Abstract
Former clinical trials and experimental research have indicated that Interferon-gamma therapy does not achieve an ideal effect in solid tumors. Autophagy has been associated with tumor chemoresistance. The aim of this study was to explore the efficacy of Interferon-gamma and autophagy inhibitor in the combination treatment of oral squamous cell carcinoma. Interferon-gamma-induced apoptosis was evaluated by the expression of relative proteins (cleaved-PARP and caspase-3) and flow cytometry. Interferon-gamma induced autophagy was assessed by the expression of Beclin1, LC3B, and P62. The synergistic effect of interferon-gamma and autophagy inhibitor (chloroquine) was evaluated in vitro and in vivo. Interferon-gamma induced anti-proliferation, apoptosis, and autophagy in oral squamous cell carcinoma cells. Autophagy-related protein 5 was a key feature in Interferon-gamma-induced autophagy flux. Interferon-gamma and chloroquine had obvious synergistic effects on cellular growth inhibition and apoptosis promotion in oral squamous cell carcinoma cells and xenograft models. Our findings suggest that Interferon-gamma-induced autophagy plays a cellular protective role, and blocking autophagy flux can promote Interferon-gamma mediated oral squamous cell carcinoma cell apoptosis. The combination of Interferon-gamma and autophagy inhibitors represents a novel strategy for oral squamous cell carcinoma therapy.