Inhibition effects of the selective COX-2 inhibitor of nimesulide on proliferation of HL-60 leukemia cells

Objectiye To investigate the effect of selective COX-2 inhibitor, nimesulide, on inhibiting proliferation of the human acute myeloid leukemia HL-60 cells. Methods HL-60 cells were treated with different concentration of nimesulide. HL-60 cell proliferation was examined by CCK-8 method. Flow cytometry, Western blotting and ELISA were used to measure the effect of nimesulide on apoptosis, cell cycle,COX-2, PGE2, bax, bcl-2 and c-myc. Results Nimesulide inhibited HL-60 cells proliferation in a dose and time dependence manner. Nimesulide induced cell apoptosis and arrested cell cycle in G0-G1 phase. The expression of COX-2 protein declined after treated with nimesulide 48 h, the total apoptosis in 100, 200,400 μmol/L nimesulide-treated group and control group were (24.97 ± 6.36) %, (34.22 ± 5.76) %, (44.59 ±6.69) % and (4.11 ± 1.26) %, there were significant differences (P ＜ 0.05). Nimesulide inhibited the synthesis of PGE2, the expressions of bcl-2 and c-myc protein and upregulated the expression of bax protein simultaneity.Conclusion Nimesulide significantly inhibited the proliferation of HL-60 cells and induced cell apoptosis,which may be associated with the downregulation of COX-2 expression, reduction of PGE2 synthesis, arrest of cell cycle and regulation bcl-2, c-myc and bax protein expression. Key words: Nimesulide;  Cyclooxygenase 2;  HL-60 cells;  Cell proliferation;  Apoptosis