1. Dept. of Radiology, School of Medicine, University of California, San Diego, CA 92093, USA;2. Dept. of Laboratory Services, Veterans Administration Medical Center, La Jolla, CA 92036, USA
Abstract:
Human colonic tumors grown in athymic mice were tested for the effect of coincident uracil (U) and Ftorafur (FT) exposure versus FT alone on 5-Fluorouracil (5-FU) metabolism. Serum and tumor FT and 5-FU levels were studied as a function of time after FT +/? U injections. The combination of U + FT led to significantly higher tumor/serum 5-FU ratios than FT alone. The data indicate that the metabolism of 5-FU released from FT can be modulated by coincident U exposure in human tumor cells in vivo. Such combinations may be of use in the development of oral 5-FU pro-drugs for applications using 5-FU as an out-patient non-invasive radiosensitizer.