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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Changes in cytoskeletal organization in T9 anaplastic glioma cells have been examined during morphological changes induced by nerve growth factor (NGF) and by glia maturation factor (GMF). Indirect immunofluorescent labeling of cytoskeletal proteins has revealed that while neither GMF nor NGF induces expression of glial fibrillary acidic protein in this cell line, changes in cytoskeletal organization induced by these factors show some features similar to those observable during maturation of normal glial cells. Changing cell shapes induced by these factors are clearly outlined by the prominent distribution of microfilaments along cellular margins. Microtubules and intermediate filaments gradually extend during morphological changes and fill the characteristic cytoplasmic processes induced by NGF and GMF.
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PMID:Cytoskeletal reorganization induced by nerve growth factor and glia maturation factor in anaplastic glioma cells. 268 92

Calmodulin-dependent phosphoprotein phosphatase (CaMDP) activity has been found in each of three cultured cell lines: rat pheochromocytoma (PC12), glioma (C6), and pituitary adenoma (GH3) cells. These CaMDP activities bind to immobilized calmodulin in the presence of Ca2+ and are eluted by EGTA. Sucrose density centrifugation revealed that the phosphatase activities exhibited sedimentation coefficients of 4.37, 4.23, and 4.59 for proteins derived from C6, GH3, and PC12 cells, respectively. The Stokes radii measured for the PC12 and C6 activities were 41.8 and 40.0 A, respectively. The estimated molecular weights calculated for the enzymes from these data are 79,100 and 72,200. The phosphatase activities required the presence of divalent cations such as Ca2+ or Mn2+ for expression of activity, which was optimal only in the presence of calmodulin. The apparent Km for phosphorylated myelin basic protein substrate was 8 microM. Affinity-purified antibodies to the B subunit of bovine brain CaMDP were found by immunoblot (Western blot) to cross-react with a single protein among proteins extracted from PC12, C6, and GH3 cells that had been resolved by two-dimensional electrophoresis. In each case, the cross-reacting protein exhibited an Mr of 16,000 and an isoelectric point of 4.7, values virtually identical to those reported previously for the B subunit of bovine brain CaMDP (sometimes called calcineurin). This cross-reacting protein was found among cellular proteins eluted from immobilized calmodulin by EGTA. Immunocytochemical localization of the cross-reacting protein in undifferentiated PC12 cells or in cells differentiated in response to nerve growth factor revealed its presence diffusely throughout the cytoplasm. These experiments support the contention that each of these cell lines contains a calmodulin-regulated phosphatase homologous physically and kinetically, and immunologically related to bovine brain CaMDP.
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PMID:Calmodulin-dependent phosphatases of PC12, GH3, and C6 cells: physical, kinetic, and immunochemical properties. 329 45

A glia-derived neurite-promoting factor has been purified from medium conditioned by C6 rat glioma cells. It induces neurite outgrowth in cultured mouse neuroblastoma cells and inhibits granule cell migration in explants of mouse cerebellum. This factor is a potent serine protease inhibitor which has recently been shown to belong to the protease nexin family. It has therefore been called glia-derived nexin (GDN). We report here that GDN also promotes neurite outgrowth in dissociated chick superior cervical ganglion neurons grown in serum-free medium. In these neurons, the presence of nerve growth factor is not required for the stimulatory effect of GDN in the initial phase of neurite outgrowth. These experiments demonstrate that a glia-derived protein with protease inhibitory activity can modulate neurite outgrowth in cultured chick sympathetic neurons.
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PMID:A glia-derived nexin promotes neurite outgrowth in cultured chick sympathetic neurons. 337 Dec 30

