Effects of germ line DHFR and FPGS variants on methotrexate metabolism and relapse of leukemia

• Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P = 1.1 x 10(-8)) related to suppression of enhancer activity, whereas rs35789560 in FPGS (p.R466C, P = 5.6 x 10(-9)) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGS variant was linked with increased relapse risk (P = .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine (hsv//eng)

Nyckelord

acute lymphoblastic-leukemia

high-dose methotrexate

maintenance

therapy

nudt15 polymorphisms

nopho all2008

free survival

chemotherapy

children

cell

polyglutamates

Hematology

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ref (ämneskategori)

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