[Mechanism for the inhibition of proliferation and promotion of apoptosis in Huh7.5 cells by iron overload].

Objective To investigate the effect of iron overload on biological activity and apoptosis in Huh7.5 cells. Methods Huh7.5 cells were cultured in the medium supplemented with 50, 100, 200 μmol/L ferric ammonium citrate (FAC). Fluorescence microscopy was employed to determine cell iron load labeled by Phen Green FL; proliferation activity of Huh7.5 cells was evaluated by MTT assay; protein and mRNA levels of transferrin receptor (TfR1), TfR2, divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) in Huh7.5 cells were detected by Western blotting and real-time PCR, respectively; cell reactive oxygen species (ROS) labeled by dichlorofluorescin diacetate (DCFH-DA) and cell apoptosis labeled by annexinV-FITC/PI were analyzed by flow cytometry. Results FAC treatment increased intracellular iron load in a dose-dependent manner. Compared with control group, mRNA and protein expressions of TfR1, TfR2 and DMT1 were down-regulated, while mRNA and protein expression of FPN1 was significantly up-regulated in FAC treated groups. With the increasing dose of FAC, intracellular ROS level increased significantly and cell proliferation activity decreased significantly. The cell apoptosis rate in FAC treated groups were remarkably higher than that in control group, but after antioxidant N-acetylcysteine (NAC) was added, the cell apoptosis in FAC treated group was inhibited obviously. Conclusion Iron overload can inhibit the proliferation and promote the apoptosis of Huh7.5 cells through oxidative stress.