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)

Culturing human central nervous system tumors has been difficult compared to other neoplasms. We report improved success rates for establishing short term human brain tumor cultures using a modified tissue processing technique. Eighty-seven brain tumor specimens (56 glioblastomas, 8 mid grade astrocytomas, 8 oligodendrogliomas, 15 other) were obtained from June 1988 to March 1997. The first twenty-three samples were processed by dissection, partial enzyme dissociation, and filtration through a tissue culture sieve. Subsequent samples were processed identically except tumor cells were centrifuged on a density gradient prior to plating. Successful cultures were defined as those surviving greater than three passages in tissue culture and growing to sufficient numbers (>10(6) cells) to allow freezing. Success rate was 42% (10/23) using standard processing methods and 86% (55/64) with the addition of density gradient centrifugation. Glial fibrillary acidic protein (GFAP) and vimentin staining, karyotypes, and growth curves were obtained for representative glioma cultures. All cultures tested were positive for vimentin (29/29) while 62% (18/29) were positive for GFAP. Of four cultures karyotyped (two glioblastomas, two oligodendrogliomas), all but one oligodendroglioma culture exhibited clonal cytogenetic abnormalities. These immunohistochemical and karyotypic results are consistent with the malignant glial origin of these cells. Of note, low passage human glioma cultures grew slower and exhibited more contact inhibition than immortalized human glioblastoma cell lines. Nevertheless, this simple method for establishing short term human brain tumor cultures should aid in further developing human brain tumor pre-clinical models as well as enhancing clinical applications dependent on in vitro human brain tumor cell growth adjust.
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PMID:Improved technique for establishing short term human brain tumor cultures. 1044 65

To begin understanding the regulation and biological significance of changes in the expression of intermediate filament proteins in astrocytic tumors, we have recently shown that TGF-alpha alters the protein level of glial fibrillary acidic protein (GFAP), nestin, and vimentin in U-373 MG glioblastoma cells. Here, we have determined the molecular mechanisms regulating these changes. In addition, to evaluate the significance of these changes we have examined whether TGF-alpha affects various cellular properties related to differentiation. Our results show that, in U-373 MG cells treated with TGF-alpha, GFAP gene transcription, mRNA level, and specific protein synthesis decrease by approximately 50%. This suggests that, in U-373 MG cells, TGF-alpha down-regulates the expression of this marker of astrocytic differentiation at the transcriptional level, resulting in decreased GFAP mRNA level and specific protein synthesis. In contrast, TGF-alpha does not change vimentin gene transcription, but increases by about 50% the transcription of the gene for nestin, a marker for undifferentiated astrocytic precursors. This differential regulation of GFAP, nestin, and vimentin gene expression indicates that TGF-alpha induces further dedifferentiation of U-373 MG cells. This notion is also supported by our findings that TGF-alpha increases the motility of U-373 MG cells and induces a less stellate morphology.
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PMID:TGF-alpha differentially regulates GFAP, vimentin, and nestin gene expression in U-373 MG glioblastoma cells: correlation with cell shape and motility. 1064 Apr 25

Keratin intermediate filaments (Ifs) are specific for epithelial cell differentiation. This study demonstrates the presence of keratin in two recently established human glioblastoma cell lines 8-MG-BA and 42-MG-BA. Immunofluorescence staining was performed on cells within passage 230 to 235 using monoclonal pan-cytokeratin antibodies. The cells were analyzed during several DIV at different cell density. Keratin-positive stained cells reached 5 to 7% in 8-MG-BA and less than 0.1% in 42-MG-BA cell line. The presence of keratin-positive cells was independent on cell density and days in vitro. Keratin-positive cells appeared unevenly distributed in both cell lines. They were observed as single or areas of keratin-positive cells. The morphological features of keratin-positive and keratin-negative cells were similar. The results are discussed with respect to previous studies on glial fibrillary acidic protein (GFAP) and vimentin to show the heterogeneity of IFs expression in glioma cell lines.
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PMID:Heterogeneity of keratin intermediate filaments expression in human glioma cell lines. 1073 69

