Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immunocharacterization of a metalloproteinase isolated from rat glioma cell conditioned medium is described and confirms that the enzyme is identical to type IV collagenase. Free, active plasminogen activator (PA) and PA-PAI complexes were identified as being secreted by the same cells. Using affinity-purified metalloproteinase we demonstrate that the enzyme can be partially activated by u-PA but not by plasmin in vitro. On the basis of these findings and previous published work we propose a scheme for the proteolytic degradation of normal brain tissue during tumour invasion.
 ...
PMID:Invasion of brain tissue by primary glioma: evidence for the involvement of urokinase-type plasminogen activator as an activator of type IV collagenase. 132 8

The gene expression of five matrix metalloproteinases (MMPs) and two tissue inhibitors of metalloproteinases (TIMPs) was studied in human gliomas in vivo and in vitro to evaluate their roles in glioma invasion. Simultaneous expression of one to four MMP genes and two TIMP genes was found in 17 surgical glioma specimens, and one MMP (gelatinase A) gene and two TIMP genes were simultaneously expressed in tissue of three brains. The concomitant overexpression of gelatinase A, gelatinase B, and occasional matrilysin genes was associated with the malignancy of gliomas and accompanied by overexpression of the TIMP-1 gene. In five human glioma cell lines, gelatinase A, TIMP-1, and TIMP-2 genes were constitutively expressed in alll cell lines: the matrilysin gene in three cell lines; the stromelysin gene in two cell lines; and the interstitial collagenase gene in one cell line. There was a clear difference in the expression of gelatinase B and stromelysin genes between surgical glioma specimens and glioma cell lines: the gelatinase B gene was not expressed constitutively in vitro but was overexpressed in vivo, whereas the stromelysin gene was not expressed in vivo but was expressed in some cell lines. To find the cause of that difference in vivo and in vitro, the transcriptional regulations of MMP and TIMP genes by tumor promoter, growth factors, or cytokines were studied in vitro. Interstitial collagenase, gelatinase B, stromelysin, and TIMP-1 genes were upregulated in many cell lines by phorbol-12-myristate-13-acetate (PMA) and in some cell lines by epidermal growth factor, tumor necrosis factor-alpha, or interleukin-1 beta. Transforming growth factor-beta 1 (TGF beta 1) upregulated gelatinase A and matrilysin genes in some cell lines, and there were no clear responses from any MMP and TIMP genes to interleukin-6. Thus, the transcriptional modulation of MMP genes by these growth factors and cytokines seemed insufficient to explain the difference in gelatinase B and stromelysin gene expressions in vivo and in vitro and was suggestive of the genetic alteration of glioma cells in vitro, the heterogeneous cell population in glioma tissues, or both. Furthermore, the in vitro invasion of glioma cells through Matrigel in response to PMA, TGF beta 1, or TIMP-1 was assessed by chemoinvasion assay. In most cell lines, invasion was significantly stimulated by PMA or TGF beta 1 but suppressed by TIMP-1.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Matrix metalloproteinases and tissue inhibitors of metalloproteinases in human gliomas. 761 76

Metalloproteinases, inhibitors of metalloproteinases, plasminogen activators, inhibitors of plasminogen activators and cathepsins are thought to be involved in invasion by tumor cells. Glioblastoma multiforme is highly malignant and extremely refractory to therapy. One reason is because of its highly invasive nature within the nervous system. However, it remains unclear how invasion/dissemination of glioblastoma multiforme proceeds. In this study, we attempted to determine which proteinases were responsible for the invasion activity of human glioma cell lines in vitro. Nine human glioma cell lines (NHG1, NHG2, IN157, IN301, IN500, U251, U343, T98G and CCF-STTG1) derived from patients with glioma were grown in culture and used. We compared the invasion activity of glioma cell lines in a Matrigel invasion assay system, and formulated the activity as invasion index (%). Among the nine cell lines, IN157, IN500 and U343 showed less than 10% invasion activity (low group); NHGI, IN301 and CCF-STTG1 showed 10-25% activity (intermediate group); NHG2, U251 and T98G showed more than 30% activity (high group). Addition of an inhibitor of metalloproteinases, TIMP-1, to the assay system was found to significantly inhibit invasion activity of T98G cells (P < 0.01). Northern blot analysis demonstrated expression of urokinase-type plasminogen activator (uPA), tissue-type PA (tPA) and PA inhibitor-1 (PAI-1) in some of the above cell lines. Cellular levels of PAs and their inhibitor mRNA, however, appeared not to be correlated with invasion activity in most glioma cell lines except for CCF-STTG1. Expression of 72 kDa type IV collagenase (MMP-2) was much lower in IN157, IN500 and U343 than other cell lines, whereas expression of TIMP-1 was much higher in IN500 than in other cell lines. Zymographic activity was found to be comparable to MMP-2 mRNA levels in all cell lines except for CCF-STTG1. Type IV collagenolytic activity was also comparable to invasion activity in nine cell lines. These observations suggest the role of type IV collagenase and its inhibitors in determining capacity for invasion by human gliomas. However, a comprehensive analysis both in vitro and in vivo is required to confirm the role for this enzyme in glioma cell invasiveness.
 ...
PMID:Expression of 72 kDa type IV collagenase and invasion activity of human glioma cells. 803 4

