Abstract
BACKGROUND/AIM: Tetratricopeptide repeat domain 21A (TTC21A) plays a crucial role in ciliary function and has been associated with various pathogenic processes, including carcinogenesis. However, its role in head and neck squamous cell carcinoma (HNSCC) has not been elucidated. MATERIALS AND METHODS: Based on the sequencing and microarray data of HNSCC from publicly available databases, the expression of TTC21A was compared between different subgroups based on clinical and molecular parameters. The survival analysis and regression analysis were conducted using the Kaplan-Meier method and the Cox method, respectively. Functional analysis was performed by the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and gene set enrichment analysis (GSEA) tools. Immune infiltration analysis was performed based on the expression of TTC21A. RESULTS: TTC21A decreased in tumor tissues and was associated with N stage, histologic grade, HPV infection, and TP53 mutation in HNSCC. TTC21A was an independent indicator of overall survival for patients with HNSCC. A high level of TTC21A expression indicated a favorable prognosis. The TTC21A expression level was involved with immune-related signaling regulation, immune-related gene expression, and immune cell infiltration. TTC21A expression was potent in predicting immunotherapeutic benefits. CONCLUSION: TTC21A, as a potential predictor of favorable outcomes and immunotherapy response for HNSCC, is related to immune-related signaling regulation, immune-related gene expression, and immune cell infiltration.