FIGURE 1.

Collaboration of RUNX1 with p53 to suppress cell growth. A, exogenous expression of p53 and RUNX1. p53-deficient H1299 cells were transiently transfected with the indicated combinations of the expression plasmids. Forty eight hours after transfection, cell lysates were prepared and analyzed for the expression levels of p53 and RUNX1 by immunoblotting. The expression level of actin was examined as a loading control. B, colony formation assay. H1299 cells were transfected with the indicated combinations of the expression plasmids. Forty eight hours after transfection, cells were cultured in fresh medium containing G418 (at a final concentration of 800 μg/ml). Two weeks after the selection, drug-resistant colonies were fixed in methanol and stained with Giemsa solution. w/o, without.