多药耐药及相关蛋白基因抗砷作用

Arsenic-resistance effect of MDR1 and MRP1

目的研究多药耐药基因(MDRI)、多药耐药相关蛋白基因(MRP1)在长期砷暴露的细胞获得对砷的耐受过程中的作用,为抗砷机制的研究提供基础依据。方法采用抑制剂维拉帕米(Verapamil)、MK571,在单一水平和联合水平上阻断MDR1和MRP1基因发挥作用,通过四甲基偶氮噻唑蓝(MTT)法检测细胞的生存率及半数致死量(IC50);通过原子荧光法(AFS)分别检测给予Verapamil、MK571的实验组和对照组在不同时间点抗砷细胞内砷的含量。结果在2,4,8,16,32,64μmol/L砷浓度下,给予抑制剂的抗砷细胞生存率分别为(73.5±0.02)%,(54.6±0.07)%,(44.2±0.05)%,(20.5±0.09)%,(13.5±0.1)%,(7.6±0.05)%,明显低于同步对照组的生存率(93.5±0.05)%,(71.5±0.02)%,(49.2±0.03)%,(38.8±0.08)%,(37.6±0.06)%,(19.5±0.04)%。Verapamil作用下IC50为8.8μmol/L,MK571作用下IC50为6.22μmol/L;同时给于2种抑制剂时,逆转作用更为明显,IC50为5.23μmol/L;MK571作用下,抗砷细胞内砷含量增加明显,至10 h时砷含量达到最大值1.62 ng,明显高出Verapmil组和对照组,差异有统计学意义(P<0.05)。结论MDR1、MRP1基因在抗砷细胞获得耐药性过程中起重要作用。

Objective To study the roles of MDR1 and MRP1 gene in acquired arsenic tolerance in chronic arsenic-exposed（CAsE） cells for arsenic-resistance gene research.Methods The roles of MDR1 and MRP1 were inhibited with inhibitor Verapami MK571 on single and combined level,respectively.MTT was used to detect the survival rates and IC50 of cells in test and control groups.AFS was used to detect arsenic within the CAsE cells at different times.Results For different arsenic concentrations（2,4,8,16,32,64 μmol/L）,the survival rates of cells with the inhibitor was 73.5±0. 02,54. 6 ±0. 07,44. 2± 0. 05,20. 5 ± 0.09,13.5 ± 0. 1,7.6 ± 0. 05 %, which were obviously lower than that of control groups （93.5± 0.05,71.5 ±0.02,49.2±0.03,38.8 ±0.08,37.6±0.06,19. 5±0.04%）. With the role of Verapamil,MK571 ,the IC50 value was 8.8 and 6.22 μmol/L, respectively. Meanwhile the two inhibitors combined plays an obviously reverse role, and the IC50 was 5.23μmol/L. The arsenic content in the CAsE cells with the role of MK571 was obviously higher than that in control and Vempamil groups and achieved the maximum value of 1.62ng at 10 hours after the treatment with statistically significant difference（ P 〈 0. 05 ）. Conclusion MDR1 and MRP1 plays an important role in the process of CAsE cells acquired tolerance to acute arsenic exposure.