ADDUCTS OF MITOMYCIN C WITH NUCLEOTIDES

丝裂霉素 C 与核苷酸的加合物

• 批准号: 3482118
• 负责人: MARIA TOMASZ
• 金额: $ 22.5万
• 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 1993-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3482118
• 关键词: DNA; DNA footprinting; DNA repair; HeLa cells; X ray crystallography; adduct; alkylating agents; alkylation; antineoplastic antibiotics; circular dichroism; covalent bond; crosslink; cytotoxicity; high performance liquid chromatography; human tissue; laboratory rat; liver; mitomycin C; neoplasm /cancer pharmacology; nucleic acid sequence; nucleic acid structure; nucleotides; radiotracer; synthetic nucleotide; tissue /cell culture

Mitomycin C (MC) is an antibiotic and antitumor agent widely used in clinical cancer chemotherapy. Its mode of action has been the subject of intensive study and speculation for more than 20 years, since the discovery that it induced covalent crosslinking of DNA. Recently we elucidated the basic chemistry of the activation of MC and its ultimate reaction products with DNA including the MC-DNA crosslink. Our objective is to relate each of the three major reaction products to the biological effects of MC, i.e. to determine (a) which is more effective for antitumor and cytotoxic activities, (b)-why is it more effective and (c) how to enhance the formation of such effective reactions in the cell. The broad and long-term objective is to understand the molecular basis of the antitumor activity of the mitomycins and make this knowledge applicable to new drug design and treatment protocols in cancer chemotherapy. First, the three adducts of MC and DNA will be examined for their location at specific DNA sequences, using footprinting techniques as well as Ba131 digestion as a tool. Effects of each adduct on DNA conformation will be assessed by examining the conformations of oligonucleotides modified at a single site by each of the three adducts, as models. Assay of adducts formed in cell cultures will be used as probe for (i) effect of intracellular 02 on crosslinking efficiency of MC, (ii) relative cytotoxicity of the three adducts, (iii) kinetics of removal of adducts by cellular repair. Excision repair of adducted DNA will be studied in an in vitro system, using single-site adducted DNA fragments. Two MC analogs, more effective than the parent MC will be examined for the molecular basis of their greater effectiveness by comparing their activation and DNA- reactivity with those of MC.

丝裂霉素C（MC）是一种广泛使用的抗生素和抗肿瘤剂 在临床癌症化疗中。 它的行动方式是 密集研究和投机的主题已有20多年了， 自从发现它诱导DNA的共价交联。 最近，我们阐明了MC激活的基本化学性质 及其与包括MC-DNA的DNA的最终反应产物 交叉链接。 我们的目的是关联三个主要 对MC的生物学作用的反应产物，即 确定（a）对抗肿瘤和细胞毒性更有效的（a） 活动，（b） - 为什么更有效，以及（c）如何增强 在细胞中形成这种有效的反应。 宽阔和 长期目标是了解 丝裂霉素的抗肿瘤活性，并使此知识 适用于癌症的新药物设计和治疗方案 化学疗法。 首先，将检查MC和DNA的三个加合物的 使用足迹技术的特定DNA序列的位置 以及BA131消化作为工具。 每个加合物对 DNA构象将通过检查构象来评估 三个位点在单个位点修饰的寡核苷酸的 加合物，作为模型。 在细胞培养物中形成的加合物的测定将 用作（i）细胞内02对交联效果的探针 MC的效率，（ii）三个加合物的相对细胞毒性， （iii）通过细胞修复去除加合物的动力学。 切除 加合的DNA的维修将在体外系统中研究，并使用 单位加合物的DNA片段。 两个MC类似物，更有效 比父mc的分子基础相比 通过比较它们的激活和DNA-的更大有效性 与MC的反应性。