Differential expression of prolactin receptor (PRLR) in normal and tumorous adrenal tissues: Separation of cellular endocrine compartments by laser capture microdissection (LCM)

PRL stimulates adrenal steroidogenesis. In this study, we compared the PRLR expression in normal and tumorous adrenal tissues and investigated a poten tial proliferative effect of PRL, in adrenal cells. mRNA expression of long and intermediate forms of PRLR was detected in both normal adrenal cortex as well as benign and malignant adrenal tumors and in the human adrenocorti cal carcinoma cell line NCI-H295. Molecular analysis of cells procured by L CM clearly demonstrated that PRLR mRNA is expressed in the adrenal cortex b ut not in the medulla. Immunostaining revealed PRLR protein in all three zo nes of the normal adrenal cortex. Furthermore, adrenal carcinomas and adeno mas stained positive for the PRLR, while in phaeochromocytomas as in the no rmal adrenal medulla, no specific staining was observed. By WST-1 test, we could show that PRL (10(-7) M) decreased proliferation and viability of adr enal cells in primary cell culture suggesting that PRL is not a mitogenic f actor of adrenocortical cells.