OBJECTIVETo investigate the effect of retrovirus mediated heme oxygenase (HO)-1 gene on chronic myeloid leukemia (CML) resistance cell apoptosis induced by nilotinib (AMN107).

METHODSHigh titer viral particles of pQCXIP-EGFP-HO-1 were prepared, and K562/A02 cells stably transfected with HO-1 gene was established. The expression of HO-1 in K562/A02 cells was detected by RT-PCR. After treated with AMN107 for 24 h, HO-1 mRNA and protein expression by RT-PCR and Western blot, respectively; Cell proliferation by MTT assay; bcr-abl fusion gene by RQ-PCR, and the apoptosis and cell cycle by flow cytometry.

RESULTSRecombinant retrovirus vector was constructed successfully and K562/A02/HO-1 cells were successfully set up. The expression of HO-1 in K562/A02 cells was expressed clearly. After three groups cells treated with AMN107 for 24 h, the expression of HO-1 mRNA and protein was significantly higher in gene-transfected group than in either empty vector or no-transfected group. The difference was statistically significant (P < 0.05). The cell proliferation ofs was inhibited, but the cell viability was significantly higher in gene-transfected group than in other two groups. The difference was statistically significant(P < 0.05); After treated with 10 µmol/L AMN107 for 24 h, the CT values of bcr-abl fusion gene were (18.15 ± 0.18) in K562/A02/HO-1 group, being significantly higher than that in K562/A02/LXSN (20.32 ± 0.20) and K562/A02 (20.51 ± 0.21) group, the difference was statistically significant (P < 0.05); the apoptosis rate were (17.26 ± 0.23)%, (39.47 ± 0.17)%, and (41.84 ± 0.09)%, respectively in three groups, and were (3.74 ± 0.03)%, (5.91 ± 0.08)% in K563/A02/HO-1 untreated with drug and K562/A02 untreated with drug group. The number of G(0)/G(1) phase and S phase cells markedly decreased. The cells were arrested in G(2)/M phase. But cell cycle in gene-transfected group did not change significantly.

CONCLUSIONAMN107 inhibits proliferation of CML resistance cells and induces cell apoptosis. HO-1 gene can protect CML resistance cells to apoptosis. There was a relationship between HO-1 gene and the growth of CML resistance cells.