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)

Biological effects of human natural tumor necrosis factor-alpha (TNF) on glioblastoma cells in vitro and on glioma patients were investigated. TNF treatment on glioblastoma cells, even at a high dose (256 U/ml), exhibited no remarkable cytocidal activity in MTT assay, but at lower doses significantly inhibited colony forming and DNA synthesis. TNF at a low dose (10 U/ml) stimulated production of prostaglandin E2, Mn-superoxide dismutase, interleukin (IL)-6 and IL-8 by glioblastoma cells. These results indicated that the direct effect of TNF on human glioblastoma cells is rather antiproliferative than cytotoxic and is to modulate their metabolic pathways. In an early Phase I clinical trial, TNF was administered intracranially to six patients bearing glioblastoma. In this trial, the author studied in vivo immunological responses in the cerebrospinal fluid and regional fluid after the regional TNF injections. TNF in these body fluids were detected with a half life of several hours. There occurred a substantial number of leukocyte migration after the TNF administration. Neutrophils appeared first peaking at 8 to 12 hours, and then CD4+CD8-T cells and CD11b+CD13+CD14+ monocytes followed. IL-8 activity in the cerebrospinal fluid simultaneously corresponded to peak of the neutrophil migration. Increases in IL-6, IL-1 beta and prostaglandin E2 levels in the cerebrospinal fluid, regional fluid or both occurred peaking at 8 to 12 hours after TNA infection. Neither IL-2 nor interferons was detected. In conclusion, TNF may act as an antineoplastic agent by its direct cytostatic effects and indirectly through immune modulatory effects.
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PMID:[In vitro and in vivo immunobiological responses of glioblastoma to human natural tumor necrosis factor-alpha]. 142 94

Human monocytes obtained from healthy volunteers and isolated by centrifugal elutriation were not cytotoxic to allogeneic tumorigenic cells. These freshly isolated monocytes were rendered tumoricidal following interaction in vitro for 24 hours with greater than 0.01 micrograms lipopolysaccharide (LPS)/ml or over 1 microgram nor-muramyl dipeptide/ml. Monocytes activated by this procedure produced a soluble factor that lysed tumor cells. Full expression of tumor cell lysis required a minimum of 18 hours' exposure of tumor cells to the factor. The degree of tumor cytotoxic factor (TCF) production was closely related to the intensity of monocyte activation to become tumoricidal. Significant production of TCF by monocytes was detected in the supernatants after treatment for 3 hours with LPS. TCF was also released by activated monocytes when cocultivated with tumorigenic cells. Similarly, the level of TCF production correlated with the monocyte density. TCF destroyed human allogeneic tumor cell lines (melanoma, glioblastoma, colon carcinoma, prostatic carcinoma, and breast carcinoma), but it did not affect nontumorigenic cell lines (lung and skin fibroblasts). TCF activity was not blocked by superoxide dismutase, catalase, or protease inhibitors; it was destroyed by being heated at 100 degrees C for 2 minutes. The ability of activated monocytes to release TCF could enhance host defense against cancer.
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PMID:Kinetics and function of tumor cytotoxic factor(s) produced by human blood monocytes activated to the tumoricidal state. 385 62

Expression of the two types of tumor necrosis factor (TNF) receptor, p55 and p75, in 12 human glioblastoma cell lines was studied. Reverse-transcription polymerase chain reaction detected messenger ribonucleic acid (mRNA) transcripts of p55 TNF receptor in all 12 cell lines tested, but p75 TNF receptor mRNA in only four cell lines. Flow cytometric analysis with anti-p55 and anti-p75 TNF receptor monoclonal antibodies demonstrated both p55 and p75 proteins in these four cell lines, but the level of expression of p75 molecule was very low. Correlation of p55 and p75 TNF receptor expression with TNF-induced growth suppression and production of bioactive molecules (interleukin-6, interleukin-8, manganase-superoxide dismutase, prostaglandin E2) showed that p55 TNF receptor mediates these TNF actions, but none of the responses were influenced by the presence of the p75 TNF receptor, which apparently has no specific role.
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PMID:p55 and p75 tumor necrosis factor receptor expression on human glioblastoma cells. 756 86

