Mechanism of FXR signaling: from liver inflammation to hepatocellular carcinoma.

OBJECTIVE: To clarify the core regulatory role and molecular mechanism of farnesoid X receptor (FXR) in the progression from liver inflammation/fibrosis to hepatocellular carcinoma (HCC), and to provide a theoretical basis for targeted prevention and treatment of liver diseases. METHODS: A systematic review was performed to integrate FXR's key regulatory mechanisms in bile acid homeostasis, inflammatory signaling, metabolic reprogramming, tumor pathways, and the tumor immune microenvironment. Intervention effects of natural compounds and FXR agonists/antagonists were analyzed for clinical translational potential. RESULTS: FXR acts as a core regulator throughout the inflammation-fibrosis-HCC axis via bidirectional mechanisms. (1) In inflammation/fibrosis, FXR activation upregulates BSEP, FGF15/19, and SHP, inhibits CYP7A1 to maintain bile acid homeostasis, suppresses the TLR4/NF-κB axis and NLRP3 inflammasome, reduces IL-6/TNF-α, and directly inhibits hepatic stellate cell activation and matrix deposition. Agonists like INT-767 block progression from chronic hepatitis to fibrosis/cirrhosis (2) In HCC, FXR dysfunction (e.g., HBx C40-mediated). causes bile acid accumulation, glucose metabolic disorders, and Notch1/STAT3 activation, driving HCC progression. FXR activation inhibits STAT3 phosphorylation, glycolytic enzymes, and Wnt activity. Quercetin and obeticholic acid suppress tumor growth via FXR signaling. (3) Aberrant FXR signaling correlates with immune microenvironment dysregulation and immune escape. FXR agonists reshape the microenvironment and enhance anti-PD-1 efficacy; combined FXR and GPC3 detection improves HCC diagnostic specificity. CONCLUSION: FXR is a central hub regulating the liver inflammation-fibrosis-HCC axis. FXR-targeting agonists, natural compounds, and combination immunotherapy hold significant translational potential. Further studies are needed to clarify FXR's tissue-specific functions and bidirectional mechanisms, and to develop highly selective modulators for precise liver disease prevention and treatment.