Valenti M, Cimoli G, Mariani G L, Conte P F, Parodi S, Russo P
Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Biochem Pharmacol. 1993 Oct 5;46(7):1199-206. doi: 10.1016/0006-2952(93)90468-c.
Tumor necrosis factor (TNF) is a pleiotropic cytokine that mediates different cellular responses including cytotoxicity, cytostasis, proliferation, differentiation and expression of specific genes. Recent studies have demonstrated that chemotherapeutic drugs that inhibit the nuclear enzyme DNA topoisomerase II synergize with TNF in tumor cell killing in vitro and in vivo. We now report that a combination of TNF and the topoisomerase II inhibitor Mitoxantrone produced dose-dependent synergistic cytotoxicity against the human ovarian cancer cell line A2774 in a clonogenic assay (1 hr treatment). This result was obtained with simultaneous administration of the drug and the cytokine under test, and is independent of modification of Mitoxantrone uptake. This combination is responsible for an evident augmentation of "cleavable complex" formation. From isolated nuclei, we have isolated also the topoisomerase II activity; we observed an increment when the cells were previously treated with TNF, 2.5 min before nuclear extraction. After 10-30 min of treatment with TNF, the topoisomerase II activity returned to normal values. If TNF is not given with but 30 min before Mitoxantrone, no potentiation of cytotoxicity or break induction is observed. These results suggest that specific timing of the association may be needed also when attempting to translate it to animals and humans.
肿瘤坏死因子（TNF）是一种多效性细胞因子，可介导不同的细胞反应，包括细胞毒性、细胞生长停滞、增殖、分化以及特定基因的表达。最近的研究表明，抑制核酶DNA拓扑异构酶II的化疗药物在体外和体内的肿瘤细胞杀伤中可与TNF协同作用。我们现在报告，在克隆形成试验（1小时处理）中，TNF与拓扑异构酶II抑制剂米托蒽醌联合使用对人卵巢癌细胞系A2774产生了剂量依赖性的协同细胞毒性。该结果是在同时给予受试药物和细胞因子的情况下获得的，并且与米托蒽醌摄取的改变无关。这种联合导致“可切割复合物”形成明显增加。从分离的细胞核中，我们还分离出了拓扑异构酶II活性；当细胞在核提取前2.5分钟先用TNF处理时，我们观察到该活性增加。用TNF处理10 - 30分钟后，拓扑异构酶II活性恢复到正常值。如果TNF不是与米托蒽醌同时而是在米托蒽醌前30分钟给予，则未观察到细胞毒性增强或断裂诱导。这些结果表明，在试图将其应用于动物和人类时，也可能需要特定的联合给药时间。
