Somatostatin and Dopamine Receptor Profile of Gastroenteropancreatic Neuroendocrine Tumors: An Immunohistochemical Study

Autor: George Kontogeorgos, Evanthia Diakatou, Gregory Kaltsas, Michail Tzivras, George Kanakis, Eugenia Papaliodi
Rok vydání: 2011
Předmět:
Zdroj: Endocrine Pathology. 22:24-30
ISSN: 1559-0097
1046-3976
DOI: 10.1007/s12022-011-9149-8
Popis: Somatostatin and its synthetic analogs act through five specific somatostatin receptors (sstr1-5), found on the cell membrane of various tumors, including endocrine ones. Dopamine--a known neurotransmitter--acts through five membranous dopamine receptors (D1R-D5R) which have recently been found to be expressed in endocrine tumors. We evaluated the immunohistochemical expression of the sstrs and D2R in a large series of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A total of 22 (28.94%) well-differentiated NETs (WDNETs), 6 (7.89%) WDNETs of uncertain biology, 26 (34.21%) well-differentiated neuroendocrine carcinomas, and 22 (28.94%) poorly differentiated neuroendocrine carcinomas were studied. Overall, 76.31% of the tumors were positive for different types of sstrs with variable intensity of the membranous staining whereas 36.95% were positive for D2R alone. The sstr2A was the most frequently expressed, followed by sstr2B, sstr1, and sstr5. Co-expression of sstrs and D2R was seen in 88.23% of positive tumors. The high rates of sstr2A and sstr2B and in a lower extent of sstr5 expression are of great importance for more accurate imaging, staging and targeted therapy of the disease. The co-expression of sstrs and D2R in a significant number of the studied cases offers a potential therapeutic alternative for GEP-NETs.
Databáze: OpenAIRE
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