Knocked down HPRT1 inhibits the progression of head and neck squamous cell carcinoma and decreases the production of lactic acid

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer with over 500,000 incident cases worldwide annually. Despite advances in anti-cancer therapy, the 5-year survival rates of HNSCC remain about 50%. Promising biomarkers effectively evaluating the prognosis of HNSCC was urgently needed. Hypoxanthine guanine phosphoribosyl transferase (HPRT1) is essential for the purine salvage pathway, which is important for the generation of purine nucleotides in cells and the maintenance function of cell growth and proliferation. Here, we identified that mRNA and protein expression level of HPRT1 is remarkably elevated in HNSCC tissues compared with normal control tissues. The mRNA level of HPRT1 was positively correlated with tumor size and lymphatic node metastasis in HNSCC patients. The area under curve (AUC) of HPRT1 in HNSCC is 0.908 (p<0.0001), using the receiver operating characteristic analysis (ROC). The HNSCC patients with higher expression of HPRT1 have shorter overall survival and recurrent-free survival. In addition, knocking down HPRT1 significantly inhibited the proliferation, migration, and invasion of HNSCC cells. Interestingly, the mRNA expression of LDHB is positively correlated with HPRT1. A lower level of lactic acid was detected in HPRT1 knocked-off HNSCC cells, suggesting that HPRT1 might play a role in regulating glycolysis. In conclusion, HPRT1 may serve as an oncogene promoting HNSCC proliferate and move by modulating glycolysis, and as a potentially valuable diagnostic and prognostic biomarker.