Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of platelet-derived growth factor- beta (PDGF-beta) receptors in the microvasculature of human healing wounds and colorectal adenocarcinoma was investigated. Frozen sections were subjected to double immunofluorescence staining using monoclonal antibodies (MAbs) specific for pericytes (MAb 225.28 recognizing the high-molecular weight-melanoma-associated antigen, expressed by activated pericytes during angiogenesis), endothelial cells (MAb PAL-E), laminin, as well as PDGF-beta receptors (MAb PDGFR-B2) and its ligand PDGF-B chain (MAb PDGF 007). Stained sections were analyzed by computer-aided imaging processing that allowed for a numerical quantification of the degree of colocalization of the investigated antigens. An apparent background colocalization, varying between 23 and 35%, between markers for cells not expected to co-localize was recorded. This background could be due to limitations of camera resolution, to out-of-focus fluorescence, and to interdigitations of the investigated structures. In all six tumor specimens, co-localization of PDGF-beta receptors and PAL-E was not different from the background co-localization, whereas that of PDGF-beta receptors and high-molecular weight-melanoma-associated antigen was significantly higher with mean values between 57 and 71%. Qualitatively, the same pattern was obtained in the two investigated healing wounds. PDGF-B chain did not co-localize with either PAL-E or high-molecular weight-melanoma-associated antigen, but PDGF-B chain-expressing cells were, however, frequently found juxtaposed to the microvasculature. The expression of PDGF-beta receptors on pericytes in activated microvessels and the presence of PDGF-B chain-expressing cells in close proximity to the microvasculature of healing wounds and colorectal adenocarcinoma is compatible with a role for PDGF in the physiology of the microvasculature in these conditions.
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PMID:Microvascular pericytes express platelet-derived growth factor-beta receptors in human healing wounds and colorectal adenocarcinoma. 823 54

Most cervical carcinomas appear to arise from cervical intraepithelial neoplasia (CIN) lesions. In addition to infection with high-risk human papilloma viruses, which is indicative of an increased risk of progression, alterations of oncogenes and tumor suppressor genes play a role. Genetic studies of CIN lesions, primary cervical carcinoma, and metastases may shed light on the relative importance of various genetic alterations involved in the progression of CIN to invasive carcinoma. We examined tumor material from 10 patients with squamous cell carcinoma of the uterine cervix and synchronous CIN lesions and lymph node metastases. The CIN component, invasive carcinoma, and lymph node metastases were analyzed separately for loss of heterozygosity (LOH) on the following loci: VHL (3p21), HLA region (6p22-23), PGL (11q 22-24), E6 associated protein (15q11-13), TP53 (17p13), DCC (18q21.1), and chromosomes 1, 2, 4, 9, 20, and X. Using immunohistochemistry, the expression of the EGF receptor, ERBB2, and TP53 was determined. In CIN lesions, frequent LOH was found at chromosome arms 3p, 6p, and 11q. Primary invasive carcinoma showed additional LOH at chromosome arms 6q, 17p, and 18q. In lymph node metastases, an additional locus on the X chromosome displayed LOH. All carcinomas and synchronous lesions but one showed high expression levels of the EGF receptor. TP53 staining, when present, was found in all synchronous lesions. Focal staining of ERBB2 was found in one CIN lesion, two invasive carcinomas, and four metastases. The molecular alterations accumulated in a fashion that paralleled the progression of the tumors. These results indicate that cervical tumorigenesis occurs in a stepwise fashion, including infection and integration of oncogenic HPV and several specific genetic alterations. Genes Chromosomes Cancer 26:346-354, 1999.
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PMID:Genetic alterations during the progression of squamous cell carcinomas of the uterine cervix. 1053 70

