Abstract

Head and neck squamous cell carcinoma (HNSCC) ranks sixth in incidence among all cancers and is associated with poor prognosis. The aggressive nature of the disease, characterized by a high risk of invasion and lymph node metastasis, contributes significantly to its unfavorable prognosis. Although both microRNAs (miRNAs) and glycolysis are known to play important roles in tumor progression, the regulatory effects and mechanisms of miRNAs on glycolysis in HNSCC remain largely unclear. In this study, we analyzed the expression levels of miR-374a-5p and miR-374b-5p in HNSCC using data from TCGA and GEO databases. Functional assays included CCK-8 for cell proliferation, Transwell for migration and invasion, and Seahorse extracellular flux analysis for glycolytic capacity. In vivo tumorigenicity was evaluated using a nude mouse xenograft model. Mechanistic investigations were performed through qPCR, western blotting, and dual-luciferase reporter assays. Additionally, the mechanisms underlying the downregulation of miR-374a-5p and miR-374b-5p in HNSCC were investigated. Our results showed that miR-374a-5p and miR-374b-5p levels were significantly downregulated in HNSCC tissues compared with normal controls. Overexpression of either miRNA inhibited proliferation, migration, invasion, and tumor growth in vivo , and reduced cellular glycolytic activity. Mechanistically, miR-374a-5p and miR-374b-5p were found to bind to the 3′UTR of DEPDC1, which is upregulated in HNSCC, thereby suppressing its expression. Further experiments confirmed that DEPDC1 promotes proliferation, migration, invasion, and glycolysis in HNSCC cells, whereas miR-374a-5p and miR-374b-5p exert their inhibitory effects by downregulating DEPDC1. Furthermore, promoter methylation was identified as a key mechanism suppressing the expression of miR-374a-5p and miR-374b-5p in HNSCC cells. These findings provide novel insights and highlight potential molecular targets for HNSCC treatment through the modulatio