IGF-I stimulated PDK1 activity in MCF7 and T47D cells.

<p>Breast cancer cell lines MCF7 and T47D were cultured in normal growth media (supplemented with 10% FBS) or serum starved for 24 hours. Growth factors EGF (<b>A</b>), TNFα (<b>B</b>)<b>,</b> IGF-I (<b>C</b>)<b>,</b> or insulin (<b>D</b>) were added to the culture media for 15 minutes after starvation. Cells were subsequently harvested and lysed, and lysates were subjected to SDS-PAGE. Western blot analysis was performed to examine the phosphorylation levels of AKT and p70S6K. GAPDH was included in each western blot analysis as a protein loading control.