Expression and processing of gastrin in hepatocellular carcinoma, fibrolamellar carcinoma and cholangiocarcinoma

Background/Aims: Gastrin is a trophic factor within the normal gastrointest inal tract and is also a mitogen for a number of gastrointestinal and non-g astrointestinal tumours. Precursor forms of gastrin including progastrin (p roG) and glycine-extended gastrin (G-gly) as well as the fully processed am idated gastrin (G-NH2) are expressed by tumours, There has been little stud y of the role of gastrin in either normal liver or liver tumours. The aim o f 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, fibro lamellar carcinoma, cholangiocarcinoma as well as normal liver biopsies wer e 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 a ppears to be little expression of the receptor and no expression of precurs or forms of gastrin in normal liver. Conclusions: Liver tumours express the CCK-BR and precursor forms of gastri n, This expression may be associated with tumour proliferation.