目的　目前慢性粒细胞性白血病 (CML)的化疗效果仍不理想 ,为寻找对CML敏感的药物 ,该研究探讨四硫化四砷、STI5 71和除莠霉素对CML细胞株K5 6 2的作用。方法　通过MTS方法检测三种药物在不同浓度 (0 .0 1 ,0 .1 ,1 .0 ,2 .0 ,5 .0 ,1 0 .0 μmol/L)下对K5 6 2细胞活力的影响。采用瑞氏染色、荧光染色和琼脂糖凝胶电泳观察药物处理后细胞形态学的变化和细胞凋亡的发生。用流式细胞仪检测细胞凋亡率。结果　用 5 .0 μmol/L的四硫化四砷、STI5 71和除莠霉素培养 3天 ,K5 6 2细胞活力明显下降 ,其吸光值分别为 0 .32± 0 .0 4 ,0 .4 9± 0 .0 1 ,0 .6 9± 0 .0 2 ,其中四硫化四砷和STI5 71对细胞的抑制作用强于除莠霉素 (P <0 .0 1 ) ,前两者间无明显差异 (P >0 .0 5 )。 1 .0 ,5 .0 ,1 0 .0 μmol/L的四硫化四砷对K5 6 2细胞的抑制作用呈时间依赖关系 (P <0 .0 1 )。小于 1 .0μmol/L的四硫化四砷对K5 6 2细胞活力无明显影响。四硫化四砷培养 2 4至 4 8小时后 ,K5 6 2细胞出现染色质浓缩、核碎片及凋亡小体等典型的凋亡形态学改变。用 5 .0 μmol/L的四硫化四砷、STI5 71和除莠霉素培养 72小时后 ,K5 6 2细胞的凋亡率分别为 6 8.8%、5 6 .7%和 35 .5 % ,2 .0与 3.0 μmol/L的四硫化四砷诱导K5 6 2细胞凋

Objective The therapeutic effect of chronic myeloid leukemia (CML) is undesirable. In order to find a new sensitive drug for CML, this study aims at exploring the effects of tetra arsenic tetra sulfide (As 4S 4) on human leukemia K562 cells. Methods The viability of K562 cells, represented by absorbance, was measured by MTS assay. The cells morphological changes were determined by Wright's staining and Hoechst33342 assay. The cell apoptosis was evaluated by DNA agarose gel electrophoresis and the cell apoptosis rate was measured by flow cytometry. Results The cell viability decreased significantly being cultured with 5.0 μmol/L As 4S 4, STI571 and herbimycin for 72 hrs (with absorbances of 0.32 ± 0.04 , 0.49 ± 0.01 and 0.69 ± 0.02 , respectively). As 4S 4 and STI571 had more inhibition on the K562 cells viability than herbimycin (P< 0.01 ), and there was no statistically significant difference between that of As 4S 4 and STI571. The effects of 1.0, 5.0 and 10.0 μmol/L As 4S 4 on K562 cells were time dependent. When the concentration was lower than 1.0 μmol/L, As 4S 4 had little effect on K562 cells. After being cultured with 2.0 μmol/L As 4S 4 for 24 to 48 hrs, typical morphological changes of apoptosis appeared in the K562 cells. After being cultured with 5.0 μmol/L As 4S 4, STI571 and herbimycin for 72 hrs, the apoptosis rate of K562 cells were 68.8%, 56.7% and 35.5%, respectively. When the concentrations of As 4S 4 changed from 2.0 to 3.0 μmol/L, the apoptosis rate increased from 25.7% to 45.3%. There was no significant difference between the apoptosis rate of K562 cells induced by 5.0 and 10.0 μmol/L As 4S 4. Conclusions As 4S 4 with the concentration of 2.0 μmol/L could inhibit the growth of K562 cells efficiently through inducing apoptosis.