ABSTRACT
Similar to uracil and thymine, 5-FU can pass through the cell membrane and then be metabolized by the pyrimidine anabolic and catabolic pathways (see Figure 48.1).1
Anabolism results in the formation of the 5-FU
monophosphate (FdUMP), 5-fluorouridine 5’- triphosphate (FUTP), and 5-fluoro-2’-deoxyuridine 5’-triphosphate (FdUTP), which, through affecting indirectly or directly nucleic acid synthesis and/or function, can in turn block cell replication. This occurs through inhibition of thymidylate synthase or via incorporation of the 5-FU nucleotides FUTP and FdUTP into RNA and DNA, respectively.
