Interferon-alpha-2b induces autophagy in hepatocellular carcinoma cells through Beclin1 pathway

OBJECTIVE To determine whether Interferon-alpha-2b (IFN-α2b) can modulate the autophagic response in hepatocellular carcinoma cells. METHODS Hepatocellular carcinoma cells were treated with IFN-α2b. Autophagy was assessed by acridine orange staining, GFP-LC3 dotted assay, transmission electron microscopy and immunoblotting. RESULTS Acridine orange staining showed that IFN-α2b triggered the accumulation of acidic vesicular and autolysosomes in HepG2 cells. The acridine orange HepG2 cell ratios were (4.3±1.0)%, (6.9±1.4)%, and (13.1±2.3)%, respectively, after treatment with 100, 1,000, and 10,000 IU/mL IFN-α2b for 48 h. A markedly punctate pattern was observed in HepG2 cells treated with 10,000 IU/mL IFN-α2b for 48 h, but only diffuse and weakly fluorescent GFP-LC3 puncta was observed in control cells. HepG2 cells treated with 10,000 IU/mL IFN-α2b for 48 h developed autophagosome-like characteristics, including single- or double-membrane vacuoles containing intact and degraded cellular debris. The Beclin1 and LC3-II protein expression was up-regulated by IFN-α2b treatment. CONCLUSION Autophagy can be induced in a dose-dependent manner by treatment with IFN-α2b in HepG2 cells, and the Beclin1 signaling pathway was stimulated by IFN-α2b.