环孢菌素A与细胞因子联合逆转白血病多药耐药性的体外研究

In vitro reversal effect of cyclosporin A in combination with cytokines on multidrug resistant cell line K562/A02

目的探讨环孢菌素Ａ（ＣｓＡ）联合细胞因子对耐药细胞系Ｋ５６２／Ａ０２的逆转作用。方法以甲基四唑蓝法测定柔红霉素（ＤＮＲ）的细胞毒性；用流式细胞仪技术测定细胞内罗丹明（Ｒｈ１２３）浓度；用ＲＴＰＣＲ及ＪＳＢ１抗体分别检测多药耐药（ＭＤＲ１）ｍＲＮＡ及其Ｐ糖蛋白的表达。结果１μｍｏｌ／ＬＣｓＡ、５００Ｕ／ｍｌ干扰素、２００Ｕ／ｍｌ白介素２（ＩＬ２）均能增加ＤＮＲ对耐药细胞系Ｋ５６２／Ａ０２的细胞毒作用，ＩＣ５０（半抑制浓度）分别为（３．７８±０．０３）μｇ／ｍｌ，（１３．７７±０．３８）μｇ／ｍｌ，（１８．５±０．６０）μｇ／ｍｌ，逆转倍数分别为６．７０、１．８４和１．３７倍。而上述剂量的ＣｓＡ和ＩＦＮα联合则ＩＣ５０为（１．７１±０．１９）μｍ／ｍｌ，逆转倍数增加到１４．８倍，且细胞内Ｒｈ１２３浓度亦明显高于单药逆转（Ｐ＜０．０５），但ＭＤＲ１ｍＲＮＡ及Ｐ糖蛋白表达无明显改变。ＣｓＡ和ＩＬ２联合应用无明显的协同效应。结论单用低剂量ＣｓＡ（１μｍｏｌ／Ｌ）或细胞因子对多药耐药只有部分逆转作用，而ＣｓＡ联合干扰素则有较好的协同效应，能明显增强耐药的逆转作用。

Objective To explore the reversal effect of cyclosporin A(CsA) in combination with cytokines on multidrug resistant cell line K562/A02. Method The cytotoxicities of daunorubicin(DNR) were assayed by MTT method. Intracellular rhodamine(Rh123) concentration was measured by flow cytometry. P glycoprotein(p gp) expression was analyzed for staining with monoclonal JSB 1. Mdr1 mRNA expression was detected by RT PCR.Results The cytotoxicities of DNR to K562/A02 were enhanced by 1μmol/L CsA, 500U/ml、IFN α and 200U/ml、IL 2 respectively, and their IC 50 was (3.78±0.03), (13.77±0.38) μ/ml, (18.5±0.60)μg/ml. Their reversal effect was 6.70, 1.84 and 1.37 times than that of K562/A02. But IC 50 of combined CsA and IFN α was (1.71±0.19) μg/ml; its reverse effect increased in 14.8 times. The combination could increase intracellular Rh123 accumulation significantly as compared with either of them alone, but p gp and mdr1 mRNA expression were not decreased obviously. CsA in combination with IL 2 didn′t show a synergistic effect.Conclusion Mdr could be partially reversed by cytokines or low doses CsA(1 μmol/L), but the combination of CsA and IFN α showed a greater synergistic reversal interaction.