α-生育酚琥珀酸酯和三氧化二砷对阿霉素诱导的白血病细胞耐药性的预防作用

Prevention of adriamycin-induced drug-resistance of leukemia cells by α-tocopheryl succinate and arsenic trioxide

目的观察α-生育酚琥珀酸酯(α-TOS)和As2O3对阿霉素(ADM)诱发的白血病细胞耐药的预防作用。方法以白血病K562细胞为模型,模拟临床化疗过程,采用间歇性给药、逐渐增量的方法诱导K562细胞对ADM产生耐药性;同时并用α-TOS或As2O3,以观察其对ADM诱导耐药性产生的影响。MTT法检测细胞耐药性,免疫荧光法观察P-糖蛋白(P-gp)表达,荧光显微镜观察细胞内ADM含量。结果经ADM诱导5个月后,K562细胞对ADM的耐受性增高约4倍,并与柔红霉素交叉耐药,P-gp表达增加,细胞内ADM的蓄积量降低;同时并用α-TOS或As2O3可不同程度地降低ADM诱导的K562细胞P-gp的表达水平和增加细胞内ADM含量,减低或延缓耐药性发生。结论α-TOS和As2O3可降低或延缓ADM诱导的白血病细胞耐药性的发生,其机制可能为抑制P-gp的表达。

Objective To observe the preventive effects of α-tocopheryl succinate（α-TOS） and arsenic trioxide on adriamycin-initiated drug-resistance of human leukemia K562 cells. Methods Human leukemia cell K562 was used as target cell, the cell was induced to produce resistance to ADM, simulating the procedure of chemotherapeutics, with the way of intermittent stimulation and gradually increasing the dosage of the drug, and simultaneous administration of α-TOS or As203 was employed to investigate its effects on the induction of drug-resistance. Drugresistance was examined with MTT colorimetric assay, and cytomorphology was checked by light microscopy. Expression of P-glycoprotein（P-gp） was detected by immunofluorescence and flow cytometry, and the cellular ADM content was detected by fluorescence microscopy. Results After five months induction with ADM, the resistance of K562 cells to ADM was 5-fold higher than that of untreated K562 cells, and cross-resistant to daunorubicin. The P-gp expression and ADM content increased markedly in ADM-treated K562 cells. Combination with α-TOS or As2Oa could inhibit P-gp expression and increase cellular ADM content at different degrees, and reduce or delay the development of drug resistance in ADM-induced K562 cells. Conclusion α-TOS and As203 are able to reduce or delay ADM-induced resistance in leukemia K562 cells via down-regulation of P-gp expression.