ENVIRONMENTAL CHEMICAL AND OXIDATIVE STRESS INDUCED DNA DAMAGE & CARCINOGENESIS

环境化学和氧化应激引起的 DNA 损伤

• 批准号: 3841038
• 负责人: J E FRENCH
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 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/3841038
• 关键词: DNA damage; bacteriophage lambda; chemical carcinogen; chemical carcinogenesis; disease /disorder model; genetically modified animals; hepatectomy; hyperplasia; laboratory mouse; nitrosourea; oxidative stress; preneoplastic state; tissue /cell culture; transfection /expression vector; transposon /insertion element

Endogenous oxidative injury to cellular DNA may be induced by exogenous chemical toxicity and/or inflammation and has been speculated to contribute to mutation frequency (MF) and mutations that may be fixed and clonally expanded (multistage carcinogenesis) by induced cellular proliferation. Our goal is to determine the mutation frequency and to characterize mutations in transgenic ZAP/lacIq mice (C57B1/6 background) using a lambda shuttle vector after treatment with selected genotoxic or non-genotoxic chemicals that induce hyperplasia with and without associated inflammation as a model for genomic DNA damage. The target transgene is recovered from treated transgenic mice by exposing the mouse genomic DNA to lambda in vitro packaging extracts, infecting repair deficient host E. coli, and culturing. Phage with mutations in the lacI target gene form colored plaques, while those with non-mutated target genes form colorless plaques. We have initiated these studies by determining mutation frequency in liver after ethylnitrosourea or vehicle exposure and induction of rapid hepatocellular proliferation following 2/3 partial hepatectomy. Ablated liver served as the To and untreated control. After 8 days (100% restoration of liver mass) EtNU followed by hepatectomy increased MF 4.4X compared to ~1.9 or 1.7X for hepatectomy alone or EtNU and sham hepatectomy. Additional studies performed with benzene, p-cresidine, 1,2,3-trichloropropane and 4-vinyl-1-cyclohexene diepoxide are undergoing analysis. Using this research strategy we expect to be able to provide insight on chemical and/or endogenous oxidative damage to DNA and this possible mechanism of carcinogenesis.

外源激素可诱导细胞DNA内源性氧化损伤 化学毒性和/或炎症，据推测是 到突变频率(Mf)和可能是固定的和克隆的突变 通过诱导细胞增殖而扩大的(多阶段癌变)。 我们的目标是确定突变频率和特征 使用lambda基因的转基因ZAP/lacIq小鼠(背景为C57B1/6)的突变 经选择的遗传毒性或非遗传毒性处理后的穿梭载体 引起伴随和不伴随炎症的增生的化学物质 作为基因组DNA损伤的模型。将目的基因从 通过将小鼠基因组DNA暴露于Lambda来治疗转基因小鼠 体外包装提取物，感染修复缺陷的宿主大肠杆菌，以及 培养。带有LacI靶基因突变的有色噬菌体 斑块，而那些没有突变的靶基因形成无色斑块。 我们通过测定肝脏中的突变频率启动了这些研究。 乙基亚硝脲或车辆暴露后，诱发快速 2/3肝部分切除术后肝细胞增殖。烧蚀 肝脏作为对照和未处理组。8天后(100% 肝质量恢复)EtNU术后肝切除增加MF4.4倍 相比之下，单纯肝切除术或EtNU+Sham的倍数约为1.9或1.7倍 肝切除手术。对苯、对氯碱进行的其他研究 1，2，3-三氯丙烷和4-乙烯-1-环己烯二环氧化物正在进行 分析。使用这一研究策略，我们希望能够提供 对DNA的化学和/或内源性氧化损伤的洞察 可能的致癌机制。