Mutations in KIT and RAS are frequent events in pediatric core-binding factor acute myeloid leukemia.
Activating mutations in RAS and receptor tyrosine kinases such as KIT and FLT3 are hypothesized to cooperate with chimeric transcription factors in the pathogenesis of acute myeloid leukemia (AML). To test this hypothesis, we genotyped 150 pediatric AML samples for mutations in KIT (exons 8, 17), NRAS and KRAS (exons 1, 2) and FLT3/ITD. This is the largest cohort of pediatric AML patients reported thus far screened for all four mutations. Of the children with AML, 40% had a mutation in KIT (11.3%), RAS (18%) or FLT3/ITD (11.1%), and 70% of cases of core-binding factor (CBF) leukemia were associated with a mutation of KIT or RAS. Mutations in RAS or FLT3/ITD were frequently found in association with a normal karyotype. Patients with a FLT3/ITD mutation had a significantly worse clinical outcome. However, the presence of a KIT or RAS mutation did not significantly influence clinical outcome. We demonstrate that KIT exon 8 mutations result in constitutive ligand-independent kinase activation that can be inhibited by clinically relevant concentrations of imatinib. Our results demonstrate that abnormalities of signal transduction pathways are frequent in pediatric AML. Future clinical studies are needed to determine whether selective targeting of these abnormalities will improve treatment results.
Goemans
B F
BF
Department of Pediatric Hematology/Oncology, VU University Medical Center, Amsterdam, The Netherlands. bf.goemans@vumc.nl
Zwaan
C M
CM
Miller
M
M
Zimmermann
M
M
Harlow
A
A
Meshinchi
S
S
Loonen
A H
AH
Hählen
K
K
Reinhardt
D
D
Creutzig
U
U
Kaspers
G J L
GJ
Heinrich
M C
MC
D000208:Acute Disease; D000293:Adolescent; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001549:Benzamides; D016466:CHO Cells; D002648:Child; D002675:Child, Preschool; D050660:Core Binding Factors; D006224:Cricetinae; D020732:Cytogenetic Analysis; D005091:Exons; D005500:Follow-Up Studies; D011905:Genes, ras / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D000068877:Imatinib Mesylate; D007223:Infant; D007231:Infant, Newborn; D007951:Leukemia, Myeloid / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D009154:Mutation; D009363:Neoplasm Proteins / Q000096:biosynthesis; D010879:Piperazines / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019009:Proto-Oncogene Proteins c-kit / Q000187:drug effects / Q000235:genetics*; D011743:Pyrimidines / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D012189:Retrospective Studies; D016019:Survival Analysis; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D016896:Treatment Outcome; D051941:fms-Like Tyrosine Kinase 3
D001549:Benzamides; D050660:Core Binding Factors; D009363:Neoplasm Proteins; D010879:Piperazines; D011518:Proto-Oncogene Proteins; D011743:Pyrimidines; D014157:Transcription Factors; D000068877:Imatinib Mesylate; C497970:FLT3 protein, human; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases; D051941:fms-Like Tyrosine Kinase 3