ALTERATION OF NAD METABOLISM BY CHEMICAL CARCINOGENS

化学致癌物改变 NAD 代谢

• 批准号: 3186348
• 负责人: MYRON K JACOBSON
• 金额: $ 17.91万
• 依托单位: TEXAS COLLEGE OF OSTEOPATHIC MEDICINE
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-01 至 1990-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3186348
• 关键词: ADP ribosylation; DNA repair; autoradiography; chemical carcinogen; chemical carcinogenesis; enzyme inhibitors; fluorimetry; gas chromatography; gel electrophoresis; gel filtration chromatography; high performance liquid chromatography; human tissue; laboratory mouse; leukocyte activation /transformation; mass spectrometry; nicotinamide adenine dinucleotide; nitrosamines; nucleic acid metabolism; radiotracer; tissue /cell culture; tritium; tumor promoters; xanthines

The occurrence of DNA damage and cellular responses to DNA damage are involved in the initiation and perhaps the promotion phase of carcinogenesis. The proposed studies will focus on the mechanism and biological significance of the rapid alteration of poly(ADP-ribose) metabolism cause by environmentally induced DNA damage. These studies will utilize intact cultured mouse cells following treatment with N-methyl-N'-nitro-N nitrosoguanidine (MNNG). The complexity of polymers of ADP-ribose will be studied by isolation of polymers using highly selective boronate affinity resins, fractionation by HPLC molecular sieve chromatography and simultaneous determination of linear and branched internal residues and terminal residues. Such experiments will allow the determination of true polymer size and branching frequency per molecule, information necessary for evaluating the importance of non-covalent interactions of the polymer with other components of chromatin. The turnover of polymers and their distribution within chromatin fractions will be studied by combining the above methods with in vivo labeling protocols and inhibitors of poly(ADP-ribose) polymerase. Labeling methods will also be used to assess the quantitative significance of poly(ADP-ribose) metabolism in non-damaged cells. The function of poly(ADP-ribose) metabolism in cellular recovery from the cytotoxic effects of MNNG will be addressed by studies of cell cycle progression in synchronized C3H10T1/2 cells using flow cytofluorimetry, autoradiography and ADP-ribosylation inhibitors. This system will also be used to make chromatin comparisons designed to yield information concerning the stabilization or alterations of chromatin structure involving poly(ADP-ribose) and normal cell cycle progression in MNNG treated cells. The involvement of poly(ADP-ribose) metabolism in other important biological responses to DNA damage in C3H10T1/2 cells will be studied by evaluating the effect of ADP-ribosylation inhibitors and nutritional manipulation of NAD levels on mutagenesis and malignant transformation. Such studies will utilize conditions where co-cytotoxic effects will be eliminated or minimized and effects on growth during expression carefully monitored. The mechanism of poly(ADP-ribose) metabolism by hyperthermia will be studied and an assessment of a possible general role of poly(ADP-ribose) metabolism in a general cellular response to environmental stress will be made.

DNA损伤的发生和对DNA损伤的细胞反应是 参与了启动，也许是 致癌作用。 拟议的研究将重点介绍机制和 聚（ADP-核糖）快速改变的生物学意义 代谢是由环境诱导的DNA损伤引起的。 这些研究会 使用完整的培养小鼠细胞处理后 N-甲基N'-硝基N硝苯胺（MNNG）。 聚合物的复杂性 通过使用高选择性分离聚合物，将研究ADP-核糖 硼酸盐亲和力树脂，HPLC分子筛的分馏 线性和分支的色谱和同时测定 内部残基和末端残基。 这样的实验将允许 确定每个分子的真实聚合物大小和分支频率， 评估非共价重要性所需的信息 聚合物与染色质的其他成分的相互作用。 这 聚合物的营业额及其在染色质分数中的分布将 通过将上述方法与体内标记协议相结合来研究 和聚（ADP-核糖）聚合酶的抑制剂。 标签方法也将 用于评估聚（ADP-核糖）的定量意义 无损细胞中的代谢。 聚（ADP-核糖）的功能 从MNNG的细胞毒性作用中恢复细胞中的代谢将是 通过对同步C3H10T1/2中细胞周期进程的研究来解决 使用流式细胞氟化，放射自显影和ADP-核糖基化细胞 抑制剂。 该系统还将用于进行染色质比较 旨在产生有关稳定或改变的信息 涉及聚（ADP-核糖）和正常细胞周期的染色质结构 MNNG处理的细胞的进展。 聚（ADP-核糖）的参与 其他重要的生物学反应中对DNA损伤的代谢 C3H10T1/2细胞将通过评估的影响来研究 ADP-核糖基化抑制剂和NAD水平的营养操纵 诱变和恶性转化。 这样的研究将利用 将消除或最小化的共同毒性作用的条件 仔细监测表达期间生长的影响。 机制 将研究高温的聚（ADP-核糖）代谢，并 评估聚（ADP-核糖）代谢在A中可能的一般作用 将对环境压力做出一般的细胞反应。