GBM cell lines capable of forming caveolae expressed more uPA and matrix metalloproteinase-2 (MMP-2) and/or -9 (MMP-9) and were more invasive than GBM cells devoid of caveola-forming proteins.
A significant decline of MMP-9 and MMP-2 secretion in cultured U87MG was detected after incubation with EBB (42.9% and 73.0%, respectively) and EBB + TMZ (38.4% and 68.5%, respectively).
Activation of PI3K/AKT signaling prevented the suppressive effects of RWDD3 downregulation on glioblastoma cell proliferation and migration, concurrent with increased protein levels of MMP2 and MMP9.
By virtue of its restricted expression in GBM and its role in invasion, Necl-5 may be an attractive target for limiting MMP-2 production in glioblastoma, and therefore limiting dispersal.
Consistent with this idea, 39% less extracellular MMP2 was measured from knockdown cells identifying one mechanism by which calpain 2 mediates glioblastoma cell invasion.
Downregulation of the miR-221/222 cluster diminished the invasion, migration, proliferation, and angiogenesis with reduced protein levels of matrix metalloproteinase-2 (MMP-2), MMP-9, and vascular endothelial growth factor in glioblastoma cells.
Finally, tissue microarray analysis of 68 GBM tissue specimens showed a significant correlation between the overexpression of IGFBP2 and elevated MMP-2 expression.
Further research into the underlying mechanism demonstrated that the effects of miR-125b on the invasion of glioblastoma CD133-positive cells were associated with the alteration of the expression of MMPs (MMP-2 and MMP-9) and corresponding inhibitors (RECK and TIMP3).
Immunohistochemically, MT1-MMP and MT2-MMP are localized to the neoplastic astrocytes in glioblastoma samples (17/17 cases and 12/17 cases, respectively), which are also positive for MMP-2.
In addition, our data suggest that MMP2 and E-cadherin, a key factor in epithelial-mesenchymal transition (EMT), are involved in the miR-633/TGF-β1-mediated metastasis of glioblastoma.
In medulloblastomas, the expression of mt1-MMP, mt2-MMP, and gelatinase A were also increased, but to a lesser extent than that observed in glioblastomas.
In this study we used RT-PCR, western blot and SDS-zymography to investigate the effect of resveratrol on the expression of genes and proteins involved in the extracellular matrix remodeling associated with tumor invasion in human cultured glioblastoma cells treated for 24, 48 and 72 h. We analyzed the expression of matrix metalloproteinase-2 (MMP-2), the main mediator of glioblastoma invasiveness, and the Secreted Protein Acidic and Rich in Cysteine (SPARC), involved in the regulation of cell-matrix interactions.
Measurements of MMP-2 intensity increased with tumor grade, and MMP-2 expression was found to be significantly higher in glioblastomas compared to normal brain tissue (p<0.001), diffuse astrocytomas (p<0.001) and anaplastic astrocytomas (p<0.05).
Moreover, the expression of MMP-2, its inhibitor TIMP-2 and the tumour invasiveness-related protein SPARC were effectively inhibited by TRAIL in glioblastoma cell lines.