[CAS NO. 112887-68-0]  Raltitrexed

Raltitrexed induces a concentration-dependent amount of double-stranded DNA breaks. Raltitrexed increases the level of Bax protein up to a factor 5 in the Lovo and LS174T cell lines containing wt p53. Raltitrexed leads to an increase of intracellular phosphoribosyl pyrophosphate (PRPD) in the case of the HCT-8 cell line, which suggests that the cytotoxic effects of raltitrexed combined with 5-FU may be due to the increased formation of 5-FU nucleotides. Raltitrexed combined with SN-38 results in synergistic cytotoxicity at broad dose-effect ranges in human colon cancer cells. Raltitrexed is actively taken up into cells and then undergoes rapid, extensive metabolism to a series of polyglutamates, which results in potent thymidylate synthase inhibition. Raltitrexed is delivered to the brain very quickly, and could be detected at 5 min in all brain tissues. Raltitrexed combined folinic acid (5FU-FA) shows a clear schedule-dependent synergistic antiproliferative interaction as demonstrated by calculating combination indexes. Raltitrexed combined with Vorinostat produces synergistic effect paralleled by evident cell cycle perturbations with major S-phase arrest. Raltitrexed is a specific, folate-based inhibitor of thymidylate synthase with activity in advanced colorectal cancer comparable with that of fluorouracil (5-fluorouracil) plus folinic acid. Raltitrexed‘s activity is enhanced by rapid cellular entry and polyglutamation, with the polyglutamated derivatives having approximately 100-fold greater inhibitory potency than the parent compound.