Novel Topoisomerase I Inhibitors

新型拓扑异构酶 I 抑制剂

基本信息

批准号：
8305654
负责人：
MARK S CUSHMAN
金额：
$ 22.38万
依托单位：
PURDUE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-09-10 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8305654
关键词：
Address African Animal Model Antibiotics Antineoplastic Agents Biochemical Biochemistry Biological Biological Assay Camptothecin Cell Culture Techniques Cell Line Charge Chemotherapy-Oncologic Procedure Clinical Clinical Research Clinical Trials Collaborations Complex Computer Graphics Crystallography DNA Drug Design Drug Kinetics Drug toxicity Electrostatics Enzyme Inhibitor Drugs Enzyme Inhibitors Evaluation Fiber Foundations Future Goals Homing Human Hybrids Hydrogen Bonding Implant Inhibition of Cell Proliferation Kinetics Ligands Link London Mammalian Cell Mediating Methods Modification Molecular Molecular Models Molecular Weight Monitor National Cancer Institute Nitrogen Normal Cell Pharmaceutical Chemistry Phosphodiesterase I Proteins Quantum Mechanics Reaction Relative (related person)Relaxation Research Resistance Solid Neoplasm Structure Superhelical DNA Testing Topoisomerase-I Inhibitor Toxic effect Trypanosoma Type I DNA Topoisomerases Xenograft procedure absorption analog base cancer cell cancer therapy charge transfer complex cytotoxicity design inhibitor/antagonist inorganic phosphate intercalation link protein molecular mechanics molecular modeling novel phosphodiester public health relevance research clinical testing tumor tumor growth tyrosyl-DNA phosphodiesterase uptake van der Waals force

项目摘要

DESCRIPTION (provided by applicant): The long-term goals of this project are to design, synthesize and evaluate novel topoisomerase I (Top1) inhibitors for the treatment of cancer. The clinical studies will allow future problems revealed by the clinical results to be addressed immediately and effectively. This could include structural modification to address potential problems resulting from drug toxicity, resistance, unfavorable pharmacokinetics, and lack of potency. The Top1 design strategy will involve an evaluation of the fundamental forces stabilizing the inhibitor/enzyme/DNA ternary complexes through medicinal chemistry, computer graphics molecular modeling, molecular mechanics, ab initio quantum mechanics, and biochemical studies. In addition, the design of new Top1 inhibitors will be aided by crystallography inhibitor/enzyme/DNA of ternary complexes, which will facilitate structure-based drug design. A variety of synthetic methods will be employed in the syntheses of new Top I inhibitors, including indenoisoquinoline-camptothecin hybrids termed "aromathecins", nitrogen analogues of the aromathecins, and azaindenoisoquinolines. The resulting anticancer agents will be targeted to cancer cells and solid tumors through attachment of low molecular weight homing ligands that will be removed metabolically after selective uptake into cancer cells as opposed to normal cells. The conjugates will be evaluated by testing the release mechanism, monitoring inhibition of cell proliferation, blocking the attachment of the homing ligand to cancer cells to help elucidate mechanism of action, and determining selectivities in the NCI panel of cancer cell cultures. The phosphodiester bond linking Tyr723 of Top I to the 3'-phosphate of DNA in stalled cleavage complexes is hydrolyzed by tyrosyl-DNA-phosphodiesterase I (Tdp1). Since Tdp1 inhibitors counteract the action of Top1 inhibitors, Tdp1 inhibitors might interact synergistically with Top1 inhibitors. A goal of this project is to incorporate both Top1 and Tdp1 inhibitory activities into the same anticancer agents, which are expected be significantly more potent than those of Top I inhibitors lacking Tdp1 inhibitory activity. This will exploit a unique discovery of Tdp1 inhibitory activity in several indenoisoquinolines. The Top1 inhibitors resulting from this study will be evaluated in a variety of assays including those involving: 1) Top1-mediated DNA cleavage reactions; 2) Top1-DNA linkage and reversibility of cleavage complexes; 3) kinetics of cleavage complex formation and reversal; 4) DNA unwinding to monitor intercalation; 5) inhibition of Top1-mediated DNA relaxation; 6) protein-linked strand breaks induced by inhibitors in mammalian cells; 7) cytotoxicity assays in cancer cell cultures, including camptothecin-resistant cells lines; 8) hollow fiber studies and xenograft testing; 9) antibiotic activity vs. African trypanosomes. PUBLIC HEALTH RELEVANCE: This is a competitive renewal application for the design and synthesis of topoisomerase I inhibitors for the treatment of cancer in humans. The project has already generated two clinical candidates, indimitecan and indotecan, which will undergo clinical evaluation at the National Cancer Institute. The continuation of the project will allow the medicinal chemistry, crystallography, and biochemistry components of the project to remain actively involved so that the potential limitations of the two clinical candidates can be addressed effectively.

