Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
BMC Cancer. 2019 Jul 15;19(1):689. doi: 10.1186/s12885-019-5891-y.
While multiagent chemotherapy has dramatically improved the prognosis of sarcoma, the novel chemotherapeutics have hardly developed over the past 30 years. Caffeine can induce apoptosis, delays in cell cycle progression and can enhance the cytocidal effects of anti-cancer agents. Citrate has been reported to enhance the cytocidal effect of cisplatin in gastric cancer in vitro. However its effect in sarcoma cells had not been reported.
This study was designed to evaluate whether the addition of caffeine, citrate, or caffeine citrate to cisplatin improved its cytocidal effect (cell survival, proliferation, and apoptosis) on human osteosarcoma (HOS), human fibrosarcoma (HT1080) and murine osteosarcoma (LM8) cell lines. We also tested the various combinations in a mouse heterotopic transplantation model in vivo. In cell survival assay, combination index (CI) of caffeine citrate was calculated as a combination of anhydrous caffeine and citric acid, and the synergy was evaluated (CI < 1.0).
In all cell lines, cisplatin combined with caffeine citrate significantly reinforced the anticancer effect compared with cisplatin alone, combination of cisplatin and anhydrous caffeine, and combination of cisplatin and citric acid. Moreover, CI was < 1.0 in all conditions. The anticancer agent reinforcement effect of caffeine citrate was synergy of anhydrous caffeine and citric acid. In cell proliferation and cell cycle assay revealed that caffeine citrate had most strong effect as a combination drug than caffeine and citric acid in inducing G0/G1 cell-cycle arrest with subsequent suppressed cell proliferation. In mitochondrial depolarization and caspase 3/7 activity assay revealed that caffeine citrate had most strong effect as a combination drug than caffeine and citric acid in apoptosis associated with decreased mitochondrial membrane potential. In vivo, three different drug concentrations were tested, and cisplatin combined with caffeine citrate was found to have the strongest antitumor effect.
This is the first report demonstrating that caffeine citrate has a significantly greater potentiating effect on cisplatin than adding either caffeine or citric acid. The combination of cisplatin with caffeine citrate is a novel treatment that might hold promise for improving the outcome of osteosarcoma and fibrosarcoma, which up till now has generally not responded well to chemotherapy.
虽然多药化疗显著改善了肉瘤的预后，但在过去 30 年中，新型化疗药物几乎没有发展。咖啡因可诱导细胞凋亡，延缓细胞周期进展，并增强抗癌药物的细胞毒性作用。已有报道称柠檬酸可增强顺铂在体外胃癌中的细胞毒性作用。然而，其在肉瘤细胞中的作用尚未报道。
本研究旨在评估在人骨肉瘤（HOS）、人纤维肉瘤（HT1080）和鼠骨肉瘤（LM8）细胞系中，加入咖啡因、柠檬酸或咖啡因柠檬酸盐是否能增强顺铂的细胞毒性作用（细胞存活、增殖和凋亡）。我们还在体内小鼠异位移植模型中测试了各种组合。在细胞存活测定中，咖啡因柠檬酸盐的联合指数（CI）计算为无水咖啡因和柠檬酸的组合，并评估了协同作用（CI<1.0）。
在所有细胞系中，与顺铂单独使用、顺铂与无水咖啡因联合使用以及顺铂与柠檬酸联合使用相比，顺铂与咖啡因柠檬酸盐联合使用显著增强了抗癌作用。此外，所有条件下的 CI 均<1.0。咖啡因柠檬酸盐的抗癌增强作用是无水咖啡因和柠檬酸的协同作用。在细胞增殖和细胞周期测定中，与咖啡因和柠檬酸相比，咖啡因柠檬酸盐作为联合药物在诱导 G0/G1 细胞周期停滞和随后抑制细胞增殖方面具有最强的作用。在线粒体去极化和 caspase 3/7 活性测定中，与柠檬酸相比，咖啡因柠檬酸盐作为联合药物在凋亡相关的线粒体膜电位降低方面具有最强的作用。体内实验测试了三种不同的药物浓度，发现顺铂联合咖啡因柠檬酸盐具有最强的抗肿瘤作用。
这是第一个报道表明咖啡因柠檬酸盐对顺铂的增强作用明显大于添加咖啡因或柠檬酸。顺铂与咖啡因柠檬酸盐的联合治疗可能为改善骨肉瘤和纤维肉瘤的预后提供新的治疗方法，这些肿瘤迄今为止对化疗反应一般不佳。
