TY - JOUR
T1 - Role of folylpolyglutamate synthetase and folylpolyglutamate hydrolase in methotrexate accumulation and polyglutamylation in childhood leukemia
AU - Rots, Marianne G.
AU - Pieters, Rob
AU - Peters, Godefridus J.
AU - Noordhuis, Paul
AU - Van Zantwijk, Christina H.
AU - Kaspers, Gertjan J.L.
AU - Hählen, Karel
AU - Creutzig, Ursula
AU - Veerman, Anjo J.P.
AU - Jansen, Gerrit
PY - 1999/3/1
Y1 - 1999/3/1
N2 - Inefficient polyglutamylation is a mechanism of resistance to methotrexate (MTX) in childhood T-lineage acute lymphoblastic leukemia (T- ALL) and in acute myeloid leukemia (AML) in comparison with childhood c/preB- ALL. We analyzed the profile of MTX polyglutamylation in childhood c/preB- ALL, T-ALL, and AML (n = 45, 15, and 14, respectively), the activity of the MTX-polyglutamate synthesizing enzyme folylpolyglutamate synthetase (FPGS) (n = 39, 11, and 19, respectively) and of the MTX-polyglutamate breakdown enzyme folylpolyglutamate hydrolase (FPGH) (n = 98, 25, and 34, respectively). MTX- Glu(4-6) accumulation after 24 hours exposure to 1 μmol/L [3H]-MTX in vitro was lower in T-ALL (threefold) and AML (fourfold) compared with c/preB-ALL (P ≤ .001). The FPGS activity was twofold lower in T-ALL and AML than in c/preB-ALL samples (P<.01). FPGH activity was not different between c/preB- ALL and T-ALL, but threefold higher in AML (P < .001). FPGS, FPGH, and the ratio FPGS/FPGH were correlated with MTX-Glu(4-6) accumulation (r=.49, r=- .34 and r=.61, respectively). Multivariate analysis showed that FPGS, but not FPGH, was an independent contributor for MTX-Glu(1-6) accumulation, but not for MTXGlu(4-6) accumulation. In conclusion, low FPGS activity is associated with low accumulation of MTX-Glu(4-6) in T-ALL and AML. For the group of AML as compared with the group of ALL, a high FPGH activity can play an additional role.
AB - Inefficient polyglutamylation is a mechanism of resistance to methotrexate (MTX) in childhood T-lineage acute lymphoblastic leukemia (T- ALL) and in acute myeloid leukemia (AML) in comparison with childhood c/preB- ALL. We analyzed the profile of MTX polyglutamylation in childhood c/preB- ALL, T-ALL, and AML (n = 45, 15, and 14, respectively), the activity of the MTX-polyglutamate synthesizing enzyme folylpolyglutamate synthetase (FPGS) (n = 39, 11, and 19, respectively) and of the MTX-polyglutamate breakdown enzyme folylpolyglutamate hydrolase (FPGH) (n = 98, 25, and 34, respectively). MTX- Glu(4-6) accumulation after 24 hours exposure to 1 μmol/L [3H]-MTX in vitro was lower in T-ALL (threefold) and AML (fourfold) compared with c/preB-ALL (P ≤ .001). The FPGS activity was twofold lower in T-ALL and AML than in c/preB-ALL samples (P<.01). FPGH activity was not different between c/preB- ALL and T-ALL, but threefold higher in AML (P < .001). FPGS, FPGH, and the ratio FPGS/FPGH were correlated with MTX-Glu(4-6) accumulation (r=.49, r=- .34 and r=.61, respectively). Multivariate analysis showed that FPGS, but not FPGH, was an independent contributor for MTX-Glu(1-6) accumulation, but not for MTXGlu(4-6) accumulation. In conclusion, low FPGS activity is associated with low accumulation of MTX-Glu(4-6) in T-ALL and AML. For the group of AML as compared with the group of ALL, a high FPGH activity can play an additional role.
UR - http://www.scopus.com/inward/record.url?scp=0033104709&partnerID=8YFLogxK
U2 - 10.1182/blood.v93.5.1677
DO - 10.1182/blood.v93.5.1677
M3 - Article
C2 - 10029597
AN - SCOPUS:0033104709
VL - 93
SP - 1677
EP - 1683
JO - Blood
JF - Blood
SN - 0006-4971
IS - 5
ER -