目的:研究α干扰素联合阿糖胞苷对白血病K562细胞的诱导凋亡作用及其作用机制。方法:以浓度2 000 U/ml的α干扰素与不同浓度的阿糖胞苷作用于体外培养的K562细胞，观察细胞生长状态的变化，检测细胞生长抑制率及细胞凋亡率的变化，并对细胞端粒酶活性及P53蛋白的表达水平进行检测。结果:α干扰素与阿糖胞苷联合应用可显著抑制K562细胞的生长，诱导细胞发生凋亡。并降低K562细胞端粒酶活性，升高P53蛋白的表达水平，其作用呈现出明显的量 效与时 效关系。结论:α干扰素与阿糖胞苷联合应用对白血病K562细胞具有明显的生长抑制及诱导凋亡作用，降低细胞端粒酶活性及升高P53蛋白的表达水平是其重要作用机制之一。

Objective: To investigate the apoptotic effects and its mechanisms on K562 cells caused by Interferon-alpha (INF-α) and Cytarabine (Ara-C). Methods: The variation of both morphology and inhibitory rate of K562 cells was observed in culture medium with IFN-α and various concentrations of Ara-C at different time in vitro. The variation of telomerase activity and P53 protein expression were detected before and after apoptosis occurred. Results:INF-α and Ara-C used concurrently could cause apoptosis and inhibit the growth of K562 cells as well as decrease the telomerase activity and increase P53 protein expression significantly. All these processes showed both in time- and dose-dependent manner. Conclusions: INF-α and Ara-C used concurrently can inhibit the growth of K562 cells and induce apoptosis, inhibiting the telomerase activity and increasing the expression of P53 protein may be one of the most important mechanisms.