VEGF-A is a major angiogenesis and permeability factor. Its cellular effects, which can be used as targets in anti-angiogenesis therapy, have mainly been studied in vitro using endothelial cell cultures. The purpose of the present study was to further characterize these effects in vivo in vascular endothelial cells and pericytes, in an experimental monkey model of VEGF-A-induced iris neovascularization. Two cynomolgus monkeys (Macaca fascicularis) received four injections of 0.5 microg VEGF-A in the vitreous of one eye and PBS in the other eye. After sacrifice at day 9, eyes were enucleated and iris samples were snap-frozen for immunohistochemistry (IHC) and stained with a panel of antibodies recognizing endothelial and pericyte determinants related to angiogenesis and permeability. After VEGF-A treatment, the pre-existing iris vasculature showed increased permeability, hypertrophy, and activation, as demonstrated by increased staining of CD31, PAL-E, tPA, uPA, uPAR, Glut-1, and alphavbeta3 and alphavbeta5 integrins, VEGF receptors VEGFR-1, -2 and -3, and Tie-2 in endothelial cells, and of NG2 proteoglycan, uPA, uPAR, integrins and VEGFR-1 in pericytes. Vascular sprouts at the anterior surface of the iris were positive for the same antigens except for tPA, Glut-1, and Tie-2, which were notably absent. Moreover, in these sprouts VEGFR-2 and VEGFR-3 expression was very high in endothelial cells, whereas many pericytes were present that were positive for PDGFR-beta, VEGFR-1, and NG2 proteoglycan and negative for alpha-SMA. In conclusion, proteins that play a role in angiogenesis are upregulated in both pre-existing and newly formed iris vasculature after treatment with VEGF-A. VEGF-A induces hypertrophy and loss of barrier function in pre-existing vessels, and induces angiogenic sprouting, characterized by marked expression of VEGFR-3 and lack of expression of tPA and Tie-2 in endothelial cells, and lack of alpha-SMA in pericytes. Our in vivo study indicates a role for alpha-SMA-negative pericytes in early stages of angiogenesis. Therefore, our findings shed new light on the temporal and spatial role of several proteins in the angiogenic cascade in vivo.
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PMID:In vivo angiogenic phenotype of endothelial cells and pericytes induced by vascular endothelial growth factor-A. 1468 16

To assess the prevalence of genetic mutations in nonsyndromic pheochromocytoma/paraganglioma (PHEO/PGL) patients we have performed a systematic search for mutations in the succinate dehydrogenase (SDH) B, C, and D subunits, von Hippel-Lindau (VHL), and RET genes by direct bidirectional sequencing. Patients were selected from the medical records of hypertension centers. After exclusion of syndromic patients, 45 patients with familial (F+, n=3) and sporadic (F-, n=42) cases of isolated PHEO/PGL were considered. They included 35 patients with PHEO, 7 with PGL, and 3 with head/neck PGL (hnPGL). Three patients with PHEO (2F-, 1F+) presented VHL mutations (P86A, G93C, and R167W), six with PGL (4F-, 2F+) were positive for SDH or VHL mutations (SDHB R230G in two patients, SDHB S8F, R46Q, R90Q, and VHL P81L in one subject each), and one with hnPGL carried the SDHD 348-351delGACT mutation. We have also detected missense (SDHB S163P, SDHD H50R and G12S), synonymous (SDHB A6A, SDHD S68S), and intronic mutations that have been considered nonpathological polymorphic variants. No mutation was found in SDHC or RET genes. Our data indicate that germline mutations of VHL and SDH subunits are not infrequent in familial as well as in sporadic cases of nonsyndromic PHEO/PGL (overall, 12 of 45 probands, 22%). Accordingly, screening for such mutations seems to be justified. However, a more precise characterization of the functional relevance of any observed sequence variant and of other genetic and environmental determinants of neoplastic transformation is essential in order to plan appropriate protocols for family screening and follow-up.
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PMID:Genetic mutation screening in an italian cohort of nonsyndromic pheochromocytoma/paraganglioma patients. 1710 82

