title: Reevaluation of sst₁ somatostatin receptor expression in human normal and neoplastic tissues using the novel rabbit monoclonal antibody UMB-7.
abstract: BACKGROUND
  The somatostatin receptor 1 (sst1) is widely distributed throughout the body and is also present in neoplastic tissues. However, little is known about its precise tissue distribution, regulation and function, which may in part be due to the lack of specific monoclonal anti-sst1 antibodies.
  
  
  METHODS
  We have characterized the novel rabbit monoclonal anti-human sst1 antibody UMB-7 using sst1-expressing cells and human pituitary samples. The antibody was then used for immunohistochemical staining of a large panel of formalin-fixed, paraffin-embedded human tissues.
  
  
  RESULTS
  Western blot analyses of BON-1 cells and human pituitary revealed a broad band migrating at a molecular weight of 45,000-60,000. After enzymatic deglycosylation the size of this band decreased to a molecular weight of 45,000. UMB-7 yielded an efficient immunostaining of distinct cell populations in the human tissue samples with a predominance of plasma membrane staining, which was completely abolished by preadsorption of UMB-7 with its immunizing peptide. The sst1 receptor was detected in anterior pituitary, pancreatic islets, distal tubules, enteric ganglion cells and nerve fibers, chief cells of the gastric mucosa, macrophages and mast cells. In addition, sst1 was observed in pituitary adenomas, gastrointestinal neuroendocrine tumors and pheochromocytoma as well as in pancreatic adenocarcinomas, gastric carcinomas, urinary bladder carcinomas and sarcomas.
  
  
  CONCLUSIONS
  UMB-7 may prove of great value in the identification of sst1-expressing tumors during routine histopathological examinations. This may open up new routes for diagnostic and therapeutic intervention.
authors: Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Germany.
authors: Amelie
authors: A
authors: Lupp
authors: Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Germany.
authors: Falko
authors: F
authors: Nagel
authors: Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Germany. Electronic address: Stefan.Schulz@mti.uni-jena.de.
authors: Stefan
authors: S
authors: Schulz
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D009369:Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016612:Paraffin Embedding; D011817:Rabbits; D017481:Receptors, Somatostatin / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D017481:Receptors, Somatostatin; C101130:somatostatin receptor type 1