Significance of Caspase-3 in etodolac-induced apoptosis of SMMC7721 cell line

Objective To investigate the possible role of Bcl-2,Bax and Caspase-3 in etodolac-induced apoptosis of liver tumor SMMC7721 cell line.Methods Cell apoptosis was determined by flowcytometry analysis using PI staining,DNA laddering.The expression of Bcl-2 and Bax protein was detected by Western blotting.Caspase-3 activity was evaluated by active Caspase-3 apoptosis kit with flow cytometry.Results Selective COX-2 inhibitor etodolac stimulated apoptosis in liver tumor SMMC7721 cell line significantly.Flowcytometry revealed the apoptotic rate was (16.3±3.1)%,(19.9±3.6)%,(22.9±3.2)%,(31.2±3.3)% with different concentrations of etodolac (0.25,0.50,1.00,2.00 mmol/L),while the apoptotic peak did not appear in the control group (0 mmol/L,P 0.001).The expression of Bax protein was up-regulated while Bcl-2 protein was down-regulated,and the percentage of the cells with active Caspase-3 was (3.61±0.32)%,(2.93±0.15)%,(10.29±0.39)%,(27.33±1.28)%, (57.40± 1.69)% separately with the increases of etodolac concentrations [(0,0.25,0.50,1.00,2.00) mmol/L, ( P 0.001)]. Conclusion Selective COX-2 inhibitor etodolac may activate Caspase-3 by regulating the expression of Bcl-2,Bax protein,which causes apoptosis of SMMC7721 cells.