Han Dingding, Ma Guibo, Gao Yujuan, Su Yanhua
Hematology Department, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Evid Based Complement Alternat Med. 2021 Oct 12;2021:3083041. doi: 10.1155/2021/3083041. eCollection 2021.
Despite the constant emergence of new methods for the treatment of multiple myeloma (MM), relapse and drug resistance still exist, especially in MM with p53 mutations. Arsenic trioxide (ATO) can be used in MM treatment, but this single drug has poor effectiveness and also side effects. Curcumin is a safe and effective compound that can enhance the anticancer effects of many drugs. Previous studies have suggested that tumor cell sensitivity to ATO is related to the intracellular arsenic content, and aquaporin 9 (AQP9) is the key factor that determines intracellular arsenic content. This study aimed to explore whether curcumin can increase ATO cytotoxicity in MM and whether the mechanism is related to the regulation of intracellular arsenic content. U266 was treated with ATO, curcumin, and their combination, and cell proliferation, apoptosis, and intracellular arsenic content were detected by CCK-8 assay, flow cytometry, and HPLC-ICP-MS, respectively. AQP9 mRNA and protein levels were detected by qPCR and western blotting. The levels of Mcl-1, Bcl-2, Bax, caspase-3, and cleaved caspase-3 protein were detected by western blotting. ATO-induced cytotoxicity to U266 occurred in a time- and dose-dependent manner, but the therapeutic efficacy at low drug concentrations was modest. The arsenic content in U266 was lower than that in NB4, and the arsenic uptake by U266 was concentration-dependent. The expression levels of AQP9 mRNA and AQP9 protein in U266 were lower than those in NB4. Curcumin significantly enhanced the lethality of ATO to U266. The arsenic content in U266 in the combined drug group increased significantly compared with ATO treatment alone. After curcumin treatment, the AQP9 mRNA and AQP9 protein expression levels in U266 also increased. Compared with the control group, the expression of antiapoptotic proteins Mcl-1 and Bcl-2 decreased, the expression of proapoptotic protein Bax increased, the ratio of Bax/Bcl-2 increased, and the expression of caspase-3 decreased and cleaved caspase-3 increased in the combined drug groups. Curcumin can enhance the killing effects of ATO on U266 by increasing the intracellular arsenic content, which may be related to the upregulation of AQP9 expression. The combination of these two drugs is expected to be a potential clinical treatment for MM.
尽管治疗多发性骨髓瘤（MM）的新方法不断涌现，但复发和耐药性仍然存在，尤其是在伴有p53突变的MM中。三氧化二砷（ATO）可用于MM治疗，但这种单一药物疗效不佳且有副作用。姜黄素是一种安全有效的化合物，可增强多种药物的抗癌作用。先前的研究表明，肿瘤细胞对ATO的敏感性与细胞内砷含量有关，水通道蛋白9（AQP9）是决定细胞内砷含量的关键因素。本研究旨在探讨姜黄素是否能增加ATO对MM的细胞毒性，以及其机制是否与细胞内砷含量的调节有关。用ATO、姜黄素及其组合处理U266，分别通过CCK-8法、流式细胞术和HPLC-ICP-MS检测细胞增殖、凋亡和细胞内砷含量。通过qPCR和蛋白质印迹法检测AQP9 mRNA和蛋白水平。通过蛋白质印迹法检测Mcl-1、Bcl-2、Bax、caspase-3和裂解的caspase-3蛋白水平。ATO对U266的细胞毒性呈时间和剂量依赖性，但低药物浓度下的治疗效果一般。U266中的砷含量低于NB4，U266对砷的摄取呈浓度依赖性。U266中AQP9 mRNA和AQP9蛋白的表达水平低于NB4。姜黄素显著增强了ATO对U266的致死性。联合用药组U266中的砷含量与单独使用ATO治疗相比显著增加。姜黄素处理后，U266中AQP9 mRNA和AQP9蛋白表达水平也增加。与对照组相比，联合用药组抗凋亡蛋白Mcl-1和Bcl-2的表达降低，促凋亡蛋白Bax的表达增加，Bax/Bcl-2比值增加，caspase-3的表达降低而裂解的caspase-3增加。姜黄素可通过增加细胞内砷含量增强ATO对U266的杀伤作用，这可能与AQP9表达上调有关。这两种药物的联合有望成为MM的一种潜在临床治疗方法。
