促凋亡蛋白Caspase-3与白血病细胞耐药的相关性

目的观察阿霉素(ADR)耐药的人慢性粒细胞白血病细胞株K562/AO2在ADR和雄黄作用下细胞活力、凋亡及加入Caspase-3抑制剂前后Caspase-3酶活性的变化,探讨促凋亡蛋白Caspase-3与白血病细胞耐药的关系。方法①四甲基偶氮唑盐法(MTT)测定药物作用下细胞株的细胞活力(A值);②DNA琼脂糖凝胶电泳观察凋亡细胞的DNA断裂情况;③酶显色活性分析法(CAA)测定Caspase-3活性水平的变化。结果①MTT法:K562/AO2细胞的A值与雄黄呈时间、剂量依赖关系。②雄黄作用组有凋亡发生。③未加抑制剂组Caspase-3活性明显升高(P<0.05),对雄黄呈时间、剂量依赖关系,加入抑制剂后此关系消失,对ADR无此关系。结论Caspase-3酶活性水平的变化能显著影响药物诱导肿瘤细胞凋亡的能力,在肿瘤耐药的发生发展中起着重要的作用。

Correlation between drug resistance of leukemic cells and Caspase-3

Objective To explore the relationship between drug resistance of leukemic cells and Caspase-3,this study took adriamycin(ADR)-resistant human chronic granulocytic leukemic cell strain K562/AO_2 as research subject,observing the cell survival and the morphological change of cell apoptosis under the action of ADR and arsenic sulfide and the Caspase-3 activity before and after putting in the Caspase-3 inhibitor.Methods ① The 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT) method was used to determine the cell survival(A value) of K562/AO_(2)cell strain under the action of ADR and arsenic sulfide.② DNA agarose gel electrophoresis was performed to observe the DNA cleavage of apoptotic cells.③ The enzyme colorimetric activity assay(CAA) method was used to measure the change of the Caspase-3 activity of K562/AO_(2) cell strain.Results ① The A value of K562/AO_(2) cells had a time and dosage dependent relation with arsenic sulfide.② Apoptosis occurred in the K562/AO_(2) cell strain affected by arsenic sulfide.③ Compared with the cell strains with the Caspase-3 inhibitor added,the Caspase-3 activity of those without the Caspase-3 inhibitor increased remarkably(P<0.05).For the K562/AO_(2) cell strain without the Caspase-3 inhibitor added,the activity of Caspase-3 had a time and dosage dependent relation with arsenic sulfide;the cell strain with the inhibitor added did not have any time and dosage dependent relation with arsenic sulfide.For the K562/AO_(2) cell strain,the activity of Caspase-3 did not have any time and dosage dependent relation with ADR no matter the Caspase-3 inhibitor was added or not.Conclusion It's found that the change of the Caspase-3 protein expression level is able to significantly change the ability of drugs inducing cell apoptosis,and it plays an important role in the occurrence and development of drug-resistance of tumors.