Figure 4

Effect of ERβ on heregulin-β1-activated HER2, HER3 and Akt. (A) T47-DERβ cells were treated for 4 days with 10 ng/mL (-ERβ) or 0.01 ng/mL (+ERβ) doxycycline in the presence or absence of 10 nM DPN with or without 100 nM ICI or 100 nM 4-OH-T and stimulated with heregulin-β1 (HRG-β1) for 30 minutes. (B) T47-DERβ cells were treated as described above and stimulated with HRG-β1 for 30 minutes up to 24 hours. Lysates were analyzed by immunoblotting.