Impact of arsenic trioxide (As_2O_3) on proliferation,cell cycle and apoptosis in human leukemia cell lines NB4, K562 and MOLt 4

OBJECTIVE:To investigate the impact of arsenic trioxide (As 2O 3) on proliferation, cell cycle and apoptosis in human leukemia cell lines NB4, K562 and MOLt 4.METHODS: Cell viability and cell growth rate were determined by the Trypan blue exclusion. Cell morphology was observed under the light microscope with Wright-Giemsa staining. Cell cycle was analysed by the flow cytometry.RESULTS: 1)As 2O 3 inhibited the proliferation of NB4, K562 and MOLt4 cells. 2) As 2O 3 at the concentration of 4 μmol/L induced M phrase arrest of K562 cells,but no significant changes were observed in NB4 and MOLt 4 cells. 3) After treated with 2 μmol/L and 4 μmol/L As 2O 3 for 48 hours,the percentage of apoptosis markedly increased in NB4 and MOLt4 cell,but no change was observed in K562 cells under the same condition. CONCLUSIONS: As 2O 3 has the effect of growth inhibition and apoptosis induction in NB4 cells and can inhibit the proliferation of K562 and MOLt4 cells without t (15;17). It can also induce apoptosis in MOLt4 cells and block K562 cells at M phase.