Study on the multiple drug resistant mechanisms in clinical materials of lung cencer

为了研究拓扑异构酶II与拓扑异构酶II抑制剂药物敏感性之间的关系，我们在人肺癌细胞株中检测了拓扑异构酶IIα的含量、催化活性以及对拓扑异构酶抑制剂阿霉素和依托泊苷的敏感性。此外，还研究了这些生化分析与制剂中胞浆拓扑异构酶II免疫染色的关系。人类肺癌细胞株对阿霉素和依托泊苷的药物敏感性差异不能用拓扑异构酶IIα水平和拓扑异构酶II催化活性来解释。拓扑异构酶II免疫染色阳性细胞百分率与拓扑异构酶IIα含量或催化活性水平相一致。我们的结果表明，拓扑异构酶II免疫染色可以用来代替生化分析。通过经支气管镜下刷检或抽吸或胸腔积液，很难从肺癌患者身上收集足够的细胞进行生化分析。因此，我们使用共聚焦激光扫描显微镜检测了药物在细胞内的分布。在本研究中，核内药物积聚的细胞比核外药物积聚的细胞更敏感。此外，用激光共聚焦扫描显微镜免疫染色方法检测到耐药细胞株拓扑异构酶II酶在核外的分布。激光共聚焦扫描显微镜可用于检测临床标本中通常含量较少的药物敏感性和耐药性。这些方法适用于胸腔内注射蒽环类药物后的恶性胸腔积液患者。核内药物积聚的患者显示恶性积液得到很好的控制。结论：该方法可用于肺癌细胞的药物敏感性评价，尤其是临床资料。

Topoisomerase II alpha content, topoisomerase II catalytic activity and drug sensitivities to the topoisomerase inhibitors, doxorubicin, and etoposide, were examined in human lung cencer cell lines to determine the relationship between topoisomerase II and drug sensitivities to the topoisomerase II inhibitors. Moreover, the relationship between these biochemical analyzes and topoisomerase II immunostaining in cytosp=in preparations was examined. The difference in drug sensitivities to doxorubicin and etoposide in human lung cencer cell lines is not explainable by the topoisomerase II alpha levels and topoisomerase II catalytic activity. The percentages of positive cells for topoisomerase II immunostaining are compatible with the levels of topoisomerase II alpha content or topoisomerase II catalytic activity. Our results indicate that topoisomerase II immunostaining can be utilized in place of biochemical analysis. It is difficult to collect sufficient cells for these biochemical analyzes from lung cencer patients by transbronchial brushing or aspiration, or pleural effusions. Therefore, we examined the intracellular drug distribution using a confocal laser scanning microscopy. In this study, the cells with intranuclear drug accumulation are more sensitive than those with extranuclear drug accumulation. Moreover, the resistant cell line showed extranuclear distribution of topoisomerase II enzyme detected by immunostaining method using the confocal laser scanning microscopy. The confocal laser scanning microscopy is useful to detect the drug sensitivity and resistant in clinical samples those are usually small amount.These methods are applied in the patients with malignant pleural effusion after intra-pleural injection of anthracyclines. The patients with intranuclear drug accumulation revealed the good control of malignant effusion. We conclude that this method is useful in the estimation of drug sensitivity of lung cencer cells, especially the clinical materials.