Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cerebrospinal fluid (CSF), serum and seminal plasma contain a small amount of SP-40,40, a modulatory protein of the human complement system. The SP-40,40 in each body fluid was different in molecular size on SDS-PAGE, and glioblastoma cells, hepatoma cells and testicular tumor cells produced SP-40,40, while neuroblastoma cells did not. Therefore, it was estimated that CSF SP-40,40 originated in glia cells, serum SP-40,40 in liver cells and seminal plasma SP-40,40 in testicular cells. SP-40,40 concentrations in CSF of the patients with Alzheimer's disease and the patients with cerebral tumor were higher than those of normal donors. beta-Amyloid deposits in the brains of the patients with Alzheimer's disease were stained with an anti-SP-40,40 monoclonal antibody (mAb) but not with an anti-S-protein mAb, while cellular processes around beta-amyloid were stained with an anti-S-protein mAb but not with an anti-SP-40,40 mAb. Therefore, beta-amyloid contained SP-40,40 in a form different from that in the soluble membrane attack complex (SMAC, SC5b-9) of the complement, which contains S-protein as well as SP-40,40.
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PMID:SP-40,40 is a constituent of Alzheimer's amyloid. 137 21

5'-Nucleotidase has been purified from rat glioblastoma cells (Rugli cells). The enzyme has been solubilized from plasma membranes by using Triton X-100 and CHAPS. Two affinity chromatographies on concanavalin A and 5'-AMP-Sepharose render the purified enzyme with a high specific activity (76.36 mumol AMP.min-1.mg-1). The purified enzyme gives a single polypeptide band on SDS-PAGE with an apparent molecular mass of 74 kDa. Active forms with an apparent molecular mass of 135 kDa and 268 kDa are observed when the purified enzyme is analyzed by gel filtration in the presence of either 0.6% sodium deoxycholate or 0.1% Triton X-100, respectively. The purified 5'-nucleotidase presents optimum activity at pH 7.8-8.1 either in the presence or in the absence of Mg2+. A linear Arrhenius plot is observed in the 25-46 degrees C temperature range and an activation energy of 33.7 KJ/mol is calculated. The enzyme is inhibited by EDTA; the activity is partially restored by different divalent cations as Zn2+, Mn2+, and Co2+. The hydrolysis of nucleosides 5'-monophosphate shows Michaelis kinetic. The enzyme is inhibited by nucleosides di- and triphosphate. 5'-Nucleotidase is a glycoprotein, being its activity inhibited at different extent by various lectins.
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PMID:Isolation and characterization of the ecto-5'-nucleotidase from a rat glioblastoma cell line. 148 Jan 62

Peripheral-type benzodiazepine receptors (PBR), unlike central-type benzodiazepine receptors, are found in low concentrations in normal brain. Because PBR have been described in neoplastic cells of neuroglial origin, they have been suggested for imaging human glial tumors and for directing cytotoxic therapy at these tumors. Little information exists, however, on the presence or pharmacology of PBR in human glial tumors. Using radioligand binding techniques, we have demonstrated that 6 out of 6 glioblastoma (GBM) specimens had high concentrations of PBR [( 3H]PK 11195 binding sites) which were significantly greater than in 5 normal human frontal cortex samples. The pharmacologic specificity of these sites differed significantly from that of PBR in human and rat kidney specimens. Saturation binding experiments revealed a small number of high affinity sites and a substantial number of sites of intermediate affinity. Under in vitro binding conditions the more numerous lower affinity site is the major contributor to specific binding measurements. The ligand recognition site of the PBR in human GBM tissue was photoaffinity labeled using [3H]PK 14105, a nitrophenyl analogue of PK 11195. Subsequent SDS-polyacrylamide gel electrophoresis revealed specific incorporation of label into a 17,300 molecular weight component. There was no specific incorporation into normal human frontal cortex, but a component of very similar molecular weight was demonstrated in human kidney. We conclude that human glioblastomas consistently express PBR sites that are present in greater density than in normal human brain. Imaging of human glial tumors with analogues of PK 11195 thus appears feasible. Further molecular characterization of the photoaffinity-labeled PBR may also provide new information on the biology of these tumors.
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PMID:Peripheral-type benzodiazepine receptors in human glioblastomas: pharmacologic characterization and photoaffinity labeling of ligand recognition site. 216 48

