联合应用化疗药物对三氧化二砷耐药白血病细胞的毒性实验研究

目的:探讨化疗药物联合应用对三氧化二砷(As2O3)耐药白血病细胞(K562/AS2)的毒性作用。方法:细胞毒实验采用MTT法,二药合用时细胞毒性作用采用ChouTalalay联合指数法分析,细胞表面P糖蛋白(Pgp)和细胞内柔红霉素(DNR)浓度测定采用流式细胞术测定。结果:K562/AS2细胞对三氧化二砷、柔红霉素、鬼臼乙叉苷(VP16)、三尖杉酯碱(H)、米托蒽醌(NVT)和阿糖胞苷(AraC)的耐药倍数分别为7.4、2.9、3.8、3.6、2.8和1.1。K562细胞和K562/AS2细胞的细胞表面Pgp或细胞内任意荧光强度无显著的统计学意义(P>0.05)。As2O3与DNR、VP16、H或NVT联合应用时,对K562、K562/AS2和Pgp表达的白血病细胞(K562/A02)细胞的联合指数均大于1。异搏定与DNR联合应用时,对K562和K562/AS2细胞的联合指数均大于1,但是对K562/A02细胞的联合指数均小于1。结论:K562/AS2细胞对As2O3、DNR、VP16和NVT耐药,其机制与Pgp表达无关。异搏定联合应用DNR可以逆转K562/A02对DNR的耐药性,不能逆转DNR对As2O3耐药细胞的耐药性。As2O3与DN、VP16、H和NVT联合应用时,对K562、K562/AS2和K562/A02细胞的毒性均为拮抗作用。

In vitro study on cytotoxicity of combination of some chemotherapy reagents towards arsenic trioxide-resistant leukemic cells

AIM: To explore the cytotoxicity of combination of some chemotherapy reagents towards K562/AS2, an arsenic trioxide (As_2O_3)-resistant leukemic cell line. METHODS: MTT assay was used to detect the cytotoxicity, and the combined drug effect of two drugs was analyzed with Chou-Talalay Combination Index (CI). Flow Cytometry was used to detect the P-glycoprotein on the cell surface and the introcellular concentration of daunorubicin (DNR). RESULTS: The relative resistant folds of K562/AS2 cell line to As_2O_3, DNR, VP16, harringtonine (H), NVT and Ara-c were 7.4, 2.9, 3.8 and 1.1, respectively. The fluorescence of the P-glycoprotein on the surface or of the DNR inside the cells detected was not significantly different between the K562 and the K562/A02 cell line (P> 0.05). The combination indexes of As_2O_3 combined with DNR, VP16, H or NVT to K562, K562/AS2 and K562/A02 cell lines were all above 1. The combination indexes of Verapamil combined with DNR to both K562 and K562/AS2 cell lines were above 1, and to the K562/A02 were below 1. CONCLUSION: K562/AS2 cell line is resistant to As_2O_3, DNR, VP16 and NVT. The mechanism of the drug resistance is not associated with the expression of P-gp. Verapamil combined with DNR can reverse the resistance of P-gp expressing leukemia cell, K562/A02, to DNR, but can not reverse the resistance of K562/AS2 cell line. The cytotoxicity of As_2O_3 combined with DNR, VP16, H and NVT shows antagonism to K562, K562/AS2 and K562/A02 cell lines.