The antimetabolites 6-mercaptopurine (6-MP) and metliotrexate (MTX) are the
cornerstones in the maintenance treatment of children's acute lymphoblasti
c leukemia (ALL). The biochemical mechanisms underlying the increased thera
peutic efficacy of the combination of these drugs have not yet been elucida
ted. However, both drugs interact with important pathways, such as purine d
e novo synthesis (PDNS), purine salvage, and methylation reactions. A revie
w of the mechanistic aspects of the interactions between 6-MP and MTX is gi
ven. (C) 1999 Elsevier Science Inc. All rights reserved.