Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association and interaction of plectin (Mr 300,000) with intermediate filaments and filament subunit proteins were studied. Immunoelectron microscopy of whole mount cytoskeletons from various cultured cell lines (rat glioma C6, mouse BALB/c 3T3, and Chinese hamster ovary) and quick-frozen, deep-etched replicas of Triton X-100-extracted rat embryo fibroblast cells revealed that plectin was primarily located at junction sites and branching points of intermediate filaments. These results were corroborated by in vitro recombination studies using vimentin and plectin purified from C6 cells. Filaments assembled from mixtures of both proteins were extensively crosslinked by oligomeric plectin structures, as demonstrated by electron microscopy of negatively stained and rotary-shadowed specimens as well as by immunoelectron microscopy; the binding of plectin structures on the surface of filaments and cross-link formation occurred without apparent periodicity. Plectin's cross-linking of reconstituted filaments was also shown by ultracentrifugation experiments. As revealed by the rotary-shadowing technique, filament-bound plectin structures were oligomeric and predominantly consisted of a central globular core region of 30-50 nm with extending filaments or filamentous loops. Solid-phase binding to proteolytically degraded vimentin fragments suggested that plectin interacts with the helical rod domain of vimentin, a highly conserved structural element of all intermediate filament proteins. Accordingly, plectin was found to bind to the glial fibrillar acidic protein, the three neurofilament polypeptides, and skin keratins. These results suggest that plectin is a cross-linker of vimentin filaments and possibly also of other intermediate filament types.
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PMID:Cytoskeleton-associated plectin: in situ localization, in vitro reconstitution, and binding to immobilized intermediate filament proteins. 334 24

To study the expression of two different subclasses of intermediate filaments in ethylnitrosourea-induced rat cerebral gliomas, the number of cells immunopositive for each subunit protein, vimentin and astroprotein (GFAP), was quantitatively analyzed. Vimentin is a subunit protein of non-specific intermediate filaments which appear transiently in immature glial cells, while astroprotein (GFAP) is a subunit protein of glial filaments, normally expressed in mature astrocytes. Although most normal astrocytes were negative for vimentin, many tumor cells showed weak to strong immunoreaction for vimentin. The expression of vimentin was more frequent and intense in anaplastic forms of gliomas than in benign forms. Accordingly, the vimentin/GFAP ratio [the number of vimentin-positive cells divided by the number of astroprotein (GFAP)-positive cells] was increased from 0.23 to 1.86, and from 0.26 to 1.85, respectively, as oligodendrogliomas and mixed gliomas become anaplastic. The present study demonstrated that the immunohistochemical study for those two subclasses of intermediate filaments can provide important informations on the cell biological nature of glial tumors.
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PMID:Intermediate filaments and anaplastic change of ENU-induced gliomass: immunohistochemical study with vimentin and astroprotein (GFAP). 344 Aug 78

The cytoskeletal properties and endogenous degradation of intermediate filaments in cultured human glioma cells (U-251MG) were studied using monoclonal antibodies in immunohistochemical and immunochemical methods. Both glial fibrillary acidic protein (GFAP)- and vimentin-antibodies gave a fibrillar cytoplasmic staining of the cells, and double immunofluorescence experiments showed the presence of both types of intermediate filaments in the same cells. GFAP and vimentin could also be located to typical coiling perinuclear bundles after vinblastine treatment of the cultures. In the detergent-resistant, adherent cytoskeletons of the glioma cells, both GFAP and vimentin persisted as fibrillar cytoplasmic arrays. Scanning and transmission electron microscopy showed that only intermediate filaments were left in the cytoplasmic domain. Electrophoretic analysis, combined with the immunoblotting method, revealed that the two major detergent-resistant cytoskeletal polypeptides of the cells, with molecular weights of 51 kD and 58 kD, were GFAP and vimentin, respectively. On the other hand, neither GFAP nor vimentin were detected in the detergent extracts of the glioma cells. Detergent-extraction in low ionic strength medium as well as inclusion of Ca2+ into the extraction medium resulted into a rapid degradation of both GFAP and vimentin. These degradation conditions produced different, partially soluble, lower MW immunoreactive polypeptides as detected by the immunoblotting technique. Interestingly, the degradation also produced soluble intact GFAP and vimentin. These results indicate that GFAP and vimentin have closely similar physicochemical properties in the cytoskeletons of human glioma cells including a nearly quantitative localization in filaments, rearrangement upon microtubule disruption, and resistance to extractions by detergents. Proteolytic degradation of both proteins can be induced by a protease activated by both low ionic strength and Ca2+.
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PMID:Cytoskeletal properties and endogenous degradation of glial fibrillary acidic protein and vimentin in cultured human glioma cells. 351 30