In this study, we investigated the expression of activated gelatinase A and membrane-type metalloproteinase (MT-MMP) induced by concanavalin A (ConA) in four highly invasive glioma cell lines (UWR2, UWR3, U251MG, and SNB-19). We also examined gelatinase A and MT-MMP expression in human brain tumor tissues in vivo. Gelatin zymography showed that all four cell lines expressed latent progelatinase A (M(r) 66,000). Activated gelatinase A (M(r) 62,000) was induced by ConA in only UWR2 or UWR3 cells. MT-MMP mRNA was present in all four cell lines prior to ConA treatment, and the relative hybridization signals were 1, 0.80, 0.25, and 0.15 in UWR2, UWR3, U251MG, and SNB-19 cells, respectively. These mRNA signals were dramatically increased (2,8-, 5.4-, and 2.2-fold in UWR2, UWR3, and U251MG cells, respectively) following ConA treatment; however, MT-MMP mRNA expression was unchanged in SNB-19 cells. MT-MMP protein was detected in various amounts in the four cell lines, but only after ConA pretreatment. The amount of MT-MMP mRNA was unchanged in SNB-19 after ConA treatment, and the MT-MMP mRNA level in ConA-treated U251MG was lower than in UWR2 and UWR3 without ConA treatment. MT-MMP protein was detected in SNB-19 and U251 cell lines only after ConA treatment. Gelatin zymography of human brain tumor tissues revealed that almost all samples examined contained a latent form of gelatinase A, whereas the activated form of gelatinase A was only seen in metastatic lung adenocarcinomas and malignant astrocytomas, and especially in glioblastomas. MT-MMP mRNA levels were significantly higher in malignant astrocytomas than in low-grade gliomas and normal brain tissues. These results were confirmed by PCR analysis, which showed that MT-MMP mRNA was absent or barely detectable in normal brain white matter but was easily detectable in malignant astrocytomas. Immunohistochemistry of MT-MMP in frozen sections showed that MT-MMP was localized in neoplastic astrocytes of malignant astrocytomas but was undetectable in normal white brain matter. The data indicate that MT-MMP is present in malignant human glial tumors and that MT-MMP expression correlates with expression and activation of gelatinase A during malignant progression in vivo. A direct correlation between the levels of MT-MMP protein and its transcripts was not found in vitro, suggesting that MT-MMP expression in glioma cell lines might be regulated either at the level of transcription message stability or at posttranscription. Altered MT-MMP expression might contribute, in part, to gelatinase A activation, which in turn facilitates invasion of these tumors.
 ...
PMID:Differential expression of membrane-type matrix metalloproteinase and its correlation with gelatinase A activation in human malignant brain tumors in vivo and in vitro. 854 96

Expression of c-Met, the receptor for hepatocyte growth factor (HGF), and the biological roles of HGF were examined in cultured human glioma cells. All of the 5 glioma cell lines examined expressed c-Met protein as well as the c-met gene. Expression of the c-met gene was also confirmed in a glioblastoma tissue. Three cell lines (MGM-3, U251, KG-1-C) demonstrated chemotactic response to HGF in a dose-dependent manner. The response was not only chemotactic but also chemokinetic as judged by a checkerboard analysis. The amounts of c-Met mRNA and protein were abundant in the cell lines which showed a migratory response to HGF. Moreover, c-Met protein expression was highest in U251 with the highest migratory response to HGF. Among the cell lines, KG-1-C produced notable amounts of HGF protein as well as of c-Met, suggesting that HGF may act in an autocrine fashion in this case. HGF did not act as an apparent growth factor in the glioma cell lines examined. Furthermore, HGF stimulated the production of metalloproteinase, probably gelatinase A, in U251 cells.
 ...
PMID:Effects of hepatocyte growth factor (HGF) on human glioma cells in vitro: HGF acts as a motility factor in glioma cells. 864 32

