POLYMORPHIC DRUG OXIDATION--THE HUMAN CYP2D6 GENE

多态性药物氧化--人类CYP2D6基因

• 批准号: 3853475
• 负责人: F J GONZALEZ
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3853475
• 关键词: alleles; chemical carcinogen; cytochrome P450; detoxification; diagnostic tests; drug metabolism; gene expression; gene mutation; genetic polymorphism; human population genetics; isoquinolines; liver metabolism; molecular cloning; molecular genetics; nucleic acid sequence; polymerase chain reaction; tobacco

The debrisoquine/sparteine genetic polymorphism is due to mutant alleles of CYP2D6. Individuals lacking production of this cytochrome P450 are unable to metabolize over 30 drugs. In several instances, lack of metabolism of a drug results in toxicity or exaggerated responses. About 7.5% of Caucasians possess two mutant alleles of CYP2D6. In order to characterize these mutant genes and in an effort to develop simple polymerase chain reaction-based diagnostic tests, a mutant CYP2D6 allele was directly cloned from leukocyte DNA taken from an individual that was unable to metabolize debrisoquine. The gene was completely sequenced and found to contain a G to A transition that alters the consensus 3 prime splice site at the junction of intron 3 and exon 4 of CYP2D6. A simple non-radioactive PCR test was developed, based on this single mutation, that can be used to screen individuals by analyzing leukocyte DNA for presence of mutant P450 genes. This mutant allele, designated CYP2D6(B), represents about 75% of all mutant CYP2D6 genes. A second mutant CYP2D6 gene, designated CYP2D6(C), was identified that produces a protein lacking a single amino acid. This enzyme is catalytically active but is not stably expressed in human liver. A polymerase chain reaction-based test was also developed for CYP2D6(C). This is a rare allele representing less than 2% of all mutant genes. Complementary DNA expression systems have been developed to evaluate the ability of CYP2D6 to metabolize drugs and activate chemical carcinogens. A lymphoblastoid cell containing the CYP2D6 CDNA was constructed and used to demonstrate metabolic activation of a carcinogen found in tobacco smoke.

异喹胍/鹰爪豆碱的遗传多态性是由突变等位基因引起的 CYP 2D 6的基因。 缺乏这种细胞色素P450产生的个体是 无法代谢超过30种药物。 在一些情况下，缺乏 药物的代谢导致毒性或过度反应。 关于 7.5%的白种人具有CYP 2D 6的两个突变等位基因。 为了 鉴定这些突变基因，并努力开发简单 基于聚合酶链反应的诊断试验，突变CYP 2D 6等位基因 是从白细胞DNA中直接克隆出来的，而白细胞DNA取自 不能代谢异喹胍。 对该基因进行了完全测序， 发现含有一个G到A的转换，改变了共有序列3的素数 CYP 2D 6内含子3和外显子4连接处的剪接位点。 一个简单 基于这种单一突变，开发了非放射性PCR检测， 通过分析白细胞DNA来筛选个体 突变P450基因的存在。 该突变等位基因被命名为CYP 2D 6（B）， 占所有突变CYP 2D 6基因的约75%。 第二个突变CYP 2D 6基因，命名为CYP 2D 6（C），被鉴定为 产生缺少一个氨基酸的蛋白质。 这种酶 具有催化活性但在人肝中不稳定表达。 一 还开发了用于CYP 2D 6（C）的基于聚合酶链反应的检测。 这是一种罕见的等位基因，占所有突变基因的不到2%。 互补DNA表达系统已被开发出来，用于评估 CYP 2D 6代谢药物和激活化学致癌物的能力。 构建并使用了含有CYP 2D 6 cDNA的淋巴母细胞样细胞 证明烟草中致癌物质的代谢活化 抽烟