Monoclonal antibodies were produced against surface antigens of live cells from a human acute monocytic leukaemia cell line (THP-1). One clone, VIC-C2, when assayed by immunofluorescence microscopy, brightly stained the surface of THP-1 cells and the cytoplasm of Langerhans cells, fibroblasts and melanocytes in sections of human skin. The immunoreactive cytoplasmic structures were filamentous and resembled intermediate filaments. By double immunofluorescence microscopy using VIC-C2 and polyclonal antibodies to vimentin, the VIC-C2 antigen was shown to be located on intermediate filaments of cultured fibroblasts and to follow these filaments during various drug-induced rearrangements. As demonstrated by immunoprecipitation, antibody gel overlay and immunoblotting of two-dimensional polyacrylamide gels, VIC-C2 recognized two different antigens in extracts of THP-1 cells: one of Mr = 43 000 and pI = 7, the other of Mr = 57 000. In extracts from various cultured fibroblast cells only the 57 000 Mr antigen was detected. This 57 000 Mr protein was identified as vimentin by immunoblotting of rat glioma C6 cytoskeletons on two-dimensional gels. When vimentin was digested with chymotrypsin, only fragments containing parts of both helical rod pieces and the connecting non-helical spacer-region were strongly antigenic, whereas the helical rods alone were only weakly crossreactive. Moreover, immunoprecipitation revealed that VIC-C2 preferentially reacted with native compared to denatured vimentin.
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PMID:Monoclonal antibody to a 43 000 Mr surface protein of a human leukaemia cell line (THP-1) crossreacts with the fibroblast intermediate filament protein vimentin. 386 May 6

Using the peroxidase-antiperoxidase (PAP) technique, we examined 35 primary brain tumors for expression of vimentin and GFAP. Both low-grade and high-grade astrocytomas contained vimentin-positive and GFAP-positive cells. Ependymomas also stained for both markers. In gliosarcomas, the glioblastomatous portions stained like astrocytomas, while only vimentin stain was seen in the fibrosarcomatous portions. Medulloblastomas and oligodendrogliomas were negative for both vimentin and GFAP, while meningiomas contained scattered areas of vimentin-positive cells. These results suggest that the expression of vimentin and GFAP is mostly confined to glial-derived tumors, and that vimentin can potentially be a useful marker for distinguishing undifferentiated GFAP-negative glial tumors and mesenchymal tumors from primitive neuroectodermal tumors.
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PMID:Vimentin and glial fibrillary acidic protein in human brain tumors. 388 31

Expression of two different types of intermediate filaments, vimentin filaments and glial filaments, was studied immunohistochemically in experimental rat gliomas. Although vimentin filaments are most commonly seen in mesenchymal cells, recent immunocytochemical study demonstrated that this type of filaments can be recognized also in glial cells during early cell differentiation and in tumor cells of epithelial origin. In the present communication, distribution of vimentin filaments in rat glial tumors was investigated and compared with that of glial filaments by using specific antiserum to each protein subunit, vimentin and astroprotein (GFAP). Ethylnitrosourea (50 mg/kg) was injected subcutaneously into 3 day-old Wistar rats. After four to ten months, brains of animals were removed, fixed in 95% ethanol and embedded in paraffin. Peroxidase-antiperoxidase method was carried out on 6 micron-thick sections. In normal portion of the brain, immunoreaction for vimentin was noted in ependymal cells and in vascular endothelial cells but not in astrocytes. This distribution contrasted with that of astroprotein (GFAP), which distributed in astrocytes but not in normal ependymal cells. These findings confirmed that the two antisera used in the present study do not crossreact to each other. In contrast to the absence of vimentin immunoreaction in normal astrocytes, a number of tumor cells showed positive reaction to the antiserum to vimentin. Mixed glioma with astrocytoma and oligodendroglioma had both astroprotein (GFAP)-positive and negative cells. Well developed cellular processes were noted in astroprotein (GFAP)-positive cells (astrocytoma cells). Weak immunoreaction for vimentin was noted in those cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Immunohistochemical study of ethylnitrosourea-induced rat gliomas with vimentin and astroprotein (GFAP)]. 409 86

