Fig. 3

Dose–response curves showing the effects of HER2 inhibitors on EGF- and NRG1b-directed HER2 signaling. a Neither pertuzumab nor lapatinib has significant effect on baseline cell signal determined before agonist addition. SKBr3 cells were seeded in sensor plates and treated with pertuzumab (10 μg/mL), lapatinib (200nM), or vehicle (control) 18 h prior to stimulation with NRG1 or EGF. CELx curves are displayed using Delta CI values to easily compare the relative change in signals from the time point of drug addition. The time points for drug addition and growth factor (GF) addition are indicated by black arrows. b and c SKBr3 cells were seeded in sensor plates and treated with serial titrations of lapatinib (0 nM to 3200 nM) or pertuzumab (0 μg/mL to 40 μg/mL) two hours prior to stimulation with EGF or NRG1b. Dose–response curves of drug inhibition on NRG1b and EGF-driven cell index signals are displayed