title: MT1-MMP proinvasive activity is regulated by a novel Rab8-dependent exocytic pathway.
abstract: MT1-matrix metalloproteinase (MT1-MMP) is one of the most critical factors in the invasion machinery of tumor cells. Subcellular localization to invasive structures is key for MT1-MMP proinvasive activity. However, the mechanism driving this polarized distribution remains obscure. We now report that polarized exocytosis of MT1-MMP occurs during MDA-MB-231 adenocarcinoma cell migration into collagen type I three-dimensional matrices. Polarized trafficking of MT1-MMP is triggered by beta1 integrin-mediated adhesion to collagen, and is required for protease localization at invasive structures. Localization of MT1-MMP within VSV-G/Rab8-positive vesicles, but not in Rab11/Tf/TfRc-positive compartment in invasive cells, suggests the involvement of the exocytic traffic pathway. Furthermore, constitutively active Rab8 mutants induce MT1-MMP exocytic traffic, collagen degradation and invasion, whereas Rab8- but not Rab11-knockdown inhibited these processes. Altogether, these data reveal a novel pathway of MT1-MMP redistribution to invasive structures, exocytic vesicle trafficking, which is crucial for its role in tumor cell invasiveness. Mechanistically, MT1-MMP delivery to invasive structures, and therefore its proinvasive activity, is regulated by Rab8 GTPase.
authors.affiliation: Confocal Microscopy and Cytometry Unit, Biotechnology Programme, Spanish Nacional Cancer Research Center (CNIO), Madrid, Spain.
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Bravo-Cordero
authors.forename: Raquel
authors.initials: R
authors.lastname: Marrero-Diaz
authors.forename: Diego
authors.initials: D
authors.lastname: Megías
authors.forename: Laura
authors.initials: L
authors.lastname: Genís
authors.forename: Aranzazu
authors.initials: A
authors.lastname: García-Grande
authors.forename: Maria A
authors.initials: MA
authors.lastname: García
authors.forename: Alicia G
authors.initials: AG
authors.lastname: Arroyo
authors.forename: María C
authors.initials: MC
authors.lastname: Montoya
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D005089:Exocytosis / Q000502:physiology*; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008863:Microspheres; D008954:Models, Biological; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D038761:Photobleaching; D021381:Protein Transport / Q000502:physiology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D022161:Transport Vesicles / Q000502:physiology; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D019012:Integrin beta1; D034741:RNA, Small Interfering; D003094:Collagen; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14; C082377:RAB8A protein, human; D020691:rab GTP-Binding Proteins