Butein induces lung adenocarcinoma A549 cell apoptosis via activating forkhead box O 3a/p27 kinase inhibitor protein 1 and cell oxidative stress

Abstract

Objective To investigate the role of Butein on lung adenocarcinoma A549 cells and the role of forkhead box O 3a (FOXO3a)/p27 kinase inhibitor protein 1 (p27kip1) and cell oxidative stress in this process. Methods A549 cells were treaded with 25, 50 and 100 μmol/L Butein, then the cell viability, cell migration, Caspase-3 activity, NADPH oxidase activity, Reactive oxygen species (ROS) and total glutathione (GSH) were detected. Further expressions of FOXO3a, p27kip1, B-cell lymphoma-2 (bcl-2) and bcl-2 associated X protein (bax) were detected by Western blotting. In addition, small interference RNA was used to knock down FOXO3a expression in A549 cell. Then the cells were divided into four groups, which were the control group, the FOXO3a siRNA group, the Butein 100 μmol/L group and FOXO3a siRNA + Butein 100 μmol/L group. Expression of FOXO3a, p27kip1, bcl-2 and bax were detected. Results After treatment of Butein (25, 50, 100 μmol/L), cell viability were reduced from 100% to (78.3±4.6)%, (63.5±4.8)% and (40.1±4.1)% (t=10.330, P=0.000) and the distance between cell boundary were increased from 100% to (120.0±8.4)%, (150.0±10.6)% and (175.0±11.1)% (t=4.777, P=0.001). In addition, Butein treatment increased Caspase-3 activity, NADPH oxidase activity and ROS production, and reduced total GSH concentration. Furthermore, Butein treatment increased FOXO3a, p27kip1 and bax expression and reduced bcl-2 expression. FOXO3a siRNA treatment blocked FOXO3a expression and p27kip1 transcription, and reversed Butein induced A549 cell apoptosis by increasing bcl-2 and reducing bax expression. Conclusion Butein can induce A549 cell apoptosis via activating FOXO3a/p27kip1 and cell oxidative stress. Key words: Butein; Lung adenocarcinoma; Forkhead box O 3a; P27 kinase inhibitor protein 1; Oxidative Stress; Cell apoptosis