Effect of polymorphisms in folate-related genes on in vitro methotrexate sensitivity in pediatric acute lymphoblastic leukemia.
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.
de Jonge
Robert
R
Department of Clinical Chemistry and Pediatric Oncology/Hematology, Erasmus MC, Rm L-102, POB 2040, 3000 CA Rotterdam, The Netherlands. r.dejonge@erasmusmc.nl
Hooijberg
Jan Hendrik
JH
van Zelst
Bertrand D
BD
Jansen
Gerrit
G
Jansen
Gerritz
G
van Zantwijk
Christina H
CH
van Zantwijk
Christine H
CH
Kaspers
Gertjan J L
GJ
Kaspers
Gert Jan L
GJ
Peters
Godefridus J
GJ
Peters
Frits G J
FG
Ravindranath
Yaddanapudi
Y
Pieters
Rob
R
Lindemans
Jan
J
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
D000964:Antimetabolites, Antineoplastic; D005492:Folic Acid; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D012696:Glycine Hydroxymethyltransferase; D008727:Methotrexate