Glial cells have been shown previously to release factors that promote survival of central and peripheral neurons [neuronotrophic factors (NTFs)]. We have investigated the release of NTFs by C6 cells, a rat glioma cell line, under different modes of conditioning. Media conditioned in the presence or absence of serum [C6 cell conditioned media (C6CMs)] were analyzed using biological, biochemical, and immunological assays. We report that (a) nuclear and cytoskeletal proteins were not present in C6CMs, indicating that C6CM proteins result from release by C6 cells rather than from cell death; (b) C6CM contained 1-3 micrograms protein/ml, corresponding to a secretion rate of about 0.5 pg protein per cell and day; (c) C6CM contained the neurite-promoting factor laminin and low amounts of nerve growth factor; (d) the presence of fetal calf serum in the culture medium was essential for synthesis and release of NTFs; and (e) our C6CM contained at least three NTFs differing by their temporal secretory patterns and three NTFs differing by biochemical properties, indicating that C6 cells produce and secrete six different NTFs. Within these, nerve growth factor seems to be the only established NTF.
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PMID:Neuronotrophic factors released by C6 glioma cells. 337 13

The ability of gangliosides to potentiate nerve growth factor (NGF)-independent trophic agents was determined by examining the capacity of an exogenous mixture of bovine brain gangliosides (BBG) and the monosialoganglioside GM1 to enhance the neuritogenic action of conditioned media (CM). CM were prepared with cultures of C6 glioma cells, neonatal rat astroglial cells, rat L6 myoblasts and chick embryonic skeletal muscle. Chick embryonic (9 day) dorsal root ganglia (DRG) were cultured on collagen-coated surfaces. The nutrient media with serum added or serum-free N1 medium were supplemented with 50% of one of the CM with or without BBG (150 micrograms/ml) or GM1 (150 micrograms/ml). The neuritogenic responses of DRG 48 h in vitro were evaluated microscopically on the basis of neurite length and number. The neurite promoting action of the factor(s) present in the various CM was potentiated by BBG or GM1 and resulted in increased neurite length and number.
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PMID:Ganglioside potentiation of NGF-independent trophic agents on sensory ganglia. 341 44

The growth of PC12 cells on a collagen substratum or on monolayers of several non-neuronal cell types was studied by measuring nerve growth factor (NGF)-dependent increases in the expression of a 150 X 10(3) (Mr) neurofilament protein subunit and the membrane glycoprotein Thy-1. Both responses were found to be greatly suppressed in cultures of fibroblasts as compared to the C2 and G8-1 muscle cell lines and the C6 glioma cell line. This suppression was associated with an inhibition of NGF-dependent neuritic outgrowth from PC12 cells grown on fibroblast monolayers. There was no evidence that fibroblasts secrete soluble molecules that directly inhibit these responses or neutralize NGF. In addition, there was no difference in the neurofilament protein response from PC12 cells that had been treated with NGF prior to coculture, and the now primed PC12 cells readily extended axons over fibroblast monolayers. These data demonstrate that cell-cell and/or cell-matrix interactions can modulate biochemical responses to NGF and suggest that responsiveness of neuronal cells to environmental cues is not immutable. Control of the latter may be at the level of expression of receptor molecules for cell-surface- or matrix-associated macromolecules and a similar mechanism operating during development could play a role in growth cone guidance.
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PMID:Cell-cell interactions modulate the responsiveness of PC12 cells to nerve growth factor. 350 97

Anaplastic glioma T9 cells were treated with either nerve growth factor (NGF) or glia maturation factor (GMF) or both. It was found that, when T9 cells were treated with these factors in a chemically defined medium, both NGF and GMF induced characteristic changes of cell morphology and growth pattern. Several differences in the effects of NGF and GMF were noted. NGF retarded growth rate, whereas GMF did not. The cells treated with NGF were characterized by a flattened extended cytoplasm with numerous protruding processes. The cell masses were somatically connected by cell bridges. GMF, on the other hand, produced slender cells with long, branching processes forming an interconnecting cell net. Concomitant administration of NGF and GMF retarded cell growth as was demonstrated with NGF alone and induced morphological changes predominantly attributable to GMF. The maximal effect of either NGF or GMF or both was attained after 4 days of treatment. A withdrawal of the factors from the medium following various periods of treatment revealed that the effects of GMF were readily reversible while morphological changes induced by NGF persisted in its absence.
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PMID:Modulation of growth and of morphological characteristics in glioma cells by nerve growth factor and glia maturation factor. 360 53

