Changes in thymidylate synthase and its inhibition rate and changes in dihydropyrimidine dehydrogenase after the administration of 5-fluorouracil with cisplatin to nude mice with gastric cancer xenograft SC-1-NU

Background Although 5-fluorouracil (5-FU) and cis-diamminedichloroplatinum (cisplatin) in combination have synergistic cytotoxicity against both murine and human neoplasms, the precise mechanism of the synergism, and the effects on thymidylate synthase and its percent inhibition, and the effects on dihydropyrimidine dehydrogenase (DPD) remained to be elucidated.