Human adrenocortical NCI-H295 cells express VIP receptors. Steroidogenic effect of vasoactive intestinal peptide (VIP)

VIP receptors are frequently overexpressed by various endocrine tumors. In this study the expression of VIP receptors in the human adrenocortical carc inoma cell line NCI-H295 and their involvement in the regulation of steroid ogenesis was investigated. NCI-H295 cells express VIP1 and VIP2 receptors a s demonstrated by RT-PCR, whereas they do not express VIP itself. The recep tors are functionally coupled to steroidogenesis since VIP (10(-9) M to 10( -6) M) exerted a dose-dependent stimulatory effect on the release of aldost erone, cortisol, and DHEA. VIP increased ACTH-stimulated releases of aldost erone and cortisol. The proliferation rate of NCI-H295 cells was not affect ed by VIP. These data show that NCI-H295 cells express both forms of the VI P receptor and that VIP is involved in an ACTH-independent regulation of st eroidogenesis in the adrenal tumor cells. (C) 1998 Elsevier Science Inc.