Protease nexin-II (PN-II) is a protease inhibitor that forms SDS-resistant inhibitory complexes with the epidermal growth factor (EGF)-binding protein, the gamma-subunit of nerve growth factor, and trypsin. The properties of PN-II indicate that it has a role in the regulation of certain proteases in the extracellular environment. Here we describe more of the amino-acid sequence of PN-II and its identity to the deduced sequence of the amyloid beta-protein precursor (APP). Amyloid beta-protein is present in neuritic plaques and cerebrovascular deposits in individuals with Alzheimer's disease and Down's syndrome. A monoclonal antibody against PN-II (designated mAbP2-1) recognized PN-II in immunoblots of serum-free culture medium from human glioblastoma cells and neuroblastoma cells, as well as in homogenates of normal and Alzheimer's disease brains. In addition, mAbP2-1 stained neuritic plaques in Alzheimer's disease brain. PN-II was a potent inhibitor of chymotrypsin with an inhibition constant Ki of 6 x 10(-10)M. Together, these data demonstrate that PN-II and APP are probably the same protein. The regulation of extracellular proteolysis by PN-II and the deposition of at least parts of the molecule in senile plaques is consistent with previous reports that implicate altered proteolysis in the pathogenesis of Alzheimer's disease.
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PMID:Protease nexin-II, a potent antichymotrypsin, shows identity to amyloid beta-protein precursor. 250 28

Two established human tumor cell lines, epidermoid carcinoma line A431 and glioblastoma line SF268, were studied to compare the interaction of each with epidermal growth factor (EGF). SF268 cells bound [125I] EGF with 35-40 fold higher affinity than did the A431 cells. The EGF binding sites of both lines were photoaffinity labeled using 2,4-NAPS-[125I] EGF, a photoreactive derivative of EGF. Extracts of photolysed cells analyzed by SDS-PAGE showed a difference between the two cell lines in the high molecular weight component corresponding to the EGF receptor. EGF in a dose range from 0.3-200 nM had no effect on thymidine incorporation by SF268 cells, whereas thymidine incorporation by A431 cells was markedly inhibited by EGF.
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PMID:Epidermal growth factor receptors in the human glioblastoma cell line SF268 differ from those in epidermoid carcinoma cell line A431. 299 56

The human glioblastoma cell line 308 constitutively secretes a soluble factor with biologic and biochemical characteristics of human monocyte-derived interleukin 1 (IL 1). The 308 cells also produce a 97,000 m.w. factor that inhibits the effects of IL 1 and interleukin 2 (IL 2) on T lymphocytes. By using sequential chromatography on Blue Affigel, hydroxyapatite, and Ultrogel AcA54, the inhibitory factor, termed glioblastoma-derived T cell suppressor factor (G-TsF), was separated from IL 1 and purified 2000-fold with respect to the protein present in the crude 308 cell supernatant. This G-TsF preparation was sensitive to tryptic proteolysis, showed a peak of pI 4.6 on isoelectric focusing, and when labeled with 125I, revealed six protein bands in the range of 30 to 100 kdaltons on SDS gel.
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PMID:Partial purification and biochemical characterization of a T cell suppressor factor produced by human glioblastoma cells. 387 Dec 5

We have used a tumorigenic glioblastoma cell line, SNB-19, as a model system to identify fucose-containing glycoprotein candidates for tumor suppressor function. Glycoproteins were analyzed after treatment with a variety of chemical differentiating agents by two-dimensional SDS-PAGE, followed by electroblotting and visualization using the fucose-specific lectin, Ulex europeaus I. Approximately 25 fucose-containing glycoproteins (FUCGLAPs) were routinely visualized in control extracts using 60-70 micrograms of protein per gel and staining with Vectastain ABC kits. Retinoic acid induced the most marked change in FUCGLAP expression, causing a fivefold increase in one FUCGLAP (M(r) = 125 kDa, pI = 6.6). Neither butyric acid, dibutyryl cAMP, nor combinations of these compounds gave a similar result. Using this model system and analytical approach, it should be possible to identify, isolate, and evaluate glycoprotein oligosaccharides for their tumor modulating capability.
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PMID:The identification of glioblastoma-associated, fucose-containing glycoproteins induced by retinoic acid. 808 41

