Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adrenomedullin is a 52-amino acid peptide that was first isolated from human pheochromocytoma. Subsequently, it was found to be distributed widely in the body, including throughout the cardiovascular system. It belongs to a family of peptides that include calcitonin gene-related peptide and amylin. Adrenomedullin causes vasorelaxation and influences vascular proliferation and interacts closely with nitric oxide, and it may have a role in the pathophysiology of hypertension, ischemic heart disease, and cardiac and renal failure. Nonpeptide agonists or antagonists of adrenomedullin may have potential therapeutic application. The role of adrenomedullin in septicemic shock also merits further investigation.
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PMID:Adrenomedullin: its role in the cardiovascular system. 1547 33

A 45-year-old man on long-term hemodialysis (HD) was incidentally discovered to have a pheochromocytoma and underwent successful resection. This patient was normotensive, and had no symptoms suggesting pheochromocytoma. The plasma concentrations of total adrenomedullin (AM-T) and mature AM (AM-m) were higher than those in normal controls. To elucidate the source of AM, we measured plasma AM levels by immunoradiometric assay before and 3 weeks after surgery in addition to plasma adrenaline, noradrenaline and dopamine. AM expression was also assessed by immunoblot and immunohistochemical analyses on normal adrenal and tumor tissues. After surgery, elevated plasma adrenaline levels returned to the normal range; however, the levels of AM-T and AM-m remained almost the same as the preoperative values. Furthermore, although AM was expressed in both normal adrenal and tumor tissues, the AM expression level was less in tumor. In this case, it was suggested that elevation in plasma AM level might be a factor associated with normotensive blood pressure; however, adrenal pheochromocytoma was not a major source of circulating AM. To our knowledge, this is the first case of pheochromocytoma in patient with HD associated with AM in the literature.
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PMID:Source of plasma adrenomedullin in a patient with pheochromocytoma receiving hemodialysis. 1673 63

Thirteen years after the isolation of adrenomedullin (AM) from a human pheochromocytoma, the literature is awash with reports describing its implication in countless physiological and disease mechanisms ranging from vasodilatation to cancer promotion. A growing body of evidence illustrates AM as a pivotal component in normal physiology and disease with marked beneficial effects in the host defense mechanism. Exogenous administration of AM as well as its ectopic overexpression and the use of drugs, which potentiates its activity, are promising strategies for treatment of septic shock and several other pathogen-related disorders. Although major progress toward this end has been achieved over the past few years, our further understanding of the pleiotropic mechanisms involved with AM as a protective peptide is paramount to maximize its clinical application.
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PMID:The central role of adrenomedullin in host defense. 1676 69

Adrenomedullin is a vasoactive peptide that is upregulated in higher-grade gliomas and promotes tumor cell proliferation. Since reduced activity of the anti-oncogene PTEN seems to also correlate with higher tumor grade, this suggests an inverse association between PTEN activity and adrenomedullin expression. PC12 pheochromocytoma and human U251 glioma cell lines were stably transfected with human PTEN or control plasmid. Adrenomedullin expression was analyzed using quantitative PCR and Western blotting. A cell proliferation assay was used to assess adrenomedullin effects on U251 cells overexpressing PTEN. PC12 and U251 cells overexpressing PTEN had 17- and 8-fold decreases in adrenomedullin mRNA levels, respectively, compared to control cells. Cellular and secreted adrenomedullin peptide was similarly reduced. Addition of adrenomedullin to medium of controlled cells induced proliferation, as described previously, but U251 cells overexpressing PTEN did not respond to exogenous adrenomedullin. Further exploration revealed that PTEN also inhibits expression of the gliomas receptor for adrenomedullin, which accounts for this effect. These data were all replicated with an inducible PTEN construct confirming that these effects are not exclusively secondary to chronic overexpression. Given the profound effects of adrenomedullin on tumor cells, this is a novel and previously unidentified mechanism by which alterations in PTEN levels or function may influence tumor growth.
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PMID:PTEN inhibits adrenomedullin expression and function in brain tumor cells. 1682 Oct 90

This study investigates the expression of human adrenomedullin (ADM) and its receptor-receptor activity modifying protein 2/calcitonin receptor-like receptor (RAMP2/CRLR) mRNA in pheochromocytoma by reverse transcriptase polymerase chain reaction (RT-PCR) and its effect on the proliferation of pheochromocytoma cells by MTT. The mRNA expression of ADM and its receptor RAMP2/CRLR was present in normal adrenal medulla and pheochromocytoma tissues. The mRNA expression of ADM, RAMP2, and CRLR is markedly higher in pheochromocytomas than in normal medulla. ADM inhibits the proliferation of human pheochromocytoma cells and exerts a possible autocrine or paracrine effect in the adrenal.
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PMID:Expression and effect of adrenomedullin in pheochromocytoma. 1710 95

