CELLULAR RESPONSE TO DNA DAMAGE

细胞对 DNA 损伤的反应

• 批准号: 2094612
• 负责人: JOHN M ESSIGMANN
• 金额: $ 102.74万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-20 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2094612
• 关键词: DNA damage; DNA repair; adduct; aflatoxins; antineoplastics; biphenyl compounds; chemical carcinogen; chemical synthesis; cis platinum compound; gene mutation; ionizing radiation; mutagen testing; plasmids; radiation genetics; recombinant DNA; transcription factor; virus DNA; virus replication

This research program focuses on the mechanisms by which cells respond to DNA damaging agents such as ionizing radiation, chemical carcinogens and anticancer drugs. The program is divided into three areas. The first is an analysis of the biochemical mechanisms by which chemical and physical agents induce the mutations that presumably initiate cells along the pathway toward malignancy. We examine the spectrum of mutations induced by a DNA damaging agents (for in the damaged DNA (adducts) may give rise to specific mutations. Using a combination of chemical synthesis and recombinant DNA tools, viral genomes are constructed containing the adducts suspected to have caused the mutations. Following replication of the site specifically modified genomes in bacterial or mammalian cells we determine the type, amount and genetic requirements for mutagenesis by each lesion studied. This work priorities the mutagenic potential of individual DNA adducts. The specific DNA adducts we proposed to study include those produced by oxidants and ionizing radiation, simple alkylating agents, aflatoxin, B1, cis- diamminedichloroplatinum (II) (cisplatin), 4-aminobiphenyl, 2-amino-3,8- dimethylimidazo94,5-f0quinoxaline (MeIQx), and vinyl chloride. The second area of proposed research is an examination of the mechanism of toxicity by the anticancer drug cisplatin. We propose to continue our investigation of a class of proteins we have termed "DRPs" (for Damage Recognition Proteins). We hypothesize that DRPs are involved in the anticancer mechanism of cisplatin by either or both of the following models. The first model proposed that DRPs bind to therapeutically effective adducts of cisplatin and shield those adducts from DNA repair. The second model is based upon recent discovery that some of the DRPs have essential natural functions (one is the transcription factor, hUBF). We shall test the hypothesis that cisplating adducts divert DRPs from their natural functions, hence disrupting cellular homeostasis. Our third proposed area of investigation is the design of a novel anticancer agent that works by the "shielding" mechanism proposed above for cisplatin. In this case, however, a DNA binding domain will be linked to a protein will bind to the adduct and shield it from repair, preserving the adduct so that its maximal lethal impact can be realized. In normal (nontumor) cells no such protection will be afforded owing to the absence of the tumor specific protein. In normal cells, therefore, the toxic effect of the adduct will be reduced by the repair system of the host.

这项研究计划的重点是细胞反应的机制 DNA损伤剂，如电离辐射，化学致癌物 和抗癌药物。 该方案分为三个领域。 的 首先是对化学和生物化学机制的分析， 物理因子诱导突变，这些突变可能引发细胞沿着 通往恶性肿瘤的途径 我们研究了突变的光谱 由DNA损伤剂诱导（因为在损伤的DNA（加合物）中， 产生特定的突变。 使用化学物质的组合 合成和重组DNA工具，构建病毒基因组 含有被怀疑导致突变的加合物 以下 在细菌中复制位点特异性修饰的基因组， 我们确定哺乳动物细胞的类型，数量和遗传要求 对于所研究的每个损伤的诱变。 这项工作的重点是 单个DNA加合物的致突变潜力。 特定的DNA加合物 我们建议研究包括那些由氧化剂和电离 辐射，简单烷化剂，黄曲霉毒素，B1，顺式- 二氨二氯铂（II）（顺铂），4-氨基联苯，2-氨基-3，8- 二甲基咪唑并94、5-氟喹喔啉（MeIQx）和氯乙烯。 的 建议研究的第二个领域是检查 抗癌药物顺铂的毒性。 我们建议继续我们的 研究了一类我们称为“DRPs”的蛋白质（用于损伤 识别蛋白）。 我们假设DRPs参与了 顺铂的抗癌机制通过以下任一或两种方式 模型 第一个模型提出DRPs与治疗性的 顺铂的有效加合物并保护这些加合物免受DNA修复。 第二个模型是基于最近的发现， 具有重要的自然功能（一种是转录因子hUBF）。 我们将检验顺式加合物将DRP从 它们的自然功能，因此破坏了细胞内稳态。 我们 第三个研究领域是设计一种新的抗癌药物， 代理人的工作，由“屏蔽”机制提出上述 顺铂 然而，在这种情况下，DNA结合结构域将被连接 会与加合物结合并保护它不被修复， 保存加合物，以便实现其最大的致命影响。 在正常（非肿瘤）细胞中，由于 缺乏肿瘤特异性蛋白。 因此，在正常细胞中， 加合物的毒性作用将通过以下修复系统降低： 主持人