Adrenal chromaffin cells from early postnatal rats maintained in culture have previously been shown to grow neuritic processes and survive better in the presence of nerve growth factor (NGF). In the present study we have quantitated the effects on chromaffin cell (postnatal day (D) 8) survival and neurite outgrowth of: NGF, ciliary neuronotrophic factor (CNTF), activities contained in various types of conditioned media (CM), and various substrata (laminin, fibronectin and polyornithine-binding neurite-promoting factor from RN 22 Schwannoma cells - PNPF). At saturating concentrations CNTF (50 ng/ml) and C6 glioma cell CM, (50-fold concentrated) supported survival over the 4-day culture period of all the chromaffin cells present in culture 2 h after seeding. NGF (50 ng/ml) and the non-concentrated CMs from primary Schwann cell and astrocytes as well as Schwannoma and C6 glioma cell cultures, achieved the maintenance of only about half the number of cells above the baseline survival as compared to CNTF and the concentrated C6-CM. These results are compatible with two subsets of D8 chromaffin cells, one only supported by CNTF and the concentrated CM and the other supported by either NGF or CNTF. Either NGF or CNTF elicited neurite outgrowth from 15-20% of the surviving cells. Combination of maximal doses of NGF and CNTF caused a small increase in neurite recruitment beyond that elicited by either factor alone. Low doses of CNTF added to the effect of NGF, shifting the NGF titration curve by about 4-fold. Neurite outgrowth was also induced by the concentrated, but not the unconcentrated C6-CM. Laminin, fibronectin and PNPF did not affect the fibronectin and PNPF did not affect the recruitment of neurites as compared to a polyornithine substratum unless the cultures were supplemented with a neuronotrophic factor and carried for 7 days. However, even before showing effects on neurite recruitment these substrata affected various neuritic performances, such as length, neurite numbers and endings per cell.
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PMID:Neuronotrophic and neurite-promoting factors: effects on early postnatal chromaffin cells from rat adrenal medulla. 398 81

We have shown that rat glioma tumors contain a protein that crossreacts with antibody against mouse 2.5S nerve growth factor prepared in rabbit in microcomplement fixation assays and has analogous isoelectric points to all the hybrids of 2.5S nerve growth factor (a dimer). Partially purified protein preparations from gliomas cause chick dorsal root ganglia to extend neurites in the nerve growth factor assay and cause morphological differentiation of mouse neuroblastoma cells. We conclude that the rat glioma protein is homologous to mouse salivary nerve growth factor and suggest the possibility that glial nerve growth factor plays a role in neuronal development and regeneration.
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PMID:Nerve growth factor in rat glioma cells. 452 10

Experiments from several different laboratories are reviewed in which clonal neuronal cell lines are being used to study neuronal cellular functions. Primary emphasis is placed on two cell lines, the neuroblastoma X glioma hybrid clone NG108-15 and the pheochromocytoma clone PC12. These particular cell lines are useful because they display many of the properties normally associated with differentiated neurons. The properties which have been studied include: the regulation of adenylate cyclase and the receptors which activate or inhibit its activity, regulation of the cholinergic properties of NG 108-15 and both adrenergic and cholinergic properties of PC12, the response of PC12 to nerve growth factor, and the regulation of synaptogenesis between NG 108-15 cells and cultured muscle. The goal of the review is to not only summarize the information obtained with these two cell lines but also to emphasize the types of research in which clonal cell lines may be most useful in the future.
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PMID:Regulation of presynaptic cellular function. Biochemical studies using clonal neuronal cells. 616 93


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