Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty-two brain tumors, consisting of 17 astrocytomas, 4 oligodendrogliomas, 20 glioblastomas, 3 neurinomas, 2 ependymomas, 1 neurofibroma, 1 ganglioneuroblastoma, 1 medulloblastoma, 1 plexus papilloma, 1 teratoma, and 1 germinoma, were tested for their content of specific somatostatin receptors using autoradiographic techniques or in vitro binding assays with membrane homogenates. Somatostatin receptors were found in most of the differentiated glia-derived tumors such as astrocytomas and oligodendrogliomas whereas the poorly differentiated glioblastomas were usually free of receptors. Tumors originating from neuroblasts, i.e., ganglioneuroblastoma and medulloblastoma, contained a high density of somatostatin receptors, whereas neurinomas and neurofibromas as well as the ependymomas, one teratoma, and one plexus papilloma were lacking such receptors. In one germinoma, low amounts of somatostatin receptors were observed over the lymphocytic elements. Receptor-positive tumors had saturable and high affinity receptors with pharmacological specificity for somatostatin and somatostatin analogues resembling that of normal human central nervous system tissue. In most instances, they could be labeled with two different iodinated radioligands, a somatostatin octapeptide derivative (204-090) or a somatostatin-28 analogue. This is the first time that somatostatin receptors have been shown to exist not only on neuronal structures of the central nervous system but also on glial elements. The precise function of such somatostatin receptors on glial cells, which may be different from neurotransmission, remains to be determined.
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PMID:Distribution and biochemical characterization of somatostatin receptors in tumors of the human central nervous system. 288 27

A selection of 90 mainly endocrine but nonpituitary tumors have been tested for their content of specific somatostatin receptors using receptor autoradiography. Somatostatin receptors were detected in the following tumors: in all 5 meningiomas tested; in 3 of 39 malignant breast tumors; and in 3 growth hormone releasing factor-producing tumors, i.e., one mediastinal carcinoid, one intestinal carcinoma, and its liver metastasis. Receptor density varied greatly among individual tumors. Some of the positive tumors were biochemically characterized using in vitro binding assay and were shown to have saturable and high affinity receptors with pharmacological specificity for somatostatin. The following tumors did not contain somatostatin receptors: prostate carcinomas (n = 17); prostate hyperplasia (n = 2); ovarian carcinomas (n = 6); endometrial carcinomas (n = 4); primary liver cell carcinomas (n = 3); pheochromocytomas (n = 3); aldosteronomas (n = 2); medullary thyroid carcinomas (n = 2); one adrenocorticotropic hormone-secreting pulmonary carcinoid; one astrocytoma; one neurofibroma; one lung tumor; and one bladder tumor. Somatostatin receptors can be found in benign or malignant tumors, originating in part from tissue not primarily known as a somatostatin target. The biological function of such receptors is, therefore, partly unknown. If they can mediate antiproliferative properties, as has been suggested to be the case for somatostatin receptors in selected endocrine tumors in rats and humans, the present data could be of potential therapeutic interest.
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PMID:Somatostatin receptors in human endocrine tumors. 302 22

The glandular peripheral nerve sheath tumor is a rare variant of nerve sheath neoplasms in which the focally occurring glands are lined by cells showing divergent differentiation. The vast majority of the reported nerve sheath tumors harboring these glands have been malignant. We herein present a case of benign glandular peripheral nerve sheath tumor in a 43-year-old woman who had no evidence of von Recklinghausen's disease. Histologically, the tumor is composed of spindle cell component and collections of glandular component. The glandular component occupied the central two-thirds of the lesion and was lined by a single layer of nonciliated cuboidal or columnar cells. No mitotic figures were recognized in the spindle cell area. This spindle cell area had neurofibroma-like features rather than schwannoma. Many of the spindle cells had positive reaction products for S-100 protein. The glandular lining epithelium were positive for cytokeratins (CAM 5.2, AE1/AE3, PKK1) and EMA. Some epithelial cells were immunoreactive for CEA, chromogranin, somatostatin and Leu-7. These immunohistochemical findings support the neuroendocrine differentiation of the epithelial element from the schwannian component.
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PMID:Benign glandular peripheral nerve sheath tumor. A case report. 752 35

We report a case of von-Recklinghausen's disease presenting with obstructive jaundice and found to have a somatostatin-containing carcinoid tumor in the papilla of Vater and a small neurofibroma in the duodenum. A 42-year-old woman with von-Recklinghausen's disease presented with intermittent jaundice, pruritus, and mild steatorrhea of a two-year duration. Abdominal ultrasonography and computed tomography showed dilated intrahepatic ducts, common bile duct and pancreatic ducts. Duodenoscopy showed a tumor at the papilla of Vater, but a preoperative biopsy failed to provide a definite diagnosis. Laparotomy revealed a yellowish tumor at the papilla of Vater and another nodule on the mesenteric side of the second section of the duodenum. Microscopically, the tumor at the papilla of Vater was found to be a somatostatin-containing carcinoid tumor. The small nodule on the mesenteric side was a neurofibroma. The jaundice, pruritus and steatorrhea disappeared after surgery.
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PMID:Somatostatin-containing carcinoid tumor of the duodenum in neurofibromatosis: report of a case. 790 72

