Downregulation of Akt and FAK phosphorylation reduces invasion of glioblastoma cells by impairment of MT1-MMP shuttling to lamellipodia and downregulates MMPs expression

Abstract

Human malignant glioblastomas are highly invasive tumors. Increased cell motility and degradation of the surrounding extracellular matrix are essential for tumor invasion. PI3K/Akt signaling pathway emerges as a common pathway regulating cellular proliferation, migration and invasion; however, its contribution to particular process and downstream cascades remain poorly defined. We have previously demonstrated that Cyclosporin A (CsA) affects glioblastoma invasion in organotypic brain slices and tumorigenicity in mice. Here we show that CsA impairs migration and invasion of human glioblastoma cells by downregulation of Akt phosphorylation. Interference with PI-3K/Akt signaling was crucial for CsA effect on invasion, because overexpression of constitutively active myr-Akt antagonized drug action. Furthermore, the drug was not effective in T98G glioblastoma cells with constitutively high level of phosphorylated Akt. CsA, comparably to pharmacological inhibitors of PI3K/Akt signaling (LY294002, A443654), reduced motility of glioblastoma cells, diminished MMP-2 gelatinolytic activity and MMP-2 and MT1-MMP expression. The latter effect was mimicked by overexpression of dominant negative Akt mutants. We demonstrate that CsA and LY294002 reduced MMP transcription partly via modulation of IκB phosphorylation and NFκB transcriptional activity. Those effects were not mediated by inhibition of calcineurin, a classical CsA target. Additionally, CsA reduced phosphorylation and activity of focal adhesion kinase that was associated with rapid morphological alterations, rearrangement of lamellipodia and impairment of MT1-MMP translocation to membrane protrusions. Our results document novel, Akt-dependent mechanisms of interference with motility/invasion of human glioblastoma cells: through a rapid modulation of cell adhesion and MT1-MMP translocation to membrane protrusions and delayed, partly NFκB-dependent, downregulation of MMP-2 and MT1-MMP expression. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.

Focal adhesion kinase is involved in the migration of human osteosarcoma cells

“…The results of the present study also indicated that in the early migration process, reduced expression of FAK significantly decreased the number of lamellipodia. This result is consistent with the results of a study by Kwiatkowska et al (15), which found that the decreased expression of phosphorylated FAK (phospho-FAK) suppressed the migration of malignant glioma cells. The study also revealed that lamellipodia formation was significantly prolonged in the cells with low levels of phospho-FAK.…”

Enterolobium contortisiliquum Trypsin Inhibitor (EcTI), a Plant Proteinase Inhibitor, Decreases in Vitro Cell Adhesion and Invasion by Inhibition of Src Protein-Focal Adhesion Kinase (FAK) Signaling Pathways

“…Several studies have indicated that FAK may have a direct role in cell survival (63)(64)(65)(66); however, there are also published data showing that inhibition of the activation of FAK does not affect cell proliferation (16,(67)(68)(69). EcTI did not alter cell cycle progression (data not shown).…”

Neurokinin-1 Receptor Directly Mediates Glioma Cell Migration by Up-regulation of Matrix Metalloproteinase-2 (MMP-2) and Membrane Type 1-Matrix Metalloproteinase (MT1-MMP)

“…Actually these kinase signalings had been correlated with the increased invasiveness of glioblastoma cells (49,50). For example, the alteration of the IP3K/Akt pathway was reported to regulate the migration and invasion of human glioma cells LN229, T89G, and U-373 through the reduction of MMP-2 and MT1-MMP (43). NK1R activation was verified to induce MAPK and Akt activation, mediating cell proliferation and the anti-apoptosis effect in glioma cells and other tumor cells (15,16,21).…”

“…Luciferase Reporter Assays for NF-B and AP-1 ActivityThe luciferase reporter gene assay was measured as described previously (38,43). Briefly, U-251 cells were seeded in a 60-mm dish to reach 80 -90% confluence overnight.…”