This study was aimed to investigate the effect of AMN107 (nilotinib) combined with heme oxygenase-1 (HO-1) inhibitor zinc protoporphyrin IX (ZnPPIX) on chronic myeloid leukemia (CML) cells and its mechanism. Proliferative rate of cells treated with AMN107 (10 µmol/L) and ZnPPIX (10 µmol/L) alone or both for different time was observed by MTT and trypan blue methods; the expression of HO-1 in the control group, ZnPPIX (10 µmol/L) group, AMN107 (10 µmol/L) group, AMN107 (10 µmol/L) combined with ZnPPIX (10 µmol/L) group was evaluated by semi-quantitative RT-PCR and Western blot at 48 h. Cell apoptosis was detected by flow cytometry with Annexin V/PI double staining at 48 h. The results showed that the strongest inhibition of cell proliferation was detected in combined group, and in a time-dependent manner; the expression level of HO-1 was lowest in combined group; the cell apoptosis rates were (11.38 ± 0.02)%, (17.44 ± 0.08)%, (39.81 ± 0.07)% and (56.46 ± 0.19)% in the control group, ZnPPIX group, AMN107 group, AMN107 combined with ZnPPIX group at 48 h respectively. It is concluded that the second-generation tyrosine kinase inhibitor AMN107 can induce the apoptosis in CML cells. Inhibition of HO-1 expression can enhance the killing effect of AMN107 on CML cells, which provides experimental evidence to further improve the clinical efficacy of CML treatment.
Apoptosis ; drug effects ; Heme Oxygenase-1 ; antagonists & inhibitors ; Humans ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; pathology ; Protoporphyrins ; pharmacology ; Pyrimidines ; pharmacology