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

• Published in: Biochimica et biophysica acta 2011-05, Vol.1813 (5), p.655-667
• Main Authors: Kwiatkowska, Aneta, Kijewska, Magdalena, Lipko, Maciej, Hibner, Urszula, Kaminska, Bozena
• Format: Article
• Language: English
• Subjects: Actins - metabolism; Animals; Biochemistry, Molecular Biology; Cell Line, Tumor; Cell Movement - drug effects; Cell Shape - drug effects; Cyclosporin A; Cyclosporine - pharmacology; Down-Regulation - drug effects; Focal Adhesion Kinase 1 - metabolism; Glioblastoma - enzymology; Glioblastoma - pathology; Humans; Invasion; Life Sciences; Matrix Metalloproteinase 14 - metabolism; Matrix Metalloproteinase 2 - metabolism; Mice; Migration; MMPs; Neoplasm Invasiveness; NF-kappa B - genetics; Phosphatidylinositol 3-Kinases - antagonists & inhibitors; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation - drug effects; PI3K/Akt signaling; Protein Transport - drug effects; Proto-Oncogene Proteins c-akt - antagonists & inhibitors; Proto-Oncogene Proteins c-akt - metabolism; Pseudopodia - drug effects; Pseudopodia - enzymology; Signal Transduction - drug effects; Transcription, Genetic - drug effects; Transcriptional regulation
• ISSN: 0167-4889; 0006-3002; 1879-2596
• DOI: 10.1016/j.bbamcr.2011.01.020

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. ► Cyclosporin A impairs phosporylation of Akt and FAK. ► Akt signaling regulates motility and invasiveness of malignant glioblastoma cells. ► PI-3K/Akt signaling regulates subcellular localisation of MT1-MMP. ► MT1-MMP locally influences MMP-2 activity and facilitates formation of invadopodia. ► Expression of MMP-2 and MT1-MMP is regulated in an Akt-dependent manner.