TAXOL--MECHANISMS OF ACTION AND RESISTANCE

描述：（申请人的摘要）本发明的长期目标是： 应用程序是为了获得一个彻底的了解机制， 紫杉醇是一种抗肿瘤药物， 有效治疗人类癌症。 知识来自 本申请中描述的研究将提高设计 具有更好治疗指数的紫杉醇类似物，并制定策略， 逆转或克服耐药性。 对紫杉醇的理解将是 应用于其他天然产品，如埃坡霉素，其机制 作用和耐药性可能与紫杉醇相似。 具体 本申请的目的是：1）。 定义绑定位点 微管中的紫杉醇。 具有放射性标记的光反应性的紫杉醇类似物 在紫杉烷核周围和紫杉烷核中的限定位置处的取代基 A-环侧链将被用于定义微管中的口袋， 哪种紫杉醇适合 每个光反应性取代基将提供另一个 药物和微管之间的接触点。 2）。 确定是否 调节细胞中β-微管蛋白同种型的水平可以改变 对紫杉醇敏感。 将采用两种方法来分析这一问题; 一种涉及用四环素和/或蜕皮激素诱导基因表达 调节系统和其他β-微管蛋白反义寡核苷酸。 3）。 扩大申请人的研究，分析水平的变化， 获得泰素耐药的人卵巢肿瘤中的β-微管蛋白同种型。 4）。 研究内源性分子，如p19，调节 微管解体，从而拮抗紫杉醇的活性， 调节对药物的低水平耐药性。 5）。 执行结构活动 相关性（SAR）研究，以确定 生物活性的结构要求。 检查灵敏度 紫杉醇耐药细胞对埃博霉素产生耐药性 以便仔细比较这两种药物。

DESCRIPTION: (Applicant's Abstract) The long-term objectives of this application are to acquire a thorough understanding of the mechanisms of action and of resistance to Taxol, an antitumor agent that is known to be efficacious in the treatment of human cancer. Knowledge gained from the studies described in this application will improve the ability to design Taxol analogs with a better therapeutic index and to develop strategies to reverse or overcome drug resistance. The understanding of Taxol will be applied to other natural products such as the epothilones, whose mechanisms of action and resistance may be similar to that of Taxol. The specific objectives of this application are to: 1). Define the binding site for Taxol in the microtubule. Taxol analogs with radiolabeled photoreactive substituents at defined positions around the taxane nucleus and in the A-ring sidechain will be used to define the pocket in the microtubule in which Taxol fits. Each photoreactive substituent will provide another contact point between the drug and the microtubule. 2). Determine if modulating the levels of beta-tubulin isotypes in cells can alter sensitivity to Taxol. Two approaches will be used to analyze this problem; one involves inducible gene expression with the tetracycline and/or ecdysone regulated system and the other beta-tubulin antisense oligonucleotides. 3). Expand the applicant's studies on analyzing alterations in the levels of beta-tubulin isotypes in human ovarian tumors that acquire Taxol resistance. 4). Investigate endogenous molecules, such as p19, that regulate microtubule disassembly and may thereby antagonize the activity of Taxol and modulate low level resistance to the drug. 5). Perform structure activity relationships (SAR) studies on epothilone analogs to determine the structural requirements for biological activity. Examine the sensitivity of Taxol-resistant cells to epothilone and develop epothilone-resistant cells so that the two drugs can be carefully compared.