Several monoclonal antibodies (mAb) reactive against a high-molecular-weight growth factor from human glioblastoma cell lines have been produced by immunizing mice with partially purified preparations from conditioned media. Antibody-secreting colonies were selected by their capacity to bind 35S-labeled glioma cell protein and by reactivity in indirect enzyme-linked immunoadsorbent assay (ELISA), using high-molecular-weight gel filtration fractions and preparative isoelectric focusing fractions containing growth factor activities. Two of the select mAbs (20F3 and 12A12) depleted mitogenic activity (> 50% inhibition, p < 0.05) from gel filtration fractions by immunoprecipitation, but could not neutralize mitogenic activity directly. Mitogenic activity recovered from affinity columns prepared with mAb 20F3 eluted at 48% and 52% acetonitrile from HPLC C4 reversed-phase columns. Immunoprecipitation of 35S-labeled cell lysates with 20F3 followed by resolution with SDS-PAGE autoradiography revealed one unique protein of 170 kD. Established glioma cell line D-54 MG showed perinuclear and cytoplasmic staining with mAb 20F3. mAb 20F3 should prove useful in purification and characterization of these glioma-derived growth factor(s).
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PMID:Monoclonal antibodies to glioma-derived growth factor(s). 820 Jun 54

Bombesin/gastrin releasing peptide (BN/GRP) receptors were solubilized and purified from human glioblastoma (U-118) and lung carcinoid cell lines (NCI-H720). The U-118 cells, when extracted with CHAPS/cholesterol hemisuccinate (CHS), bound (125I-Tyr4)BN with high affinity (Kd = 2 nM) to a single class of sites (Bmax = 150 fmol/mg protein). Specific (125I-Tyr4)BN binding was inhibited with high affinity by BN, GRP, GRP14-27, and receptor antagonists such as (D-Phe6)BN6-13methylester(ME) and (D-Phe6)BN6-13 propylamide(PA) (IC50 = 2, 22, 3, 1 and 2 nM, respectively) but not GRP1-16 or BN1-12. The solubilized and cellular receptor bound peptides with similar affinity. The solubilized receptor was purified using (Lys0, Gly1-4, D-Ala5)BN and (Lys3, Gly4,5, D-Tyr6)BN3-13 PA affinity resins. When eluted from the affinity resins by NaCl, the receptor bound (125I-D-Tyr6)BN6-13ME with high affinity. The NCI-H720 BN/GRP receptor was purified 86,000-fold after extraction with CHAPS/CHS and purification using both affinity resins. SDS-PAGE analysis indicated that major 65 and 115 kDa proteins were purified. These data indicate that BN/GRP receptors can be solubilized from human cells and purified using affinity chromatography techniques with retention of ligand binding activity.
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PMID:Solubilization and purification of bombesin/gastrin releasing peptide receptors from human cell lines. 839 Dec 95

Tumor necrosis factor-alpha (TNF) markedly stimulates the synthesis and secretion of immunoreactive nerve growth factor (NGF) in quiescent mouse fibroblasts, which is a result of increase in the NGF mRNA level. NGF produced by TNF-treated fibroblasts has a molecular mass of 13 kDa on SDS-polyacrylamide gel electrophoresis, which is consistent in size with the subunit of mouse beta-NGF, and induces neurite outgrowth in paravertebral sympathetic neurons. Several peptide growth factors such as basic fibroblast growth factor (bFGF) and epidermal growth factor also stimulate NGF production in the cells, but not platelet-derived growth factor. The dose responses of TNF and bFGF to stimulate NGF production in the cells are, respectively, similar to those to induce cell proliferation. However, no correlation is observed between the ability of these growth factors to stimulate NGF production and that to induce cell proliferation. Thus, the stimulation of NGF production in the cells seems to be a specific activity of TNF and some other growth factors. TNF stimulates the synthesis and secretion of NGF also in other cells such as human glioblastoma cells. These findings suggest that TNF plays a role in regulating neuronal cell function through an indirect mechanism by which it stimulates NGF production in glial cells and fibroblasts.
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PMID:Tumor necrosis factor stimulates the synthesis and secretion of biologically active nerve growth factor in non-neuronal cells. 842 34


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