MDR1基因转染的Swiss 3T3细胞经秋水仙碱孵育后多药抗药性模式改变

为观察长期药物筛选对多药抗药性模式的影响，用MDR1 cDNA转染了Swiss 3T3细胞. 秋水仙碱选择培养两个月前后，以MTT方法测定各转化子对阿霉素，长春新碱，秋水仙碱的抗药性，以确定其多药抗药性模式. 还测定了维拉帕米对各转化子的增敏效应. 在非选择培养液中生长的转化子观察到基本一致的抗药性模式，即对长春新碱高度抗性，对秋水仙碱中度抗性，对阿霉素低度抗性. 而在选择培养液中生长两个月后，各转化子的抗药性模式变得参差不齐. 结果说明，MDR1基因表达可造成一致的抗药性模式，长期秋水仙碱孵育可改变抗药性模式的均一性.

Alteration of multidrug resistant profiles in MDR1 gene trans-fected Swiss 3T3 cells after incubation in colchicine

To observe the influence of drug selection of multidrug resistant (MDR) cells on their MDR profile, Swiss 3T3 cells were transfected with human MDR1 cDNA expression plasmid. The resistance to doxorubicin (Dox), vincristine (Vcr) and colchicine (Col) was tested with MTT assay before and after the transfectants were incubated with Col (0.3 μmol·L^-1), and the MDR profiles of them were determined. The che-mosensitizing effect of verapamil on transfectants was also observed. A similar profile was shown in each transfectant grown in drug-free medium, which had a high level of resistance to vincristine, a moderate level to colchicine, and a low level to doxorubicin. The multidrug resistant profile changed heterogeneously when the transfectants were grown in Col containing medium for two months. The results suggested that MDR1 gene expression may confer identical MDR profile, which was altered by long term incubation with Col.