In vivo bioassay to detect irinotecan-stabilized DNA/topoisomerase I complexes in rats
In vivo bioassay to detect irinotecan-stabilized DNA/topoisomerase I complexes in rats
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DOI：
10.1002/biot.200900174
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发表时间：
2010-03-01
影响因子：
4.7
通讯作者：
Esselen, Melanie
中科院分区：
文献类型：
--
作者：
Barth, Stephan W.;Briviba, Karlis;Esselen, Melanie
伊立替康是一种稳定拓扑异构酶I/DNA复合体的抗癌药物。到目前为止，还没有直接测定伊立替康诱导的拓扑异构酶I/DNA复合体在体内器官中稳定的测试系统。我们采用体内酶-DNA复合体(ICE)生物测定法，对单次口服伊立替康(100 mg/kg体重)的雄性Wistar大鼠的胃、十二指肠、结肠和肝脏中伊立替康的活性进行了评估。这与接受0.9%氯化钠腹腔注射的对照组进行了比较。此外，采用单细胞凝胶电泳法(彗星试验)检测伊立替康在大鼠远端结肠粘膜细胞中的DNA断裂特性，以探讨体内拓扑异构酶中毒与DNA损伤的关系。单剂量伊立替康可显著增加胃、十二指肠、结肠和肝脏中与DNA共价结合的拓扑异构酶I的数量。同时，伊立替康治疗组与对照组相比，结肠粘膜细胞的DNA链断裂数量显著增加。ICE生物测定法和彗星测定法是研究拓扑异构酶I毒物对Wistar大鼠结肠组织DNA完整性影响的两个测试系统。
Irinotecan is an anticancer agent that stabilizes topoisomerase I/DNA complexes. So far, no test system has been reported for directly determining irinotecan-induced stabilization of topoisomerase I/DNA complexes in organs in vivo. We adapted an 'in vivo complexes of enzyme to DNA' (ICE) bioassay to assess irinotecan activity in the stomach, duodenum, colon and liver of male Wistar rats after a single treatment with irinotecan (100 mg/kg body weight, intraperitoneally). This was compared to the control group receiving 0.9% sodium chloride intraperitoneally. In addition, the DNA strand breaking properties of irinotecan were measured in mucosal cells from the distal colon by single-cell gel electrophoresis (comet assay) to investigate the association of topoisomerase poisoning and DNA damage in vivo. A single dose of irinotecan significantly increased amounts of topoisomerase I covalently bound to DNA in stomach, duodenum, colon and liver. Concomitantly, the irinotecan-treated group showed significantly higher amounts of DNA strand breaks in colon mucosa cells compared to the control group. The ICE bioassay and the comet assay represent two test systems for investigating the impact of topoisomerase I poisons on DNA integrity in colon tissues of Wistar rats.