新型多胺缀合物NMMB逆转K562/ADM细胞多药耐药及其机制

目的：研究新型多胺缀合物NMMB对白血病细胞株K562/ADM的多药耐药（MDR）逆转作用，并进一步探讨其耐药逆转机制。方法：分别以不同浓度的NMMB(10～1 000 mg/L)作用于体外培养的K562和K562/ADM细胞24 h,采用MTT 法检测细胞增殖抑制率,确定NMMB的非毒性剂量;采用非毒性剂量,NMMB 0、 2.5 、5.0 和10.0 mg/L组，分别与不同浓度ADM（0.25～100.00 mg/L）联合作用，检测各组细胞生长抑制50%的ADM浓度，即IC50，计算逆转倍数；利用流式细胞术检测NMMB联合ADM作用后K562/ADM 细胞内ADM蓄积程度和细胞周期变化。结果：随着NMMB浓度的增加，细胞增殖抑制率也相应增加，呈剂量-效应关系；NMMB的最大无毒剂量为12.5 mg/L，逆转倍数为4倍；NMMB可明显提高ADM在K562/ADM细胞内的蓄积，与未加NMMB对照组比较差异有显著性（P<0.05）；K562/ADM细胞被阻滞在G0/G1期，与未加NMMB对照组比较差异有显著性（P<0.01）。结论：NMMB对白血病耐药细胞株K562/ADM有增殖抑制和多药耐药逆转作用，其部分逆转机制可能是通过增加细胞内化疗药物蓄积和将K562/ADM细胞阻滞在G0/G1期而实现的。

Effect of a novel polyamine conjugate on MDR reversal of K562/ADM cells and its mechanism

Objective To investigate the reversal effect of a novel polyamine conjugate,NMMB,on muhidrug resistance (MDR) of myelogenous leukemia K562/ADM cells and discuss the possible correlative mechanism. Methods K562 and K562/ADM cells in culture medium were treated with NMMB(10-1 000 mg·L~(-1)) respectively.The inhibitory rates of these cells were measured by MTT assay.Non-cytotoxic dose of NMMB was determined.K562/ADM cells at logarithmic growth phase were randomly divided into ADM control,NMMB 2.5, 5.0,1 0.0 mg·L~(-1) groups.The inhibitory rate 50% (IC_(50)) and the reversal index in all groups were determined. The effects of NMMB on ADM accumulation in K562/ADM cells and cell cycle were examined by flow cytometry (FCM).Results The inhibitory rates were significantly increased when the cells were treated with different doses of NMMB(10-1 000 mg·L~(-1)) in a dose-dependent manner.The available reversal concentration of NMMB was 12.5 mg·L~(-1) and the reversal index was 4 folds on K562/ADM cells.ADM accumulation in K562/ADM cells was significantly increased (P<0.05).The cells were blocked at the period of G_0/G_1 (P<0.01). Conclusion NMMB has an effect on proliferation inhibition and MDR reversal of K562/ADM cell line.The reversal mechanisms of NMMB may be due to increasing the accumulation of chemo-drugs in cells and arresting the cells at G_0/G_1 phase.