V3 vasopressin receptor and corticotropic phenotype in pituitary and nonpituitary tumors.
Pituitary corticotropic cells express a specific vasopressin receptor, called V1b or V3, through which vasopressin stimulates corticotropin secretion. We recently cloned a cDNA coding for this receptor and showed that it belongs to the G protein-coupled receptor family. V3 mRNA is readily detected by RT-PCR in normal human pituitaries and corticotropic pituitary adenomas but not in PRL or GH-secreting adenomas, thus demonstrating that, like POMC itself and the CRH receptor, V3 is a marker of the corticotropic phenotype. Nuclease protection experiments suggest that V3 is overexpressed in some corticotropic adenomas, and thus may play a role in tumor development by activating the phospholipase C-signalling pathway. In addition analysis of its expression in nonpituitary neuroendocrine tumors showed a striking association with carcinoids of the lung responsible for the ectopic ACTH syndrome.
de Keyzer
Y
Y
Groupe d'Etudes en Physiopathologic endocrinienne, Université René-Descartes, Institut Cochin de Génétique moléculaire, Paris, France.
René
P
P
Lenne
F
F
Auzan
C
C
Clauser
E
E
Bertagna
X
X
D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis*; D015870:Gene Expression; D006801:Humans; D010641:Phenotype; D010902:Pituitary Gland / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D017483:Receptors, Vasopressin / Q000235:genetics*
D012333:RNA, Messenger; D017483:Receptors, Vasopressin; D000324:Adrenocorticotropic Hormone