TUBB2A expression and its prognostic significance in hepatocellular carcinoma revealed by cholesterol-metabolism-related gene profiling.

[INTRODUCTION] Hepatocellular carcinoma (HCC) exhibits significant molecular heterogeneity and is associated with a poor prognosis. The lack of validated biomarkers limits early diagnosis and effective prognosis. Identifying oncogenic drivers in HCC may enhance risk stratification and provide new therapeutic targets. Recent evidence links disrupted cholesterol metabolism to hepatic oncogenesis, and a comprehensive profiling of cholesterol-related genes may help identify metabolic oncogenic signatures and prognostic biomarkers for HCC.

[METHODS] Bioinformatic analyses were performed using public databases to assess differential expression and the prognostic significance of TUBB2A. Gene set enrichment analysis (GSEA) was conducted to identify key biological pathways associated with TUBB2A expression in HCC. These findings were validated through RT-qPCR, Western blot, and immunohistochemistry on patient tissues. Functional studies included siRNA knockdown and plasmid overexpression in HCC cell lines, followed by assays for cellular proliferation, clonogenicity, migration, and invasion. Tumorigenicity was tested using xenograft models in nude mice. The prognostic value of TUBB2A was evaluated through survival curves and time-dependent ROC analysis.

[RESULTS] TUBB2A was identified as a dysregulated and prognostically significant biomarker in HCC through bioinformatic analyses. Pathway analysis using databases like KEGG, GOBP, and Hallmark revealed significant enrichment of TUBB2A in pathways related to cholesterol metabolism, fatty acid biosynthesis, and steroid biosynthesis. Experimental validation demonstrated that TUBB2A is overexpressed in HCC tissues and cell lines. Elevated TUBB2A expression correlated with higher AFP levels, microvascular invasion, advanced tumor stages, and poorer overall survival. Functional assays showed that knockdown of TUBB2A suppressed proliferation, migration, invasion, and tumorigenicity. Furthermore, TUBB2A was found to be associated with key regulators of cholesterol metabolism, including HMGCR, LDLR, SREBP2, and CYP7A1, suggesting its role in regulating cholesterol metabolic homeostasis.

[DISCUSSION] TUBB2A plays a key role in promoting HCC tumorigenesis and is associated with adverse clinical outcomes. The integration of bioinformatic analyses and experimental validation establishes TUBB2A as a potential prognostic biomarker in HCC. Its role in regulating cholesterol metabolism suggests that TUBB2A may be a novel target for therapeutic interventions. Further studies should explore the clinical utility of TUBB2A, including its integration into multi-marker models and as a target for targeted therapy, offering potential avenues to improve HCC treatment strategies.