BackgroundHepatocellular carcinoma is a widespread cancer worldwide, ranking as the fifth most frequent cancer and the fourth leading cause of cancer-related deaths. According to comprehensive research, TLK2, a phosphorylated kinase, has been discovered to play a crucial role in promoting tumor development. However, the prognostic significance and influence of TLK2 on hepatocellular carcinoma tumor cells and the immune microenvironment remain unexplored, warranting further investigation. The aim of this study was to investigate the role of TLK2 in promoting the development of hepatocellular carcinoma.MethodsThe present study utilized The Cancer Genome Atlas (TCGA) database and other databases as training sets to examine the expression of TLK2 and its prognostic significance. The findings were subsequently validated through cell proliferation assays and cell colony assays. Gene set enrichment analysis (GSEA) was employed to investigate the tumor-related biological processes associated with TLK2 in hepatocellular carcinoma, while the relationship between TLK2 expression and Wnt/β-catenin signaling pathway was analyzed via TCGA dataset analysis. Western blotting and immunofluorescence assays were used to confirm the experimental results.ResultsTLK2 showed higher expression levels in tumor tissues than in normal tissues. Alpha fetoprotein (AFP), T stage, pathological stage, and histological grade were significantly associated with TLK2 expression. High TLK2 expression correlated with worse overall survival (OS) [hazard ratio (HR) =1.62, 95% confidence interval (CI): 1.14-2.29, P=0.007], progression-free survival (PFS) (HR =1.88, 95% CI: 1.40-2.52, P<0.001) and disease specific survival (DSS) (HR =1.86, 95% CI: 1.18-2.93, P=0.007) in the training and validation sets. Both univariate and multivariate analyses showed that TLK2 was an independent prognostic factor. GSEA showed that TLK2 was significantly enriched in tumor-related biological processes. TLK2 induced the activation of β-catenin signaling, resulting in sustained tumor growth. Methyl thiazolyl tetrazolium (MTT) and colony formation assays demonstrated that TLK2 could promote hepatocellular carcinoma progression. Furthermore, TLK2 showed a significant association with β-catenin in the Wnt pathway.ConclusionsTLK2 represents an independent prognostic factor in hepatocellular carcinoma and can promote cancer progression via the β-catenin signaling pathway.
