The mechanism of hypoxanthine-guanine phosphoribosyltransferase 1 (HPRT1) upregulation and its function in head and neck squamous cell carcinoma (HNSCC) remains obscure. Herein, the expression and function of HPRT1 and the mechanism underlying its upregulation in HNSCC were explored. Firstly, the expression of HPRT1 and its prognostic values were simultaneously validated using bioinformatic analysis and quantitative real-time PCR (qRT-PCR), and immunohistochemistry staining with local HNSCC samples. The effects of HPRT1 knockdown on proliferation and invasion of HNSCC cells were detected using cell counting kit-8 (CCK-8), plate clone formation, Transwell invasion, nude mouse xenograft model assays. Moreover, the miRNA targeting HPRT1 was validated using dual-luciferase report assay, qRT-PCR and Western blot analysis. The functions of miRNA targeting HPRT1 and its dependence on HPRT1 were further investigated in HNSCC. The results indicated that HPRT1 was highly expressed in HNSCC tissues and cells, which positively correlated with advanced tumor progression and predicted poor prognosis in patients with HNSCC. HPRT1 knockdown markedly inhibited proliferation and invasion of HNSCC cells both and . MiR-125b-5p, which was downregulated and positively correlated with a favorable outcome for patients, directly targeted and downregulated HPRT1 expression, and subsequently suppressed cell proliferation and invasion in HNSCC. Collectively, the present study demonstrates that HPRT1 upregulation, at least partially caused by miR-125b-5p downregulation, could promote the malignant progression of HNSCC, highlighting the potential application of the miR-125b-5p/HPRT1 axis as a novel indicator and target in the diagnosis and treatment of HNSCC.
