Antitumor Agents. I. DNA Topoisomerase II Inhibitory Activity and the Structural Relationship of Podophyllotoxin Derivatives as Antitumor Agents.
作者:Tadafumi TERADA、Katsuhiko FUJIMOTO、Makoto NOMURA、Jun-ichi YAMASHITA、Takashi KOBUNAI、Setsuo TAKEDA、Konstanty WIERZBA、Yuji YAMADA、Hideo YAMAGUCHI
DOI:10.1248/cpb.40.2720
日期:——
Various podophyllotoxin derivatives from desoxypodophyllotoxin (DPT) were synthesized to examine the structural relationships between the biological significance (cytotoxic effect, effects on DNA topoisomerase II and tubulin polymerization) in vitro and antitumor activity in vivo (L 1210).An intact 6, 7-methylenedioxy group of DPT is necessary to inhibit tubulin polymerization and topoisomerase II. 4'-Phenolic hydroxyl group of DPT is essential to inhibit DNA topoisomerase II and the inhibitory effect on DNA topoisomerase II contributes to a high cytotoxicity.The introduction of an aminoalkoxy group at 1-position of DPT enhances the inhibitory activity against DNA topoisomerase II and cytotoxic effect, causing the inhibitory activity against tubulin polymerization to disappear. The results of antitumor test in mice bearing L 1210 on podophyllotoxin derivatives suggest the following : 1) the strong cytotoxic effect itself is not a good indication of antitumor activity in vivo as long as it is associated with inhibition of tubulin polymerization. DNA topoisomerase II inhibitory effect contributes to an antitumor activity in vivo; 2) detailed measurements of cytotoxicity and inhibition on DNA topoisomerase II and tubulin polymerization in vitro are necessary to evaluate podophyllotoxin derivatives.
合成了多种来自脱氧髓鞘素(DPT)的紫苑毒素衍生物,以研究其在体外的生物重要性(细胞毒性、对 DNA 拓扑异构酶 II 的影响和微管聚合影响)与在体内的抗肿瘤活性(L 1210)之间的结构关系。DPT 的完整 6, 7-亚甲基二氧基基团是抑制微管聚合和拓扑异构酶 II 所必需的。DPT 的 4'-酚羟基对于抑制 DNA 拓扑异构酶 II 是必不可少的,而对 DNA 拓扑异构酶 II 的抑制作用导致了高细胞毒性。DPT 在 1 位置引入氨基烷氧基团增强了对 DNA 拓扑异构酶 II 的抑制活性和细胞毒性,导致对微管聚合的抑制活性消失。在 L 1210 移植小鼠中对紫苑毒素衍生物的抗肿瘤测试结果表明:1)只要与抑制微管聚合相关,强细胞毒性本身并不是评估体内抗肿瘤活性的良好指征。DNA 拓扑异构酶 II 的抑制作用对体内抗肿瘤活性有贡献;2)为了评估紫苑毒素衍生物,需详细测定体外的细胞毒性及对 DNA 拓扑异构酶 II 和微管聚合的抑制作用。