Antitumor effects of a selenium heteropoly complex in K562 cells

The aim of this study was to investigate the anti-tumor effects and mechanism of the selenium heteropoly compound (C2H10N2)5 (NH4)4H2[Se2W10V8O62]·9H2O (SeWV) in K562 cells. The results showed that 0.32–10.15 × 10–3 mmol/L SeWV could significantly inhibit the proliferation of K562 cells in vitro, as determined by the MTT assay, with IC50 values of 3.07 and 2.69 × 10–3 mmol/L after 48 and 72 h of treatment with SeWV, respectively. Studies of the cell cycle indicated that SeWV could induce K562 cells gathered in the G2/M phase upon treatment for 24 and 48 h, and a significant sub-G1 peak was evident at 0.32 and 2.54 × 10–3 mmol/L after treatment for 24 h. Morphological observations revealed typical apoptotic features. SeWVcaused the accumulation of Ca2+, Mg2+ and ROS, and the reduction of pH and mitochondrial membrane potential (MMP) in K562 cells as evidenced by confocal laser scanning microscopy. Experiments also showed that the expression of Bcl-2 was significantly inhibited, but Bax was increased by SeWV at 5.07 × 10–3 mmol/L. Additionally, the content of cytochrome-C was increased after treatment for 24 h. The experiment implied that SeWV had anti-tumor activity and that its mechanism was partially attributable to the induction of cell cycle distribution and apoptosis that was induced by a change in intracellular ion homeostasis.