Immunofluorescence and immunoperoxidase (peroxidase-antiperoxidase, PAP) techniques for the demonstration of neural and non-neural cell markers are contributing greatly to increase the diagnostic accuracy of difficult tumors of the central nervous system. Well characterized nervous system markers include glial fibrillary acidic (GFA) protein, the three protein subunits of neurofilaments, neuron-specific enolase (NSE), myelin basic protein, and S-100 protein. The most important and reliable of these is GFA protein, which is widely in use for the immunohistochemical diagnosis of tumors of the glioma group. Its many practical applications are reviewed and illustrated. Other neural markers, in particular the specificity of NSE and S-100 protein, need to be critically evaluated. Problems related to the immunohistochemical diagnosis of central neuroepithelial tumors of putative neuroblastic origin remain complex and still need to be resolved. Non-neural markers, such as vimentin, desmin, cytokeratins, Factor VIII, alpha-fetoprotein, human chorionic gonadotropin, and immunoglobulins have well defined, although more restricted, applications in surgical neuropathology.
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PMID:Immunohistochemistry of central nervous system tumors. Its contributions to neurosurgical diagnosis. 620 56

We have used a human glioma cell line (U-251MG) to study the expression and cytoplasmic organization of vimentin (decamin) and the glial filament protein (GFP). Four clones of the parental U-251 cultures were isolated and found to express GFP from 1-2% to 99% of the cells in the population. Double immunofluorescence microscopy with antibodies to vimentin and GFP has shown that, in all four clonal cell lines, vimentin-containing filaments are expressed in most cells as an organized network and, in GFP-positive cells, GFP and vimentin are associated with the same filament network. Immunoelectron microscopy with specific antibodies labeled with colloidal gold particles of various sizes shows that GFP and vimentin are localized in the same filaments. These findings confirm in vitro studies of the copolymerization of subunits of different biochemical nature into the same intermediate filament and suggest the in vivo probability of the coassembly of GFP and vimentin from a possible soluble pool of monomers.
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PMID:Identification of glial filament protein and vimentin in the same intermediate filament system in human glioma cells. 637 9

Certain glia cells, notably astrocytes and tumor cells derived therefrom, express simultaneously two types of proteins of intermediate-sized filaments, vimentin and glia filament protein (GFP). We have used an established human glioma (astrocytoma) cell culture line (U 333 CG/343 MG) in which both proteins are seen in partly overlapping fibrillar structures by immunofluorescence microscopy, to examine the possible existence of heteropolymer filaments of these two proteins by using reversible oxidative cross-linking facilitated by the 1,10-phenanthroline-cupric ion complex. Dimeric cross-link products are characterized by one-dimensional and two-dimensional gel electrophoresis under non-reducing and reducing conditions as well as by peptide mapping. The relatively large proportions of heterodimers of vimentin and GFP obtained in cytoskeletal filaments cross-linked in this way, demonstrate the frequency of heteropolymer filaments in this cell as well as the frequency of face-to-face 'pairs' of GFP and vimentin in such filaments. Together with our related observations on heteropolymer filaments between vimentin and desmin in some smooth muscle cells [Quinlan, R. A. and Franke, W. W. (1982) Proc. Natl Acad. Sci. USA, 79, 3452-3456], we discuss this as evidence for common principles of molecular arrangements of vimentin, GFP and desmin, at least in the cysteine-containing surface domains. The results are also discussed in relation to cytoskeletal changes during glial differentiation.
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PMID:Molecular interactions in intermediate-sized filaments revealed by chemical cross-linking. Heteropolymers of vimentin and glial filament protein in cultured human glioma cells. 668 57

Past studies of norepinephrine-stimulated protein phosphorylation in intact C-6 glioma cells had identified a 58,000 molecular weight, 5.7 isoelectric point protein (58K-5.7) as a cyclic AMP-dependent phosphoprotein and had shown that 58K-5.7 was one of the most abundant proteins of the nuclear fraction. Initial experiments of present studies showed that the 58K-5.7 protein remained with the nuclear ghost, or matrix structure, after removal of chromatin. Based on the size, acidity, abundance, nonsolubilization by nonionic detergent and salt, and solubilization by urea, the hypothesis was advanced that the 58K-5.7 protein was the vimentin-type intermediate filament protein. The hypothesis was tested by two types of immunochemical experiments. Antisera against hamster vimentin reacted selectively with only the 58K-5.7 protein in polyacrylamide gels of urea-solubilized cellular residues (i.e., nonionic detergent and 0.6 M salt-insoluble material) as determined by immunoautoradiography. Antisera against the pure 58K-5.7 protein of C-6 cells bound selectively to a fibrous array of cellular material typical of vimentin filaments as determined by indirect immunofluorescence. It is concluded that the 58K-5.7 protein is vimentin.
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PMID:Vimentin: a phosphoprotein under hormonal regulation. 702 79


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