Department of Immunopathology, Division of Allergology, Immunology and Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Lodz, Poland.
Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
Mol Biol Rep. 2020 Jan;47(1):67-76. doi: 10.1007/s11033-019-05105-x. Epub 2019 Oct 3.
Etoposide (VP-16) is the topoisomerase 2 (Top2) inhibitor used for treating of glioma patients however at high dose with serious side effects. It induces DNA double-strand breaks (DSBs). These DNA lesions are repaired by non-homologous DNA end joining (NHEJ) mediated by DNA-dependent protein kinase (DNA-PK). One possible approach to decrease the toxicity of etoposide is to reduce the dose while maintaining the anticancer potential. It could be achieved through combined therapy with other anticancer drugs. We have assumed that this objective can be obtained by (1) a parallel topo2 α inhibition and (2) sensitization of cancer cells to DSBs. In this work we investigated the effect of two Top2 inhibitors NK314 and VP-16 in glioma cell lines (MO59 K and MO59 J) sensitized by DNA-PK inhibitor, NU7441. Cytotoxic effect of VP-16, NK314 alone and in combination on human glioblastoma cell lines, was assessed by a colorimetric assay. Genotoxic effect of anticancer drugs in combination with NU7441 was assessed by comet assay. Cell cycle distribution and apoptosis were analysed by flow cytometry. Compared with VP-16 or NK314 alone, the combined treatment significantly inhibited cell proliferation. Combination treatment was associated with a strong accumulation of DSBs, modulated cell cycle phases distribution and apoptotic cell death. NU7441 potentiated these effects and additionally postponed DNA repair. Our findings suggest that NK314 could overcome resistance of MO59 cells to VP-16 and NU7441 could serve as sensitizer to VP-16/NK314 combined treatment. The combined tripartite approach of chemotherapy could reduce the overall toxicity associated with each individual therapy, while concomitantly enhancing the anticancer effect to treat human glioma cells. Thus, the use of a tripartite combinatorial approach could be promising and more efficacious than mono therapy or dual therapy to treat and increase the survival of the glioblastoma patients.
依托泊苷（VP-16）是一种拓扑异构酶 2（Top2）抑制剂，用于治疗神经胶质瘤患者，但高剂量会产生严重的副作用。它会诱导 DNA 双链断裂（DSB）。这些 DNA 损伤通过 DNA 依赖性蛋白激酶（DNA-PK）介导的非同源 DNA 末端连接（NHEJ）修复。降低依托泊苷毒性的一种可能方法是降低剂量，同时保持抗癌潜力。这可以通过与其他抗癌药物联合治疗来实现。我们假设，这一目标可以通过（1）平行抑制 Top2α 和（2）使癌细胞对 DSB 敏感来实现。在这项工作中，我们研究了两种 Top2 抑制剂 NK314 和 VP-16 在 DNA-PK 抑制剂 NU7441 敏化的神经胶质瘤细胞系（MO59 K 和 MO59 J）中的作用。通过比色法评估 VP-16、NK314 单独和联合对人神经母细胞瘤细胞系的细胞毒性作用。通过彗星试验评估抗癌药物与 NU7441 联合的遗传毒性作用。通过流式细胞术分析细胞周期分布和细胞凋亡。与 VP-16 或 NK314 单独治疗相比，联合治疗显著抑制了细胞增殖。联合治疗与 DSBs 的大量积累、细胞周期相分布的调节和凋亡细胞死亡有关。NU7441 增强了这些作用，并额外推迟了 DNA 修复。我们的研究结果表明，NK314 可以克服 MO59 细胞对 VP-16 的耐药性，NU7441 可以作为 VP-16/NK314 联合治疗的增敏剂。化疗的三联方法可以降低与每种单独治疗相关的整体毒性，同时增强抗癌效果，以治疗和提高神经母细胞瘤患者的生存率。因此，与单药或双药治疗相比，三联组合方法的使用可能更有前途，更有效。
