Immunohistochemical and quantitative mRNA assessment of ghrelin expression in gastric and oesophageal adenocarcinoma.
BACKGROUND
Ghrelin is an orexigenic gut peptide produced predominantly by the stomach. Gastric mucosal ghrelin production could be compromised by an infiltrating adenocarcinoma.


OBJECTIVE
To assess the expression of ghrelin mRNA and peptide in oesophagogastric adenocarcinomas and adjacent non-neoplastic mucosa.


METHODS
10 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 immunohistochemistry. Quantitative reverse transcriptase polymerase chain reaction (PCR) for ghrelin mRNA was also performed on 24 gastric and 8 oesophageal adenocarcinoma specimens and adjacent non-neoplastic mucosa.


RESULTS
Immunohistochemistry and reverse transcriptase PCR confirm a negligible expression of ghrelin in adenocarcinoma specimens. By contrast, non-neoplastic gastric mucosa was rich in ghrelin-positive cells and ghrelin mRNA. The number (median and range) of ghrelin-positive cells per 2 mm section of non-neoplastic mucosa was 73 (45-215) in the corpus; this was significantly higher than in cardia mucosa (9 (0-64), p<0.001) and antral mucosa (5 (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 oesophagogastric malignancy.
Mottershead
Marcus
M
Department of Gastroenterology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK.
Karteris
Emmanuel
E
Barclay
Jill Y
JY
Suortamo
Saira
S
Newbold
Mark
M
Randeva
Harpal
H
Nwokolo
Chuka U
CU
D000230:Adenocarcinoma / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D054439:Ghrelin; D006801:Humans; D007124:Immunoenzyme Techniques; D009490:Neurosecretory Systems / Q000378:metabolism; D036361:Peptide Hormones / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013274:Stomach Neoplasms / Q000378:metabolism*
D054439:Ghrelin; D036361:Peptide Hormones; D012333:RNA, Messenger; D012334:RNA, Neoplasm