CKAP5: Unraveling Its Crucial Function in Liver Hepatocellular Carcinoma Progression and Prognosis.

[BACKGROUND] Liver hepatocellular carcinoma (LIHC) remains a leading cause of cancer-related mortality worldwide, with limited therapeutic options for advanced stages. Cytoskeleton-associated protein 5 (CKAP5), a key regulator of microtubule dynamics, has emerged as a potential oncogene in multiple cancers, yet its precise role and clinical relevance in LIHC pathogenesis and tumor immunity are not fully understood.

[METHODS] We systematically evaluated CKAP5 expression patterns using multi-omics data from TCGA, GEO, and the Human Protein Atlas. Prognostic significance was assessed through Kaplan-Meier survival analysis, Cox regression, and ROC curves. The association between CKAP5 and the tumor immune microenvironment was investigated via immune cell infiltration analysis, immune checkpoint correlation, and single-cell RNA sequencing. Mechanistic insights were explored through gene set enrichment analysis (GSEA), transcription factor activity inference, and protein-protein interaction network construction. Functional validation was performed using CRISPR-Cas9-mediated CKAP5 knockdown in HepG2 cells, followed by comprehensive assays measuring proliferation, migration, and invasion capabilities.

[RESULTS] CKAP5 was significantly overexpressed in LIHC tissues at both mRNA and protein levels, and its elevated expression correlated strongly with advanced tumor stage, poor differentiation, and unfavorable patient survival. CKAP5 expression was associated with distinct immune cell infiltration patterns and positively correlated with key immune checkpoint molecules (PD1, PDL1, and CTLA4). Bioinformatic analyses further revealed a potential mechanistic link between CKAP5 and immunosuppressive signaling pathways, including JAK-STAT and NF-κB. Functional studies demonstrated that CKAP5 depletion markedly suppressed LIHC cell proliferation, colony formation, migration, and invasion.

[CONCLUSIONS] Our integrated analysis establishes CKAP5 as a critical promoter of LIHC progression and a modulator of the tumor immune microenvironment. These findings nominate CKAP5 as a promising prognostic biomarker and a potential therapeutic target, providing new insights into LIHC pathogenesis and future treatment strategies.