LOCALIZATION OF EPIDERMAL GROWTH-FACTOR (EGF) AND EPIDERMAL GROWTH-FACTOR RECEPTOR (EGFR) IN HUMAN PITUITARY-ADENOMAS AND NONTUMOROUS PITUITARIES - AN IMMUNOCYTOCHEMICAL STUDY

Epidermal growth factor (EGF) and epidermal growth factor receptor (EG Fr) were investigated by immunocytochemistry (ICH) in 57 human pituita ry adenomas and 10 nontumorous autopsy pituitaries, EGF immunoreactivi ty was demonstrated in 24 adenomas (42%), representing 23 functioning tumors and 1 nonfunctioning tumor of oncocytic type, and in all nontum orous pituitaries. Among 40 tumors, EGFr was found positive in 15 func tioning adenomas (37.5%), representing 50% of them. The presence of bo th EGF and EGFr was found mainly in corticotroph adenomas (60%) and le ss frequently in somatotroph and lactotroph adenomas (20%). ICH on ser ial sections with EGF or EGFr and adrenocorticotrophic hormone (ACTH) or 5-100 protein revealed that EGF and EGFr are localized specifically in corticotrophs and EGFr in stellate cells of nontumorous adenohypop hysis. These results confirm the presence of EGF and EGFr in human pit uitary adenomas and nontumorous pituitaries and highlight their freque nt occurrence in hormone-producing adenomas. Further work is required to explore the possibility that EGF and EGFr play a role in hormone pr oduction, release, and tumor progression.