The HIF-1α/LGR5/MAPK axis enhances hypoxia-induced metastatic potential in LGR5-positive hepatocellular carcinoma

While transarterial chemoembolization (TACE) is widely used as a bridging therapy for hepatocellular carcinoma (HCC) patients awaiting liver transplantation (LT), the prognostic value of TACE-induced tumor necrosis and the mechanisms driving post-TACE recurrence remain poorly understood. In a cohort of 265 HCC patients beyond the Milan criteria undergoing LT, we stratified them by pre-transplant TACE response: extensive necrosis (EN, n = 74), limited necrosis (LN, n = 79), and non-TACE ( n = 112). Strikingly, patients with LN exhibited significantly higher post-LT recurrence rates than both the EN ( P = 0.007) and non-TACE ( P = 0.026) groups. RNA-sequencing of matched HCC specimens revealed significant up-regulation of leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) in TACE-treated residual tumors compared to untreated tumors. Clinically, high LGR5 expression ( n = 60) correlated with reduced recurrence-free survival compared to low expression ( n =147, P = 0.015) and was an independent predictor of tumor recurrence (HR = 1.89). Mechanistically, isolated LGR5 high cells demonstrated more malignant biological properties than LGR5 low cells. Hypoxia-inducible factor 1α (HIF-1α) greatly up-regulated the expression of LGR5 in cell lines and patient-derived organoids under hypoxic stress. This HIF-1α-driven LGR5 induction markedly enhanced the invasive capacity and epithelial–mesenchymal transition of LGR5 high cells, effects that were abrogated by LGR5 knockdown. Furthermore, LGR5 activated the MAPK signaling pathway under hypoxia, and its silencing suppressed this activation. Our findings establish the extent of TACE-induced necrosis as a critical prognostic marker and unveil the novel HIF-1α/LGR5/MAPK axis as a key driver of metastatic progression in residual HCC, positioning LGR5 as a promising therapeutic target to prevent post-TACE recurrence.