Figure 6-4260.

EGFR activation induced by E-cadherin cross-linking. HSC-3 cells were detached with 5 mmol/L EDTA and kept in suspension in poly-HEMA-coated dishes. After incubation for 1 hour at 4°C with a saturating concentration of anti-E-cadherin HECD-1 mAb (50 μg/ml), surface clustering of E-cadherin receptors was induced by further incubation with goat anti-mouse IgG (5 μg/ml) for the indicated times at 37°C. Equivalent protein was then immunoblotted with antibodies to activated EGFR (p-EGFR) and total EGFR. Relative protein densities of activated EGFR were determined; EGFR kinase activity is expressed as fold increase relative to the HSC-3 cells in suspension. Data reported here are representative of three independent experiments.