title: Overexpression of the orotate phosphoribosyl-transferase gene enhances the effect of 5-Fluorouracil in head and neck squamous cell carcinoma in vitro.
abstract: 5-Fluorouracil (5-FU) is a widely used drug in head and neck squamous cell carcinoma (HNSCC). In the anabolic pathway of 5-FU, the first step in activation of the drug is phosphorylation of 5-FU by orotate phosphoribosyltransferase (OPRT), which directly metabolizes 5-FU to 5-fluorouridine monophosphate (FUMP) in the presence of 5-phosphoribosyl-1-pyrophosphate. To date, OPRT expression in the tumors has been related to the clinical response or survival of cancer patients receiving 5-FU-based chemotherapy. In this study, we examined whether OPRT expression correlates with the chemosensitivity to 5-FU and cell proliferation in HNSCC. We constitutively expressed an OPRT cDNA in an HNSCC cell line. The effects of OPRT expression on in vitro cell growth and 5-FU cytotoxicity were examined. OPRT transfection increases the cytotoxicity of 5-FU without affecting cell proliferation of HNSCC cells in vitro. These results indicate that OPRT expression plays an important role in the sensitivity of HNSCC to 5-FU chemotherapy.
authors.affiliation: Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Yasumatsu
authors.forename: Torahiko
authors.initials: T
authors.lastname: Nakashima
authors.forename: Shizuo
authors.initials: S
authors.lastname: Komune