Immunohistochemical expression of insulin-like growth factor 1 and its receptor in normal and neoplastic human adrenal cortex

Abstract

Background: Insulin-like growth factor 1 (IGF-1) may influence cellular growth, differentiation and secretion.

Material and methods: Cryosectioned normal human adrenal glands (n = 6), cortical adenoma (n = 21), and carcinoma (n = 17) were stained immunohistochemically for IGF-1 and its receptor, and human adrenocortical cancer cells expressing the receptor were analysed for influences on proliferation.

Results: Normal cortical parenchyma generally displayed faint IGF-1 reactivity and intracellular receptor staining. Similar labelling encompassed the adenomas, but only 6 of them were receptor reactive. IGF-1 expression was conspicuous in 11 carcinomas, and 6 of them displayed cell surface receptor reactivity. All aldosterone producing lesions were receptor antibody unreactive. Recombinant IGF-1 dose-dependently stimulated the cell proliferation, and this effect was reversed by the receptor antibody.

Conclusion: IGF-1 may interact with function and proliferation of the human adrenal cortex with particular reference to cortical carcinomas lacking discernible aldosterone excess.