OBJECTIVETo determine effects of berbamine on the growth of leukemia cell line NB4 and explore its possible mechanisms.

METHODSThe growth of NB4 cells was examined with MTT assay. Morphological analysis and DNA agarose electrophoresis were used to detect apoptosis in NB4 cells, and the apoptosis rate was measured by flow cytometry. The PML/RAR alpha mRNA was determined by nested-PCR, and the Survivin mRNA was tested by RT-PCR. The expression of caspase 3 protein in NB4 cells was evaluated by flow cytometry.

RESULTThe growth of NB4 cells was inhibited significantly after treated with berbamine at different concentrations for different time points, the IC(50)value was 3.860 microg/ml at 48 hours. Morphology analysis showed the characteristics of apoptosis, and the DNA agarose electrophoresis showed the typical DNA ladder. The apoptosis rate increased from 2.83% to 58.44% after treated with berbamine at 12 microg/ml for 48 hours. The expression of PML/RAR alpha mRNA presented no significant changes, however, Survivin mRNA was decreased dramatically. The protein expression of Caspase 3 increased significantly from 2.06% to 70.89% after treated with berberine at a concentration of 12 mug/ml for 48 hours.

CONCLUSIONBerbamine could inhibit the growth of leukemia cell line NB4. The induction of cell apoptosis may be one of the mechanisms for suppressing the growth of leukemia cell line NB4. Inhibition of Survivin mRNA and upregulation of Caspase 3 protein might be also involved in cell apoptosis.