Transcriptional response assays of the AML1 mutants found in patients with MDS.

(A) HeLa cells were transfected only with pM-CSF-R-luc (lane 1), 3.2 μg of pM-CSF-R-luc and 1.6 μg of pME-AML1-FLAG (lane 2), pME-AML1 V105ter-FLAG (lane 3), or pME-AML1 R139G-FLAG (lane 4), in combination with pME-PEBP2β/CBFβ. The relative expression levels of AML1 and PEBP2β/CBFβ proteins are indicated in Western blotting with the anti-FLAG and the anti-PEBP2β antibody. (B) HeLa cells were transfected only with pNE-luc (lane 1), 3.2 μg of pNE-luc and 1.6 μg of pME-AML1-FLAG (lanes 2, 3, and 4), 0.8 μg of pME-AML1 R139G-FLAG (lane 3), or 1.6 μg of pME-AML1 R139G-FLAG (lane 4). The relative expression levels of AML1 proteins are indicated in Western blotting with the anti-FLAG antibody. Luciferase activities were normalized by using the internal control of transfection efficiency. The means and SD of 2 independent transfections are shown. Similar results were obtained in 6 additional independent transfection in 3 separate experiments.