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)

A clonal human glioma cell line, U-343 MGa 31L, which expresses the A-type but not the B-type receptor for platelet-derived growth factor (PDGF), was used in a functional study of the A-type receptor. PDGF-AA induced, in a dose- and time-dependent manner, phosphorylation on tyrosine residues of the receptor in metabolically labelled cells. The optimal dose was around 30 ng/ml; at 100 ng/ml, phosphorylation was maximal at 15 min and had almost returned to the control level after 60 min. The phosphorylation on tyrosine residues of the PDGF A-type receptor was stimulated by PDGF-AA, PDGF-AB and PDGF-BB; these isoforms also stimulated [3H]thymidine incorporation into U-343 MGa 31L cells. In addition, activation of the A-type PDGF receptor induced transmodulation of the epidermal growth factor receptor.
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PMID:The A-type receptor for platelet-derived growth factor mediates protein tyrosine phosphorylation, receptor transmodulation and a mitogenic response. 248 43

100 tumours of the human nervous system were investigated by means of immunohistochemistry in order to determine the expression of epidermal growth factor receptor (EGFr) and the proliferative activity as evaluated by demonstration of the proliferation-associated Ki-67 antigen. Epidermal growth factyr receptor immunoreactivity was present in 79% (23/29) of the high-grade malignant gliomas examined but in only 9% (2/22) of the low-grade gliomas. Besides the gliomas, EGFr-expression was detectable in smaller amounts in most (13/15) meningiomas, in one anaplastic neurinoma and in individual tumour cells of one medulloblastoma. In addition, EGFr-expression was found in 50% (6/12) of metastatic carcinomas. Seven of eight medulloblastomas, two cerebral primitive neuroectodermal tumours (PNETs), three benign neurinomas, one ganglioneuroma, one metastatic intracerebral malignant melanoma, three spinal plasmacytomas and one immunocytoma showed no detectable EGFr-expression. Our results indicate that (1) the expression of EGFr in human tumours of the nervous system depends on the histological tumour type and (2) in the glioma group is related to the grade of malignancy. A close correlation between EGFr-expression and proliferative activity as evaluated by Ki-67 staining could not, however, be established.
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PMID:Epidermal growth factor receptor expression and growth fraction in human tumours of the nervous system. 256

Twenty-seven patients with brain glioma were scanned using 123I-labeled monoclonal antibodies against epidermal growth factor receptor (EGFR1) or placental alkaline phosphatase (H17E2). Successful localization was achieved in 18 out of 27 patients. Eleven out of 27 patients were also studied using a nonspecific control antibody (11.4.1) of the same immunoglobulin subclass and observable tumor localization was also achieved in five patients. The specificity of targeting was assessed by comparing images obtained with specific and nonspecific antibodies and by examining tumor and normal tissue biopsies after dual antibody administration. Ten patients with recurrent grade III or IV glioma who showed good localization of radiolabeled antibody were treated with 40-140 mCi of 131I-labeled antibody delivered to the tumor area intravenously (n = 5) or by infusion into the internal carotid artery (n = 5). Six patients showed clinical improvement lasting from 6 mo to 3 yr. One patient continues in remission (3 yr after therapy), but the other five who responded initially relapsed 6-9 mo after therapy and died. No major toxicity was attributable to antibody-guided irradiation. Targeted irradiation by monoclonal antibody may be clinically useful and should be explored further in the treatment of brain gliomas resistant to conventional forms of treatment.
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PMID:Antibody guided diagnosis and therapy of brain gliomas using radiolabeled monoclonal antibodies against epidermal growth factor receptor and placental alkaline phosphatase. 279 4

In a patient with recurrent grade IV glioma of the brain resistant to conventional treatment an antibody guided isotopic scan showed uptake by the tumour of a monoclonal antibody (9A) that was developed against epidermal growth factor receptor but cross reacted with blood group A antigen. As a therapeutic attempt antibody labelled with 1665 MBq (45.0 mCi) iodine-131 was delivered to the tumour area by infusion into the internal carotid artery. Computed tomography showed regression of the tumour after treatment, and an appreciable and sustained clinical improvement was noted without any toxicity. Delivery of irradiation guided by monoclonal antibody delivered by arterial infusion of the tumour area may be of clinical value in the treatment of brain gliomas resistant to conventional forms of treatment.
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PMID:Antibody guided irradiation of brain glioma by arterial infusion of radioactive monoclonal antibody against epidermal growth factor receptor and blood group A antigen. 298 52

