MECHANISM OF ACTION OF THE VINCA ALKALOIDS

这一建议的重点是深入调查这一机制。 长春花碱的作用。长春花碱是一组 化学相关的吲哚-二氢吲哚类药物，目前用于 治疗多种形式的癌症。它们似乎能抑制细胞 生长至少部分是由微管的破坏造成的。尽管一个 已经了解了相当多的长春花碱是如何抑制 微管在体外组装，其确切的作用机制 定量动力学项几乎完全未知，就像一个 对创新能力与创新能力关系的认识 生物碱抑制微管聚合，并破坏 直接预制微管。此外，其抗肿瘤的特异性 长春花碱的个体是不同的，可以想象 不同的长春花碱同系物对人体具有化疗活性。 细胞通过多种不同机制的结合。 我们的研究策略分为三个具体领域。一个主要目标是 继续我们实验室以前开始的关于定量的研究 微管组装抑制机制的表征 长春花碱。这些研究将涉及动力学表征。 在稳态的相反两端的微管蛋白添加和损失 微管，使用来自不同来源的微管和 不同的分子组成。第二个目标是描述 长春花碱的相互作用导致直接的 微管的解聚(原丝束在 微管末端)。这种相互作用之间的关系 长春花碱与微管和导致组装的相互作用 抑制力将被确定。第三个目标是调查 长春花碱类化合物的构效关系 单个同系物抑制微管的能力 细胞内的聚合，以及同系物抑制细胞的能力 使用人类细胞系(Hela)生长，其微管特性在 已经在体外进行了表征。其目的是确定是否 一种特定长春花碱衍生物抑制细胞生长的作用 完全是由于细胞内微管的破坏，或者发生 通过协同能力抑制微管功能和其他 细胞过程。

This proposal focuses on an in-depth investigation into the mechanism of action of the vinca alkaloids. The vinca alkaloids are a group of chemically related indole-dihydroindole drugs that are currently used in the treatment of a number of forms of cancer. They appear to inhibit cell growth at least in part by the disruption of microtubules. Although a considerable amount has been learned about how the vinca alkaloids inhibit microtubule assembly in vitro, the precise mechanism of action in quantitative kinetic terms is almost completely unknown, as is an understanding of the relationship between the ability of the vinca alkaloids to inhibit the polymerization of microtubules, and to destroy preformed microtubules directly. Further, the antitumor specificities of the individual vinca alkaloids are different, and it is conceivable that the different vinca congeners exert their chemotherapeutic activities on cells by a combination of distinct mechanisms. Our research strategies fall into three specific areas. One major aim is to continue studies begun previously in our laboratory on the quantitative characterization of the mechanism of microtubule assembly inhibition by the vinca alkaloids. These studies will involve the kinetic characterization of tubulin addition and loss at the opposite ends of steady-state microtubules in vitro, using microtubules from several sources and of different molecular compositions. The second goal is to characterize the interactions of the vinca alkaloids that result in the direct depolymerization of microtubules (the peeling of protofilament strands at microtubule ends). The relationship between this interaction of vinblastine with microtubules and the interaction that results in assembly inhibition will be determined. The third goal is to investigate the structure-activity-relationship of the vinca alkaloid derivatives in terms of the abilities of individual congeners to inhibit microtubule polymerization in cells, and the abilities of the congeners to inhibit cell growth, using a human cell line (Hela) whose microtubule properties in vitro have been characterized. The purpose is to determine whether the action of a particular vinca alkaloid derivative in inhibiting cell growth is due exclusively to the disruption of microtubules in cells, or occurs through a concerted ability to inhibit microtubule function and other cellular processes.