METABOLIC DETERMINANTS OF SPONTANEOUS MUTAGENESIS

自发突变的代谢决定因素

• 批准号: 2895852
• 负责人: Toby G. Rossman
• 金额: $ 31.51万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2895852
• 关键词: DNA damage; DNA repair; adduct; antioxidants; ascorbate; cell line; free radical scavengers; gene mutation; genetic markers; hypoxanthine phosphoribosyltransferase; lipid peroxides; metallothionein; nucleic acid repetitive sequence; oxidative stress; tocopherols; transfection /expression vector; zinc

DESCRIPTION: The goal of this proposal is to evaluate the ability of the antioxidants Vitamin C (ascorbate), Vitamin E (a-tocopherol) and metallothionein (MT) to reduce the frequency and spectrum of spontaneous mutations at the HPRT locus. Ascorbate is anticipated to reduce DNA damage resulting from direct oxidation of the nitrogenous bases, a-tocopherol by blocking DNA adduct formation by lipid peroxidation products and metallothionein by scavenging cellular free radicals. The spectra of spontaneous mutations and pattern of DNA damage will be evaluated in three human cell lines: HCT116, a mismatch repair deficient colon carcinoma cell line; HCT116/ch3, and HCT116 derivative into which an intact human chromosome 3 has been introduced, and SW480, a mismatch repair proficient colon carcinoma cell line. Cells will be incubated with one of the two antioxidants or transfected with a metallothionein expression vector and incubated with Zn, HPRT mutants collected and the mutational spectra and DNA damage profile determined. In addition, the mismatch repair deficient cell line will be evaluated for an undescribed panel of microsatellite markers for determination of whether oxidative damage is a principal cause of microsatellite mutations.

描述：该提议的目的是评估 抗氧化剂维生素C（抗坏血酸），维生素E（A-Topherol）和 金属硫蛋白（MT）以降低自发的频率和光谱 HPRT基因座的突变。 预计抗坏血酸会减少DNA损伤 由氮基碱的直接氧化，A-Topherol的直接氧化。 通过脂质过氧化产物和 金属硫蛋白通过清除细胞自由基。 光谱 将在三个中评估自发突变和DNA损伤模式 人类细胞系：HCT116，一种不匹配的修复缺陷结肠癌细胞 线; HCT116/CH3和HCT116衍生物完整的人 已经引入了3染色体，SW480是一种不匹配的维修 结肠癌细胞系。 细胞将与两者之一孵育 抗氧化剂或用金属硫硫蛋白表达载体转染和 与Zn，收集的HPRT突变体以及突变光谱和DNA孵育 确定损坏概况。 另外，不匹配的维修缺乏细胞 将评估未描述的微卫星标记面板 确定氧化损伤是否是主要原因 微卫星突变。