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)

Anisoylated Lys-plasminogen streptokinase activator complex (APSAC) was purified from Eminase by chromatography on Superose-12. Purified APSAC did not significantly deacylate within 4 h at 4 degrees C in solution as determined by hydrolysis of D-Val-L-leu-L-lys-p-nitroanilide HCl (S-2251). At 37 degrees C, maximum amidase activity developed in 120 min; epsilon-amino-n-caproic acid (EACA) did not affect the apparent rate of APSAC deacylation but stabilized the streptokinase-plasmin(ogen) complex (SkPl) which formed. APSAC bound to C6 glioma cells and human umbilical vein endothelial cells (HUVECs) in culture. Binding as completely inhibited by EACA suggesting an essential role for the plasminogen kringle domains. Cell-associated APSAC deacylated to form active SkPl which hydrolyzed S-2251 and D-Val-Leu-Lys-7-amino-4-methyl coumarin. The rate of APSAC deacylation was increased when the APSAC was cell-associated. APSAC that was initially bound to C6 cells or HUVECs also activated 125I-plasminogen. This activity may have reflected cell-associated APSAC or APSAC but dissociated into solution. Plasmin was recovered bound to cells and in solution. These studies demonstrate that APSAC associates with cell-surfaces and retains activity. In the circulation, cell-surfaces may provide a significant pharmacologic compartment for intravenously administered APSAC.
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PMID:Binding of anisoylated Lys-plasminogen streptokinase activator complex to cells in culture. 838 80

Malignant features in three glioma cell lines were studied in four defined media of various complexity. The cell lines D37MG, D54MG, and GaMG were able to grow in monolayer culture in all media examined, and as multicellular tumor spheroids in the two most nutrient-rich media. In the defined media, none of the cell lines were able to migrate in a migration assay on poly-D-lysine-coated plastic surfaces. Flow cytometric analysis of the GaMG cell line demonstrated no medium-dependent selection of subclones of glioma cells in spheroids cultured for 30 d. Morphological diversity of spheroids varied according to the supplementation of the media. The capacity of glioma cells to invade cellular rat brain aggregates was intact in the media examined. However, glioma migration was severely inhibited by the lack of specific serum components. This study demonstrates that glioma growth and invasion was heterogeneously preserved in the defined media used. Depending on the assay to be used in the study of glioma cell behavior, the degree of medium supplementation has to be considered.
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PMID:Heterogeneic modulation of malignant behavior in human glioma cells in defined and serum-containing media. 892 38

The preferential localization of the L1 cell adhesion molecule in the axons and growth cones of differentiating neurons suggests the existence of a mechanism for targeting or anchoring the molecule to these locations. We have used B28 glioma cells, which have an extremely flattened morphology, as a model system to study the organization of L1 on the cell structure. Transfection of L1 cDNA into B28 cells results in expression of the L1 protein in organized linear cell surface arrays which are codistributed with cytoskeletal stress fibers, but not with microtubles or intermediate filaments. Transfection studies with L1 deletion mutants identify the juxtamembrane segment of the cytoplasmic domain as the critical entity for arrangement of L1 into ordered cell surface arrays. The seventh cytoplasmic amino acid of L1, lysine 1150, and to a lesser extent the fourth cytoplasmic amino acid, lysine 1147, appear to be critical residues for maintaining normal L1 anchorage and distribution.
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PMID:Mutational analysis of the L1 neuronal cell adhesion molecule identifies membrane-proximal amino acids of the cytoplasmic domain that are required for cytoskeletal anchorage. 924 98

Embryonic rat hippocampal neurons were cultured in a serum-free defined medium (MEM/N3) either directly on poly-D-lysine (PDL) or on a confluent monolayer of postnatal cortical astrocytes, C6 glioma cells, or Rat2 fibroblasts. Neurons on PDL were grown in MEM/N3 or in MEM/N3 conditioned for 24 h by astrocytes or C6 cells. Membrane capacitance (Cm) and gamma-aminobutyric acid (GABA)-, glycine-, kainate-, and N-methyl-D-aspartate (NMDA)-induced currents were quantified using whole-cell patch-clamp recordings. Cm as well as the amplitude and the density of these currents in neurons cultured on astrocytes were significantly greater than those in neurons grown on PDL after 24 and 48 h. C6 cells mimicked astrocytes in promoting Cm and GABA-, glycine-, and NMDA-evoked, but not kainate-evoked, currents. Cm and currents in neurons grown on Rat2 cells were comparable to those in neurons on PDL. Astrocytes maintained in culture for 3 months were noticeably less effective than freshly prepared ones just grown to confluence. Suppression of spontaneous cytoplasmic Ca2+ (Ca[c]2+) elevations in astrocytes by 1,2-bis(2-aminophenoxy) ehane-N, N, N, N-tetraacetic acid acetoxymethyl ester (BAPTA-AM) loaded intracellularly blocked the observed modulatory effects. Medium conditioned by either astrocytes or C6 cells mimicked the effects of direct coculture of neurons on these cells in promoting Cm and amino acid-evoked currents. Inclusion of antagonists at GABA and glutamate receptors in coculture experiments blocked the observed effects. Thus, diffusible substances synthesized and/ or secreted by astrocytes in a Ca(c)2+-dependent manner can regulate neuronal growth and aminoacid receptor function, and these effects may involve neuronal GABA and glutamate receptors.
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PMID:Astrocytes regulate amino acid receptor current densities in embryonic rat hippocampal neurons. 936 56

