title: Antifolate screening using yeast expressing Plasmodium vivax dihydrofolate reductase and in vitro drug susceptibility assay for Plasmodium falciparum.
abstract: The presence of homologous point mutations in the dhfr gene in Plasmodium vivax and Plasmodium falciparum is associated with resistance to antifolate drugs. The spread of antifolate resistance encouraged research for novel antifolate drugs active against both wild-type and dhfr-mutant strains of malaria parasites. Because P. vivax cannot be easily maintained in culture, we transformed a Saccharomyces cerevisiae DHFR-deleted mutant to express wild-type P. vivax dhfr gene and its mutant forms. Twenty-five dicyclic and tricyclic 2,4-diaminopyrimidine derivatives were screened. Six quinazoline compounds showed selective inhibition of yeast transformants expressing P. vivax dhfr genes. The 50% inhibitory concentration (IC(50)) of these six compounds was determined against field isolates of P. falciparum. Our results suggest that a close relationship between the yeast assay based on expression of P. vivax dhfr genes and the in vitro test using P. falciparum parasites in culture is a promising initial step for drug screening.
authors.affiliation: CNRS-UMR 8621, F-91405, Orsay, France.
authors.forename: Liselotte Yimga
authors.initials: LY
authors.lastname: Djapa
authors.forename: Leonardo K
authors.initials: LK
authors.lastname: Basco
authors.forename: Ruth
authors.initials: R
authors.lastname: Zelikson
authors.forename: Andre
authors.initials: A
authors.lastname: Rosowsky
authors.forename: Joseph Allico
authors.initials: JA
authors.lastname: Djaman
authors.forename: Jeanne Ngogang
authors.initials: JN
authors.lastname: Yonkeu
authors.forename: Monique
authors.initials: M
authors.lastname: Bolotin-Fukuhara
authors.forename: André
authors.initials: A
authors.lastname: Mazabraud
mesh_terms: D000818:Animals; D005493:Folic Acid Antagonists / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D009154:Mutation; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development; D010966:Plasmodium vivax / Q000201:enzymology* / Q000235:genetics; D011799:Quinazolines / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000378:metabolism
chemical_list: D005493:Folic Acid Antagonists; D011799:Quinazolines; D013762:Tetrahydrofolate Dehydrogenase