title: Cellular pharmacology of DUP-785, a new anticancer agent.
abstract: DUP-785, a new inhibitor of dihydroorotate dehydrogenase, is currently undergoing clinical evaluation for anticancer activity. We developed a GC/MS method to quantitate dihydroorotate that accumulates in cultures of L1210 cells exposed to growth inhibitory concentrations of DUP-785. This method was used to follow the onset, extent, and duration of inhibition of de novo pyrimidine synthesis in intact L1210 cells and to compare this inhibition with cell proliferation and cellular concentrations of pyrimidine nucleotides. There were direct relations between inhibition of de novo pyrimidine synthesis, changes in pyrimidine nucleotide concentrations, and cell proliferation following short (less than 24 hr) drug exposures; with prolonged exposures (greater than 24 hr), however, there was a departure from these relationships in that restoration of pyrimidine nucleotide pools and de novo pyrimidine pathway activity did not restore cell proliferation. Exposure of L1210 cells to 15 microM DUP-785 produced a maximum cell kill (99.9% as determined by cloning efficiency) at 24 hr, and no increase in cell kill was observed with drug exposure up to 96 hr.
authors.affiliation: Laboratory of Biological Chemistry, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
authors.forename: L W
authors.initials: LW
authors.lastname: Anderson
authors.forename: J M
authors.initials: JM
authors.lastname: Strong
authors.forename: R L
authors.initials: RL
authors.lastname: Cysyk
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002849:Chromatography, Gas; D004081:Dihydroorotate Oxidase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007939:Leukemia L1210 / Q000188:drug therapy*; D013058:Mass Spectrometry; D051379:Mice; D013997:Time Factors; D014529:Uridine / Q000494:pharmacology; D011798:Quinaldines
chemical_list: D000970:Antineoplastic Agents; D001713:Biphenyl Compounds; D004081:Dihydroorotate Oxidase; D014529:Uridine; C046943:brequinar; D011798:Quinaldines