Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, 90-236 Lodz, Poland.
Int J Mol Sci. 2021 Sep 29;22(19):10557. doi: 10.3390/ijms221910557.
This study examined the effect of combination treatment with the poly (ADP-ribose) polymerase inhibitor olaparib and metformin on homologous recombination (HR)-proficient epithelial ovarian cancer (EOC). Ovarian cancer cell lines (OV-90 and SKOV-3) were treated with olaparib, metformin, or a combination of both. Cell viability was assessed by MTT and colony formation assays. The production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential were examined using the specific fluorescence probes, DCFH2-DA (2',7'-dichloro-dihydrofluorescein diacetate) and JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine). Apoptotic and necrotic changes were measured by double staining with Hoechst 33258 and propidium iodide, orange acridine and ethidium bromide staining, phosphatidylserine externalization, TUNEL assay, caspase 3/7 activity, and cytochrome c and p53 expression. Compared with single-drug treatment, the combination of olaparib and metformin significantly inhibited cell proliferation and colony formation in HR-proficient ovarian cancer cells. ROS production preceded a decrease in mitochondrial membrane potential. The changes in ROS levels suggested their involvement in inducing apoptosis in response to combination treatment. The present results indicate a shift towards synergism in cells with mutant or null p53, treated with olaparib combined with metformin, providing a new approach to the treatment of gynecologic cancers. Taken together, the results support the use of metformin to sensitize EOC to olaparib therapy.
本研究探讨了聚（ADP-核糖）聚合酶抑制剂奥拉帕利和二甲双胍联合治疗同源重组（HR）功能正常的上皮性卵巢癌（EOC）的效果。用奥拉帕利、二甲双胍或两者联合处理卵巢癌细胞系（OV-90 和 SKOV-3）。通过 MTT 和集落形成测定评估细胞活力。使用特异性荧光探针 DCFH2-DA（2'，7'-二氯二氢荧光素二乙酸酯）和 JC-1（5,5'，6,6'-四氯-1,1'，3,3'-四乙基苯并咪唑羰花青）检测活性氧（ROS）的产生和线粒体膜电位的变化。通过 Hoechst 33258 和碘化丙啶、橙色吖啶和溴化乙锭染色、磷脂酰丝氨酸外翻、TUNEL 测定、半胱天冬酶 3/7 活性以及细胞色素 c 和 p53 表达双重染色来测量凋亡和坏死变化。与单药治疗相比，奥拉帕利和二甲双胍联合显著抑制 HR 功能正常的卵巢癌细胞的增殖和集落形成。ROS 的产生先于线粒体膜电位的降低。ROS 水平的变化表明它们参与了对联合治疗的凋亡诱导。这些结果表明，在具有突变或缺失 p53 的细胞中，奥拉帕利联合二甲双胍治疗具有协同作用，为妇科癌症的治疗提供了一种新方法。总之，这些结果支持使用二甲双胍使 EOC 对奥拉帕利治疗敏感。
