Genistein-induced mitochondrial dysfunction and FOXO3a/PUMA expression in non-small lung cancer cells

CONTEXT: Genistein is a multifunctional natural compound. OBJECTIVE: In this study, we demonstrate the activity of genistein on non-small lung cancer A549 and 95D cells. MATERIALS AND METHODS: A CCK8 assay was used to detect the cytotoxicity of genistein (0, 25, 50, 100, 150, 200 and 250 μM) on A549 and 95D cells for 48 h. AnnexinV-FITC/PI and TUNEL assay were performed to examine the apoptotic cell death induced by genistein (0, 50, 100 and 150 μM, 48 h). Intracellular reactive oxygen species (ROS) generation and mitochondrial membrane potential were measured by flow cytometry. Mitochondrial activity in A549 and 95D cells, treated with 0, 50, 100 and 150 μM genistein for 48 h was detected by MitoTracker Orange staining. Western blot analysis was performed to evaluate the expression of the mitochondrial apoptosis-related proteins. Meanwhile, the expression level of FOXO3a/PUMA signalling was measured by flow cytometry and Western blot assay. RESULTS: IC(50) value of genistein against 95D cells and A549 cells was 32.96 ± 2.91 and 110.6 ± 2.41 μM, respectively. The percentage of apoptotic death cells was 20.03%, 29.26% and 27.14% in 95D cells, and 41.62%, 55.24% and 43.45% in A549 cells when treated with 50, 100 and 150 μM genistein, respectively. Our observations also revealed that genistein could elevate intracellular ROS generation, decrease mitochondrial membrane potential, decrease mitochondrial activity (MitoTracker Orange staining), and up-regulate the expression of mitochondrial apoptosis-related proteins. Further examinations revealed that the expression level of FOXO3a and PUMA in NSCLC was significantly increased by genistein. DISCUSSION AND CONCLUSIONS: Our data may provide basic information for further development of genistein as a promising lead compound targeting NSCLC by inducing mitochondrial apoptosis.