Combinatorial Development of Blood Stable Camptothecins

描述：(改编自申请者的摘要)喜树碱 广泛应用于实体瘤的治疗。两种喜树碱类似物 已经在市场上销售了，其他一些也处于不同阶段 研究和开发。然而，对于他们所有的承诺，都是众所周知的 喜树碱类似物包含一种基本的结构倾向：不稳定 E环内酯。直到最近，这一领域的教条一直是 E-环内酯的存在对生物活性是必不可少的。然而， 最近有迹象表明，E环中的官能团可以改变 没有损害，而且确实是有好处的。这是这笔赠款的假设 仍然需要显著改进的喜树碱衍生物，而且 下一代喜树碱衍生物应该包含一种 表现出显著改善的稳定性或不含内酯的试剂 E环内酯。这笔赠款的目的是发现这些衍生品 通过化学合成修饰内酯或内酯的聚焦文库 喜树碱的非内酯类似物及其快速检测 稳定性/化学性质、抑制酶的能力的文库 拓扑异构酶1和抗肿瘤活性。在这笔赠款中，我们建议进行 实验内容如下：1)合成A、B、E环修饰的α-羟基 内酯Campothecins，以及关于以下方面的探索性和重点文库 非内酯喜树碱。重点图书馆将建立在有希望的基础上 在早期的体外分析中已经确定的候选者。2) 鉴定探索性和聚焦文库的体外效力 对9个不同的人类癌细胞株使用快速和 高通量MTS检测。这项化验将在缺席的情况下进行 存在生理相关水平的人血清白蛋白，以便 确定这种高度丰富的血液蛋白对类似物可能产生的任何影响 活动。显示优异IC50值的模拟(在10 NM范围内或 在人血清白蛋白存在的情况下，将被选择用于合成 放大和更彻底的体外表征。3)执行彻底的 分析每个模拟量的物理属性，以确保网络稳定 在此之前进行了更广泛的体内表征。4)比较领先地位， 血液稳定的喜树碱衍生物与FDA批准的喜树碱 对荷人肿瘤移植瘤小鼠的活性。药代动力学与药物 将确定每种先导剂的代谢参数。

DESCRIPTION: (Adapted from the applicant's abstract) The camptothecins are being widely used in the treatment of solid tumors. Two camptothecin analogs are already on the market and a number of others are in various stages of research and development. However, for all their promise, all known camptothecin analogs contain a fundamental structural liability: the unstable E-ring lactone. Until recently it has been dogma in this field that the presence of the E-ring lactone was essential to biological activity. However, there are recent signs that the functionality in the E-ring can be changed without detriment and, indeed, with benefit. It is the hypothesis of this grant that significantly improved derivatives of camptothecin are still needed and that the next generation of camptothecin derivatives should either contain a lactone displaying markedly improved stability or agents that do not contain the E-ring lactone. It is the aim of this grant to discover these derivatives through the chemical synthesis of focused libraries of modified-lactone or non-lactone analogs of camptothecin followed by the rapid assaying of these libraries for stability/chemical properties, ability to inhibit the enzyme toposisomerase 1, and anti-tumor activity. In this grant we propose to conduct the following experiments: 1) Synthesize A,B,E-ring modified alpha-hydroxy lactone campothecins, as well as exploratory and focused libraries concerning non-lactone camptothecins. The focused libraries will be based on promising candidates that have been identified during the early in vitro analyses. 2) Characterize the in vitro potency of the exploratory and focused library of analogs against 9 distinct human cancer cell lines utilizing a rapid and high-throughput MTS assay. This assay will be performed in the absence and presence of physiologically relevant levels of human serum albumin in order to determine any effect this highly abundant blood protein may exert on analog activity. Analogs displaying superior IC50 values (within the 10 nM range or below) in the presence of human serum albumin will be selected for synthetic scale-up and a more thorough in vitro characterization. 3) Perform a thorough analysis of the physical properties of each analog to ensure the net stability prior to more extensive in vivo characterization. 4) Compare the lead, blood-stable camptothecin derivatives with FDA-approved camptothecins for activity in mice bearing human tumor xenografts. Pharmacokinetic and drug metabolism parameters for each of the lead agents will be determined.