Recently, some cytokines were used as immunotherapy for leukemic patients, which improved cancer therapy by apoptosis induction. This study investigated the effects of interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) on induction of cell apoptosis in leukemic cell lines, K562 and HL60. Both of leukemic cell lines were treated with IL-1β and TNF-α in various concentrations and incubation times. Cell viability and growth inhibition were analyzed by using trypan blue staining and MTT assay, respectively. Apoptotic cells were stained with Annexin-V-FITC and analyzed by flow cytometry. In addition, the involvement of caspase activation in the apoptotic pathway was investigated. The results indicated that percentage of cell viability was decreased while cell apoptosis increased after treatment with 2 ng/ml IL-1β or 20 ng/ml TNF-α in both leukemic cell lines. The increased sub G1 population from cell cycle analysis and cell morphology indicated increasing apoptosis in cytokines treated cells. Caspase 3 and caspase 8 activity were increased after IL-1β and TNF-α treatment. These results suggest that IL-1β and TNF-α could induce apoptosis via caspase cascade pathway in K562 and HL60 cell lines.