Retinoic acid (RA) has been used to induce the regression of refractory T-cell lymphoma. In vitro and in vivo studies have shown that RA exerts this effect through the induction of apoptosis. This study was designed to investigate the molecular pathway of RA-induced apoptosis in T-lymphoma cell lines.RA-induced apoptosis was verified by morphology, flow cytometry, and DNA ladder analysis. Differential display method using a combination of 12 poly(A)-anchored primers and 20 arbitrary primers was adopted for gene cloning. Total RNAs were extracted from H9 cell line at 0, 6, 12, and 24 hours after All-trans RA (ATRA) treatment and the serial expression patterns of the candidate fragments were recognized. The cloned gene fragments were then analyzed and confirmed by Northern blot analysis on H9 and SR786 cell lines.ATRA-induced apoptosis of T-cell lymphoma was protein synthesis-dependent. The execution or irreversible phase of apoptosis appeared to occur at 6-12 hours of RA treatment. Among the 60,000 arbitrarily displayed bands, 25 of 250 candidate fragments were selected for further cloning and sequencing. A total of 14 clones could be matched to known genes and were categorized into four groups: A) transcription factors: prothymosin, CA150, p78 serine/threonine kinase, IL-1beta-stimulating gene, glucocorticoid receptor, MLN64/CAB1, gastrin-binding protein, and polypeptide from glioblastoma; B) chaperone: 90 kDa heat shock protein; C) ion channel: chloride channel protein 3; and D) cytoskeleton: cytovillin2/ezrin and vimentin. Another two clones of genes were of unrecognized functions. The remaining 11 clones belonged to unmatched or novel genes. The expression of these genes varied, either upregulated or downregulated, in response to ATRA treatment.RA-induced apoptosis may involve a cascade of genes that are related to transcription regulation, stress response, housekeeping, and the execution of apoptosis. The clarification of the RA-induced apoptotic pathway will help us to understand the molecular mechanism of cancer differentiation agents.
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PMID:Retinoic acid-induced apoptotic pathway in T-cell lymphoma: Identification of four groups of genes with differential biological functions. 1114 66

Glial fibrillary acidic protein (GFAP), vimentin (Vi) and cytokeratin (CK) intermediate filament (IF) proteins were studied in glioblastoma cell line GL-15. The immunofluorescence staining revealed strong positive staining for vimentin in all cultured cells. Approximately 20% of analyzed cells showed strong and 50% moderate intensity of staining for GFAP. About 3% of all cells were positively stained with a mixture of anti-CK monoclonal antibodies. The expression of all IF was not in relation to the cell density or days in vitro after passage. The double immunofluoresce revealed that all CK-positive cells express GFAP and vimentin. This study demonstrates the heterogeneity of the clonal GL-15 glioma cell line which consists in three immunocytochemically distinct cell types: Vi+/GFAP-/CK-, Vi+/GFAP+/CK-, and Vi+/GFAP+/CK+. These findings give further evidence about the expression of non-glial IF in cultured glioma cells.
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PMID:Co-expression of GFAP, vimentin and cytokeratins in GL-15 glioblastoma cell line. 1126 60

Ever since the development of human monoclonal antibody CLN-IgG in 1982, we anticipated the identification of the antigen that is recognized by this antibody. Despite its scarce expression on the cell surface, susceptibility to proteolytic enzymes and adherence to experimental equipment, we finally succeeded in determining the antigen moiety that is recognized by this antibody by means of CLN-IgG conjugated column affinity chromatography, two-dimensional electrophoresis, MALDI-TOF/MS and use of glioblastoma cell line U-251MG. The antigen was found to be vimentin, a cytoskeletal protein, and we succeeded in determining a 79 amino acids sequence of the epitope which turned out to comprise a part of the c2 (coil 2 of the central rod) domain of vimentin.
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PMID:Determination of the antigen/epitope that is recognized by human monoclonal antibody CLN-IgG. 1167 62

This work demonstrates the expression of extracellular matrix (ECM) components in a highly infiltrative brain tumor model developed by simple inoculation of spheroids from five human glioma biopsy tissues directly into the brains of immunodeficient rats. Non-invasive tumors derived from one glioblastoma biopsy specimen and two glioma cell lines (D-54MG and U-251MG) were also included in this study. The extent of tumor cell infiltration was studied using a pan-human monoclonal anti-vimentin antibody. The cellular origin for several of these ECM components was identified using human-specific monoclonal antibodies and polyclonal antibodies detecting epitopes from both species. Immunostaining revealed a diffuse parenchymal staining of glioma-produced tenascin, whereas vitronectin was produced mainly by the invading glioma cells. ECM components such as laminin, fibronectin and collagen type IV were most probably produced by the host and were mainly associated with the blood vessels in the tumors. However, some parenchymal staining with regional variations was observed. The expression pattern of these components was different in cell lines tumors as compared to the biopsy specimen tumors. The alpha3 and beta1 integrin subunits were mainly observed in areas of tumor cell invasion in the invasive tumors. In conclusion, the observed staining patterns clarify the cellular origin and indicate the possible biological function of tenascin, vitronectin, laminin, fibronectin and collagen type IV in these highly invasive malignant tumors of glial origin.
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PMID:Expression of extracellular matrix components in a highly infiltrative in vivo glioma model. 1247 61

