Anti-ERBB3 mAbs inhibit ligand-mediated ErbB3 signaling.

<p>A) Serum-starved BT-474, NCI-N87 and ACHN cells were treated with appropriate antibodies or PBS for 30 minutes followed by HRGβ stimulation for 10 minutes. B) NCI-N87 cells were treated with either the A5/F4 oligoclonal or PBS and stimulated with HRGβ, as appropriate, over a 60 minute time course. Cell lysates were analyzed by western blot and probed with anti-pAKT(S473) as a marker for ligand-induced signaling. Membranes were probed with anti-beta actin mAb that served as loading control.