre-loxP系统敲除该基因，然后将小鼠与“floxed”杂交敲除白蛋白启动子 Cre 转基因小鼠。转基因动物 Nat 基因中的一个或两个的过度表达也将被开发。一种白蛋白启动子将允许过度表达至肝脏。小鼠的不同之处在于 Nat 基因将暴露于 4AB 和 DNA 加合物中，在目标和使用单克隆抗体和免疫组织化学检测非靶组织。这些研究将表明 4AB 基因毒性是否受 Nat 表达调节。这结果将提供对易感性的遗传调控的深入了解烟草烟雾中发现致癌物质。