CEP72 Promotes Malignant Progression and Shapes the Tumor Immune Microenvironment in Hepatocellular Carcinoma: Integrated Multi-cohort Bioinformatics and In Vitro Validation

Background Immune checkpoint inhibitors (ICIs) benefit only a subset of patients with hepatocellular carcinoma (HCC), and biomarkers linking ICI response with tumor biology remain limited. We investigated CEP72 as an ICI-response–associated gene and evaluated its prognostic, immune, and functional relevance in HCC. Methods Anti–PD-1 response–associated differentially expressed genes (DEGs) were identified in GSE35640 and screened for prognostic relevance in TCGA-LIHC using univariate Cox models for overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI). Intersected prognostic genes were used to construct and validate multigene survival models across TCGA-LIHC and independent cohorts. CEP72 was prioritized for pathway activity (GSVA/GSEA), tumor microenvironment deconvolution, validation in independent immunotherapy cohorts, drug sensitivity association (GDSC), and single-cell localization in HCC (TISCH2). CEP72 was silenced with two siRNAs followed by qPCR, CCK-8, colony formation, and wound-healing assays, and protein expression was assessed by immunohistochemistry. Results Of 209 anti–PD-1–associated DEGs, 25 were consistently prognostic for OS/DSS/PFI, and 23 were dysregulated between tumor and adjacent liver. A Ridge-based signature showed stable discrimination (mean AUC ~ 0.66) and stratified survival across cohorts, supported by meta-analysis (pooled HR 1.84, 95% CI 1.21–2.78). CEP72 was upregulated in HCC and associated with proliferative programs (cell cycle and DNA damage/repair), higher PI3K activity, and distinct immune infiltration patterns. Higher CEP72 expression was associated with ICI response and predicted sensitivity to multiple targeted agents. Single-cell analyses localized CEP72 predominantly to malignant/epithelial compartments. Functionally, CEP72 knockdown reduced proliferation, clonogenicity, and migration, while increasing apoptosis. Conclusions CEP72 integrates prognostic stratification with tumor-intrinsic oncogenic programs and immune/therapeutic response signals, supporting CEP72 as a candidate biomarker and potential vulnerability in HCC.