Growth factor receptor expression in human gastroenteropancreatic neuroendocrine tumours

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)‐βR1, TGF‐βR2] 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‐βR1, TGF‐βR2 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.