Effect of Dimethyl Sulfides on the Induction of Apoptosis in Human Leukemia Jurkat Cells and HL-60 Cells

Organosulfur compounds have been established to possess anticancer effects. To provide a better understanding of the biological function of dimethyl sulfides, dimethyl monosulfide (Me₂S), dimethyl disulfide (Me₂S₂), dimethyl trisulfide (Me₂S₃) and dimethyl tetrasulfide (Me₂S₄) were used as experimental materials to investigate their effects on apoptosis induction in human leukemia Jurkat cells and HL-60 cells. Treatment with 20 μM dimethyl sulfides for 24 h decreased the viability of both cells. The cell viability-reducing effect of these sulfides was in the following order: Me₂S₄ ≈ Me₂S₃ > Me₂S₂ ≈ Me₂S for Jurkat cells and Me₂S₄ > Me₂S₃ > Me₂S₂ ≈ Me₂S for HL-60 cells. Me₂S₃ and Me₂S₄ significantly induced DNA fragmentation and caspase-3 activation. The addition of GSH or NAC completely suppressed the sulfide-induced apoptosis. Our results indicate that dimethyl sulfides with a larger number of sulfur atoms more strongly induced apoptosis in both human leukemia cells via ROS production and caspase-3 activation.