The existence of specific rabies virus (RV) glycoprotein (G) binding sites on the surfaces of neuroblastoma cells is demonstrated. Spodoptera frugiperda (Sf21) cells expressing G of the RV strain CVS (Gcvs-Sf21 cells) bind specifically to neuroblastoma cells of different species but not to any other cell type (fibroblast, myoblast, epithelial, or glioma). Attachment to mouse neuroblastoma NG108-15 cells is abolished by previous treatment of Gcvs-Sf2 cells with anti-G antibody. Substitutions for lysine at position 330 and for arginine at position 333 in RV G greatly reduce interaction between Gcvs-Sf21 cells and NG108-15 cells. These data are consistent with in vivo results: an avirulent RV mutant bearing the same double mutation is not able to infect sensory neurons or motoneurons (P. Coulon, J.-P. Ternaux, A. Flamand, and C. Tuffereau, J. Virol. 72:273-278, 1998) after intramuscular inoculation into a mouse. Furthermore, infection of NG108-15 cells by RV but not by vesicular stomatitis virus leads to a reduction of the number of binding sites at the neuronal-cell surface. Our data strongly suggest that these specific attachment sites on neuroblastoma cells represent a neuronal receptor(s) used by RV to infect certain types of neurons in vivo.
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PMID:Neuronal cell surface molecules mediate specific binding to rabies virus glycoprotein expressed by a recombinant baculovirus on the surfaces of lepidopteran cells. 944 3

Wild-type Daniel's strain of Theiler's virus (wt-DA) induces a chronic demyelination in susceptible mice which is similar to multiple sclerosis. A variant of wt-DA (designated DA-P12) generated during the 12th passage of persistent infection of a G26-20 glioma cell line failed to persist and induce demyelination in SJL/J mice. To identify the determinants responsible for this change in phenotype, we sequenced the capsid coding sequence (nucleotides [nt] 2991 to 3994) and found three mutations in VP1: residues 99 (Gly to Ser), 100 (Gly to Asp), and 103 (Asn to Lys). To study the role of these mutations in neurovirulence and demyelination, we prepared a recombinant virus, DAP-1C-2A/DA, with replacement of wt-DA nt 2991 to 3994 with the corresponding region of DA-P12, and viruses with individual point mutations at VP1 residues 99(Ser), 100(Asp), and 103(Lys). DAP-1C-2A/DA and viruses with a mutation at VP1 residue 99 or 100 (but not 103) completely attenuated the ability of wt-DA to induce demyelination. Failure to induce demyelination was not due to a general failure in growth, since DA-P12 and other mutant viruses lysed L-2 cells in vitro as effectively as wt-DA. The change in disease phenotype was independent of the specific B- or T-cell immune recognition because a decrease in the neurovirulence of mutant viruses was observed in neonatal mice and immune-deficient RAG1 -/- mice. This difference in neurovirulence is not the complete explanation for the failure of DA-P12 to demyelinate, since virus with a mutation at residue 103(Lys) had decreased neurovirulence but did induce demyelination. Therefore, point mutation at VP1 residue 99 or 100 altered the ability of wt-DA to demyelinate, perhaps related to a disruption in interaction between virus and receptor on certain neural cells.
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PMID:Molecular characterization of a nondemyelinating variant of Daniel's strain of Theiler's virus isolated from a persistently infected glioma cell line. 944 26

The vast majority of brain cancers (gliomas) express a receptor (R) for interleukin 13 (IL13). In order to achieve specific targeting of the IL13R in gliomas, we have mutagenized human (h) IL13. The mutation was made to alter IL13 interaction with the shared functional IL13/4 normal tissue receptor, but not with the glioma-associated receptor. We have thus produced hIL13.E13K (glutamic acid at position 13 changed to lysine) and fused it to derivatives of Pseudomonas exotoxin A. The hIL13.E13K-based cytotoxins are less active on normal cells and thus less toxic, and are better antitumor agents compared with the cytotoxins containing nonmutagenized hIL13.
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PMID:Novel anti-brain tumor cytotoxins specific for cancer cells. 959 93