Type beta transforming growth factor (beta-TGF) is a potent regulator of cell growth and differentiation. The human glioblastoma cell line, T-MGI, was growth inhibited by beta-TGF under anchorage independent conditions. The antiproliferative effect of beta-TGF was potentiated to nearly total arrest by low doses of retinoic acid (RA) or tumor necrosis factor (TNF), while epidermal growth factor, platelet-derived growth factor, interleukin-2, and gamma interferon did not have this potentiating effect. The potentiation of the beta-TGF effect by RA and TNF could not be explained by modulation of the epidermal growth factor receptor, the beta-TGF receptor, or the TNF receptor. beta-TGF alone and in combination with RA or TNF were further tested on primary cultures from freshly resected human glioma biopsies (n = 13). There was great individual variation in sensitivity to beta-TGF, RA, or TNF. The astrocytoma and oligodendroglioma cells were inhibited to various degrees by beta-TGF or TNF, while most of the glioblastomas were not sensitive to these agents. Most of the biopsies were stimulated by RA. RA or TNF did not potentiate the growth inhibitory effect of beta-TGF on biopsy cells. We therefore think it unlikely that beta-TGF in combination with RA or TNF will be effective agents in the treatment of gliomas.
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PMID:Effects of type beta transforming growth factor in combination with retinoic acid or tumor necrosis factor on proliferation of a human glioblastoma cell line and clonogenic cells from freshly resected human brain tumors. 316 58

Xenografts from eight malignant human gliomas were established in athymic mice and were used to study amplification and expression of the epidermal growth factor receptor (EGFR) gene. Tissue identity between biopsy and xenografts was confirmed by karyotypic profiles, which showed that each glioma xenograft retained structural abnormalities, including double minute chromosomes, present in the parent glioma. EGFR gene amplification was found in six of the eight glioma biopsies and their corresponding xenografts. Expression of the EGFR gene was measured by Scatchard analysis, affinity reactions, immunoprecipitations, Western immunoblots, and immunocytochemistry; significant expression of the EGFR gene was only detectable in xenografts with EGFR gene amplification. Moreover, five of the six xenografts with EGFR gene amplification demonstrated structural alterations of the EGFR gene, which was associated with low-molecular-weight EGFR proteins. These xenografts represent an excellent tissue source and in vivo model system for characterizing the epidermal growth factor receptor in malignant human gliomas.
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PMID:Amplification and expression of the epidermal growth factor receptor gene in human glioma xenografts. 325 89

A monoclonal antibody (Amersham) to epidermal growth factor receptor (EGFR) was used for immunohistochemical study to confirm the presence of EGFR in the glioma tissue. Fresh surgical material was stored at -80 degrees C, and frozen sections were stained. Positive staining was demonstrated in 8 of 9 gliomas. In 2 of 8, more than 50% of tumor cells were positively stained. In 4 of 8, positive cells were seen scattered in the tissue. In the remaining 2 gliomas, few tumor cells were positively stained. The most representative staining was seen on the cytoplasmic membrane. But there were also nuclear and cytoplasmic stainings. The distribution of EGFR in the glioma cells suggests possible role of the epidermal growth factor in the proliferation of gliomas.
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PMID:[Distribution of epidermal growth factor receptor in glioma]. 326 29

