Antitumor Effect of Interferon-α on U937 Human Acute Leukemia Cells in vitro and Its Molecular Mechanism

In order to investigate the antitumor effect and molecular mechanism of interferon-α(IFN-α) on human acute myeloid leukemia cell line U937 cells in vitro,the proliferation of U937 cells was determined by MTT assay,the apoptosis rate was analyzed by flow cytometry(FCM),and the mRNA expression of cell cycle regulatory protein cyclin E was detected by RT-PCR.The results showed that IFN-α could inhibit the proliferation of U937 cells significantly in a dose-and time-dependent way(P<0.01),and induce the apoptosis of U937 cells also in a dose-and time-dependent manner at the concentration of 1000-4000 U/L(P<0.01).The apoptosis rate of U937 cells was even over 50% when cultured with IFN-α for 36-48 h at the concentration of 2000-4000 U/L.Moreover,the expression of cyclin E mRNA was markedly inhibited by the addition of IFN-α,and the inhibition was time-dependent(P<0.01).It was concluded that the anti-leukemia mechanism of IFN-α might be correlated with its antiproliferative and apoptotic inducing effects,and the down-regulation of the cyclin E expression might be one of its molecular mechanisms.     

干扰素-α对 U937细胞的促凋亡和抗增殖作用及其机制

为了研究干扰素α对白血病细胞U937细胞的抗增殖作用及其机制，用不同浓度的干扰素仪（500U／L、1000U／L、2000U／L、3000U／L、4000U／L）对U937细胞作用不同时间（0、12、24、36和48小时），用MTT法检测细胞生长抑制率，应用流式细胞术（FCM）检测细胞凋亡率，RT-PCR方法分析cyclin E mRNA的表达。结果表明：不同浓度的干扰素α处理细胞后，U937细胞生长明显受抑，2000U／L干扰素α能引起细胞凋亡，凋亡率为25．28％-70．54％（P〈0.01），细胞周期相关基因cyclin E mRNA表达降低；干扰素α对U937细胞的抑制率，呈浓度-时间依赖性。结论：干扰素α对U937细胞有明显抗增殖和促凋亡作用，此结果将为干扰素-α在白血病临床治疗方面的应用提供有力的实验证据。