The aim of this project was to develop procedures necessary to study mechanisms of receptor mediated gene transfer by means of integrated microscopy. Plasmid DNA was incorporated into a transfection complex consisting of poly(L)lysine and transferrin to which the nuclear localization signal was conjugated. This complex was presented to cultured glioma cells. Preparation of the transfected DNA for imaging was pursued by two methods. In the first method tetramethylrhodamine, nanogold, and ferritin were linked through streptavidin to the biotinylated plasmid DNA. Trafficking of the fluorescent derivatives was studied in living cells with fluorescence microscopy. Then, selected cells were rapidly cryo-immobilized. Ultra-structural distribution of the transfected DNA was imaged with energy filtering transmission electron microscopy. In the second method, the unmodified transfected DNA was detected in cryo-immobilized cells by in situ polymerase chain reaction and in situ hybridization. For laser scanning fluorescence microscopy probes were labeled with tetramethylrhodamine. For ultrastructural analysis by electron spectroscopic imaging, probes containing incorporated digoxigenin were labeled with anti-digoxigenin boronated antibodies. Based upon the developed procedures, it has been demonstrated that the presence of the nuclear localization signal in the transfection complex resulted in rapid nuclear import of the transfected DNA.
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PMID:Preparation of plasmid DNA in transfection complexes for fluorescence and electron spectroscopic imaging. 960 25

Recombinant adenovirus (Adv)-mediated gene transduction is a powerful technology for cancer gene therapy. In this article, we report the generation of a fiber-mutant Adv vector, using the Adv genomic DNA-terminal protein complex (DNA-TPC) cotransfection method. First, a fiber-mutant construct in a plasmid carrying the right-side two-thirds of the human adenovirus type 5 (Ad5) genome (pTR) was cotransfected with Ad5 DNA-TPC, yielding the recombinant Adv with the desired fiber mutation. The DNA-TPC from the mutant Adv was then utilized to produce a second-step recombinant Adv with an expression cassette in the place of E1. By this procedure, we generated a fiber mutant, F/K20, that has a linker and a stretch of 20 lysine residues added at the C terminus of the fiber. By using Adv carrying a reporter lacZ gene (AxCAZ2) with either F/K20 or wild-type fiber (F/wt), we examined the transduction efficiency of F/K20-Adv. No significant difference in the transduction efficiency between F/K20 and F/wt-Adv was observed for a human fibroblast line, WI-38, or various tumor cell lines, including melanoma, prostate, esophageal, and pancreatic cancer lines. In clear contrast, F/K20-Adv showed a remarkably enhanced efficiency in genetic transduction of human glioma cells. In all four human glioma lines tested, the multiplicities of infection (MOIs) for transduction of 50% of the population (ED50) were decreased with F/K20-Adv compared with F/wt-Adv: 7-fold for T98G, 14-fold for U251, 9-fold for U373, and 42-fold for U87 cells. Therefore, we attempted to apply F/K20-Adv for gene therapy of malignant glioma. Glioma cells infected with F/K20-Adv carrying genes for interleukin 2 or interleukin 12 produced a high level of each cytokine at a much lower MOI than did cells infected with F/wt-Adv. Infection with F/K20-Adv carrying the wild-type p53 tumor suppressor gene resulted in an enhanced level of p53 protein expression and an increased incidence of F/K20-Adv in transduction efficiency for malignant glioma, providing promising tools for gene therapy.
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PMID:Generation of fiber-mutant recombinant adenoviruses for gene therapy of malignant glioma. 985 17

An E1B 55-kDa gene-defective adenovirus (Adv), ONYX-015, has been reported to be a highly useful replication-competent Adv that shows cytopathic effect for cancers with an abnormal p53 gene, without damaging normal tissues. In this study, we combined this Adv (Adv-E1AdB) with a fiber mutation, F/K20, which has a stretch of 20 lysine residues added at the COOH-terminus of the fiber and shows high transduction efficiency to gliomas. In U-373 MG glioma cells, the transduction efficiency of Adv-F/ K20 for lacZ was nine times higher than that of the Adv with wild-type fiber (Adv-F/wt) for lacZ. At a multiplicity of infection of 30, the replication efficiency of Adv-E1AdB-F/K20 was 11 times higher than that of Adv-E1AdB with wt fiber (Adv-E1AdB-F/wt). The ED50 value of AdvE1AdB-F/K20 to U-373 MG cells, which is a measure of the in vitro cytopathic effect, was 32 times greater than that of Adv-E1AdB-F/wt. injection of Adv-E1AdB-F/K20 suppressed the in vivo growth of tumors. The antitumoral effect of Adv-E1AdB-F/K20 was remarkably stronger than that of Adv-E1AdB-F/wt. A greater quantity of replicated virus protein (hexon) by infection with Adv-E1AdB-F/K20 was demonstrated in vitro and in vivo, compared with that of Adv-E1AdB-F/wt. In conclusion, gene therapy using Adv-E1AdB-F/K20, which drastically augmented the antitumoral effect of Adv-E1AdB, will be a promising therapeutic approach for gliomas.
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PMID:Highly augmented cytopathic effect of a fiber-mutant E1B-defective adenovirus for gene therapy of gliomas. 1041 3


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