Sixteen primary pancreatic tumors were found in a retrospective study of bovine pancreatic lesions detected in slaughtered cattle. Eleven islet cell tumors and three pancreatic exocrine carcinomas were identified based on light microscopy and immunohistochemistry. Nine of 11 islet cell tumors were classified as malignant. Metastatic sites included iliac, mediastinal, hepatic, and mesenteric lymph nodes, peritoneum, mesentery, and liver. Six cows with multiple islet cell tumors also had pheochromocytomas. All 11 islet cell tumors had positive immunoreactivity to insulin and somatostatin. Three tumors also contained cells immunoreactive for glucagon and two tumors contained pancreatic polypeptide immunoreactive cells. Immunoreactivity of tumor cells in metastatic sites was similar to their respective primary tumors. All exocrine pancreatic carcinomas metastasized widely and were immunonegative for insulin, somatostatin, glucagon, and pancreatic polypeptide. No mixed endocrine-exocrine tumors were identified. None of the endocrine or exocrine tumors contained amyloid. Additional primary tumors of the bovine pancreas included one neurofibroma and one neurofibrosarcoma. Additional cases with lesions of the bovine pancreas included nodular hyperplasia in 15 cows, exocrine acinar atrophy and fibrosis in four cows (two of which also had pancreatic lithiasis), pancreatitis in one cow, peripancreatic fibrosis in two cows, pancreatic steatosis in one animal, and pancreatic hemorrhages in one cow.
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PMID:A retrospective study of pancreatic tumors in slaughter cattle. 881 37

Long-acting somatostatin analogs have recently become supplemental drugs in the treatment of neurofibroma because of their marked tumor growth inhibitory effect. Somatostatin is currently under extended evaluation in other cancers as a possible supplemental drug to the treatment protocols in use. The mode of action is not known. Somatostatin has been shown to cause glucose intolerance by inhibiting glucose-6-phosphate dehydrogenase (G6PD) in fish liver. Recent data generated in our laboratory indicate that it is this pathway and the transketolase reactions of the pentose cycle (PC) which are directly involved in the ribose synthesis process of pancreatic adenocarcinoma cells. In cell culture, somatostatin alone inhibited glucose carbon recycling through the PC by 5.7%, which was increased to 19.8% in combination with oxythiamine, a competitive inhibitor of transketolase. Oxythiamine produced strong apoptosis in in-vitro hosted tumor cells. We hypothesize that somatostatin- and oxythiamine-induced antiproliferative action is mediated by the inhibition of G6PD, transketolase, or both.
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PMID:Inhibition of the oxidative and nonoxidative pentose phosphate pathways by somatostatin: a possible mechanism of antitumor action. 971 Mar 24

Although somatostatin receptors have been detected in many normal and neoplastic tissues, little is known of their expression and function in peripheral nerve tumors. In the present study, we examined the expression of all 5 somatostatin receptor subtypes (sst1-5) in 3 normal peripheral nerves, 3 traumatic neuromas, 27 schwannomas, 18 neurofibromas, and 177 malignant peripheral nerve sheath tumors (MPNSTs) by immunohistochemistry as well as by Western blot and reverse transcriptase-polymerase chain reaction investigations in 2 normal peripheral nerves, one neurofibroma, 5 schwannomas, and 5 MPNSTs. Immunoreactive somatostatin receptors were not detectable in normal peripheral nerve and in nonneoplastic Schwann cell proliferations. In contrast, sst2A mRNA and protein was present in 89% of schwannomas. This receptor subtype was less frequently detected in neurofibromas (22%) and MPNSTs (15%). Interestingly, sst4 was seen in 32% of MPNSTs and was almost exclusively expressed in this malignant tumor type. In support of a role in Schwann cell tumor growth control by somatostatin was the observation of induced internalization of sst2A and inhibition of cell proliferation in an NF1-associated MPNST cell line. Moreover, administration of an sst2A-selective agonist resulted in induction of MPNST cell apoptosis. We conclude that peripheral nerve sheath tumors often express at least one functional somatostatin receptor. Furthermore, our findings suggest a potential clinical role for somatostatin receptor agonists in tumor imaging and/or treatment of schwannomas and MPNSTs.
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PMID:Expression and function of somatostatin receptors in peripheral nerve sheath tumors. 1631 18

The clinical presentation, histopathology and immunoelectron microscopic features of two cases of duodenal somatostatinoma are described, one of which is a hitherto unreported example of a collision tumour with a neurofibroma. Ultrastructural morphometric immunoelectron microscopy studies revealed the presence of four types of cells in both tumours, but there was no difference in the proportions of these cells between the collision tumour and the non-collision tumour. Neurosecretory granules ranging in size from 255-815 nm were generally larger than those previously reported for somatostatinomas and somatostatin was identified in granules of all sizes across this range. Neither tumour was associated with the somatostatinoma syndrome comprising associated diabetes mellitis, steatorrhoea and cholelithiasis.
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PMID:Somatostatinoma: collision with neurofibroma and ultrastructural features. 1687 60