title: NBT-II cell locomotion is modulated by restricting the size of focal contacts and is improved through EGF and ROCK signaling.
abstract: Focal contacts, large macromolecular complexes that link the extracellular matrix and the internal cell cytoskeleton, are thought to govern cell locomotion. However, the maturation process through which focal contacts control the cellular migratory machinery by changes in size and molecular composition remain unclear. Here, we fabricated cell growth substrates that contained linear ECM strips of micron- or submicron-width in order to limit the enlargement of focal contacts. We found that NBT-II cells plated on the submicron substrate possessed smaller focal complexes that exhibited a highly dynamic turnover. These cells possessed various leading edges at multiple sites of the cell periphery, which prevented the cell from advancing. In contrast, cells grown on the micron-width substrate possessed large and stable focal adhesions. Most of these cells were elongated bipolar cells that were tethered at both ends and were immobile. Further, EGF and ROCK signaling pathways can modulate the cellular migratory responses according to the substrate guidance. On the submicron-width substrate, EGF treatment increased the focal contact size and the contractile force, causing these cells to develop one leading edge and migrate along the submicron-sized ECM paths. In contrast, inhibition of ROCK signaling decreased the focal contact size for cells plated on the micron substrate. These cells became less tethered and were able to migrate along or even across the micron-sized ECM paths. Our results indicate that formation and maturation of focal contacts is controlled by both ECM cues and intracellular signaling and they play a central role in directed cell motion.
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Liu
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chia-Ping
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Jia
authors.initials: YJ
authors.lastname: Liou
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Hsu
authors.affiliation: National Nano Device Laboratory, Hsinchu, Taiwan.
authors.forename: Jung-Yen
authors.initials: JY
authors.lastname: Yang
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan; Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan; Department of Health, Taipei City Government, Taipei, Taiwan. Electronic address: linch@ym.edu.tw.
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Lin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D022001:Focal Adhesions / Q000201:enzymology / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction; D014162:Transfection; D001749:Urinary Bladder Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D004815:Epidermal Growth Factor; D054460:rho-Associated Kinases
keywords: Cell motility; Extracellular matrix; Fluorescence recovery after photobleaching (FRAP); Focal adhesion; Microcontact printing