Adducts of mitomycin C with nucleotides.

丝裂霉素C与核苷酸的加合物。

• 批准号: 6888100
• 负责人: MARIA TOMASZ
• 金额: $ 22.77万
• 依托单位: HUNTER COLLEGE
• 依托单位国家: 美国
• 财政年份: 1980
• 资助国家: 美国
• 起止时间: 1980-07-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6888100
• 关键词: DNA repair; adduct; alkylation; antineoplastic antibiotics; binding proteins; cell line; chemical structure; congenital aplastic anemia; cytotoxicity; drug design /synthesis /production; drug hypersensitivity; drug screening /evaluation; free radical oxygen; high performance liquid chromatography; mitomycin C; neoplasm /cancer chemotherapy; neoplasm /cancer pharmacology; nuclear magnetic resonance spectroscopy; nucleic acid sequence; pharmacokinetics; southern blotting; synthetic nucleotide

DESCRIPTION (provided by applicant): Mitomycin C (MC) is a natural antitumor antibiotic used in the clinic for cancer chemotherapy. MC generates six different DNA adducts in tumor cells. One of these is a DNA interstrand cross-link, as a result of bifunctional alkylation of the complementary DNA strands by MC, while the others are adducts of the drug, linked to only one strand of DNA (monoadducts and an intrastrand crosslink). The broad, long-range objective of the present proposal is to elucidate the relationship of each of the six adducts to the cytotoxicity/antitumor activity of MC. In addition, the putative toxic role of reactive oxygen species (ROS), generated by redox cycling of MC, will be examined using Fanconi's Anemia (FA) cells. The first aim of the proposal is to determine whether the known hypersensitivity of FA cells to MC is primarily due to ROS generation or to DNA adduct formation by the drug. These studies will better define the biochemical basis of the unique sensitivities of Faneoni's anemia cells, as well as providing insights into the activities of the mitomycins. The other specific aims serve to detect and characterize biochemical responses unique to the different DNA adducts of MC. In this context we shall investigate differential rates of repair of the adducts in living EMT6 tumor cells in cell culture. Differential modes of nucleotide excision repair of cross-link and monoadducts will be investigated in subcellular systems by constructing 91-mer oligonucleotide duplexes modified site-specifically with the various MC adducts, and using these as substrates for uvrABC excinuclease, or for the repair enzymes present in a mammalian whole cell extract. The same substrates will be used to search for "adduct binding proteins", specific for the cross-link, in cell extracts. Differential inhibition of lesion bypass by DNA polymerases by the different mitomycin monoadducts will also be investigated, using synthetic adduct-template-primer complexes as substrates. These latter experiments are aimed at identifying the basis for the unusually low cytotoxicity of the monoadducts 5 and 6. This research will lead to a better understanding of the molecular and biochemical basis of the antitumor activity and toxicology of MC and, more generally, of other DNA cross-linking agents, a major class of drugs currently used in cancer chemotherapy.

描述（由申请人提供）：丝裂霉素C（MC）是癌症化学疗法中使用的天然抗肿瘤抗生素。 MC在肿瘤细胞中产生六种不同的DNA加合物。其中之一是MC的双功能DNA链双功能烷基化的结果，而其他人则是药物的加合物，仅与一链DNA有关（单aductss和astastrand intastrand crosslink）。本提案的广泛，远程目标是阐明六个加合物中的每一个与MC的细胞毒性/抗肿瘤活性的关系。此外，将使用Fanconi的贫血（FA）细胞检查，由MC氧化还原循环产生的活性氧（ROS）的推定毒性作用。该提案的第一个目的是确定FA细胞对MC的已知超敏反应是主要是由于ROS的产生或药物形成DNA加合物。这些研究将更好地定义Faneoni贫血细胞独特敏感性的生化基础，并提供对丝裂霉素活性的见解。另一个特定的目的是检测和表征MC不同DNA加合物所特有的生化反应。在这种情况下，我们将研究活细胞培养中活的EMT6肿瘤细胞中加合物修复的差异速率。核苷酸切除修复的差异模式将在亚细胞系统中研究通过与各种MC加合物特异性修饰位点修饰的位点，并使用这些用作uvrabcCCinucleable酶的底物，以uvrabcccinuclease sectinucles，或用于维修enzymes every Enzymal extralian the mamamal themamal themamal themamal themamal themalian syperstime。相同的底物将用于搜索细胞提取物中特定于交联的“加合结合蛋白”。还将使用合成加合物 - 板岩 - 培养基复合物作为底物来研究不同丝裂霉素单核酶对DNA聚合酶对病变旁路的差异抑制作用。这些后一个实验的目的是确定单核5和6的异常低细胞毒性的基础。这项研究将使MC的抗肿瘤活性和毒素学的分子和生化基础更好地了解MC的分子和生化基础，以及其他DNA交叉连接药物的其他DNA交叉链接药物，目前在癌症中使用了其他药物的药物。