FIG. 7.
Determination of the role of Erk and Akt signaling in regulation of p21WAF1/Cip1 and p27Kip1 expression. (A) Western blot analysis of pathway activation. FaDu control and cortactin knockdown cells were synchronized into G1 phase by serum starvation and hydroxyurea (HU) treatment and then released into complete medium for the time periods indicated. Cell lysates were subjected to Western blotting with the indicated antibodies. Data shown are representative of at least three independent experiments. (B) Inhibition of Akt does not affect p21WAF1/Cip1 and p27Kip1 levels. The Akt inhibitor Akti-1/2 (1 μM) was administered during synchronization and release of FaDu control cells. Western blotting was undertaken as indicated. Data shown are representative of at least three independent experiments.