The familial forms of pheochromocytoma have recently been demonstrated to be more frequent than believed in the past. The genes currently known to be responsible for tumor formation are RET, VHL, NF1, SDHB, SDHC and SDHD. Germline mutations of these genes increase the risk of developing pheochromocytomas and/or paragangliomas which variably associate with other neoplasms and characterize diverse clinical syndromes such as MEN 2, von Hippel-Lindau (VHL), and neurofibromatosis type 1 (NF 1), or the PGL syndromes, respectively. Although the pathogenesis of pheochromocytoma/paraganglioma formation is still largely unknown, studies of the familial forms have started to uncover some pathways that favor tumor formation, such as activation of tyrosine-kinase, induction of hypoxia-inducible factors, activation of the oncogene Ras or reduced apoptosis. These studies have also demonstrated that various gene mutations can differently affect the biological characteristics of pheochromocytoma: for example, while the tumors are mostly adrenergic (epinephrine secreting) and episodically secreting in MEN 2, they are mostly noradrenergic (norepinephrine secreting) and continuously secreting in VHL. Biological variability can also be observed in the PGL syndromes where tumors develop in the head and neck and are parasympathetic in origin and non-secreting, or in the thorax and the abdomen, where they are sympathetic in origin and catecholamine secreting. Genetic testing in patients with pheochromocytomas or paragangliomas is, at present, strongly recommended and is mandatory in young patients or in cases of multiple or recurrent tumors. The clinical picture and the biological characteristics of the tumor may suggest the priority of the genes to be tested first.
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PMID:Genetics and biology of pheochromocytoma. 1742 3

1. Recent clinical and fundamental research studies have revolutionized our understanding of the genetics of phaeochromocytoma (PH) and functional paraganglioma (FPGL). It was widely thought that only 10% of PH patients had familial disease and that the malignant phenotype of PH could not be diagnosed before occurrence of the first metastasis. 2. Human genetic studies have now shown that 25-30% of patients have hereditary PH due to a germline mutation in the SDHB, SDHD, VHL, RET or NF1 gene and that the identification of a germline SDHB mutation is associated with a high risk of malignancy and a poor prognosis in PH/PGL patients. 3. Fundamental research studies have shown that SDH genes are tumour suppressor genes and that succinate dehydrogenase inactivation induces abnormal stimulation of the hypoxia-angiogenesis pathway. 4. Finally various fundamental research studies, conducted through the Cortico and Medullo-surrenale: les Tumeurs Endocrines (COMETE) network in France and by other groups worldwide, have produced new recommendations for genetic counselling and testing and for the management of PH patients. They have also improved our understanding of the molecular mechanisms involved in PH tumorigenesis.
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PMID:Recent advances in the genetics of phaeochromocytoma and functional paraganglioma. 1830 24

Pheochromocytomas/paragangliomas(PHEOs/PGLs) are rare but treacherous catecholamine-producing tumors which, if overlooked or improperly treated, will almost invariably prove fatal. Patients with MEN2 PHEOs have a high incidence of paroxysmal attacks and a higher prevalence of hypertension and other cardiovascular problems than do patients with Von-Hippel-Lindau (VHL) PHEOs. Compared to measurements of deconjugated metanephrines, plasma concentrations of free metanephrines are relatively independent of renal function and therefore more suitable for diagnosis of PHEO/PGL. Recently, the focus of Positron Emission Tomography (PET) imaging for these tumors has been the localization of PHEO. Although a limited number of studies are available, [18F]-fluorodopamine ([18F]DA) PET has been found to be the best overall imaging modality in the localization of PHEO. For adrenal PHEOs, this method seems to be comparable to other functional modalities such as [18F]-fluorodopa ([18F]DOPA) PET or [123I]-metaiodobenzylguanidine ([123I]MIBG)scintigraphy. For extraadrenal PHEOs, data are limited and more extensive studies are needed. In patients with metastatic PHEO, the sensitivity of [18F]DA PET is superior to [123I]MIBG. The so called "flip-flop" imaging showing superiority of non-specific [18F] flurodeoxyglucose (FDG) PET over specific [18F]DA PET has been described in rapidly progressive, often metastatic SDHB-associated PHEOs. Whether these data reflect PHEO cell dedifferentiation (e.g. losing Norepinephrine Transporter-NET) or increased metabolic rate remains to be established.
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PMID:Diagnosis of pheochromocytoma with special emphasis on MEN2 syndrome. 1957 Jul 38

