Dysregulated miRNA Expression and Its Association with Immune Checkpoints in Head and Neck Cancer

<b>Background</b>: Head and neck cancer (HNC) remains a global health challenge with a poor 5-year survival rate among patients with relapsed or advanced-stage disease. Immune checkpoint blockade therapies have emerged as a promising approach to improve outcomes; however, their effectiveness is limited, with response rates of only 15-20% because of immune evasion mechanisms. MicroRNA (miRNA) dysregulation plays a key role in facilitating such immune evasion. In this study, we aim to identify specific miRNAs whose altered expression contributes to immune escape in HNC. <b>Methods</b>: We employed an integrated bioinformatics approach, incorporating differential expression analysis, survival analysis, target prediction, KEGG immune pathway analysis, a protein-protein interaction network, and the identification of hub genes using in silico tools. <b>Results</b>: Our analysis revealed that a high expression of miR-18a and miR-2355 was associated with reduced survival, with the median survival decreasing from 42.9 to 27.8 months, respectively, in advanced-stage patients. Conversely, a low expression of let-7c and miR-6510 was linked to poor prognosis, with survival decreasing from 40.1 to 19.2 months and from 50.1 to 26.8 months, respectively, across disease progression. Further pathway analysis revealed that these miRNAs are significantly involved in the regulation of key immune evasion signaling pathways, including T cell receptor, PD-L1/PD-1 checkpoint, JAK-STAT, TGF-beta, NF-kappa B, and TNF signaling pathways. Hub gene analysis identified AKT1, STAT3, NFKB1, CD4, IL2RB, TLR4, and CTLA-4 as potential dysregulated miRNA targets, with enrichment in immune-related signaling pathways. <b>Conclusions</b>: Taken together, these findings suggest that targeting these miRNAs could modulate immune evasion mechanisms and potentially enhance the efficacy of ICB therapies in HNC.