Figure 5

Akt, but not Erk1/2, is important for IGF-1R mediated regulation of LIP expression. A). Western blot analysis demonstrating that pretreatment of MCF10A cells with the MEK inhibitor U0126 (5 and 10 μM) blocks IGF-1R activated phosophorylation of Erk1/2, but not phosphorylation of Akt at 10 min. IGF-1R mediated increases in LIP expression were not inhibited by 16 hour of treatment with U0126. Similar results were observed in > 3 independent experiments. B, C). Increasing doses of the Akt inhibitor, SH-6 (1-5 μM), prior to stimulation of cells with IGF-1 (2.6 nM) leads to an inhibition of Akt activity and results in decreased LIP expression at 16 hours in both MCF10A (B) and MCF7 (C) cells. The LIP/LAP ratio is provided.