Immunohistochemical and quantitative mRNA assessment of ghrelin expression in gastric and oesophageal adenocarcinoma
Marcus Mottershead 1, Emmanuel Karteris 2, Jill Y Barclay 1, Saira Suortamo 1, Mark Newbold 1, Harpal Randeva 2 and Chuka U Nwokolo 1*
1 University Hospital Coventry and Warwickshire, United Kingdom
2 Biomedical Research Institute, University of Warwick, United Kingdom
* To whom correspondence should be addressed. E-mail: chukanwokolo{at}compuserve.com.
Accepted 25 April 2006
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Abstract |
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Background and Aims: Ghrelin is an orexigenic gut peptide produced predominantly by the stomach. Gastric mucosal ghrelin-production could be compromised by an infiltrating adenocarcinoma. We assessed the expression of ghrelin mRNA and peptide in oesophago-gastric adenocarcinomas and adjacent non-neoplastic mucosa.
Methods: Ten gastric and 22 oesophageal adenocarcinoma archival samples were randomly selected from a database. The presence of ghrelin-positive cells was assessed in cancer and corresponding non-neoplastic mucosa by immuno-histochemistry. Quantitative RT-PCR for ghrelin mRNA was also performed on 24 gastric and 8 oesophageal adenocarcinoma specimens and adjacent non-neoplastic mucosa.
Results: Immunohistochemistry and RT-PCR confirm a negligible expression of ghrelin in adenocarcinoma specimens. In contrast, non-neoplastic gastric mucosa was rich in ghrelin positive cells and ghrelin mRNA. The number (median and range) of ghrelin positive cells per 2mm section of non-neoplastic mucosa was 73, range 45-215 in the corpus; this was significantly higher than in cardia mucosa (9, range 0-64, p<0.001) and antral mucosa (5, range 0-14, p<0.001).
Conclusions: Gastric and oesophageal adenocarcinomas have no ghrelin-producing cells. The highest level of ghrelin expression was noted in the non-neoplastic mucosa of the gastric corpus. Disruption of the gastric ghrelin producing mechanism may occur during oesophago-gastric malignancy.
Key Words:
gastric cancer, ghrelin, immuno-histochemistry, oesophageal cancer, quantitative RT-PCR