Recent studies using a rat model of pneumococcal meningitis have shown that nitric oxide synthase (NOS) inhibitors greatly attenuated microvascular changes and brain edema formation. The site of NO production during bacterial meningitis is unknown. In this study we tested whether primary astrocyte cultures from neonatal rat cortex can be induced to release NO upon stimulation with pneumococci. NO production was assessed by measuring nitrite in the cell culture supernatant using the Griess reaction. Stimulation with heat-killed unencapsulated pneumococci (HKP) increased nitrite concentrations in astrocyte culture supernatants in a dose-dependent fashion. Administration of N-nitro-L-arginine (L-NA), aminoguanidine, L-canavanine, cycloheximide, and dexamethasone prevented the increase in nitrite concentrations. Addition of L-arginine, but not of D-arginine, partially reversed the inhibitory effect of L-NA. Administration of SOD increased nitrite accumulation. Moreover, at 72 h after stimulation with heat-killed pneumococci (10(7) cfu/ml) astrocytes showed an inducible NOS-like immunoreactivity. Accumulation of nitrite was also observed when rat cerebellar neurons and microglia were stimulated with HKP, whereas there was only a slight increase of nitrite in media of rat C6 glioma cells, but no increase of nitrite when the human glioblastoma cell line LN-229 was stimulated with HKP. There was a stronger increase in nitrite levels when astrocytes from Lewis rats were used compared to that from Wistar rats. In conclusion, our study indicates that astrocytes, neurons and microglia are inducible for NO production upon stimulation with pneumococci.
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PMID:Production of nitrite by primary rat astrocytes in response to pneumococci. 764 48

Although tumor necrosis factor-alpha (TNF) has been applied to early clinical trials for patients with malignant glioma, majority of human glioma cells has been reported to be resistant to TNF cytocidal effect in vitro. This study investigated antiproliferative effect of the TNF associated with induction of differentiation and expression of two distinct TNF receptors on human glioblastoma cell lines. The expression of p55 and p75 TNF receptors on 12 human glioblastoma cell lines was assessed by polymerase chain reaction and flow cytometry. p55 TNF receptor was detected in all cell lines, and only 4 cell lines concomitantly expressed p75 TNF receptor. Twelve human glioblastoma cell lines were treated with low-dose TNF, up to 256 U/ml for 7 days. TNF did not exhibit its cytocidal effect, but showed antiproliferative effects with inhibition of DNA synthesis in majority of cell lines tested. Flow cytometry with the bromodeoxyuridine-propidium iodide dual staining technique demonstrated that this antiproliferative effect of TNF was attributed to accumulation of glioblastoma cells in G0/G1 phase, suppressing the proliferative pathway. Furthermore the TNF stimulation increased glial fibrillary acidic protein and production of bioactive molecules including interleukin(IL)-6, IL-8, granulocyte-macrophage colony stimulating factor, prostaglandin E2 and manganous superoxide dismutase. In conclusion, human glioblastoma cells had p55 TNF receptor as a functional receptor and well responded to low-dose TNF stimulation, but not susceptible TNF cytocydal effect. The effect of TNF on glioblastoma cells appeared to modulate cell differentiation. TNF may be utilized as an agent for a differentiation therapy for human glioblastomas.
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PMID:[Antiproliferative effect of tumor necrosis factor-alpha on human glioblastoma cells]. 777 79

5,8,11,14-eicosatetraynoic acid (ETYA), an isomorphic competitive analogue of arachidonic acid, spontaneously generates a chemiluminescence signal detected with a liquid scintillation spectrometer operated at ambient temperature in the out-of-coincidence mode. The intensity of the signal was 10- or more-fold above background, required oxygen for its generation, was inhibited by antioxidants, and approximately doubled in D2O. Arachidonic acid, which contains 4-alkene rather than alkyne bonds did no more than double the chemiluminescent signal above background. When examined at 37 degrees C in a Berthold AutoLumat 958 luminometer, DBA (lucigenin) was required to detect a signal above background. Catalase or peroxidase, and to a lesser extent mannitol or histidine but not superoxide dismutase, strongly diminished the signal intensity. These observations provide a baseline for interpreting the functional and electron microscopic changes produced by ETYA in PC3 prostate and A172 glioblastoma cell lines, consistent with a contribution from oxidative stress associated with free radicals, and the absence of these morphological changes in U937 monoblastoid cells.
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PMID:Spontaneous chemiluminescence of ETYA (5,8,11,14-eicosatetraynoic acid) is inhibited by catalase or peroxidase. 784 95

Responses and susceptibility of 14 human glioblastoma cell lines to human natural tumor necrosis factor-alpha (TNF) were studied in vitro. Susceptibility of glioblastoma cells to TNF varied in experimental conditions applied. Most of glioblastoma cell lines were resistant to cytotoxic activity of TNF in a MTT assay at concentrations below 16 U/ml for 72 h exposure. However, TNF at higher dose, in prolonged exposure and against low density of target cells was antiproliferative for certain glioblastoma cultures. TNF exposure at 10 U/ml for 48 h suppressed DNA synthesis in 9 of 14 glioblastoma cultures, but increased in 3 cultures. In addition, colony forming assay showed anti-clonogenic activity of TNF in 5 of 6 glioblastoma cell lines tested. In spite of their low susceptibility to TNF, glioblastoma cells well responded to TNF stimulation at low dose (10 U/ml) for a short period in the absence of cell damage. Productions of Interleukin-6 (IL-6), IL-8-like activity, granulocyte-macrophage colony stimulating factor (GM-CSF), prostaglandin E2 (PGE2) and manganous superoxide dismutase (Mn-SOD) were enhanced or induced by the low-dose TNF stimulation. Mn-SOD, a protein protective against oxidative cell damage, was well induced in time- and dose-dependent manner, however did not correlate with TNF resistance. Whereas the levels of PGE2 in TNF-susceptible cell lines, H-4 and SF-188, were higher than those of other lines. In conclusion, most of glioblastoma cells are resistant to TNF cytotoxic effects, but highly responsive to TNF stimulation. Its effect on glioblastoma cells appears to modulate cell differentiation rather than to kill the cells.
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PMID:Responses of human glioblastoma cells to human natural tumor necrosis factor-alpha: susceptibility, mechanism of resistance and cytokine production studies. 836 Jul 7