Biopsies of 33 malignant human gliomas were karyotyped and evaluated for amplification (more than eight gene copies per cell) of the epidermal growth factor receptor (EGFR), N-myc, c-myc, and gli genes by Southern blot analysis. Fifteen of 33 tumors showed amplification of EGFR, none had amplified c-myc, one tumor had amplified N-myc, and one had amplification of gli. Thirteen of the 16 (81%) evaluable tumors with gene amplification contained double minutes (DM), and only four of 16 (25%) tumors without demonstrable amplification contained these structures. Polysomy for chromosome #7, in contrast, occurred in 58% of tumors with EGFR amplification and 53% of tumors without amplification of the gene. Structural abnormalities of 7p occurred in two tumors with EGFR amplification and in one tumor without amplification of this gene. These studies suggest that DM are the usual locus for amplified genes (usually EGFR) in human glioma biopsies, but that structural abnormalities of 7p may be associated with EGFR amplification in a small proportion of these tumors. The presence of polysomy 7, however, probably is unrelated to amplification of the EGFR gene.
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PMID:Relationship between gene amplification and chromosomal deviations in malignant human gliomas. 347 27

Three cell samples in different passages of the line U-343 MGa, derived from a human malignant glioma biopsy, gave rise to clones with different amounts of platelet-derived growth factor (PDGF)-like activity secreted to extracellular medium, and of 125I-labeled PDGF binding. Sixteen clones were completely karyotyped with the G-banding technique. The unique markers 1p-q+, 16p- found in all clones, as well as in the parallel uncloned line, U-343 MG, provided evidence of their common origin. The deduced early, possibly partly primary, deviations had the formula 44, XY, 1p-q+, -14, 16p-, -22, where loss of one chromosome 22 is in accordance with previous reports on early chromosomal deviations in gliomas. Two clones, the hypodiploid 26L and 5H, represented early progressional changes. The other clones followed two patterns of late progressional changes, probably starting from the karyotype of 5H, with additional markers and doubling of the stemlines. In late progressional line I 12q+ and in II +7 were the most characteristic findings. Northern blot analysis using complementary DNA clones for the A and B chains of PDGF showed that both PDGF chains were expressed in 26L and 5H indicating that activation of the PDGF genes could have been an early event in the development of this glioma. Clones with late progression pattern II had been subjected to the highest selective pressure in vitro, and they secreted the highest amount of PDGF-like activity to the extracellular medium. Among them were the most rapidly and tightly growing cells and some clones with high 125I-labeled epidermal growth factor binding. Possibly these findings reflect progressional changes including defective regulation of the growth factor/growth factor receptor genes, selected for in vitro, without involving gross rearrangements or amplifications of the genes. The possible significance of extra chromosomes 7, with the PDGF A chain and epidermal growth factor receptor genes, and of the 12q+ marker, located near the gamma interferon gene is discussed.
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PMID:Evidence for progressional changes in the human malignant glioma line U-343 MGa: analysis of karyotype and expression of genes encoding the subunit chains of platelet-derived growth factor. 349 14

Murine IgG2a monoclonal antibody (MAb) 425 specifically detects epidermal growth factor receptor, which is expressed on human gliomas and tumors of other tissue origin but rarely on normal brain tissues, and not at all on bone marrow and peripheral blood cells. 131I-labeled F(ab')2 fragments of this MAb injected into nude mice grafted with U-87 MG glioma cells preferentially localized in tumor tissue compared to normal mouse tissues, as determined by differential tissue counting of radioactivity. The mean tumor-to-tissue ratios of radioactivity ranged between 8.2 (blood) and 55.8 (muscle) at 2 days after the injection of 15 muCi of 131I-425 F(ab')2/mouse. Radiolabeled fragments of an anti-hepatitis virus IgG2a MAb did not localize in tumors. The localization index derived from the ratios of specific antibody to indifferent antibody in tumor tissue relative to blood was 9.94 at 2 days following the MAb injection. The labeled MAb did not localize in a xenograft of colorectal cancer tumor, which does not express the epidermal growth factor receptor. Tumors could be located by whole-body gamma-scintigraphy without background subtraction following the injection of 100 muCi of radiolabeled MAb 425 F(ab')2 fragments. The data suggest that MAb 425 is a likely candidate for clinical diagnostic and radioimmunotherapy trials.
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PMID:Radioimmunodetection of human glioma xenografts by monoclonal antibody to epidermal growth factor receptor. 359 41


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