Hydrogen Sulfide Is Increased in Oral Squamous Cell Carcinoma Compared to Adjacent Benign Oral Mucosae

BACKGROUND/AIM: Hydrogen sulfide (H(2)S) and the enzymes that synthesize it, cystathionine-b-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate, are increased in different human malignancies. Due to its short half-life, H(2)S concentrations have not been directly measured in a human malignancy. Here we directly measured in vivo H(2)S levels within oral squamous cell carcinoma (OSCC). PATIENTS AND METHODS: Punch biopsies of OSCC and benign mucosae from 15 patients were analyzed by HPLC, western blotting, and tissue microarray analyses. RESULTS: H(2)S concentrations were significantly higher in OSCC compared to adjacent benign oral mucosae. Western blot and tissue microarray studies revealed significantly increased cystathionine-b-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate, phopho-Stat3, mitoNEET, hTERT, and MAPK protein levels in OSCC. CONCLUSION: H(2)S concentrations and the enzymes that synthesize it are significantly increased in OSCC. Here, for the first time H(2)S concentrations within a living human malignancy were measured and compared to adjacent counterpart benign tissue.