[Induction of apoptosis in HL-60 cells by bortezomib alone or in combination with harringtonine in vitro].

The aim of this study was to investigate the effect of bortezomib alone and in combination with harringtonine on apoptosis of HL-60 cells. HL-60 cells were treated with bortezomib, harringtonine in different concentrations for 12 - 48 hours. Cell proliferation was analyzed by MTT assay; the apoptosis of HL-60 cells was observed by DNA gel electrophoresis, fluorescence microscopy and flow cytometry. The results showed that 10 - 50 nmol/L bortezomib could effectively inhibit HL-60 cell proliferation, and induced its apoptosis. After treating for 12 hours, 10 nmol/L bortezomib could trigger cells apoptosis. With time prolongation or dose increase, HL-60 cell apoptotic rate significantly increased. Furthermore, co-administration of bortezomib (10 nmol/L) with harringtonine (30 nmol/L) resulted in a higher cell apoptotic rate when compared with that induced by those agents used alone. It is concluded that the bortezomib can induce HL-60 cells apoptosis in a time-and-dose-dependent manner and synergistic effectiveness can be found when bortezomib combined with harringtonine.