title: Effect of polymorphisms in folate-related genes on in vitro methotrexate sensitivity in pediatric acute lymphoblastic leukemia.
abstract: 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)) MTX exposure. DNA was isolated from lymphoblasts obtained from cytospin slides. Polymorphisms in methylenetetrahydrofolate reductase (MTHFR 677C>T, MTHFR 1298A>C), methionine synthase (MTR 2756A>G), methionine synthase reductase (MTRR 66A>G), methylenetetrahydrofolate dehydrogenase (MTHFD1 1958G>A), serine hydroxymethyl transferase (SHMT1 1420C>T), thymidylate synthase (TS 2R3R), and the reduced folate carrier (RFC 80G>A) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or real-time PCR. Patients with the MTHFR 1298AC variant or the MTRR 66 G-allele showed decreased in vitro MTX sensitivity measured under both test conditions. SHMT1 1420TT homozygotes only showed decreased MTX sensitivity in the TSI(50, cont). In conclusion, polymorphisms in the folate-related genes MTHFR, MTRR, and SHMT1 are related to MTX resistance in pediatric patients with ALL.
authors.affiliation: Department of Clinical Chemistry and Pediatric Oncology/Hematology, Erasmus MC, Rm L-102, POB 2040, 3000 CA Rotterdam, The Netherlands. r.dejonge@erasmusmc.nl
authors.forename: Robert
authors.initials: R
authors.lastname: de Jonge
authors.forename: Jan Hendrik
authors.initials: JH
authors.lastname: Hooijberg
authors.forename: Bertrand D
authors.initials: BD
authors.lastname: van Zelst
authors.forename: Gerrit
authors.initials: G
authors.lastname: Jansen
authors.forename: Gerritz
authors.initials: G
authors.lastname: Jansen
authors.forename: Christina H
authors.initials: CH
authors.lastname: van Zantwijk
authors.forename: Christine H
authors.initials: CH
authors.lastname: van Zantwijk
authors.forename: Gertjan J L
authors.initials: GJ
authors.lastname: Kaspers
authors.forename: Gert Jan L
authors.initials: GJ
authors.lastname: Kaspers
authors.forename: Godefridus J
authors.initials: GJ
authors.lastname: Peters
authors.forename: Frits G J
authors.initials: FG
authors.lastname: Peters
authors.forename: Yaddanapudi
authors.initials: Y
authors.lastname: Ravindranath
authors.forename: Rob
authors.initials: R
authors.lastname: Pieters
authors.forename: Jan
authors.initials: J
authors.lastname: Lindemans
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D002648:Child; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005287:Ferredoxin-NADP Reductase / Q000235:genetics; D005492:Folic Acid / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008727:Methotrexate / Q000494:pharmacology*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D011110:Polymorphism, Genetic; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D005492:Folic Acid; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D012696:Glycine Hydroxymethyltransferase; D008727:Methotrexate