title: Vasodilator-Stimulated Phosphoprotein (VASP) depletion from breast cancer MDA-MB-231 cells inhibits tumor spheroid invasion through downregulation of Migfilin, β-catenin and urokinase-plasminogen activator (uPA).
abstract: A hallmark of cancer cells is their ability to invade surrounding tissues and form metastases. Cell-extracellular matrix (ECM)-adhesion proteins are crucial in metastasis, connecting tumor ECM with actin cytoskeleton thus enabling cells to respond to mechanical cues. Vasodilator-stimulated phosphoprotein (VASP) is an actin-polymerization regulator which interacts with cell-ECM adhesion protein Migfilin, and regulates cell migration. We compared VASP expression in MCF-7 and MDA-MB-231 breast cancer (BC) cells and found that more invasive MDA-MB-231 cells overexpress VASP. We then utilized a 3-dimensional (3D) approach to study metastasis in MDA-MB-231 cells using a system that considers mechanical forces exerted by the ECM. We prepared 3D collagen I gels of increasing concentration, imaged them by atomic force microscopy, and used them to either embed cells or tumor spheroids, in the presence or absence of VASP. We show, for the first time, that VASP silencing downregulated Migfilin, β-catenin and urokinase plasminogen activator both in 2D and 3D, suggesting a matrix-independent mechanism. Tumor spheroids lacking VASP demonstrated impaired invasion, indicating VASP's involvement in metastasis, which was corroborated by Kaplan-Meier plotter showing high VASP expression to be associated with poor remission-free survival in lymph node-positive BC patients. Hence, VASP may be a novel BC metastasis biomarker.
authors.affiliation: Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Cyprus.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Gkretsi
authors.affiliation: Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Cyprus.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stylianou
authors.affiliation: Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Cyprus. Electronic address: tstylian@ucy.ac.cy.
authors.forename: Triantafyllos
authors.initials: T
authors.lastname: Stylianopoulos
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D006801:Humans; D061986:MCF-7 Cells; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D018874:Spheroids, Cellular; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; C473794:FBLIM1 protein, human; D008840:Microfilament Proteins; D010750:Phosphoproteins; D051176:beta Catenin; D000098662:Vasodilator-Stimulated Phosphoprotein; D014568:Urokinase-Type Plasminogen Activator
keywords: Extracellular matrix; Migfilin; Tumor spheroid invasion; Urokinase plasminogen activator; Vasodilator stimulated phosphoprotein