Human glioma cells (T98G and A172 cell lines) were cultured on various extracellular matrix (ECM) components including type I, IV and V collagens, fibronectin, laminin, and reconstituted basement membrane (Matrigel), and the role of matrix metalloproteinases (MMPs) in their growth and invasion was examined. T98G glioma cells grew well on these ECM components and invaded the reconstituted basement membrane. In contrast, A172 glioma cells showed growth inhibition on collagen types IV and V and Matrigel without invasion of the Matrigel. Gelatin zymography and enzyme immunoassays demonstrated that T98G glioma cells, but not A172 cells, secrete a large amount of matrix metalloproteinase-2 (MMP-2, 72 kD gelatinase/type IV collagenase = gelatinase A), and this was confirmed by immunoblotting and immunohistochemistry. Of the two different tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2), T98G cells produced only TIMP-1 during culture on Matrigel, whereas A172 cells secreted both. Although both human recombinant TIMP-1 and TIMP-2 stimulated T98G cell growth slightly on Matrigel, the in vitro invasiveness was significantly reduced by only recombinant TIMP-2. These results suggest that MMP-2 plays an important role in the ECM invasion of T98G human glioma cells in vitro.
 ...
PMID:Secretion of matrix metalloproteinase-2 (72 kD gelatinase/type IV collagenase = gelatinase A) by malignant human glioma cell lines: implications for the growth and cellular invasion of the extracellular matrix. 874 May 87

Scatter factor (SF), also known as hepatocyte growth factor, is angiogenic in systemic tissue, and SF titers correlate with the malignancy and metastatic phenotype of certain systemic cancers. Human gliomas express SF and its receptor c-met, but their role in the malignant progression of these tumors has not been defined. To examine this, 9L glioma cells that express c-met but not SF were transfected with human SF cDNA, and their behavior in vitro and in vivo was examined. SF gene expression was detected in conditioned medium of 9L-SF but not in control 9L-neo-transfected cell lines, by reverse transcriptase-PCR, immunoblot, ELISA, and scatter activity assays. Gliomas derived from 9L-SF and control 9L-neo cell lines implanted in the caudate/putamen of Fisher 344 rats (intracranially) and in the flanks of SCID/Beige mice (subcutaneously) were examined. Extracts from intracranial (i.c.) gliomas contained elevated levels of SF protein as determined by ELISA (1 to 5.5 ng SF/mg protein), whereas no SF was detected in control tumors. Reverse transcriptase-PCR of RNA from i.c. gliomas revealed that only 9L-SF gliomas expressed SF and both 9L-neo and 9L-SF gliomas expressed the c-met SF receptor. By postimplantation Day 14, 9L-SF i.c. gliomas were approximately 5-fold larger than 9L-neo control tumors (p < 0.001). Subcutaneous 9L-SF glioma growth was also greater than that in controls, although the differences were more variable. SF-producing i.c. gliomas contained elevated levels of 48-kd urokinase (3.5-fold) and 92-kd type IV collagenase (2.8-fold), both enzymes that correlate with the malignant progression of human gliomas (p < 0.001). SF-producing and control 9L cell lines did not differ in rates of proliferation, thymidine incorporation, or adhesion-independent growth in vitro. Conditioned medium from 9L-SF cells stimulated thymidine incorporation into microvessel brain endothelial cells 3- to 4-fold higher than did CM from 9L-neo controls (p < 0.001). Intracranial 9L-SF gliomas were more angiogenic than controls based on elevated peak (2.25-fold; p < 0.005) and mean (1.7-fold; p < 0.008) blood vessel densities. These results suggest that SF production by glioma cells enhances glioma malignancy in vivo, in part, by paracrine mechanisms involving glioma-associated angiogenesis.
 ...
PMID:Scatter factor/hepatocyte growth factor gene transfer enhances glioma growth and angiogenesis in vivo. 911 17

Progression of glioma is associated with local degenerative processes which are attributed to the activity of gelatinases. As glioma cells are candidate for secretion of these enzymes, we have studied in vitro the potential of cytokines (interleukin-1alpha (IL-1), tumor necrosis factor-alpha (TNFalpha) and transforming growth factor-beta (TGFbeta2)) to regulate the expression of gelatinase A and B (Gels A and B, respectively) in two glioma cells of human (A172) and rat origin (C6). We showed that IL-1 and TNFalpha both induced gene expression and protein secretion of Gel B in both cell lines, as revealed by RT-PCR and gelatin zymography, respectively. In C6 cells, TNFalpha had no effect on Gel A constitutive expression while IL-1 increased its production, but only at high doses. We have also demonstrated that TGFbeta2 inhibited both IL-1- or TNFalpha-induced gene expression and Gel B production in a dose-dependent manner but had no effect on Gel A secretion. The effect of TGFbeta2 on Gel B secretion was reversed by phorbol myristate acetate (PMA). Taken together, these data suggest that IL-1, TNFalpha and TGFbeta2 tightly regulate Gel B secretion in glioma cells, an enzyme which is believed to play an important role in the local invasion of brain tissue by tumor cells.
 ...
PMID:In vitro expression of MMP-2 and MMP-9 in glioma cells following exposure to inflammatory mediators. 962 99

