RESUMO
Objective: To study the effect of wortmannin (WM), a PI3K/Akt inhibitor, on the proliferation and apoptosis of leukemia cells and the possible mechanism. Methods: Human leukemia cell line K562 was treated with different concentrations of WM. The proliferation of K562 cells was examined by MTT assay. DNA damage in K562 cells was examined by single cell gel electrophoresis assay, and apoptosis of K562 cells was detected by Annexin V-FITC/PI double-staining. The expressions of total Akt, phosphorate-Akt (p-Akt), and NF-κB p65 mRNA and protein were detected by RT-PCR and Western blotting, respectively. Results: WM inhibited the proliferation of K562 cells in a dose- and time-dependent manner, with the IC((50) value of 24 h being 25 nmol/L. WM also induced apoptosis of K562 cells in a dose-dependent manner. DNA damage in K562 cells was demonstrated by appearance of comet tail after treatment with WM, with the rate of DNA tail and the tail length being significantly higher than those in the control group (P<0.01). WM dose-dependently inhibited P-Akt and NF-κB p65, but not the total Akt, mRNA and protein expressions. Conclusion: WM can inhibit proliferation and induce apoptosis of K562 cells in a dose- and time-dependent manner, probably through down-regulation of phosphorate PI3K/Akt signal pathway and NF-κB expression.