Figure 3.

Persistent transactivation of epidermal growth factor (EGF) receptor (EGFR) and ErbB2 induced by thrombin in invasive breast carcinoma. Serum-starved MDA-MB-231 cells (a), BT549 cells (b) and normal human mammary epithelial cells (HMECs) (c) were incubated with 10 nM thrombin various times at 37 °C. Cells were lysed and EGFR and ErbB2 tyrosine phosphorylation were detected as described in Figure 1. (d) The data shown are from the thrombin treated 120 min time point and is expressed as the fold increases over untreated control. (e) MDA-MB-231 cells were incubated in the absence or presence of 10 nM thrombin or 16 nM EGF for 4 min at 37 °C and EGFR and ErbB2 tyrosine phosphorylation was examined. The data shown are representative of at least three independent experiments.