We have studied the formation of hydroxyl radical (OH.) induced by doxorubicin in a series of doxorubicin- or vincristine-selected variants of C6 rat glioblastoma cells in culture by electron-spin resonance spectroscopy using 5,5'-dimethyl-1-pyrroline-1-oxide as a spin trap. Wild-type cells, sensitive to doxorubicin, exhibited in the presence of this drug a concentration-dependent OH. formation which could be inhibited by preincubation with superoxide dismutase, catalase or an antibody against cytochrome P450-reductase. In highly doxorubicin-resistant cells, OH. formation was reduced to about 20% of the level obtained in sensitive cells. In cells presenting a very low level of resistance to doxorubicin or in cells selected with vincristine, both presenting a pure multidrug-resistant phenotype, OH. formation was identical to that obtained in sensitive cells. In cells of intermediate resistance or in revertant cells, intermediate levels of OH. formation were obtained. Protection against OH. formation and action can be identified at the levels of superoxide dismutase and glutathione peroxidase activities, which are both enhanced in the resistant cells.
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PMID:Doxorubicin-induced oxygen free radical formation in sensitive and doxorubicin-resistant variants of rat glioblastoma cell lines [corrected and republished erratum originally printed in FEBS Lett 1993 May 17;322(3):295-8]. 839 2

Mechanism of merocyanine 540 (MC540) mediated photosensitization in glioblastoma (U-87MG) and neuroblastoma (Neuro 2a) cells was investigated. Photoinduced lipid peroxidation was measured in the presence of mechanistic probes-deuterium oxide (D2O), sodium azide, superoxide dismutase (SOD), mannitol and sodium benzoate. In both the types of cells, the photoinduced lipid peroxidation was enhanced in D2O whereas it showed inhibition in the presence of sodium azide. SOD also inhibited the lipid peroxidation while sodium benzoate and mannitol had no effect. These results suggest that photosensitization of U-87MG and Neuro 2a cells by MC 540 involves both type I (free radical mediated) and type II (singlet oxygen mediated) mechanisms.
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PMID:Mechanism of photosensitization of glioblastoma and neuroblastoma cells by merocyanine 540: a lipid peroxidation study. 949 48

The relationship between the degree of the expression of Cu/Zn SOD, GST-pi and bcl-2 in the initial and recurrent tumor tissue after radiotherapy and/or chemotherapy and the cellular heterogeneity obtained from DNA content by image cytometry was investigated. Subjects were 7 patients who had glial tumors which were surgically removed at onset and removed a second time at recurrence. Radiotherapy and chemotherapy were also administered after initial resection. Immunoreactivity for copper/zinc super oxide dismutase (Cu/Zn SOD), GST (glutathione-S-transferase)-pi, and bcl-2 were evaluated from routinely prepared tissue blocks. Tumors were classified into two groups by cytometric analysis of DNA ploidy in the G2M cell cycle phase. One tumor group consisted of single clonal cells in both the initial and recurrent tumors and the other group consisted of tumors with polyclonal cells in the initial and recurrent tumor. In this study, one patient (case 3) with single clonal cell glioblastoma at recurrence did not show high Cu/Zn SOD activity after radiotherapy and chemotherapy but showed a short survival time after recurrence. In three patients (cases 1, 2, 3) with single clonal-cell glioblastoma, the recurrent tumor cells showed high GST-pi immunoreactivity and survival time was short after recurrence. Tumor cells in two patients (cases 5, 7) with single clonal cell anaplastic glioma at recurrence, showed high GST-pi immunoreactivity and had a short survival time after recurrence. In three single clonal glioblastomas (cases 1, 2, 3), the recurrent tumor showed the increased bcl-2 immunoreactivity and showed a short survival time after recurrence. In two patients (case 5, 7) with single clonal cell anaplastic glioma at recurrence, tumor cells showed a high bcl-2 immunoreactivity and these patients showed a short survival time after recurrence. Although the number of subjects is very small, our study shows that the immunoreactivity of bcl-2 and GST-pi in malignant gliomas may be very important factors in radio- and chemosensitivity, and shows that GST-pi is induced by radiation and anti-cancer drugs.
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PMID:Expression of enzymes and oncogene induced after radiotherapy and/or chemotherapy in patients with brain tumors. 1143 58


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