Ouabain attenuates filopodia formation.

<p>A: H292 cells were treated with 30 pM ouabain (OB) or left untreated as control cells for 24 h. The cells were stained with either sulforhodamine B or phalloidin and visualized under a fluorescence microscope at 40×. Filopodia protrusions are indicated by arrows and are represented as an average number of filopodia per cell in each field relative to untreated cells. Data represent the means ± SD (n = 4). *<i>P</i><0.05 vs. untreated control cells. B: After the indicated treatment, the cells were collected and analyzed for cell division cycle 42 (Cdc42) expression by Western blotting. The blots were reprobed with β-actin to confirm equal loading. The immunoblot signals were quantified by densitometry, and mean data from independent experiments were normalized to the results. The bars are the means ± SD (n = 4). *<i>P</i><0.05 vs. untreated control cells.