Abstract:
Objective To investigate the pro-apoptotic effect of berberine (Ber) on human lung adenocarcinoma PC-9 cell line, and to detect the role of c-Jun N-terminal kinase (JNK)/forkhead box protein O3 (FOXO3) signaling in this process.
Methods The PC-9 cells were randomly divided into the control group and the Ber group, which was treated with 30 and 60 μM Ber. The survival rate, apoptotic rate, ROS generation, caspase-3 activity, and mitochondrial membrane potential of cells were detected. Western blot was performed to detect the expression of JNK/FOXO3 signaling and apoptosis-related proteins. A JNK-specific activation inhibitor, SP600125, was used to block the phosphorylation of FOXO3 in PC-9 cells, and then treated with Ber (30 and 60 μM) for further detection after 24h.
Results Ber treatment resulted in an obvious reduction in cell viability, promotion of cell apoptosis, downregulation of mitochondrial membrane potential, and an increase of ROS and caspase-3 in a dose-dependent manner. Western blot analysis demonstrated that Ber treatment resulted in a significant upregulation of p-JNK, FOXO3, and Bax expression, and a downregulation of p-FOXO3 and Bcl2 levels. Moreover, the inhibition of JNK activation by SP600125 antagonized the anti-FOXO3 phosphorylation role and the pro-apoptotic role of Ber on PC-9 cells.
Conclusion Ber treatment effectively inhibits the viability of PC-9 cells and enhances apoptosis and oxidative stress injury, which may be related to the upregulation of p-JNK and FOXO3 and the downregulation of p-FOXO3.