Growth factor receptor expression in human gastroenteropancreatic neuroendocrine tumours.

ABSTRACT

BACKGROUND: Human gastroenteropancreatic neuroendocrine tumours are functionally and biologically heterogeneous, but their exact growth factor receptor expression pattern, important for onco- and carcinogenesis, remains unknown. METHODS: This study searched for the mRNA expression pattern of six tyrosine- and serine/threonine kinase receptors [hepatocyte growth factor (HGFR), fibroblast growth factor (FGFR), epidermal growth factor (EGFR), insulin-like growth factor (IGF)-1R, transforming growth factor (TGF)-betaR1, TGF-betaR2] together with the five somatostatin receptors in human gastroenteropancreatic neuroendocrine tumours (gastrinomas, insulinomas, tumours with carcinoid syndrome, functionally inactive neuroendocrine tumours) using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: EGF receptor was expressed almost exclusively in gastrinomas. Among the four tumour subtypes, expression frequencies of the somatostatin receptors 1 and 5, HGF-, IGF-1-, TGF-betaR1, TGF-betaR2 and the EGF-receptor varied significantly. CONCLUSIONS: In spite of the common cellular origin of these tumours, differences in growth factor receptor expression suggest the existence of different pathways during tumour subtype development.