Expression of somatostatin receptor types 1-5 in 81 cases of gastrointestinal and pancreatic endocrine tumors: A correlative immunohistochemical and reverse-transcriptase polymerase chain reaction analysis

• Published in: Virchows Archiv : an international journal of pathology Vol. 440; no. 5; pp. 461 - 475
• Main Authors: PAPOTTI, M, BONGIOVANNI, M, VOLANTE, M, ALLIA, E, LANDOLFI, S, HELBOE, L, SCHINDLER, M, COLE, S. L, BUSSOLATI, G
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.05.2002
• Subjects: Adult; Aged; Biological and medical sciences; Female; Gastrinoma - chemistry; Gastroenterology. Liver. Pancreas. Abdomen; Gastrointestinal Neoplasms - chemistry; Gene Expression; Glucagonoma - chemistry; Humans; Immunohistochemistry; In Situ Hybridization; Insulinoma - chemistry; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Membrane Proteins; Middle Aged; Neoplasms, Glandular and Epithelial - chemistry; Pancreatic Neoplasms - chemistry; Receptors, Somatostatin - analysis; Receptors, Somatostatin - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Somatostatinoma - chemistry; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tumors; Human; Immunohistochemistry; Somatostatin receptor; Reverse transcription; Malignant tumor; Gastrointestinal; Polymerase chain reaction; Pathology; Digestive diseases; Intestinal disease; Benign neoplasm; Diagnosis; Somatostatin; Technique; Molecular biology; Pancreas; Neuroendocrine tumor; Comparative study; Gastric disease; Pancreatic disease
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-002-0609-x

Somatostatin receptors (SSTRs) have been extensively mapped in human tumors by means of autoradiography, reverse-transcriptase polymerase chain reaction (RT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC). We analyzed the SSTR type 1-5 expression by means of RT-PCR and/or IHC in a series of 81 functioning and non-functioning gastroenteropancreatic (GEP) endocrine tumors and related normal tissues. Moreover, we compared the results with clinical, pathological and hormonal features. Forty-six cases (13 intestinal and 33 pancreatic) were studied for SSTR 1-5 expression using RT-PCR, IHC with antibodies to SSTR types 2, 3, 5 and ISH for SSTR2 mRNA. The vast majority of tumors expressed SSTR types 1, 2, 3 and 5, while SSTR4 was detected in a small minority. Due to the good correlation between RT-PCR and IHC data on SSTR types 2, 3, and 5, thirty-five additional GEP endocrine tumors were studied with IHC alone. Pancreatic insulinomas had an heterogeneous SSTR expression, while 100% of somatostatinomas expressed SSTR5 and 100% gastrinomas and glucagonomas expressed SSTR2. Pre-operative biopsy material showed an overlapping immunoreactivity with that of surgical specimens, suggesting that the SSTR status can be detected in the diagnostic work-up. It is concluded that SSTRs 1-5 are heterogeneously expressed in GEP endocrine tumors and that IHC is a reliable tool to detect SSTR types 2, 3 and 5 in surgical and biopsy specimens.