THYMIDYLATE SYNTHASE FLUORODEOXYURIDINE RESISTANCE

胸苷酸合成酶氟脱氧尿苷抗性

• 批准号: 2091340
• 负责人: FRANKLIN G. BERGER
• 金额: $ 11.72万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-03-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2091340
• 关键词: aminoacid; antineoplastics; athymic mouse; carcinoma; cell bank /registry; chemical substitution; clone cells; colon neoplasms; complementary DNA; drug resistance; enzyme mechanism; enzyme structure; floxuridine; gene expression; human population genetics; human tissue; ligands; microorganism genetics; neoplasm /cancer genetics; neoplasm /cancer pharmacology; pharmacogenetics; prognosis; protein sequence; restriction fragment length polymorphism; thymidylate synthase; transfection

Clinical resistance to chemotherapeutic drugs is a major impediment to the successful treatment of human neoplasia. though a great deal of research on model cell lines and tumors has allowed an understanding of the determinants of response and the mechanisms of resistance to a variety of useful drugs, there is need to expand existing information and to assess its significance in the clinical setting. Thus, it is pertinent to examine the extent and impact of genetic variation on parameters of drug response in human tumor cells of relevant histological origin. The fluoropyrimidine anti-metabolite 5-fluoro-2'-deoxyuridine (FdUrd) inhibits cell growth through the formation of 5-fluoro-2'- deoxyurdylic acid (FdUMP), which binds to and inhibits thymidylate synthase (TS). In previous work, we have shown that response to FdUrd varies considerably among human colonic tumor cell lines. Of particular interest is cell line HCT116, which produces a variant form of TS exhibiting a reduced affinity for FdUMP; this alteration results from a T -> C mutation in the TS gene, which causes the replacement of a tyrosine by a histidine at residue 33 of the TS polypeptide. The Tyr33 - > His33 change confers relative resistance to the inhibitory effects of FdUrd in both mammalian and bacterial cells. In the present application, we propose to conduct further studies of this mutation and its role in response to FdUrd in colonic tumor cells. We will: (1) determine the origin and frequency of the Tyr33 -> His33 substitution among colon tumor cell lines; (2) compare the Tyr33 and His33 forms of human TS with regard to their kinetics of interactions with ligands; (3) characterize the effects of different amino acid substitutions at residue 33; (4) identify and study additional variations in TS structure and function among a variety of human colonic tumor cell lines. These experiments will provide information on the mechanism by which the Tyr33 -> His33 mutation perturbs the function of TS as a fluoropyrimidine target. In all, the study of TS and its function as a drug target will generate fundamental knowledge on the relationship between protein structure and function, promoting the development of improved strategies for the design and utilization of anti-neoplastic agents. Furthermore, these studies will result in a deeper understanding of the genetic factors that govern drug response, and may lead to the identification of markers that could be useful in the pre-clinical prediction of therapeutic response in many patients.

对化学治疗药物的临床抗性是对 人类肿瘤的成功治疗。 虽然很多 对模型细胞系和肿瘤的研究允许了解 反应的决定因素和对A的抗性机制 各种有用的药物，需要扩展现有信息， 评估其在临床环境中的重要性。 因此，是 遗传变异对遗传变异的程度和影响的相关 相关组织学的人类肿瘤细胞中药物反应的参数 起源。 氟嘧啶抗代谢物5-氟2'-脱氧尿苷 （fdurd）通过形成5-氟-2'--的形成来抑制细胞生长 脱氧硫酸（fdump），该甲酸与胸腺胸酯结合并抑制 合酶（TS）。 在以前的工作中，我们已经证明了对FDURD的回应 在人类结肠肿瘤细胞系中有很大不同。 特别 感兴趣的是细胞系HCT116，它产生了TS的变异形式 表现出对Fdump的亲和力降低；这种改变是由 TS基因中的T-> C突变，导致替换 在TS多肽的残基33处的组氨酸酪氨酸。 Tyr33- > HIS33变更赋予对抑制作用的相对抵抗力 哺乳动物和细菌细胞中的fdurd。 在本应用程序中， 我们建议对这种突变及其在 对结肠肿瘤细胞中FDURD的反应。 我们将：（1）确定 Tyr33-> HIS33在结肠肿瘤中取代的起源和频率 细胞系； （2）将Tyr33和HIS33形式的人类TS与 他们与配体相互作用的动力学； （3）表征 残基33上不同氨基酸取代的影响； （4）识别 并研究TS结构和功能的其他变化 各种人类结肠肿瘤细胞系。 这些实验会 提供有关Tyr33-> His33突变的机制的信息 将TS作为氟嘧啶靶标的功能。 总的来说， TS的研究及其作为药物目标的功能将产生基本 了解蛋白质结构与功能之间的关系， 促进改进设计策略的发展和 抗肿瘤剂的利用。 此外，这些研究将 导致对控制药物的遗传因素有更深入的了解 回应，并可能导致标记可能是 在许多人的治疗反应前临床前预测中有用 患者。