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

Abstract

Background/Aim: Hydrogen sulfide (H₂S) 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, H₂S concentrations have not been directly measured in a human malignancy. Here we directly measured in vivo H₂S 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: H₂S 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: H₂S concentrations and the enzymes that synthesize it are significantly increased in OSCC. Here, for the first time H₂S concentrations within a living human malignancy were measured and compared to adjacent counterpart benign tissue.