华蟾素对Raji/ADR细胞多药耐药的逆转作用及机制

Reversal Effect of Cinobufacini on Multidrug Resistance of Raji /ADR Cells and Its Mechanisms

本研究旨在探讨华蟾素对Raji/ADR细胞多药耐药的逆转作用及其机制。采用MTT法检测华蟾素对Raji及Raji/ADR细胞的生长抑制率、半数抑制浓度(IC50)、逆转阿霉素耐药倍数,并绘制生长抑制率曲线;应用RTPCR法测定MDR-1和MRP-1基因的转录;Western blot法和流式细胞术法测定P-gp、MRP-1蛋白的表达。结果表明:华蟾素对Raji及Raji/ADR细胞72 h增殖抑制率为75.6%和69.3%,IC50分别为3.9 mmol/L和4.6 mmol/L,逆转阿霉素耐药倍数为255.7倍。华蟾素作用于Raji/ADR前后,MDR-1和MRP-1基因转录水平明显下降(P<0.05),P-gp和MRP-1蛋白表达明显降低。结论华蟾素可逆转Raji/ADR细胞对阿霉素的耐药,其机制为通过转录途径下调P-gp和MRP-1蛋白的表达。华蟾素是一种有效的肿瘤多药耐药逆转剂。

The aim of this study was to explore the reversing effect of cinobufacini on multidrug resistance of Raji/ADR cells and its mechanisms.The growth inhibitory rate,half inhibitory concentration （IC50）,reversing multiples to adriamycin-resistance were detected by MTT,and the curve of growth inhibitory rate was drawn; the MDR-1 and MRP-1 gene transcription was determined by RT-PCR; the expressions of P-gp and MRP-1 proteins were assayed by Western blot and flow cytometry.The results showed that the inhibitory rates of cinobufacini on Raji and Raji/ADR cells at 72 h were 75.6% and 69.3% respectively,the IC50 were 3.9 mmol/L and 4.6 mmol/L without significant difference （P 〉 0.05）.The reversing multiples to adriamycin-resistance were 255.7 multiples,the transcription of mdr-1 and mrp-1 genes and the expression of P-gp and MRP-1 proteins significantly decreased （P 〈 0.05） in Raji/ADR cells after the treatment with cinobufotalin.It is concluded that cinobufotalin can reverse the adriamycin-resistance in Raji/ADR cells and the expression of P-gp and MRP-1 proteins were down-regulated through the transcriptional pathway.The cinobufotalin is an effective reversal agent for the multidrug resistance of tumors.