The ability of herpes simplex virus type 1 thymidine kinase (HSV-tk)-expressing cells incubated with ganciclovir (GCV) to induce cytotoxicity in neighboring HSV-tk-negative (bystander) cells has been well documented. Although it has been suggested that this bystander cell killing occurs via the transfer of phosphorylated GCV, the mechanism(s) of this bystander effect and the importance of gap junctions for the effect of prodrug/suicide gene therapy in primary human glioblastoma cells remains elusive. Surgical biopsies of malignant gliomas were used to establish explant primary cultures. Proliferating tumor cells were characterized immunohistochemically and found to express glial tumor markers including nestin, vimentin, glial fibrillary acidic protein (GFAP), S-100, and gap junction protein connexin 43 (Cx43). Western blot analysis revealed the presence of phosphorylated isoforms of Cx43 and Calcein/DiI fluorescent dye transfer showed evidence of efficient gap junction communication (GJC). In order to study the effect(s) of prodrug/suicide gene therapy in these cultures, human glioblastoma cell cultures were transfected with the HSVtk gene for transient or stable expression. Ganciclovir treatment of these cultures led to >90% of cells dead within 1 week. Eradication of cells could be inhibited by the addition of alpha-glycyrrhetinic acid (AGA), a GJC inhibitor. In parallel experiments, AGA decreased the immunodetection of phosphorylated Cx43 as analyzed by Western blot and inhibited fluorescent dye transfer. In conclusion, these observations are consistent with GJC as the mediator of the bystander effect in primary cultures of human glioblastoma cells by the transfer of phosphorylated GCV from HSVtk gene transfected cells to untransfected ones.
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PMID:Gap junction-mediated bystander effect in primary cultures of human malignant gliomas with recombinant expression of the HSVtk gene. 1265 Nov 52

Peroxisome proliferator-activated receptor gamma (PPARgamma) is involved in the control of cell proliferation, apoptosis and differentiation in various tumor cells. Among PPARgamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 (PGJ2), the ultimate metabolite of PGD2, plays a role in the biology of brain tumors. It is still unclear to which extent the anti-proliferative and differentiation-promoting activity of PGJ2 is mediated through PPARgamma. We compared the effects of PGJ2 with those of rosiglitazone - the synthetic agonist with the highest affinity for PPARgamma - in 4 human glioblastoma cell lines (A172, U87-MG, M059K, M059J). All cell lines expressed high levels of PPARgamma, consistent with the high levels of PPARgamma protein in 5 tumor samples. Both PGJ2 and rosiglitazone inhibited proliferation of all cell lines with a G2/M arrest and apoptosis, but only PGJ2 up-regulated p21Cip/WAF1. The growth inhibitory effect was partially reversed by the PPARgamma antagonist GW9662. We studied the time sequence of selected molecular events, that lead glioblastoma cells to apoptosis and/or differentiation, after treatment with both agonists. M059K cells committed to undergo apoptosis by PGJ2, initially up-regulated PPARgamma, and then down-regulated PPARgamma as they began apoptosis. Apoptotic cells also increased their expression of retinoic acid receptor beta (RARbeta) and retinoid X receptor alpha (RXRalpha). PGJ2 increased expression of glial fibrillary acidic protein (GFAP) and decreased levels of vimentin, structural proteins modulated during astrocytic differentiation. Unexpectedly, PGJ2 up-regulated the expression of cyclooxygenase-2 (COX-2). Rosiglitazone caused the same pattern of PPARgamma, RARbeta and RXRalpha expression as PGJ2, but no significant modulation of p21Cip/WAF1, cytoskeletal proteins or COX-2 occurred. Our data indicate that PGJ2, and rosiglitazone suppress cell proliferation and cause apoptosis in glioblastoma cell lines, most likely through a PPARgamma-dependent pathway. By contrast, the modulation of differentiation-associated proteins by PGJ2, but not rosiglitazone, suggests that PGJ2 promotes differentiation of glioblastoma cells independently of PPARgamma activation.
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PMID:The PPARgamma ligands PGJ2 and rosiglitazone show a differential ability to inhibit proliferation and to induce apoptosis and differentiation of human glioblastoma cell lines. 1525 49

Astroblastoma is one of the very unusual type of tumors, whose histogenesis has not been clarified. It occurs mainly among children or young adults. Astroblastoma is grossly well-demarcated, and shows histologically characteristic perivascular pseudorosettes with frequent vascular hyalinization. Perivascular pseudorosettes in astroblastoma have short and thick cytoplasmic processes and blunt-ended foot plates. A 15-yr-old girl presented with headache and diplopia for one and a half year. A well-demarcated mass, 9.7 cm in diameter, was found in the right frontal lobe in brain MRI, and it was a well-enhanced inhomogenous mass. Cystic changes of various sizes were observed inside the tumor mass as well as in the posterior part of the mass, but no peritumoral edema was found. Histologically, this mass belongs to a typical astroblastoma, and no sign of anaplastic astrocytoma, gemistocytic astrocytoma or glioblastoma was found in any part of the tumor. Immunohistochemically, the tumor cells showed diffuse strong positivity for glial fibrillary acidic protein, S-100 protein, vimentin and neuron specific enolase, and focal positivity for epithelial membrane antigen and CAM 5.2, while showing negativity for synaptophysin, neurofilament protein, pan-cytokeratin and high molecular weight keratin.
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PMID:Astroblastoma: a case report. 1548 62


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