The present study aimed to investigate whether artesunate (ART) could enhance the rate of apoptosis induced by decitabine (DAC) in the high-risk myelodysplastic syndrome (MDS) SKM-1 cell line, and examine the potential underlying mechanisms. The cytotoxicity and effect upon the apoptosis of ART and DAC in the SKM-1 cells was detected using the cell counting kit-8 assay and flow cytometry, respectively. The SKM-1 protein expression levels of activated caspase-3, -9 and -8, cleaved poly(ADP-ribose) polymerase and apoptosis-inducing factor (AIF) were measured by western blotting. The laser confocal microscope analysis revealed AIF transfer to the nucleus. The growth inhibition and apoptosis rates of the ART- and DAC-treated SKM-1 cells were significantly increased compared with those of the single agent-treated SKM-1 cells (P<0.05). In addition, ART and DAC induced caspase-dependent apoptosis, while ART, but not DAC, induced caspase-independent apoptosis via AIF transfer from the mitochondria to the nucleus. In addition, ART-DAC-induced cell death was not attenuated by the caspase-3/7 inhibitor, Ac-DEVD-CHO. The results of the present study suggested that the ART-DAC combination exhibited increased effectiveness compared with the single-agent therapy, in vitro. The ART-DAC combined therapy not only activated a caspase-dependent apoptotic pathway, but also a caspase-independent mitochondrial pathway.
Keywords: apoptosis-inducing factor; artesunate; caspase; decitabine; myelodysplastic syndrome.