胰腺癌多药耐药细胞株BxPC-3/ADM的建立及耐药机制的初步探讨

目的 构建胰腺癌多药耐药细胞株BxPC-3/ADM,通过动态监测诱导耐药过程,探讨其耐药的可能机制.方法 逐步增加阿霉素浓度对BxPC-3细胞进行诱导,在不同的阿霉素诱导浓度,MTT法检测细胞对多种化疗药物的耐药指数,RT-PCR和Western印迹法检测细胞MDR1和MRP mRNA和蛋白的表达.结果 成功构建多药耐药细胞株BxPC-3/ADM;在0.05 μg/ml至8 μg/ml阿霉素诱导浓度,细胞对5-Fu、MMC和Gem的耐药指数无明显增加;在16 μg/ml浓度3种化疗药物的耐药指数有较明显上升,同时伴有MDR1 mRNA表达的明显增加;至32 μg/ml 5-Fu和Gem的耐药指数未再有继续上升,而MMC的耐药指数则继续上升,同时MDR1 mRNA表达未再增加,而MRP mRNA表达则明显增加.Western印迹实验显示MDR1和MRP蛋白表达变化与mRNA表达变化趋势一致.结论 MDR1基因在诱导早期的耐药中起主导作用,在后期则和MRP基因协同发挥作用.

Construction of multidrug resistant cell line BxPC-3/ADM of pancreatic cancer and initial investigation of its resistance mechanism

Objective To construct muhidrug resistance cell line BxPC-3/ADM of pancreatic cancer and investigate its resistance mechanism through dynamically monitoring the inducing course. Methods BxPC-3 cell was induced by increasing the concentration of ADM gradually. At the different inducing concentrations of ADM, the resistance indexes to multiple chemotherapeutics were detected by MTT and the mRNA and protein expression of MDR1 and MRP were determined by RT-PCR and Western blot, respectively. Results Muhidrug resistant cell line BxPC-3/ADM was constructed suc-cessfully. When the inducing concentration of ADM was from 0.05 μg/ml to 8 μg/ml, the resistance indexes to 5-Fu, MMC and Gem did not significantly increase. When the inducing concentration of ADM was 16 μg/ml, the resistance indexes to three chemotherapeutics increased significantly and the mRNA expression of MDR1 obviously rose simultaneously. When the inducing concentration of ADM was 32 μg/ml, the resistance indexes to 5-Fu and Gem did not increase continually, whereas the re-sistance index to MMC increased continually. Meanwhile, the mRNA expression of MDR1 did not keep on rising, whereas the mRNA expression of MRP obviously increased. Western blot showed that the change of MDR1 and MRP protein expression was consistent with the change of mRNA expres-sion. Conclusion During the inducing course, MDR1 has its main contribution at the early stage, whereas MDR1 and MRP have co-contributing action at the late stage.