CK2B is a Prognostic Biomarker and a Potential Drug Target for Hepatocellular Carcinoma

Background: Although casein kinase II subunit beta (CK2B) was previously reported to be involved in human cancers, such as hepatocellular carcinoma (HCC), there has been no systematic assessment of CK2B in HCC. Objective: To assess the potential function of CK2B as a prognostic biomarker and possible druggable target in HCC. Methods: The Cancer Genome Atlas database was accessed to investigate the potential oncogenic and prognostic roles of CK2B in HCC. Diverse analytical methods were used to obtain a fuller understanding of CK2B, including CIBERSORT, The Tumor Immune Estimation Resource (TIMER), gene set enrichment analyses (GSEA), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene ontology (GO). Furthermore, the Comparative Toxicogenomic Database (CTD) was used to identify potential drugs to treat CK2B-overexpressing HCC. Patents for these drugs were reviewed using Patentscope^® and Worldwide Espacenet^®. Results: Upregulated CK2B expression was markedly associated with more aggressive pathological features, including G3, G4 (vs. G1, G2), and T2, T3 (vs. T1). Kaplan-Meier survival curves indicated that patients with HCC with higher expression of CK2B had worse overall survival (P = 0.005), progression-free interval (P = 0.001), and disease-specific survival (P = 0.011). GO and KEGG analysis revealed that CK2B dysregulation affects mitotic chromosome condensation, protein stabilization and binding, regulation of signal transduction of p53 class mediator, and cancer-related pathways. GSEA identified six well-known pathways, including MAPK, WNT, Hedgehog, and TGFβ signaling pathways. Finally, CTD identified six compounds that might represent targeted drugs to treat HCC with CK2B overexpression. A review of patents indicated these compounds showed promising anticancer results; however, whether CK2B interacts with these drugs and improves drug outcomes for patients with HCC was not confirmed. Conclusion: CK2B is a biomarker for HCC prognosis and could be a potential new drug target. Moreover, the association between infiltrating immune cells and CK2B in the HCC tumor microenvironment might provide a solid basis for further investigation and a potent strategy for immunotherapy of HCC.