An Integrative Pan-Cancer Analysis of the Prognostic and Immunological Role of Casein Kinase 2 Alpha Protein 1 (CSNK2A1) in Human Cancers: A Study Based on Bioinformatics and Immunohistochemical Analysis

BACKGROUND: Although emerging animal- or cell-based evidence supports the relationship between casein kinase 2 alpha protein 1 (CSNK2A1) and cancers, no pan-cancer analysis is available. Thus, this report aimed to display the prognostic landscape of CSNK2A1 in pan-cancer and investigate the relationship between CSNK2A1 and tumor immunity. METHODS: In the current study, we investigated the expression pattern, genetic alterations and survival analysis of CSNK2A1 in pan-cancer across multiple datasets and online platforms. The correlations between CSNK2A1 expression and tumor immunity were explored and visualized via R language software. Following this, immunohistochemical (IHC) staining and Kaplan–Meier survival analysis were conducted in clinical patients for proving the bioinformatic findings. Analysis of protein–protein interaction and gene functional enrichment was conducted using GeneMANIA platform and gene set enrichment analysis (GSEA), respectively. RESULTS: In TCGA, tumor tissue had a higher expression level of CSNK2A1 compared with that in corresponding normal tissue. An increased expression level of CSNK2A1 was related to poor clinical prognosis in most types of cancer such as LIHC. The following expression and survival analysis in clinical liver hepatocellular carcinoma (LIHC) patients confirmed these TCGA findings. CSNK2A1 expression had significant positive correlations with pro-tumor-infiltrating immune cells (TIICs) like M1-macrophages and fibroblasts, and significant negative correlations with anti-tumor-TIICs like activated CD8+ T cells and NK cells, suggesting specific interactions between CSNK2A1 and certain TIICs subtypes. Furthermore, CSNK2A1 expression had the most significant positive correlations with common markers of immune checkpoint including programmed death ligand-1 (PDL1) in LIHC. These findings were validated by an IHC analysis. GSEA analysis demonstrated that high expression of CSNK2A1 was related to cell signaling pathways and immunity-related activities. CONCLUSION: These findings suggested that CSNK2A1 was not only related to poor clinical prognosis in cancer like LIHC but also a novel immunotherapy-related biomarker in cancers, especially in LIHC, shedding new light on anti-tumor strategy.