Pheochromocytomas are catecholamine-producing tumors which are generally benign, but which can also present as or develop into malignancy. Molecular pathways of malignant transformation remain poorly understood. Pheochromocytomas express various trophic peptides which may influence tumoral cell behavior. Here, we investigated the expression of trophic amidated peptides, including pituitary adenylate cyclase-activating polypeptide (PACAP), neuropeptide Y (NPY), and adrenomedullin (AM), and their receptors in benign and malignant pheochromocytomas in order to assess their potential role in chromaffin cell tumorigenesis and malignant transformation. PACAP, NPY, and AM are expressed in the majority of pheochromocytomas studied; NPY exhibiting the highest mRNA levels relative to reference genes. Although median gene expression or peptide levels were systematically lower in malignant compared to benign tumors, no statistically significant difference was found. Among all the receptors of these peptides that were analyzed, only the AM receptor RDC1 displayed a differential expression between benign and malignant pheochromocytomas. This receptor exhibited a fourfold higher expression in malignant than in benign tumors. AM and stromal cell-derived factor 1, which has also been described as a ligand for RDC1, increased the number of human pheochromocytoma cells in primary culture and exerted anti-apoptotic activity on rat pheochromocytoma PC12 cells. In addition, RDC1 gene silencing decreased the number of viable PC12 cells. This study shows the expression of several trophic peptides and their receptors in benign and malignant pheochromocytomas, and suggests that AM and its RDC1 receptor could be involved in chromaffin cell tumorigenesis through pro-survival effects. Therefore, AM and RDC1 may represent valuable targets for the treatment of malignant pheochromocytomas.
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PMID:Expression of trophic amidated peptides and their receptors in benign and malignant pheochromocytomas: high expression of adrenomedullin RDC1 receptor and implication in tumoral cell survival. 2048 10

Adrenomedullin (ADM) was first isolated from pheochromocytoma tissue as a novel vasodilative peptide in 1993. ADM binds to two receptors on plasma membrane which are comprised of Calcitonin Receptor-Like Receptor (CRLR), a member of serpentine receptor superfamily, and Receptor Activity Modifying Protein (RAMP) type 2 or 3. ADM is known to have hypotensive activity. Recently, ADM has been shown to be an almost ubiquitous peptide, synthesized in many mammalian tissues. ADM has potent in vivo angiogenic activity and tumor growth promoting effect in animal models. Many human tumors express ADM. However, only little information exists regarding the expression or the role of ADM in bone and its effect in bone metabolism. It is still not clear whether ADM is involved in pathogenesis and development of osteosarcoma, the most common form of bone tumor. The purpose of this review is to examine the most salient features of adrenomedullin biology, its expression in tumors and its potential implication in the treatment of bone tumors.
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PMID:Adrenomedullin and its expression in cancers and bone. A literature review. 2051 77

Pheochromocytomas are catecholamine-producing tumors arising from chromaffin cells of the adrenal medulla or extra-adrenal location. Along with catecholamines, tumoral cells produce and secrete elevated quantities of trophic peptides which are normally released in a regulated manner by the normal adrenal medulla. Among these peptides, the amounts of pituitary adenylate cyclase-activating polypeptide (PACAP), adrenomedullin (AM), and neuropeptide Y (NPY) are particularly high. These peptides can exert endocrine, paracrine or autocrine effects in numerous cell types. In particular, they have been shown to be involved in cell proliferation and survival, catecholamine production and secretion, and angiogenesis. Some of these processes are exacerbated in pheochromocytomas, raising the possibility of the involvement of trophic peptides. Here, we review the expression levels of NPY, PACAP, and AM and theirs receptors in chromaffin cells and pheochromocytomas, and address their possible implication in the adrenal medulla tumorigenesis and malignant development of pheochromocytomas.
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PMID:Expression of trophic peptides and their receptors in chromaffin cells and pheochromocytoma. 2104 51

Adrenomedullin is a peptide initially isolated from pheochromocytoma. It has a wide distribution and has multiple actions in many systems including the cardiovascular, renal, endocrine, reproductive, immune, nervous and musculoskeletal systems. This is reflected in the patents. These cover the use of adrenomedullin in diagnosis and as a biomarker for prognosis, especially in cardiovascular diseases and diabetes. It has also been proposed as a therapeutic agent, as a method to promote regeneration and repair, such as in ischaemic conditions and bone fractures. Conversely, its antagonists or antibodies binding it are claimed to have potential use in blocking angiogenesis in cancers.
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PMID:Adrenomedullin: exciting new horizons. 2221 76

First isolated from human pheochromocytoma cells, adrenomedullin (ADM) is a peptide hormone with natriuretic, vasodilatory, and hypotensive effects mediated by cyclic adenosine monophosphate (cAMP), nitric oxide, and renal prostaglandin systems. ADM expression occurs in many tissues and organ systems, including cardiovascular, renal, pulmonary, cerebrovascular, gastrointestinal, and endocrine tissues where it acts as a circulating hormone and a local autocrine and paracrine hormone. ADM plasma concentrations are increased in hypertension, chronic renal disease, and heart failure. As ADM is unstable in vitro, it is necessary to measure its mid-regional pro-hormone fragment, the levels of which correspond to ADM concentration (MR-proADM). The prognostic potential of MR-proADM was recently demonstrated in the Biomarkers in Acute Heart Failure (BACH) trial. In this trial of 568 acute heart failure patients, MR-proADM was superior to both brain natriuretic peptide (BNP) and NT-proBNP in predicting mortality within 14 days. MR-proADM also provided significant additive incremental predictive value for 90-day mortality when added to BNP and NT-proBNP.
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PMID:Novel biomarkers in acute heart failure: MR-pro-adrenomedullin. 2475 62


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