Exploration Biomarkers for Recurrence of Hepatocellular Carcinoma After Liver Transplantation Based on Bioinformatics Analysis

This study aimed to explore thrombin-related prognostic biomarkers for hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). Bioinformatics analyses were conducted using TCGA-LIHC and GEO datasets. LASSO Cox regression screened thrombin-related genes (TRGs). Differential expression analysis, GSEA, and protein-protein interaction (PPI) network analysis were performed to identify key pathways and hub genes. Clinical validation included immunohistochemistry (IHC) on 78 post-LT HCC tissues. In vitro assays (CCK-8, Transwell, Colony formation) assessed MMP1/SPP1 roles in HCC cell proliferation and migration. Nine TRGs were prognostic in HCC, with MMP1 and SPP1 emerging as core regulators linked to EMT. Both genes were significantly upregulated in recurrent HCC tissues (1-year recurrence group vs. non-recurrence, P < 0.05) and correlated with reduced overall survival (OS) and recurrence-free survival (RFS). GSEA revealed EMT as a key enriched pathway. PPI network analysis highlighted MMP1/SPP1 centrality in ECM remodeling and cell adhesion. Clinical samples confirmed MMP1 association with vascular invasion (P = 0.023) and poor differentiation. In vitro, MMP1/SPP1 overexpression enhanced HCC cell proliferation, migration, and colony formation. Multivariate analysis identified MMP1 expression and tumor differentiation as independent recurrence risk factors. MMP1 and SPP1 are potential biomarkers for predicting post-LT HCC recurrence, likely driving metastasis via EMT activation. Their overexpression correlates with aggressive tumor behavior and adverse outcomes, offering prognostic utility and therapeutic targets to improve transplant outcomes.