Identification of Potential Immune Checkpoint Inhibitor Targets in Gliomas via Bioinformatic Analyses

BACKGROUND: Glioma is a common tumor originating from the glial cells of the brain. Immune checkpoint inhibitors can potentially be used to treat gliomas, although no drug is currently approved. METHODS: The expression levels of the immune checkpoint genes in glioma and normal tissues, and their correlation with the IDH mutation status and complete 1p/19q codeletion, were analyzed using The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA) databases. Survival analyses were conducted using the CGGA database. Protein-protein interaction and functional enrichment analyses were performed via the STRING database using GO, KEGG, and Reactome pathways. The correlation between the immune checkpoints and the immune cell infiltration was determined using the TISIDB and TIMER databases. RESULTS: HAVCR2 was overexpressed in the gliomas compared to normal brain tissues, as well as in the high-grade glioma patients and significantly downregulated in IDH mutant or 1p/19q codeletion patients. Overexpression of HAVCR2 was associated with poor survival in tumor grades II, III, and IV and was the most correlated with immune infiltration of B and T cells. CONCLUSION: HAVCR2 can be a potential therapeutic target for cancer immunotherapy for glioma patients.