Molecular and immunohistochemical analysis of somatostatin and dopamin receptors in clinically nonfunctioning pituitary tumors

• Grant number: 12/09150-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2012
• End date: June 30, 2013
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal Investigator: Ericka Barbosa Trarbach
• Grantee: Paulo Vinicius Gonçalves Holanda Amorim
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Nonfunctioning pituitary adenomas (NFPA) are the most frequent pituitary tumors. These tumors received this definition because they do not result in anterior pituitary hormonal hypersecretion or a clinical hormone-excess syndrome, and their diagnosis rests on the clinical recognition of compressive symptoms. Somatostatin (SRIF) and dopamine (DA) are two critical regulators of pituitary cells' function, being their actions mediated by specific G-protein-coupled receptors: SRIF receptor (SSR) and the subtype 2 (D2R ) of DA receptors, respectively. Of these, SSR subtypes 1, 2, 3, and 5, and D2R are present in both normal gland and tumoral pituitary cells, including ACNF. The activation of SSR and D2R by the corresponding physiological ligands or agonist/analogs is related to negative control of hormonal secretion and to anti-proliferative and apoptotic effects on tumoral cells. However, few studies are available correlating SST and D2R expression and drug therapy with SRIF analogs or DA agonists in ACNF. Therefore, the objective of this study is to evaluate the mRNA and protein expressions of SSR 2, 3, and 5 and D2R in ACNF and correlated with it related drug therapy.(AU)