Epidermal growth factor receptors in the oesophagus.

Abstract

The quantity and distribution of epidermal growth factor receptors (EGF-R) in oesophageal mucosa was studied in the oesophagus in order to determine its role in oesophageal disease. Fifty five biopsies were taken from different levels of the oesophagus in 25 consecutive patients undergoing endoscopy. Another group of eight patients with histologically proven Barrett's oesophagitis had a biopsy taken from the area of columnar lined oesophagus. A peripheral, membranous pattern was seen predominantly confined to the basal and immediately suprabasal cells in all of the first group of patients. In the superficial cells a few granular cytoplasmic structures were positive. All patients with Barrett's oesophagitis showed EGF-R staining of the surface epithelium. A computerised planimeter was used to determine the proportion of stained areas of squamous cells which were expressed as a percentage of the total area of squamous cells. The difference in the area of cells stained for EGF-R between normal and inflamed oesophageal mucosa (29.5% and 43*1% respectively) was significant (p<0001).

Gene expression alterations in formalin-fixed, paraffin-embedded Barrett esophagus and esophageal adenocarcinoma tissues.

“…46 β-catenin, which was reduced at the mRNA level in this study, has a pattern of progressive loss of membranous protein expression with, in some studies, an increase in nuclear accumulation. [47][48][49][50][51][52] Variable findings have been reported for EGFR (epidermal growth factor receptor) expression 53 or amplification, 54 but the progressive reduction in EGFR expression in this study, together with the failure to identify significant differences in EGFR protein expression in normal, BE and EAC tissues in another study, 47 raise doubts regarding the applicability of EGFR-targeted therapy for this cancer type. 55 Another monoclonal antibody target, HER-2/erbB-2, was the most stably expressed gene in this study, with very similar mRNA levels in normal, BE and EAC tissues.…”

Comparison of Kinome Profiles of Barrett's Esophagus with Normal Squamous Esophagus and Normal Gastric Cardia

“…Of particular interest is the kinase activity of the phosphorylated EGFR, which is a transmembrane protein receptor that may trigger numerous signaling pathways (20). Previously, Jankowski et al (29) reported expression of EGFR in Barrett's esophagus; however, to our knowledge, no research has been done on EGFR activation in Barrett's esophagus. The immunoblot results show that EGFR is significantly more activated in normal squamous esophagus compared with Barrett's esophagus.…”

Molecular alterations during development of esophageal adenocarcinoma

“…These factors will bind to their receptors and transduce the growth signal to an intracellular signaling pathway that will eventually lead to proliferation. Aberrant expression of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) has been reported in Barrett's esophagus, dysplasia, and esophageal adenocarcinoma [48,49]. Another growth factor receptor that resembles EGFR is c-ErbB-2, which is considered to be an orphan receptor since no ligand has yet been identified [50].…”