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Membrane-type 1 matrix metalloprotease (MT1-MMP) enables invasive migration of glioma cells in central nervous system white matter.

Beliën AT, Paganetti PA, Schwab ME - J. Cell Biol. (1999)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Brain Research Institute, University of Zurich and Swiss Federal Institute of Technology, 8057 Zurich, Switzerland. belien@hifo.unizh.ch

ABSTRACT
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.

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MT1-MMP–transfected fibroblasts migrate on  CNS myelin. (a) MT1-MMP– transfected fibroblasts were  plated in a defined area  (marked by circle). After 24 h  the area covered with cells  doubled in size. (b and c) Enlargements of the rim of the  migration zone show the migration of single MT1-MMP– transfected cells. (d) These  “pioneer” cells are expressing  high levels of MT1-MMP  with foci of MT1-MMP on  their processes as shown by  MT1-MMP immunostaining  (same field as c). Bars: (a)  300 μm; (b) 150 μm; (c and d)  50 μm.
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Figure 7: MT1-MMP–transfected fibroblasts migrate on CNS myelin. (a) MT1-MMP– transfected fibroblasts were plated in a defined area (marked by circle). After 24 h the area covered with cells doubled in size. (b and c) Enlargements of the rim of the migration zone show the migration of single MT1-MMP– transfected cells. (d) These “pioneer” cells are expressing high levels of MT1-MMP with foci of MT1-MMP on their processes as shown by MT1-MMP immunostaining (same field as c). Bars: (a) 300 μm; (b) 150 μm; (c and d) 50 μm.

Mentions: To determine the involvement of MT1-MMP in cell migration on CNS myelin, cells were seeded on the inhibitory CNS protein substrate or on PLYS control substrate with the help of the cell manifold holder in a round, well-defined area. 24 h after seeding, MT1-MMP–transfected 3T3 cells showed a large increase in the migration area compared with 2 h after seeding (Fig. 7 a and Fig. 8). In contrast, mock-transfected fibroblasts had hardly migrated out of the starting area (Fig. 8). At the rim of the migration zone single MT1-MMP–transfected cells were moving on the CNS myelin substrate (Fig. 7, b and c). This strongly indicates that these cells were not pushed out of the center due to proliferation effects. Since the transfection rate was ∼15%, only a minor population of MT1-MMP–transfected fibroblasts would be expected to migrate out of the starting area. However, more than 15% migrating cells were observed. Typically, the cells at the front of the migration zone often were characterized by long processes (Fig. 7 c). Immunofluorescence for MT1-MMP revealed that these cells were strongly MT1-MMP positive (Fig. 7 d). Cells in the center of the migration area often had shorter processes on which less MT1-MMP was expressed. The “pioneers” may have proteolytically modified the inhibitory CNS substrate, allowing also non- or low MT1-MMP– expressing cells to migrate. The time-course of fibroblast migration is shown in Fig. 8. MT1-MMP–transfected fibroblasts almost doubled the area covered with cells within 24 h, whereas mock-transfected cells could hardly migrate on the inhibitory substrate. Both cell types were migrating equally well on the control substrate.


Membrane-type 1 matrix metalloprotease (MT1-MMP) enables invasive migration of glioma cells in central nervous system white matter.

Beliën AT, Paganetti PA, Schwab ME - J. Cell Biol. (1999)

MT1-MMP–transfected fibroblasts migrate on  CNS myelin. (a) MT1-MMP– transfected fibroblasts were  plated in a defined area  (marked by circle). After 24 h  the area covered with cells  doubled in size. (b and c) Enlargements of the rim of the  migration zone show the migration of single MT1-MMP– transfected cells. (d) These  “pioneer” cells are expressing  high levels of MT1-MMP  with foci of MT1-MMP on  their processes as shown by  MT1-MMP immunostaining  (same field as c). Bars: (a)  300 μm; (b) 150 μm; (c and d)  50 μm.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2132902&req=5

Figure 7: MT1-MMP–transfected fibroblasts migrate on CNS myelin. (a) MT1-MMP– transfected fibroblasts were plated in a defined area (marked by circle). After 24 h the area covered with cells doubled in size. (b and c) Enlargements of the rim of the migration zone show the migration of single MT1-MMP– transfected cells. (d) These “pioneer” cells are expressing high levels of MT1-MMP with foci of MT1-MMP on their processes as shown by MT1-MMP immunostaining (same field as c). Bars: (a) 300 μm; (b) 150 μm; (c and d) 50 μm.
Mentions: To determine the involvement of MT1-MMP in cell migration on CNS myelin, cells were seeded on the inhibitory CNS protein substrate or on PLYS control substrate with the help of the cell manifold holder in a round, well-defined area. 24 h after seeding, MT1-MMP–transfected 3T3 cells showed a large increase in the migration area compared with 2 h after seeding (Fig. 7 a and Fig. 8). In contrast, mock-transfected fibroblasts had hardly migrated out of the starting area (Fig. 8). At the rim of the migration zone single MT1-MMP–transfected cells were moving on the CNS myelin substrate (Fig. 7, b and c). This strongly indicates that these cells were not pushed out of the center due to proliferation effects. Since the transfection rate was ∼15%, only a minor population of MT1-MMP–transfected fibroblasts would be expected to migrate out of the starting area. However, more than 15% migrating cells were observed. Typically, the cells at the front of the migration zone often were characterized by long processes (Fig. 7 c). Immunofluorescence for MT1-MMP revealed that these cells were strongly MT1-MMP positive (Fig. 7 d). Cells in the center of the migration area often had shorter processes on which less MT1-MMP was expressed. The “pioneers” may have proteolytically modified the inhibitory CNS substrate, allowing also non- or low MT1-MMP– expressing cells to migrate. The time-course of fibroblast migration is shown in Fig. 8. MT1-MMP–transfected fibroblasts almost doubled the area covered with cells within 24 h, whereas mock-transfected cells could hardly migrate on the inhibitory substrate. Both cell types were migrating equally well on the control substrate.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Brain Research Institute, University of Zurich and Swiss Federal Institute of Technology, 8057 Zurich, Switzerland. belien@hifo.unizh.ch

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus