Glycyrrhetinic acid orchestrates ERS-pyroptosis crosstalk to elicit immunogenic cell death in hepatocellular carcinoma.

[BACKGROUND] Hepatocellular carcinoma (HCC) remains a magnitude global public health challenges since its aggressive biological behavior and persistently high morbidity and mortality rates. Glycyrrhetinic acid (GA), a bioactive triterpenoid extracted from Glycyrrhiza glabra, has been reported in certain contexts to suppress HCC cell migration and proliferation. In addition, the markedly immunosuppressive tumor microenvironment of HCC represents a major obstacle to achieving durable responses with immunotherapy.

[PURPOSE] This study focused on elucidating the anti-hepatoma activity of GA, uncover the underlying molecular pathways, and assess its ability to trigger immunogenic cell death (ICD) as a potential therapeutic strategy for HCC.

[METHODS] Tumor-suppressive effects of GA were evaluated through histopathological analysis in multiple murine models, including cell line-derived xenografts (CDX), orthotopic liver implantation, and lung metastasis models. Transmission electron microscopy (TEM), intracellular calcium (Ca) assays, ROS staining, and immunofluorescence were used to investigate GA-induced endoplasmic reticulum stress (ERS) and pyroptosis in HCC cells. Proteomics and transcriptomics were applied to profile changes in protein and transcript expression. CETSA, DARTS, pull-down and molecular docking were employed to identify the direct molecular target of GA.

[RESULTS] The studies suggested that GA exhibited considerably similar anticancer efficacy (IRT = 46.62 %) compared with DOX (IRT = 48.87 %) in a CDX mouse model. Additionally, GA robustly activated ERS via PERK signaling and induced GSDME-mediated pyroptosis, increasing the cytoplasmic Ca concentration, driving the translocation of calreticulin (83.32 %) to the tumor cell surface, resulting in the strong release of proinflammatory cytokines and immunogenic signals. This coordinated interaction enhanced DC maturation and T-cell dependent adaptive immune responses, amplifying antitumor immunity.

[CONCLUSION] Our findings highlight a novel mechanism whereby GA exploits the ERS-pyroptosis axis to potentiate ICD and amplify antitumor immunity in HCC, providing mechanistic insight and potential therapeutic implications.