We studied whether common polymorphisms in genes involved in folate metabolism affect MTX sensitivity. Ex-vivo MTX sensitivity of lymphoblasts obtained from pediatric ALL patients (n=157) was determined by the in-situ thymidylate synthase inhibition assay after either continuous (21-h; TSI50,cont) or short-term (3-h; TSI50,short) MTX exposure. DNA was isolated from lymphoblasts obtained from cy...

We studied whether common polymorphisms in genes involved in folate metabolism affect methotrexate (MTX) sensitivity. Ex vivo MTX sensitivity of lymphoblasts obtained from pediatric patients with acute lymphoblastic leukemia (ALL; n = 157) was determined by the in situ thymidylate synthase inhibition assay after either continuous (21 hours; TSI(50, cont)) or short-term (3 hours; TSI(50, short))...

Synthesis and biological evaluation are described of seven new analogues (3-9) of two potent thymidylate synthase inhibitors, 10-propargyl-5,8-dideazafolate (1) and its 2-methyl-2-deamino congener ICI 198583 (2). While the new compunds 3 and 4 were analogues of 1 and 2, respectively, containing a p-aminobenzenesulfonyl residue in place of the p-aminobenzoic acid residue, the remaining 5 new com...

Cancer drugs such as 5-fluorouracil (5-FU) that target the enzyme thymidylate synthase (TS) have been and are still being widely used in cancer treatment, but as with other anti-cancer drugs, the majority of tumors do not respond to the treatment, whereas the patients still suffer drug-related toxicity. The most recent attempts at improving cancer treatment have taken the pharmacogenetic approa...

We have subjected 12 different codons of a synthetic Lactobacillus casei thymidylate synthase (TS) gene to saturation site-directed mutagenesis to create amino acid "replacement sets" at each of those positions. The target residues were chosen because they are highly conserved and because they are important for the structure and function of the protein as indicated by solution and structural st...