title: MT1-MMP- and Cdc42-dependent signaling co-regulate cell invasion and tunnel formation in 3D collagen matrices.
abstract: Complex signaling events control tumor invasion in three-dimensional (3D) extracellular matrices. Recent evidence suggests that cells utilize both matrix metalloproteinase (MMP)-dependent and MMP-independent means to traverse 3D matrices. Herein, we demonstrate that lysophosphatidic-acid-induced HT1080 cell invasion requires membrane-type-1 (MT1)-MMP-mediated collagenolysis to generate matrix conduits the width of a cellular nucleus. We define these spaces as single-cell invasion tunnels (SCITs). Once established, cells can migrate within SCITs in an MMP-independent manner. Endothelial cells, smooth muscle cells and fibroblasts also generate SCITs during invasive events, suggesting that SCIT formation represents a fundamental mechanism of cellular motility within 3D matrices. Coordinated cellular signaling events are required during SCIT formation. MT1-MMP, Cdc42 and its associated downstream effectors such as MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) and Pak4 (p21 protein-activated kinase 4), protein kinase Calpha and the Rho-associated coiled-coil-containing protein kinases (ROCK-1 and ROCK-2) coordinate signaling necessary for SCIT formation. Finally, we show that MT1-MMP and Cdc42 are fundamental components of a co-associated invasion-signaling complex that controls directed single-cell invasion of 3D collagen matrices.
authors.affiliation: Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA.
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Fisher
authors.forename: Anastasia
authors.initials: A
authors.lastname: Sacharidou
authors.forename: Amber N
authors.initials: AN
authors.lastname: Stratman
authors.forename: Anne M
authors.initials: AM
authors.lastname: Mayo
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Fisher
authors.forename: Rachel D
authors.initials: RD
authors.lastname: Mahan
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davis
authors.forename: George E
authors.initials: GE
authors.lastname: Davis
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000378:metabolism* / Q000503:physiopathology; D015398:Signal Transduction; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D003094:Collagen; D053511:Matrix Metalloproteinase 14; D020764:cdc42 GTP-Binding Protein