Pheochromocytomas and paragangliomas (PCC/PGL) are tumors derived from the adrenal medulla or extra-adrenal ganglia, respectively. They are rare and often benign tumors that are associated with high morbidity and mortality due to mass effect and high circulating catecholamines. Although most PCCs and PGLs are thought to be sporadic, over one third are associated with 10 known susceptibility genes. Mutations in three genes causing well characterized tumor syndromes are associated with an increased risk of developing PCCs and PGLs, including VHL (von Hippel-Lindau disease), NF1 (Neurofibromatosis Type 1), and RET (Multiple Endocrine Neoplasia Type 2). Mutations in any of the succinate dehydrogenase (SDH) complex subunit genes (SDHA, SDHB, SDHC, SDHD) can lead to PCCs and PGLs with variable penetrance, as can mutations in the subunit cofactor, SDHAF2. Recently, two additional genes have been identified, TMEM127 and MAX. Although these tumors are rare in the general population, occurring in two to eight per million people, they are more commonly associated with an inherited mutation than any other cancer type. This review summarizes the known germline and somatic mutations leading to the development of PCC and PGL, as well as biochemical profiling for PCCs/PGLs and screening of mutation carriers.
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PMID:Pheochromocytoma and paraganglioma: understanding the complexities of the genetic background. 2242 92

The identification of 9 susceptibility genes for paraganglioma/pheochromocytoma between 2001 and 2010 has led to the development of routine genetic tests. To study the evolution in genetic screening for paraganglioma/pheochromocytoma over the past decade, we carried out a retrospective study on the tests performed in our laboratory from January 2001 to December 2010. A genetic test for paraganglioma/pheochromocytoma was assessed for 2 499 subjects, 1 620 index cases, and 879 presymptomatic familial genetic tests. A germline mutation in a PGL/PCC susceptibility gene was identified in 363 index cases (22.4%): 269 in SDHx genes (137 in SDHB, 100 in SDHD, 30 in SDHC, 2 in SDHA), 64 in VHL, 23 in RET, and 7 in TMEM127. A presymptomatic paraganglioma/pheochromocytoma test was positive in 427 subjects. Advances in molecular screening techniques led to an increase in the total number of mutation-carriers diagnosed each year. Overall, during the last decade, our laboratory identified a germline mutation in 44.7% of patients with a suspect hereditary PGL/PCC and in 8% of patients with an apparently sporadic PGL/PCC. During the past decade, the discoveries of new paraganglioma/pheochromocytoma susceptibility genes and the subsequent progress of molecular screening techniques have enabled us to diagnose a hereditary paraganglioma/pheochromocytoma in about 22% of patients tested in routine practice. This genetic testing is of major importance for the follow-up of affected patients and for the genetic counselling of their families.
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PMID:A decade (2001-2010) of genetic testing for pheochromocytoma and paraganglioma. 2251 57

The genes for the succinate dehydrogenase (SDH) subunits SDHA, SDHB, SDHC and SDHD are encoded in the autosome. The proteins are assembled in the mitochondria to form the mitochondrial complex 2, a key respiratory enzyme which links the Krebs cycle and the electron transport chain. Thirty percent of phaeochromocytoma and paraganglioma (PHEO/PGL) are hereditary and perhaps as many as half of these familial cases are caused by germline mutations of the SDH subunits. Negative immunohistochemical staining for the SDHB subunit identifies PHEO/PGL associated with germline mutation of any of the mitochondrial complex 2 components and can be used to triage formal genetic testing of all PHEO/PGL for SDH mutations. PHEO/PGL associated with SDHA mutation also show negative staining for SDHA as well as SDHB.A unique subgroup of gastrointestinal stromal tumours (GISTs) are driven by mitochondrial complex 2 dysfunction. These SDH deficient GISTs can also be definitively identified by negative staining for SDHB and show distinct clinical and morphological features including frequent onset in childhood and young adulthood, gastric location, a tendency to multifocality, absence of KIT and PDGFRA mutations, a prognosis not predicted by size and mitotic rate and a tendency to indolent behaviour of metastases. Some of these SDH deficient GISTs are driven by classical SDH mutations, but the precise mechanisms of tumourigenesis in many (including those associated with the Carney triad) remain unknown. Germline SDHB mutation is associated with a newly recognised type of renal carcinoma which commonly but not always demonstrates distinctive morphology and can also be recognised by negative staining for SDHB.Immunohistochemistry for SDHB therefore has emerged as a useful tool to recognise these distinct neoplasias driven by mitochondrial complex 2 dysfunction and to triage formal genetic testing for the associated syndromes.
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PMID:Succinate dehydrogenase (SDH) and mitochondrial driven neoplasia. 2254 11


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