title: ADP-ribosylation factor 6 regulates tumor cell invasion through the activation of the MEK/ERK signaling pathway.
abstract: Tumor cell invasion through the extracellular matrix is accompanied by the formation of invadopodia, which are actin-rich protrusions at the adherent surface of cells at sites of extracellular matrix degradation. Using the invasive human melanoma cell line LOX as a model system, we demonstrate that the ADP-ribosylation factor 6 (ARF6) GTPase is an important regulator of invadopodia formation and cell invasion. We show that ARF6 localizes to invadopodia of LOX cells. Sustained activation of ARF6 significantly enhances the invasive capacity of melanoma as well as breast tumor cell lines, whereas dominant negative ARF6 abolishes basal cell invasive capacity as well as invasion induced by growth factors. Furthermore, using biochemical assays, we show that enhanced invasive capacity is accompanied by the activation of endogenous ARF6. Finally, we provide evidence that ARF6-enhanced melanoma cell invasion depends on the activation of the extracellular signal-regulated kinase (ERK), and that the ARF6 GTPase cycle regulates ERK activation. This study describes a vital role for ARF6 in melanoma cell invasion and documents a link between ARF6-mediated signaling and ERK activation.
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-0369, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Tague
authors.forename: Vandhana
authors.initials: V
authors.lastname: Muralidharan
authors.forename: Crislyn
authors.initials: C
authors.lastname: D'Souza-Schorey
mesh_terms: D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008545:Melanoma / Q000201:enzymology* / Q000473:pathology*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009361:Neoplasm Invasiveness
chemical_list: D000089982:ADP-Ribosylation Factor 6; D006133:Growth Substances; D006160:Guanosine Triphosphate; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human