Objective:To study the effects of specific inhibitor of COX-2 celecoxib in different concentration on cell apoptosis

cell cycle and expression of Egr-1 of A549 cells

and to investigate the molecular mechanism of anti-tumor effects.Methods:A549 cells were cultured in vitro and treated by 25.0

50.0 μmol/L and 100.0 μmol/L celecoxib.Then the TUNEL assay was used to detect apoptosis;FCM assay was used to determine cell cycle

and RT-PCR assay was performed to evaluate the Egr-1 and Fas mRNA expression levels.Results:Treated by celecoxib in the concentration of 25.0

50.0 μmol/L and 100.0 μmol/L

the cell cycle was arrested in c phase in A549 cells respectively;the apoptotic index of A549 cells were 10.67%±1.46%

18.83%±2.54% and 25.67%±2.10% respectively

and the expression levels of Egr-1 and Fas mRNA were up-regulated synchronously.Conclusion:Celecoxib

a specific inhibitor of COX-2

can inhibit the proliferation of A549 cells by regulating the cell cycle and inducing the cell apoptosis.The molecular mechanism may be that COX-2 inhibitor up-regulates the expression of Fas by up-regulating the expression of Egr-1

and then induces the cell apoptosis by blocking the A549 cells in G0/G1 period.