WNT-4mRNA Expression in Human Adrenocortical Tumors and Cultured Adrenal Cells

Abstract

The members of the Wnt glycoprotein family are important in embryogenesis and adult tissue homeostasis, and deletion of WNT-4 gene in mice leads to improper development of many organs including the adrenals. The objective of this study was to investigate the expression of WNT-4 gene in human adrenals and adrenocortical tumors. The WNT-4 mRNA expression (analyzed by quantitative real-time RT-PCR) was significantly higher in Conn's adenomas (p<0.01) and lower in Cushing's adenomas, virilizing carcinomas and fetal adrenals (p<0.05) compared with normal adult adrenals. WNT-4 mRNA expression was clearly upregulated by ACTH and 8-bromo-cAMP (8-BrcAMP) in primary cultures of normal adult adrenocortical cells, but downregulated by 8-BrcAMP and 12- O-tetradecanoylphorbol-13-acetate (TPA) in human NCI-H295R adrenocortical carcinoma cells. Angiotensin II tended to increase WNT-4 mRNA expression at 24 hours and decreased it at 48 hours time point in both cell culture types. The abundant WNT-4 mRNA expression in Conn's adenomas and its hormonal regulation in adrenocortical cells suggest a role for WNT-4 in human adrenocortical function.