增加细胞内三氧化二砷浓度恢复耐三氧化二砷的K562细胞对其敏感性的研究

目的 探讨耐受三氧化二砷（ATO）的白血病ATO耐药K562细胞（K562/AS2细胞）内砷浓度与耐药性的关系.方法 亲代敏感K562细胞（K562/S细胞）按照逐步增加ATO浓度诱导,建立K562/AS2细胞.采用原子荧光光谱法检测细胞内砷浓度.采用四甲基偶氮唑蓝（MTT）法检测不同浓度ATO对细胞的毒性作用.结果 1μg/ml ATO培养24、48、72h后,K562/S细胞内的砷浓度比K562/AS2细胞增高（15.63±0.42） μg/L比0μg/L、（22.27±0.15） μg/L比（3.51±0.12） μg/L、（24.31±0.21） μg/L比（3.61±0.11） μg/L;均P＜0.05].随着ATO浓度的增加及培养时间的延长,K562/AS2细胞内砷浓度逐渐增加（P＜0.05）,在1μg/ml和2μg/ml间砷浓度增加较快.K562/AS2细胞生长抑制率也逐渐增加（P＜0.05）,在1μg/ml和2μg/ml间增加较快.直线相关分析显示,当K562/AS2细胞与ATO接触分别为24、48和72 h时,其细胞生长抑制率均与细胞内ATO浓度呈正相关.结论 增加ATO浓度或延长ATO作用时间均可增加耐药细胞内ATO浓度,细胞内ATO浓度与ATO对细胞的毒性呈正相关,增加细胞内ATO浓度能够增强耐ATO K562细胞对ATO的敏感性.

Increasing the intracellular concentration of arsenic trioxide restores the sensitivity of arsenic trioxide-resistant K562 cells to arsenic trioxide

Objective To explore the relationship between intracellular concentration of arsenic trioxide （ATO） in ATO-resistant K562 cells （K562/AS2） and ATO resistance level.Methods The K562/AS2 cells were established by gradually increasing the concentration of ATO from the parental cell line,K562.Arsenic concentration was measured with atomic fluorescence photometry.Cell viability was assessed using MTT assay.Results At exposure to 1 μg/ml ATO for 24 h,48 h and 72 h,the arsenic concentration in the K562/S cells were all significantly higher than that in the K562/AS2 cells,（15.63± 0.42） μg/L vs 0 μg/L,（22.27±0.15） μg/L vs （3.51±0.12） μg/L and （24.31±0.21） μg/L vs （3.61±0.11） μg/L （P 〈 0.05）.With increasing concentration and the extension of incubation time,concentration of arsenic in cells was gradually increased （P 〈 0.05）,which increase quickly between 1 μg/ml and 2 μg/ml.The growth inhibition rate of K562/AS2 cells was also gradually increased （P 〈 0.05）,which increased quickly between 1 μg/ml and 2 μg/ml.Linear correlation analysis showed that when the K562/AS2 cells was exposed to ATO for 24 h,48 h and 72 h,respectively,the cell growth inhibition rates were positively correlated with the intracellular concentration of ATO.Conclusions Either increasing concentrations of ATO or prolonging the exposure time to ATO can increase intracellular concentration of ATO in ATO-resistant cells,and intracellular arsenic concentration is positively related to the cytotoxicity of ATO to K562/AS2 cells.Therefore,the sensitivity to ATO of ATOresistant K562 cells could be restored by increasing the intracellular concentration of ATO.