In vitro analyses of known and novel RUNX1/AML1 mutations in dominant familial platelet disorder with predisposition to acute myelogenous leukemia: implications for mechanisms of pathogenesis
Details
Publication Year 2002-02-15,Volume 99,Issue #4,Page 1364-1372
Journal Title
BLOOD
Publication Type
Journal Article
Abstract
Familial platelet disorder with predisposition to acute myelogenous leukemia (FPD/AML) Is an autosomal dominant familial platelet disorder characterized by thrombocytopenia and a propensity to develop AML. Mutation analyses of RUNX1 in 3 families with FPD/AML showing linkage to chromosome 21q22.1 revealed 3 novel heterozygous point mutations (K83E, R135fsX177 (IVS4 + 3deIA), and Y260X). Functional investigations of the 7 FPD/AML RUNX1 Runt domain point mutations described to date (2 frameshift, 2 nonsense, and 3 missense mutations) were performed. Consistent with the position of the mutations in the Runt domain at the RUNX1-DNA interface, DNA binding of all mutant RUNX1 proteins was absent or significantly decreased. In general, missense and nonsense RUNX1 proteins retained the ability to heterodimerize with PEBP2beta/CBFbeta and inhibited transactivation of a reporter gene by wild-type RUNX1. Colocalization of mutant RUNX1 and PEBP2beta/CBFbeta in the cytoplasm was observed. These results suggest that the sequestration of PEBP2beta/CBFbeta by mutant RUNX1 may cause the inhibitory effects. While haploinsufficiency of RUNX1 causes FPD/AML in some families (deletions and frameshifts), mutant RUNX1 proteins (missense and nonsense) may also inhibit wild-type RUNX1, possibly creating a higher propensity to develop leukemia. This is consistent with the hypothesis that a second mutation has to occur, either in RUNX1 or another gene, to cause leukemia among Individuals harboring RUNX1 FPD/AML mutations and that the propensity to acquire these additional mutations is determined, at least partially, by the Initial RUNX1 mutation. (C) 2002 by The American Society of Hematology.
Publisher
AMER SOC HEMATOLOGY
Keywords
ACUTE MYELOID-LEUKEMIA; STORAGE POOL DEFICIENCY; CORE-BINDING-FACTOR; GASTROINTESTINAL STROMAL TUMORS; TRANSCRIPTION FACTOR PEBP2/CBF; FACTOR-RECEPTOR PROMOTER; CLEIDOCRANIAL DYSPLASIA; RUNT DOMAIN; DNA-BINDING; ALPHA-SUBUNIT
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Creation Date: 2002-02-15 12:00:00
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