Figure 7

Ectopic expression of PU.1 restricts the proliferative capacity but is unable to induce MEL-R cell differentiation. A) Western blot analysis of lysates derived from MEL-R PU.1-ER transfectants stimulated with β-estradiol. Equal amounts of protein (50 μg) were fractionated by SDS-polyacrylamide gel electrophoresis and analyzed by immunoblotting with an anti-PU.1 antibody. Numbers above the panel correspond to different clones. B) Percentage of benzidine positive cells (B+) in PU.1 and GATA-1 stable transfectants activated by β-estradiol and cultured in the presence of 5 mM HMBA. Each bar indicates the mean and standard deviation of three independent experiments. C) PU.1-ER transfectants were cultured in the presence or absence of β-estradiol and cell counts were recorded at the indicated times.