α-干扰素联合脂多糖对白血病细胞株U937细胞周期的影响及其机制研究

Effects of IFN-α-Lipopolysaccharide Combination on the Cell Cycle of Leukemia Cell Line U937 and Its Possible Mechanisms

目的探讨α-干扰素联合脂多糖在体外对髓系白血病(acute myelogenous leukemia,AML)细胞U937细胞增殖、凋亡及细胞周期的影响及其机制。方法四甲基偶氮唑蓝法(MTT法)检测细胞增殖;Annexin V FITC/PI双染色法流式细胞仪检测细胞凋亡率;流式细胞仪检测细胞周期,Western blotting检测cyclinA2和cyclinD1蛋白质表达。结果α-干扰素和(或)脂多糖组较对照组能显著地抑制U937细胞的增殖、增加细胞的凋亡率和G1期细胞比例(P<0.05);α-干扰素联合脂多糖组较单用α-干扰素、脂多糖组能显著抑制U937细胞增殖、增加细胞凋亡率和G1期细胞比例(P<0.05),能够显著下调CyclinA2蛋白质表达、上调CyclinD1蛋白质表达(P<0.05)。结论α-干扰素与脂多糖对U937细胞的增殖抑制、细胞凋亡和G1期细胞的比例有协同增强作用,其机制可能与细胞周期素Cy-clinA2、CyclinD1蛋白的调节有关。

Objective To explore the effects of IFN-α combinated by lipopolysaccharide on the proliferation,apoptosis,and cell cycle of U937 acute myelogenous leukemia（AML） cells and its possible mechanisms in vitro.Methods MTT assay was applied to determine cell proliferation,AnnexinⅤ/PI double labeling was used in the flow cytometry（FCM） method to analyze cell apoptosis and cell cycle,Western blotting were employed to quantify the expression of cyclinA2 and cyclinD1 protein.Results IFN-α and/or lipopolysaccharide inhibited leukemic proliferation,induced cell apoptosis and caused cell cycle arrest in G1 phase（P0.05）.IFN-α-LPS combination exhibited better effects in inhibiting leukemic proliferation,promoting cells apoptosis,and inducing cell cycle arrest in G1phase compared with IFN-α or LPS used alone（P0.05）.IFN-α-LPS combination significantly decreased cyclinA2 protein expression and increased cyclinD1 protein expression in U937in comparison with IFN-α or LPS used alone.Conclusion Synergistic effects of IFN-α and LPS exist in inhibiting leukemic proliferation,inducing cell apoptosis and causing G1 phase cell cycle arrest in U937 cell line,which were partially explained by the regrulation of cyclinA2 and CyclinD1 protein expression.