Nutrient Restriction Improves the Therapeutic Efficacy of Sorafenib by Inducing Ferroptosis via the NRF2/HO-1/GPX4 Pathway in Hepatocellular Carcinoma.

[BACKGROUND AND AIMS] Hepatocellular carcinoma (HCC) is a prevalent malignant tumor with a high fatality rate, making it imperative to explore novel therapeutic approaches. This study aimed to assess the effectiveness and underlying mechanism of nutrient restriction in potentiating Sorafenib-induced cell death.

[METHODS] Cell viability was measured using MTT assays. Mitochondrial membrane potential (MMP) was assessed by the JC-1 probes. The levels of Reactive oxygen species (ROS) were determined using a DCFH-DA probe. Lipid peroxidation was quantified using the C11-BODIPY probe and a malondialdehyde (MDA) kit. Intercellular Fe was assessed using the FerroOrange probe. Western blot, HE staining, and immunohistochemistry (IHC) techniques were utilized to analyze the impact of combination therapy on NRF2, HO-1, and GPX4 proteins. Nude mice xenograft models were established to evaluate the inhibitory effects of the combination therapy in vivo.

[RESULTS] Nutrient restriction/Intermittent fasting enhanced Sorafenib-induced cell death both in vivo and in vitro by elevating ROS and MDA levels, promoting excessive lipid peroxidation, and increasing intercellular Fe accumulation. Notably, key ferroptosis-associated proteins, including NRF2, GPX4, and HO-1, were significantly down-regulated by combination treatment, while glutathione (GSH) supplementation reversed this downregulation.

[CONCLUSION] The combination of nutrient restriction and Sorafenib significantly enhanced anti-tumor efficacy both in vivo and in vitro. Mechanistically, nutrient restriction potentiated Sorafenib-induced ferroptosis via the NRF2/HO-1/GPX4 pathway in HCC cells.