Expression and processing of gastrin in hepatocellular carcinoma, fibrolamellar carcinoma and cholangiocarcinoma.
OBJECTIVE
Gastrin is a trophic factor within the normal gastrointestinal tract and is also a mitogen for a number of gastrointestinal and non-gastrointestinal tumours. Precursor forms of gastrin including progastrin (proG) and glycine-extended gastrin (G-gly) as well as the fully processed amidated gastrin (G-NH2) are expressed by tumours. There has been little study of the role of gastrin in either normal liver or liver tumours. The aim of this study was to identify the expression of CCK-B/gastrin receptor (CCK-BR), proG, G-gly and G-NH2 in normal liver and liver tumours.


METHODS
Tissue sections from patients with hepatocellular carcinoma, fibrolamellar carcinoma, cholangiocarcinoma as well as normal liver biopsies were assessed for expression of CCK-BR and gastrin isoforms.


RESULTS
Most liver tumours express CCK-BR and are able to process gastrin as far as proG and G-gly, although not as far as the amidated form. There appears to be little expression of the receptor and no expression of precursor forms of gastrin in normal liver.


CONCLUSIONS
Liver tumours express the CCK-BR and precursor forms of gastrin. This expression may be associated with tumour proliferation.
Caplin
M
M
Royal Free Hospital School of Medicine, London, UK. caplin@rfhsm.ac.uk
Khan
K
K
Savage
K
K
Rode
J
J
Varro
A
A
Michaeli
D
D
Grimes
S
S
Brett
B
B
Pounder
R
R
Dhillon
A
A
D001650:Bile Duct Neoplasms / Q000378:metabolism*; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D018281:Cholangiocarcinoma / Q000378:metabolism*; D005755:Gastrins / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
D005755:Gastrins