SPARC upregulates MT1-MMP expression, MMP-2 activation, and the secretion and cleavage of galectin-3 in U87MG glioma cells
| Autor: | Stacey L. Thomas, Pamela Osenkowski, Heather M. McClung, Priya Menon, Marta Toth, Sandra A. Rempel, Avraham Raz, Rafael Fridman |
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| Rok vydání: | 2007 |
| Předmět: |
Galectin 3
Matrix metalloproteinase Biology Article Downregulation and upregulation Western blot Glioma Cell Line Tumor medicine Matrix Metalloproteinase 14 Humans Secretion Neoplasm Invasiveness Osteonectin Metalloproteinase medicine.diagnostic_test Brain Neoplasms General Neuroscience medicine.disease Molecular biology Extracellular Matrix Up-Regulation Gene Expression Regulation Neoplastic Cell Transformation Neoplastic Galectin-3 biology.protein Matrix Metalloproteinase 2 |
| Zdroj: | Neuroscience letters. 419(2) |
| ISSN: | 0304-3940 |
| Popis: | Secreted protein acidic and rich in cysteine (SPARC) is highly expressed in human gliomas and promotes glioma invasion. We have shown by cDNA array analysis that SPARC upregulates membrane type 1-matrix metalloproteinase (MT1-MMP) and matrix metalloproteinase-2 (MMP-2) transcripts. To confirm these findings at the protein level and determine whether SPARC expression correlates with increased MMP activity, we used Western blot to assess the levels of MT1-MMP, and gelatin zymography to assess MMP-2 levels and activity. We also examined the expression, secretion, and cleavage of galectin-3, a target of MT1-MMP and MMP-2. Our data confirm that SPARC upregulates MT1-MMP levels and MMP-2 activity. There was also an increase in secreted galectin-3, as well as an increase in the proteolytically processed form of galectin-3. Previous studies have demonstrated that MT1-MMP, MMP-2, and galectin-3 are increased in gliomas. Our results suggest that their upregulation and activation may be a consequence of increased SPARC expression. These data provide a provisional mechanism whereby SPARC contributes to brain tumor invasion. |
| Databáze: | OpenAIRE |
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