Interferon-γ affects leukemia cell apoptosis through regulating Fas/FasL signaling pathway.

OBJECTIVE Imbalance of hematopoietic cell proliferation and apoptosis is one of the major causes of leukemia. Enhanced cell proliferation and reduced apoptosis lead to hemocytes accumulation. Fas/FasL signaling pathway promotes cell apoptosis. This study investigated the impact of interferon γ (IFN-γ) on chronic myelogenous leukemia cell proliferation and apoptosis to elucidate its interaction with Fas/FasL signaling pathway. PATIENTS AND METHODS Leukemia K562 cells were routinely cultivated and treated with 10 U/ml, 100 U/ml, and 1000 U/ml interferon for 12 h, 24 h, and 48 h, respectively. MTT assay was applied to test cell proliferation. TUNEL assay was adopted to determine cell apoptosis. Western blot was selected to detect Fas/FasL expression. RESULTS Different concentrations of IFN-γ inhibited cell proliferation at various time points. IFN-γ at 1000 U/ml treatment for 48 h exhibited the strongest suppressive effect on cell proliferation (p < 0.05). IFN-γ intervention enhanced K562 cell apoptosis with concentration and time dependence (p < 0.05). Fas and FasL proteins expressions upregulated after treated by IFN-γ following dose elevation and time extension (p < 0.05). CONCLUSIONS IFN-γ inhibits leukemia K562 cell proliferation and promotes cell apoptosis via facilitating Fas and FasL proteins expressions.