Tissue factor promotes vascular invasion and metastasis in hepatocellular carcinoma via combined activation of β-catenin/STAT3 signaling.

Vascular invasion critically determines intrahepatic and extrahepatic metastasis and early recurrence in hepatocellular carcinoma (HCC), yet its underlying mechanisms remain poorly defined. In this study, we employed EdU proliferation, colony formation, wound healing, transwell, spheroid formation, and immunofluorescence assays, along with xenograft tumor and liver/lung metastasis models, immunohistochemistry, and western blotting to investigate the biological functions of tissue factor (TF) and the therapeutic potential of targeting TF and its downstream signaling. Our results demonstrate that TF is upregulated in HCC tissues and correlates with poor prognosis. TF overexpression significantly enhanced HCC cell proliferation, migration, invasion, and spheroid formation in vitro, and promoted tumor growth and metastasis in vivo. Clinical sample analysis further revealed that high TF expression increases the dissemination potential of circulating tumor cells (CTCs) and circulating tumor microemboli (CTMs) in peripheral blood, thereby facilitating hematogenous spread. Mechanistically, TF activates PAR1 on HCC cell surfaces, leading to activation of both the Wnt/β-catenin and JAK2/STAT3 pathways, with nuclear translocation and accumulation of β-catenin and STAT3. Notably, nuclear STAT3 enhances TF promoter activity, forming a positive feedback loop that sustains downstream signaling. TF also promotes extracellular matrix degradation. Importantly, combined inhibition of TF with β-catenin and STAT3 blockers effectively suppressed HCC tumorigenesis and metastasis both in vitro and in vivo. These findings elucidate the oncogenic role of TF in vascular invasion-mediated HCC metastasis and suggest a promising combinatorial therapeutic strategy for HCC treatment.