[Expression of epidermal growth factor receptor and MUC5AC on human airway with chronic obstructive pulmonary...

To determine the relationship between epidermal growth factor receptor (EGFR) expression and mucin 5AC (MUC5AC) synthesis in human airways with chronic obstructive pulmonary disease (COPD).

Lung specimens were obtained from 38 patients who were undergoing lobectomy, and the samples were taken from areas remote to the lesion. EGFR and MUC5AC protein expression were examined using immunohistochemical analysis and Western blot in peripheral airways (less than 2 mm in diameter) from 16 subjects with COPD, 10 subjects with a history of more than 30 pack-year smoking and 12 nonsmokers or exsmokers (0 - 10 pack-year smoker).

Weak EGFR protein signals were detected in the lungs of the controls (2.01 +/- 1.02) in comparison with stronger signal in the COPD patients (4.62 +/- 1.65, P < 0.01) and the smokers (4.89 +/- 1.89, P < 0.01). EGFR immunoreactivity was observed mainly in goblet cells in the controls, the percentage of positive cell being 71.1% +/- 14.3%, which was higher than those in COPD (21.1% +/- 8.6%) or in the smoker (21.9% +/- 9.7%) airways. In contrast, COPD or smoker airways showed more expression of EGFR which expressed mainly in basal cells (42.9% +/- 14.2%, 52.1% +/- 13.5%, respectively) than that in the control airways (23.7% +/- 9.5%, P < 0.01). However there was no significant differences in EGFR expression and location in peripheral airways between COPD patients and smokers (P > 0.05). There was significant positive correlation between EGFR immunoreactivity and the area of the MUC5AC positive staining in all subjects (r = 0.877 4, P < 0.001).

It is suggested that EGFR activation is involved in mucin expression in COPD airways.