FIG. 2.
The effect of cortactin knockdown on key cell cycle regulators. (A) Western blot analysis of specific cyclins and CDKIs. FaDu control and cortactin knockdown cells were synchronized into G1 phase by serum starvation and hydroxyurea treatment and then released into complete medium for the time periods indicated. The expression of the indicated proteins was then analyzed by Western blotting. (B) Quantification of Western blotting results. Data were normalized using actin as a loading control and then expressed relative to the value for control cells, which was arbitrarily set at 100%. Data represent the mean ± standard error from three independent experiments. *, P < 0.05. (C) Expression of murine cortactin reverses the effect of human cortactin knockdown. Cells were treated and analyzed as in panel A. Data shown are representative of at least three independent experiments. HU, hydroxyurea.