甲基莲心碱对耐长春新碱人胃癌细胞多药耐药性逆转机制的初步研究

摘要

目的 探讨新的钙阻断剂甲基莲心碱(Nef)对耐长春新碱人胃癌细胞多药耐药性(MDR)的逆转作用及其机制.方法 采用MTT比色法,检测药物的细胞毒作用;应用免疫细胞化学SP法及流式细胞术,检测Nef对人胃癌细胞Bcl-2蛋白表达的影响.结果 10 μmol/L Nef对SGC7901及 SGC7901/VCR无显著细胞毒作用;2.5、5、10 μmol/L Nef能使VCR对SGC7901/VCR细胞的IC50从2.32 μg/ml依次下降至0.340、0.128、0.053 μg/ml,逆转倍数分别为6.8、18.1、43.8.当Nef浓度为10 μmol/L时,逆转SGC7901/VCR多药耐药活性较VRP高(P＜0.01);SGC7901/VCR细胞中Bcl-2蛋白表达水平较SGC7901细胞高,经Nef处理后,SGC7901/VCR细胞中Bcl-2蛋白表达水平明显下降,表明Nef能下调SGC7901/VCR细胞中Bcl-2蛋白表达水平.结论 甲基莲心碱在体外能逆转耐长春新碱人胃癌细胞(SGC7901/VCR)的多药耐药性,其机制可能与下调Bcl-2蛋白表达水平有关.%Objective To study the reversal of multidrug resistance ( MDR ) and its mechanism by neferine which is a new calcium channel blocker in human gastric carcinoma cell line SGC7901/VCR. Methods The cytotixic effect was tested by MTT assay. The expression of Bcl-2 protein in human gastric carcinoma cells was examined by immunocytochemical and flow cy-tometry. Results Neferine of the concentration 10 μmol/L was not of significant cytotoxicity to SGC7901 and SGC7901/VCR cells. Neferine of the concentration 2. 5 ,5 ,10 μmol/L decreased the IC50 value of VCR to SGC7901/VCR cells from 2. 32 μg/ml to 0. 340,0. 128 and 0. 053 μg/ml, respectively and with the increase by 6.8-,18. 1-and 43. 8-fold in the chemosensitivity, respectively. It had more potent reversal action on SGC7901/VCR cells than verapamil at the concentration of 10μmol/L( P < 0. 01 ). The level of Bcl-2 protein expression was more higher in SGC7901/VCR cells than in SGC7901 cells. After treatment with neferine,the level of Bcl-2 protein expression in SGC7901/VCR cells was significantly down-regulated, which denominated that neferine could decline the level of Bcl-2 protein expression in SGC7901/VCR cells. Conclusion Neferine could reverse multi-drug resistance of human gastric carcinoma cells SGC7901/VCR in vitro. Its reversal mechanism might be associated with down-regulation the level of Bcl-2 protein expression in SGC7901/VCR cells