Profilin overexpression reduces cell velocity and directionality.

<p>A) GFP-PfnI transfected cells (green) were mixed with control non-transfected MDA-MB-231 cells, and the nuclei were stained with Draq5 nuclear vital dye (red). Cultures were visualized for 8 hours; the images were two examples taken at the beginning of the experiment (time 0 m) and after two hours (120 m). Notice that the same sample contains transfected and non-transfected cells. Fluorescence levels are oversaturated to facilitate visualization. B) Individual cell velocity distribution. GFP-PfnI transfected cells displayed lower velocities (black columns) while control cells displayed a broad distribution (white columns), with a low velocity population (between 10 and 70 µm/h) and a clear second population of faster cells with velocities between 90 and 130 µm/h. C) Plot summaries of the mean velocity. Control cells and GFP-PfnI transfected cells have an average velocity of 53.5±5.5 µm/h and 36. 7±0.3 µm/h, respectively D) Mean values of the D/T ratio comparing control (0.29±0.03) and after GFP-PfnI transfecction (0.17±0.01) (p<0.005; Student's t-test).