title: ARF6 promotes the formation of Rac1 and WAVE-dependent ventral F-actin rosettes in breast cancer cells in response to epidermal growth factor.
abstract: Coordination between actin cytoskeleton assembly and localized polarization of intracellular trafficking routes is crucial for cancer cell migration. ARF6 has been implicated in the endocytic recycling of surface receptors and membrane components and in actin cytoskeleton remodeling. Here we show that overexpression of an ARF6 fast-cycling mutant in MDA-MB-231 breast cancer-derived cells to mimick ARF6 hyperactivation observed in invasive breast tumors induced a striking rearrangement of the actin cytoskeleton at the ventral cell surface. This phenotype consisted in the formation of dynamic actin-based podosome rosette-like structures expanding outward as wave positive for F-actin and actin cytoskeleton regulatory components including cortactin, Arp2/3 and SCAR/WAVE complexes and upstream Rac1 regulator. Ventral rosette-like structures were similarly induced in MDA-MB-231 cells in response to epidermal growth factor (EGF) stimulation and to Rac1 hyperactivation. In addition, interference with ARF6 expression attenuated activation and plasma membrane targeting of Rac1 in response to EGF treatment. Our data suggest a role for ARF6 in linking EGF-receptor signaling to Rac1 recruitment and activation at the plasma membrane to promote breast cancer cell directed migration.
authors: Institut Curie, Research Center, 75005 Paris, France; Membrane and Cytoskeleton Dynamics, Centre National de la Recherche Scientifique UMR144, 75005 Paris, France.
authors: Valentina
authors: V
authors: Marchesin
authors: Institut Curie, Research Center, 75005 Paris, France; Membrane and Cytoskeleton Dynamics, Centre National de la Recherche Scientifique UMR144, 75005 Paris, France.
authors: Guillaume
authors: G
authors: Montagnac
authors: Institut Curie, Research Center, 75005 Paris, France; Membrane and Cytoskeleton Dynamics, Centre National de la Recherche Scientifique UMR144, 75005 Paris, France.
authors: Philippe
authors: P
authors: Chavrier
mesh_terms: D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
chemical_list: D000089982:ADP-Ribosylation Factor 6; D000199:Actins; D034741:RNA, Small Interfering; C114864:WASF1 protein, human; D051300:Wiskott-Aldrich Syndrome Protein Family; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human; D020830:rac1 GTP-Binding Protein