目前正在开发新的抗癌药物，以避免目前可用药物的毒性和化疗抵抗性。已获得美国食品药品监督管理局批准的抗疟药阿托伐醌（atovaquone）被认为通过竞争与线粒体复合物II和III中的CO Q10结合来作为线粒体选择性氧化磷酸化抑制剂。本研究旨在通过检测不同犬细胞系中的Na+/K+-ATP酶（NKA）活性，探讨阿托伐醌的作用。将犬细胞系分别用2.5、5、10、15和20μM的阿托伐醌处理24、48和72小时。使用人类细胞系作为对照验证犬癌细胞系。使用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四唑溴化物酶联免疫吸附测定法测量药物对癌细胞系的抑制作用。通过测量腺苷酸磷酸二核苷酸依赖性细胞氧化还原酶的活性来确定细胞代谢活性。使用单细胞贴片钳技术测量NKA活性。阿托伐醌通过提高肿瘤细胞内反应性氧化物（ROS）浓度导致细胞凋亡，从而引发细胞死亡。使用N-乙酰半胱氨酸（ROS抑制剂）处理犬癌细胞可以减少药物活性。此外，阿托伐醌抑制了超过45%的NKA离子电流。本研究证明了阿托伐醌对犬癌细胞系的作用。这些数据可能有助于将该药物重新用于犬临床试验中的新型抗癌药物，从而有助于对抗人类癌症。版权：©阿尔哈比。

New anticancer drugs are being developed to avoid the toxicity and chemoresistance of the currently available drugs. The Food and Drug Administration-approved anti-malarial drug atovaquone is known to act as a selective oxidative phosphorylation inhibitor in the mitochondria by competing with CO Q10 (mitochondrial complex II and III). This study aimed to investigate the effect of atovaquone by examining the Na+/K+-ATPase (NKA) activity in various canine cell lines.Canine cell lines were treated with various concentrations (2.5, 5, 10, 15, and 20 μM) of atovaquone for 24, 48, and 72 h. Human cell lines were used as a control to validate the canine cancer cell lines. The activities of the drugs against the cancer cell lines were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromideassay. The cell metabolic activity was determined by measuring the activities of the nicotinamide adenine dinucleotide phosphate-dependent cellular oxidoreductase enzymes. The NKA activity was measured using the single-cell patch clamping assay.Atovaquone-induced apoptosis by elevating the concentration of reactive oxygen species (ROS) in the tumor cells, leading to cell death. Treatment of canine cancer cells with N-acetylcysteine (ROS inhibitor) reduced the activity of the drug. Furthermore, atovaquone inhibited more than 45% of the NKA ion current.This study demonstrated effects of atovaquone against canine cancer cell lines. The data may prove beneficial in repurposing the drug as a new anticancer agent in canine clinical trials, which might aid in fighting human cancer.Copyright: © Alharbi.