描述（由申请人提供）：该项目的长期目标是设计、合成和评估用于治疗癌症的新型拓扑异构酶 I (Top1) 抑制剂。临床研究将使临床结果揭示的未来问题能够得到立即有效的解决。这可能包括结构修饰，以解决由药物毒性、耐药性、不利的药代动力学和缺乏效力引起的潜在问题。 Top1 设计策略将涉及通过药物化学、计算机图形分子建模、分子力学、从头算量子力学和生物化学研究来评估稳定抑制剂/酶/DNA 三元复合物的基本力。此外，新的Top1抑制剂的设计将得到晶体学抑制剂/酶/DNA三元复合物的辅助，这将有利于基于结构的药物设计。多种合成方法将用于合成新的Top I抑制剂，包括被称为“芳香霉素”的茚并异喹啉-喜树碱杂种、芳香霉素的氮类似物和氮杂茚并异喹啉。由此产生的抗癌剂将通过附着低分子量归巢配体靶向癌细胞和实体瘤，这些配体在选择性摄取到癌细胞（而不是正常细胞）后将被代谢去除。将通过测试释放机制、监测细胞增殖抑制、阻断归巢配体与癌细胞的附着以帮助阐明作用机制以及确定 NCI 癌细胞培养物组中的选择性来评估缀合物。在停滞的裂解复合物中，将 Top I 的 Tyr723 连接到 DNA 3'-磷酸的磷酸二酯键被酪氨酰-DNA-磷酸二酯酶 I (Tdp1) 水解。由于 Tdp1 抑制剂抵消 Top1 抑制剂的作用，因此 Tdp1 抑制剂可能与 Top1 抑制剂产生协同相互作用。该项目的目标是将 Top1 和 Tdp1 抑制活性纳入相同的抗癌药物中，预计其比缺乏 Tdp1 抑制活性的 Top I 抑制剂更有效。这将利用几种茚并异喹啉中 Tdp1 抑制活性的独特发现。本研究产生的 Top1 抑制剂将在多种测定中进行评估，包括：1) Top1 介导的 DNA 裂解反应； 2) Top1-DNA 连接和裂解复合物的可逆性； 3) 裂解复合物形成和逆转的动力学； 4) DNA解旋以监测嵌入； 5) 抑制Top1介导的DNA松弛； 6) 哺乳动物细胞中抑制剂诱导的蛋白连接链断裂； 7) 癌细胞培养物中的细胞毒性测定，包括喜树碱抗性细胞系； 8) 中空纤维研究和异种移植测试； 9) 抗生素活性与非洲锥虫的比较。公共健康相关性：这是一项竞争性更新申请，旨在设计和合成用于治疗人类癌症的拓扑异构酶 I 抑制剂。该项目已经产生了两种临床候选药物，indimitecan和indotecan，将在国家癌症研究所进行临床评估。该项目的继续将使该项目的药物化学、晶体学和生物化学部分继续积极参与，以便有效解决两个临床候选药物的潜在局限性。