Fig. 5
Areg-mediated stimulation of esophageal epithelial cell proliferation via the Areg-EGFR signaling pathway. A Schematic representation of the EGFR signaling pathway and the experimental design for EGF and Areg treatment of human esophageal epithelial cell lines (CP-A and HET-1A). B Total viable cell counts of CP-A and HET-1A cells treated with rmEGF (10 ng/ml) and rmAreg (100 ng/ml) for 3 days. C, D Western blotting (C) and densitometry quantification (D) of EGFR phosphorylation and downstream pathway activation induced by EGF and Areg in CP-A cell lines. E, F Western blotting (E) and densitometry quantification (F) of EGF- or Areg-treated HET-1A cells. G Experimental scheme for erlotinib (EGFR tyrosine kinase inhibitor) treatment of the CP-A and HET-1A cell lines. H Total viable counts of CP-A and HET-1A cells treated with rmAreg (100 ng/ml) for 3 days in the presence or absence of erlotinib (200 ng/ml). I Western blot analysis of EGFR phosphorylation and activation of downstream pathways (ERK1/2 and AKT) induced by Areg in CP-A and HET-1A cells treated with or without erlotinib. The data were pooled from at least 2‒3 independent experiments and are presented as the means ± SEMs. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, and ****P ≤ 0.0001; ns, not significant
