ERα potentiates the basal and maximum phosphorylation of ERK1/2 and Akt by IGF-I stimulation.

<p>NWTB3 cells transfected with ERα or vector control were stimulated with 10 nM IGF-I for 0–60 min. (<b>A</b>) Protein lysates were immunoblotted with phospho-ERK1/2, ERK1/2, phospho-Akt, Akt, or ERα antibodies. Transfection of ERα gradually increased phosphorylation of ERK1/2 and Akt after IGF-I stimulation. (<b>B</b>) The ratios of p-ERK1/2 <i>vs</i>. ERK1/2. The maximum phospho-ERK1/2 appeared in 5 min in ERα transfected NWTB3 cells after IGF-I stimulation, while it was 15 min in ERα-negative control cells. (<b>C</b>) The ratios of p-Akt <i>vs</i>. Akt. The maximum of phosphorylation of Akt was at 15 min in ERα-positive cells, but at 60 min in ERα-negative cells. <i>N</i> = 3, *, <i>P</i><0.05 as compared to controls.