【摘要】 目的观察丙戊酸对白血病细胞P27Kip1、P170表达水平和耐药性的影响,探讨其可能的作用机制。方法递增压力选择培养法建立白血病耐药细胞株HL-60/HT,MTT法检测丙戊酸作用前后细胞的增殖情况及对Ara-C耐药性的改变,流式细胞术测定HL-60细胞、HL-60/HT细胞中P27Kip1、P170的表达和细胞周期。结果成功诱导培养建立耐药HL-60/HT细胞,其对HT、VCR、DNR、Ara-C的耐药倍数分别为9.30、5.20、4.91、3.65倍,耐药性能稳定。HL-60/HT细胞P27Kip1表达水平明显低于正常人单个核细胞及HL-60细胞(P<0.05),P170表达水平则明显高于正常人单个核细胞及HL-60细胞(P<0.05)。丙戊酸+Ara-C联合用药对HL-60、HL-60/HT细胞的生长抑制率明显高于单独用药的丙戊酸组和Ara-C组,q值分别为1.37和1.51,说明合用具有协同作用。丙戊酸作用于HL-60、HL-60/HT细胞后,细胞中P27Kip1表达水平、G1期细胞比加药前增加(P<0.05);P170表达水平在加药前后无明显变化(P>0.05)。结论耐药白血病HL-60/HT细胞中P27Kip1的表达低于敏感细胞HL-60,丙戊酸能抑制HL-60/HT细胞增殖,并降低其对Ara-C的耐药性。作用机制可能与改变P27Kip1的表达、增加G1期细胞含量有关,与P170作用无关。更多还原

【Abstract】 Objective To investigate the effect of valproic acid on the expression of P27Kip1 and P170 and drug resistance of leukemia HL60/HT cell line and explore its possible mechanisms.Methods HL-60/HT cells were derived from HL-60 cells induced by harringtonine(HT) in gradient concentrations.The inhibitory effect of valproic acid on the proliferation of HL-60 and HL-60/HT cells was evaluated by MTT assay,and the P27Kip1 expression,P170 expression and cell cycle of the cells were analyzed with flow cytometry.Results The multidrug-resistant HL-60/HT was acquired,which showed a stable drug-resistant index with increased IC50 of HT,VCR,DNR and Ara-c by 9.30,5.20,4.91 and 3.65 folds,respectively,as compared with those of HL60 cells.The expression of P27Kip1 in HL-60/HT cells was significantly lower but P170 expression significantly higher than that of HL-60 cells and normal mononuclear cells(P<0.05).The expressions of P27Kip1 and P170 showed no significant difference between normal mononuclear cells and HL-60 cells.The growth inhibition rate of VPA combined with Ara-C was significantly higher than that of valproic acid or Ara-C alone in HL-60/HT cells and HL-60 cells(q=1.37 and 1.51,respectively).HL-60/HT and HL-60 cells cultured in the presence of VPA resulted in a significant increase in the expression of P27Kip1 and the G1-phase cells(P<0.05),but the expression of P170 underwent no significant changes(P>0.05).Conclusion HL-60/HT cells have lower P27Kip1 expression compared with HL-60 cells.Valproic acid can inhibit the growth of HL-60/HT cells and enhance their Ara-C sensitivity possibly by increasing P27Kip1 expression and causing cell cycle arrest in G1 phase.更多还原