Invasive glioma cells migrate preferentially along central nervous system (CNS) white matter fiber tracts irrespective of the fact that CNS myelin contains proteins that inhibit cell migration and neurite outgrowth. Previous work has demonstrated that to migrate on a myelin substrate and to overcome its inhibitory effect, rat C6 and human glioblastoma cells require a membrane-bound metalloproteolytic activity (C6-MP) which shares several biochemical and pharmacological characteristics with MT1-MMP. We show now that MT1-MMP is expressed on the surface of rat C6 glioblastoma cells and is coenriched with C6-MP activity. Immunodepletion of C6-MP activity is achieved with an anti-MT1-MMP antibody. These data suggest that MT1-MMP and the C6-MP are closely related or identical. When mouse 3T3 fibroblasts were transfected with MT1-MMP they acquired the ability to spread and migrate on the nonpermissive myelin substrate and to infiltrate into adult rat optic nerve explants. MT1-MMP-transfected fibroblasts and C6 glioma cells were able to digest bNI-220, one of the most potent CNS myelin inhibitory proteins. Plasma membranes of both MT1-MMP-transfected fibroblasts and C6 glioma cells inactivated inhibitory myelin extracts, and this activity was sensitive to the same protease inhibitors. Interestingly, pretreatment of CNS myelin with gelatinase A/MMP-2 could not inactivate its inhibitory property. These data imply an important role of MT1-MMP in spreading and migration of glioma cells on white matter constituents in vitro and point to a function of MT1-MMP in the invasive behavior of malignant gliomas in the CNS in vivo.
 ...
PMID:Membrane-type 1 matrix metalloprotease (MT1-MMP) enables invasive migration of glioma cells in central nervous system white matter. 992 62

We monitored the volume of C6 glioma cells in suspension using a Coulter Counter and exposed the cells to micromolar or nanomolar levels of collagenase or clostripain. In 13 experiments, type IV collagenase (310 units ml-1; approximately 3 microM L-1) decreased the volume by 8-12%, 8 min after addition. In 13 of 21 experiments, the volume decrease was followed by a volume regulatory increase (VRI) back to control levels in the continued presence of collagenase. The shrinkage evoked by type IV collagenase was eliminated by heat-inactivation of the enzyme preparation. A highly purified collagenase (type VII) at the same concentration evoked a relatively minor decrease in volume. A well-known contaminating protease present in type IV collagenase, clostripain, which specifically cleaves arginyl peptide bonds, evoked a 7 +/- 2% shrinkage (100 nM L-1, 7 experiments). Clostripain did not evoke a volume regulatory increase. The initial velocity of shrinkage evoked by clostripain (0.0012 pL min-1, 0.0034 pL min-1, 0.0132 pL min-1; 1 pL = 10(-12) liters) scaled with its concentration (1 nM L-1, 10 nM L-1, 100 nM L-1). The effect of clostripain was inhibited by heat-inactivation of the enzyme. Leupeptin, an inhibitor of clostripain, prevented the decrease in volume evoked by clostripain. The activity of stretch-activated ion channels was unaffected by type IV collagenase. Barium, cesium, amiloride, DIDS, or bumetanide failed to block the shrinkage evoked by type IV collagenase. These results demonstrate that clostripain, present in crude collagenase enzyme preparations, causes the shrinkage, and that C6 glioma cells can undergo a volume regulatory increase at virtually constant osmotic pressure. In addition, cleavage of a cell surface moiety, which contains arginine, and possibly proline, causes shrinkage. This moiety may be part of the extracellular or intracellular matrix providing mechanical support to the cells. VRI reflect actions of another substance in the type IV crude collagenase preparations, on a receptor independent of the arg-pro moiety. The enzymatic modulation of glioma cell volume by these two receptors may reflect a new mechanism by which such cells, and possibly other glia, regulate their contact area and interactions with other cells in the central nervous system.
 ...
PMID:Enzymatic modulation of cell volume in C6 glioma cells. 1040 29


1 2 3 4 Next >>