SOX9 and IL1A as the Potential Gene Biomarkers of the Oral Cancer

Abstract

Objective: Oral cancer is one of the most common malignant tumors in the head and neck. It is easy to relapse, and the prognosis is poor. However, the molecular mechanism in the development of oral cancer is still unclear.

Methods: A total of 30 normal individuals and 30 patients with head and neck cancer who underwent surgery were recruited in the Fourth Hospital of Hebei Medical University between February 2019 and November 2021. Furthermore, Human Protein Atlas (HPA) analysis, RT-qPCR, and immunofluorescence were used to verify the expression of SOX9 and IL1A. The GSE69002 dataset was downloaded from the Gene Expression Omnibus (GEO) database. GEO2R was used to identify the differentially expressed genes (DEGs). The Protein-Protein Interaction (PPI) network was constructed by using the STRING, and Cytoscape software was performed for visualization. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for enrichment analysis were made via the DAVID, Metascape, Gene Set Enrichment Analysis (GSEA), and Bin Gene Ontology (BINGO) analysis. Gene Expression Profiling Interactive Analysis (GEPIA) analysis was used to analyze the expression level of hub genes and pathological stage. The cBioPortal can be used for mutation analysis and pathway prediction of hub genes. Kaplan Meier Plotter was used for survival analysis of hub genes.

Results: The relative expression level of SOX9 (P=0.021, t=4.332) and IL1A (P=0.011, t= -4.213) in oral cancer was significantly higher than that in the standard group (P<0.05). The DEGs are mainly enriched in cell division, inflammation, interleukin-12 beta-subunit binding, and interleukin- 10 receptor binding. All the differentially expressed gene pathways eventually converge in cell growth and apoptosis. No relationship between the pathologic stage and the expression of hub genes. The poor overall survival of patients with the high expression of SOX9 (Hazard Ratio (HR) = 1.46, P = 0.009) and IL1A (HR = 1.49, P = 0.008). There were strong correlations between the hub genes and the head and neck neoplasms via the Comparative Toxicogenomics Database (CTD). The immunofluorescence and PCR results showed that the level of SOX9 (P<0.001, t = -23.368) in the cancer group was significantly higher than that in the normal group; The level of IL1A in the cancer group was significantly higher than that in the normal group (P<0.001, t = -11.960).

Conclusion: SOX9 and IL1A genes are highly expressed in oral cancer and might be potential therapeutic targets for oral cancer. The poor overall survival of patients with the high expression of SOX9 and IL1A.

Keywords: IL1A; SOX9; bioinformatics; biomarkers; oral cancer; potential gene.