DNA REPAIR AFTER POLYCYCLIC HYDROCARBON ADMINISTRATION

多环烃施用后的 DNA 修复

• 批准号: 3174253
• 负责人: EDWARD BRESNICK
• 金额: $ 12.4万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-05-01 至 1989-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3174253
• 关键词: DNA methylation; DNA repair; alkylating agents; asbestos; benzanthracenes; benzopyrenes; carbopolycyclic compound; chemical carcinogenesis; gel electrophoresis; gel filtration chromatography; high performance liquid chromatography; newborn animals; nitrosourea; nutrition related neoplasm /cancer; nutrition related tag; pathogenic diet; radiotracer; respiratory epithelium; squamous cell carcinoma; trachea; tritium; vitamin A deficiency

A major hypothesis in chemical carcinogenesis is that an interaction between the chemical and cellular is a prerequisite for transformation. Cells generally possess DNA repair pathways for at least some of the resulting damage. The absence or deficiency of a repair process may predispose to cancer. This research will investigate the repair of two types of DNA damage, that induced by either benzo(a)-pyrene or methylnitrosourea; in the latter case, repair of a specific lesion, 0/6-methylguanine. Previous experiments with hamster tracheal epithelial cells suggest that benzo(a)pyrene adducts in DNA are repaired by a pathway that differs from ultraviolet light-induced pyrimidine dimers. This will be confirmed by purification of the enzymes involved. Furthermore, DNA repair-deficient cells will be isolated and used both for comparison of the different repair mechanisms, as well as for experiments to isolate the repair genes. With regard to repair of 0/6-methylguanine, we have already transfected DNA from human liver into repair-deficient Chinese hamster ovary cells and selected a clone that expresses the methyltransferase gene. The gene will now be isolated from these cells and used to obtain information on the mRNA and protein structure. Antibodies to the protein, will be obtained using, as immunogen, either the purified protein or a synthetic polypeptide, the sequence of which can be obtained directly from the DNA sequence. The antibodies and genetic probes will be used to assess variations within the human population.

化学致癌作用的一个主要假设是相互作用 化学与细胞之间的转化是先决条件。 细胞通常至少具有某些 DNA 修复途径 造成的损坏。 修复过程的缺失或缺陷可能会 容易患癌症。 这项研究将调查两个 由苯并(a)-芘或苯并(a)-芘引起的DNA损伤类型 甲基亚硝基脲；在后一种情况下，修复特定病变， 0/6-甲基鸟嘌呤。 先前的仓鼠气管上皮实验 细胞表明DNA中的苯并(a)芘加合物是通过一条途径修复的 这与紫外线诱导的嘧啶二聚体不同。 这将 通过纯化所涉及的酶来证实。 此外，DNA 修复缺陷细胞将被分离出来并用于比较 不同的修复机制，以及分离实验 修复基因。 关于0/6-甲基鸟嘌呤的修复，我们已经 将人类肝脏 DNA 转染至修复缺陷型中国仓鼠体内 卵巢细胞并选择表达甲基转移酶的克隆 基因。 现在将从这些细胞中分离出该基因并用于获得 有关 mRNA 和蛋白质结构的信息。 蛋白质抗体， 将使用纯化的蛋白质或免疫原作为免疫原来获得 合成多肽，其序列可以直接从 DNA 序列。 抗体和基因探针将用于评估 人群内部的差异。