TOXICOLOGICAL CONTROL MECHANISMS OF HUMAN CYP1A2 GENE

人CYP1A2基因的毒理学控制机制

• 批准号: 2546035
• 负责人: LINDA C QUATTROCHI
• 金额: $ 16.94万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 1999-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2546035
• 关键词: DNA binding protein; DNA footprinting; RNase protection assay; antisense nucleic acid; carbopolycyclic compound; cytochrome P450; cytotoxicity; dioxins; environmental toxicology; gene expression; genetic enhancer element; genetic promoter element; genetic regulatory element; human tissue; liver function; northern blottings; nucleic acid sequence; polymerase chain reaction; site directed mutagenesis; tissue /cell culture; toxicant interaction; toxin metabolism; transcription factor; transfection; western blottings

Toxicity of the chemical class of xenobiotics that include polycyclic aromatic hydrocarbons (PAH) and halogenated hydrocarbons, such as polychlorinated biphenyls and dibenzodioxins, most likely occurs through control of gene expression. The molecular mechanism is largely unknown, but is currently believed to involve, In part, a cytosolic receptor, the aryl hydrocarbon or Ah-receptor. If the mechanism responsible for the many toxic effects associated with these classes of chemicals is to be unraveled, it will be necessary to study other genes that may be regulated through additional cellular mediators. This grant proposal focuses on the human cytochrome P4501A2 gene (CYP1A2), a member of the PAH-inducible CYP1A gene family that is prominent in human liver, and metabolizes drugs, such as acetaminophen, caffeine, environmental agents such as arylamines and dietary constituents, such as heterocyclic amines and aflatoxins. The molecular mechanism for the regulation of the human CYP1A2 gene will be studied through the characterization of cis-acting elements and identification of trans-acting factors utilizing transient transfection assays and in vitro DNA binding assays, such as DNase I footprinting. In vivo footprinting studies in human primary hepatocytes will be conducted to examine the temporal relationship among transcription factors in regulating CYP1A2 gene expression. Several model systems will be utilized for the proposed research, including human hepatoma cell lines, human liver and non-proliferating cultures of human hepatocytes. A Cell Culture Core and Human Tissue Bank will provide the necessary support for these studies. It is believed that a combination of these molecular and cell culture approaches will elucidate the mechanism by which this important gene is regulated.

毒性的化学类外生物质，包括多环