Abstract: Objective:To investigate the regulation effect of Wnt5a on the apoptosis of lung adenocarcinoma A549 cells,and to clarify its mechanism. Methods: The human lung adenocarcinoma cells were selected.The A549 cells treated with Wnt5a were used as treatment group,and the A549 cells treated with C culture solution were used as control group.The apoptotic body induced by Wnt5a was assessed with TUNEL assay; the apoptotic rates of the A549 cells in various groups were detected by Annexin Ⅴ-FITC/PI double staining;the reactive oxygen species(ROS) levels in the A549 cells in various groups were determined with DCFH-DA fluorescence probe,and the mitochondria membrane potential was assessed with JC-1 staining method.Western blotting was used to analyze the expression levels of apoptosis-related proteins in the A549 cells in various groups. Results: Compared with control group,the apoptotic rates of the A549 cells in treatment group 12,24,and 48 h after treatment were significantly increased(P<0.01);the ROS levels were increased(P<0.05);the mitochondria membrane potentials were decreased(P<0.05),the expressing amount of BAX was up-regulated and the expression amount of AIF was down-regulated. Conclusion: Wnt5a has regulation on the apoptosis of human lung adenocarcinoma cells and can promote the apoptosis of A549 cells through mitochondrial pathway.

Key words: apoptosis, Wnt5a, reactive oxygen species, lung adenocarcinoma A549 cells, mitochondria membrane