Selenium dioxide induces leukemia cell apoptosis and changes of intracellular reactive oxygen species (ROS) and Ca2+ levels

AIM: The effects of selenium dioxide (SeO2) on proliferation, apoptosis, intracellular reactive oxygen species (ROS) and Ca2+ levels in three leukemia cell lines NB4, K562 and HL-60 were investigated. METHODS: Three leukemia cell lines were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis rate, and analyze the changes of ROS and Ca2+ level within cells. RESULTS: SeO2 at 10 and 30 μmol/L inhibited proliferation in three leukemia cell lines. Treatment with 30 μmol/L SeO2 for 48 h induced 54.0%, 46.5%, 49.6% apoptosis in NB4, K562, and HL-60 cells, respectively, and also markedly decreased ROS and Ca2+ levels among three cell lines. The rate of ROS positive cells in NB4 and HL-60 decreased with the increase in SeO2 concentrations. ROS was clearly reduced with 30 μmol/L SeO2 in K562. Ca2+ levels were tardily declined with 10, 30 μmol/L SeO2 in NB4 and HL-60 cells. Ca2+ levels were clearly reduced with 30 μmol/L SeO2 in K562. CONCLUSION: SeO2 induces apoptosis in three leukemia cells. The declines of intracellular ROS and Ca2+ levels are involved in apoptosis induced by SeO2.