三氧化二砷联合丁硫氨酸亚砜胺诱导人白血病K562/ADM细胞凋亡

目的 观察三氧化二砷(As2O3)联合丁硫氨酸亚砜胺(BSO)对肿瘤多药耐药细胞K562/ADM的诱导凋亡效应,探讨谷胱甘肽(GSH)的含量变化对As2O3作用效果的影响.方法 以0.5、2.0、5.0 μmol/L As2O3单独及联合100 μmol/L BSO作用于K562/ADM细胞,应用二苯基溴化四氮唑蓝(MTT)比色法检测细胞的增殖活性,Annexin V/PI标记法观察细胞的凋亡效应,分光光度法检测细胞内GSH含量的变化.结果 K562/ADM细胞内GSH含量为(81.13±3.91)mg/g prot,明显高于K562细胞(P＜0.01).BSO单独或联合As2O3作用下,随作用时间的延长,K562/ADM细胞内GSH含量逐渐降低.临床剂量(0.5、2.0 μmol/L)As2O3联合BSO作用下,抑制作用逐步增强,72 h两组的细胞增殖抑制率分别为(90.63±5.95)%和(86.12±6.11)%,均分别高于单用相应剂量As2O3组(P＜0.01);凋亡效应逐步增强,72 h两组的细胞凋亡率分别为(82.15±9.28)%和(92.72±9.41)%,均分别高于单用相应剂量As2O3组(P＜0.01).结论 GSH的含量变化与As2O3的作用效果密切相关,As2O3联合BSO可有效诱导K562/ADM细胞发生凋亡.

Arsenic trioxide combined with buthionine sulfoximine enhances apoptosis in multidrug-resistant human leukemia K562/ADM cells in vitro

OBJECTIVE: To investigate the apoptosis-inhancing effect of the combination of arsenic trioxide (As2O3 ) and buthionine sulfoximine (BSO) on multidrug-resistant human leukemic K562/ADM cells, to compare the effect of As2O3 alone and As2O3 combined with BSO and As2O3 alone, and to determine the effect of intracellular GSH content on this treatment. METHODS: As2O3 was used in a dose of 0.5 micromol/L, 2.0 micromol/L and 5.0 micromol/L, respectively, and BSO was used in a dose of 100 micromol/L in the culture of multidrug-resistant human leukenic K562/ADM cells. The cell proliferation activity was assessed with MTT assay. The cell apoptosis was detected by flow cytometry using Annexin-V and propidium iodide (PI) staining. Intracellular GSH content was measured using glutathione assay kit by spectrophotometry. RESULTS: After the GSH contents were reduced by the combination of arsenic in clinic dose (0.5, 2 micromol/L) and BSO (100 micromol/L), respectively, the K562/ADM cell proliferation activity was obviously inhibited and the cell apoptosis-inducing effect was advanced in 24 hours. In 48 and 72 hours, the effect of the combination group (clinic dose arsenic group) was significantly stronger than that of clinic dose arsenic alone group and the high dose arsenic alone group. CONCLUSION: The cell apoptosis-inducing effect of arsenic in combination of BSO on multidrug resistant human leukemia K562/ADM cells is significantly enhanced in comparison with that of arsenic alone. The reduction of intracellular glutathione content is closely correlated with this apoptosis-enhancing effect.