Cancer Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran.
Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran.
Sci Rep. 2018 Feb 22;8(1):3446. doi: 10.1038/s41598-018-21710-5.
Cytotoxic activities of acetylshikonin and acetoxyisovalerylshikonin alone and in combination with chemotherapeutic agents against parental and drug resistant cell lines were determined using the MTT assay. Effects of Shikonin derivatives on BCRP, MDR1 and MRP transcript and protein levels were relatively measured. Finally, accumulation and efflux kinetics were conducted. The results revealed cell- and concentration-dependency of the cell cytotoxicity. Acetylshikonin and acetoxyisovalerylshikonin transiently made the mRNA ocean turbulent, but FACS analyses using fluorescent-labeled antibodies showed no significant change in the MDR-protein levels. Functional kinetics revealed significant block of MDR1, BCRP and MRP transporter in the presence of shikonin derivatives. Maximum accumulation fold changes was quantified to be 4.4 and consequently, acetoxyisovalerylshikonin pretreated EPG85.257RDB cells was chemosensitized to daunorubicin tension 3.1-fold. Although, the MDR blockage was reported to follow time- and cell-dependent patterns, MDR1, BCRP and MRP2 responses to the shikonins are concentration-independent. These data suggest uncompetitive transporter blockage behavior of these agents. The results indicated that shikonin derivatives stimulate uptake and reduce efflux of chemotherapeutic agents in the malignant cancer cells, suggesting that chemotherapy in combination with shikonin compounds may be beneficial to cancer cells that overexpress multidrug resistance transporters.
采用 MTT 法测定乙酰紫草素和乙酰异戊酰紫草素单独及与化疗药物联合对亲本和耐药细胞系的细胞毒性作用。相对测定紫草素衍生物对 BCRP、MDR1 和 MRP 转录本和蛋白水平的影响。最后，进行了积累和外排动力学研究。结果表明细胞毒性具有细胞和浓度依赖性。乙酰紫草素和乙酰异戊酰紫草素使 mRNA 短暂地变得混乱，但使用荧光标记抗体的 FACS 分析显示 MDR 蛋白水平没有显著变化。功能动力学研究表明，在紫草素衍生物存在的情况下，MDR1、BCRP 和 MRP 转运体被显著阻断。最大积累倍数变化被量化为 4.4，因此，乙酰异戊酰紫草素预处理的 EPG85.257RDB 细胞对柔红霉素的敏感性增加了 3.1 倍。尽管报道 MDR 阻断遵循时间和细胞依赖性模式，但 MDR1、BCRP 和 MRP2 对紫草素的反应是浓度独立的。这些数据表明这些药物具有非竞争性转运体阻断行为。结果表明，紫草素衍生物刺激恶性癌细胞中化疗药物的摄取并减少其外排，提示化疗联合紫草素化合物可能有益于过度表达多药耐药转运体的癌细胞。
