Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proopiomelanocortin (POMC) gene expression is not restricted to the pituitary corticotroph cell, but also takes place in many normal and tumoral nonpituitary tissues. In contrast, the ectopic ACTH syndrome is a rare event. Because it is most often associated with lung tumors, we specifically studied this tissue, analyzing the different forms of POMC RNAs in normal specimens as well as in various types of tumors. The endocrine nature of the tumors was assessed by both histological examination and measurements of secretogranin-I fragments in the tissue extracts. POMC RNA was first detected by Northern blot analysis; its absolute amounts and its various molecular forms were more precisely quantified and discriminated by S1 mapping studies using a single stranded DNA probe located at the 5' end of exon 3. In five bronchial carcinoid tumors associated with the ectopic ACTH syndrome, a highly predominant, if not single, POMC RNA identical to the 1200-nucleotide (nt) pituitary message was present, the high amounts of which were correlated with those of POMC peptides in the same tissues. In five bronchial carcinoid tumors not associated with the ectopic ACTH syndrome, the same message was detected (four of five), with a second, often predominant, short RNA of about 800 nt (five of five), and the overall amounts of POMC RNAs were low. Similar patterns of POMC RNAs were observed in squamous cell tumors, adenocarcinomas, and normal lung, where the short 800-nt RNA tended to be predominant. These results show that POMC gene expression can be demonstrated in normal lung tissue and in all types of lung tumors. The ectopic ACTH syndrome only occurs with tumors capable of generating high amounts of the pituitary-like message, a phenomenon that seems to be restricted to an occasional tumor with features of neuroendocrine differentiation.
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PMID:Proopiomelanocortin gene expression in normal and tumoral human lung. 185 67

Carcinoid tumours (bronchial and intestinal) were analyzed by immunoblotting for the presence of chromogranin A, B and secretogranin II. In all tumours an antigen corresponding in electrophoretic behaviour to adrenal chromogranin A was present. Lung carcinoids (3 out of 5) contained a relatively high concentration of a proteoglycan form of this antigen in addition. Chromogranin B was found in all tumours. In one and two dimensional immunoblotting it appeared identical to the corresponding adrenal antigen. Secretogranin II was also present, however concentrations (especially in intestinal carcinoids) were low and variable. Furthermore, in intestinal tumours it differed from the adrenal antigen by having a slightly higher molecular size and a more alkaline pI. Immunohistochemistry revealed that the tumour tissues stained positively for all three antigens. For secretogranin II the staining in intestinal tumours was relatively weak and quite variable. These results should provide a defined basis for immunohistochemical screening of carcinoids for the chromogranin/secretogranin antigens.
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PMID:Chromogranin A and B and secretogranin II in bronchial and intestinal carcinoids. 244 96

Chromogranins belong a unique family of secretory chromogranin and secretogranin proteins. They are present in the secretory vesicles throughout the neuroendocrine system. Chromogranin A is the major component. Its primary structure is well known but not yet its biological function. Chromogranin A performs as a prohormon which submits to processes of degradation. Active peptides are generated. Chromogranin A is a very used immunohistochemical marker. Reliable chromogranin A assays have been developed. In numerous studies it appear that the chromogranin A assay is reliable for the diagnosis and the follow-up of various endocrine tumors (principally the pheochromocytomas, neuroblastomas, gastrinomas and carcinoid tumors). The concentration of this general marker, in serum, reflects to the mass of the tumor. The chromogranin A levels will been interpreted in accordance to the localization of the primitive tumor, the existence of associated hormonal secretions and possible renal failure.
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PMID:[Chromogranin A: a marker of neuroendocrine tumors]. 1244 27

This short review deals with our investigations in neuroendocrine tumors (NETs) with antibodies against defined epitopes of chromogranins (Cgs) A and B and secretogranins (Sgs) II and III. The immunohistochemical expression of different epitopes of the granin family of proteins varies in NE cells in normal human endocrine and non-endocrine organs and in NETs, suggesting post-translational processing. In most NETs one or more epitopes of the granins were lacking, but variations in the expression pattern occurred both in benign and malignant NETs. A few epitopes displayed patterns that may be valuable in differentiating between benign and malignant NET types, e.g., well-differentiated NET types expressed more CgA epitopes than the poorly differentiated ones and C-terminal secretoneurin visualized a cell type related to malignancy in pheochromocytomas. Plasma concentrations of different epitopes of CgA and CgB varied. In patients suffering from carcinoid tumors or endocrine pancreatic tumors the highest concentrations were found with epitopes from the mid-portion of CgA. For CgB the highest plasma concentrations were recorded for the epitope 439-451. Measurements of SgII showed that patients with endocrine pancreatic tumors had higher concentrations than patients with carcinoid tumors or pheochromocytomas. SgIII was not detectable in patients with NETs.
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PMID:Immunohistochemical and biochemical studies with region-specific antibodies to chromogranins A and B and secretogranins II and III in neuroendocrine tumors. 2104 54