title: Focal adhesion kinase activity is required for actomyosin contractility-based invasion of cells into dense 3D matrices.
abstract: The focal adhesion kinase (FAK) regulates the dynamics of integrin-based cell adhesions important for motility. FAK's activity regulation is involved in stress-sensing and focal-adhesion turnover. The effect of FAK on 3D migration and cellular mechanics is unclear. We analyzed FAK knock-out mouse embryonic fibroblasts and cells expressing a kinase-dead FAK mutant, R454-FAK, in comparison to FAK wild-type cells. FAK knock-out and FAKR454/R454cells invade dense 3D matrices less efficiently. These results are supported by FAK knock-down in wild-type fibroblasts and MDA-MB-231 human breast cancer cells showing reduced invasiveness. Pharmacological interventions indicate that in 3D matrices, cells deficient in FAK or kinase-activity behave similarly to wild-type cells treated with inhibitors of Src-activity or actomyosin-contractility. Using magnetic tweezers experiments, FAKR454/R454cells are shown to be softer and exhibit impaired adhesion to fibronectin and collagen, which is consistent with their reduced 3D invasiveness. In line with this, FAKR454/R454cells cannot contract the matrix in contrast to FAK wild-type cells. Finally, our findings demonstrate that active FAK facilitates 3D matrix invasion through increased cellular stiffness and transmission of actomyosin-dependent contractile force in dense 3D extracellular matrices.
authors.affiliation: Institute of Experimental Physics I, Biological Physics Division, Faculty of Physics and Earth Science, University of Leipzig, Leipzig, Germany.
authors.forename: Claudia T
authors.initials: CT
authors.lastname: Mierke
authors.affiliation: Institute of Experimental Physics I, Biological Physics Division, Faculty of Physics and Earth Science, University of Leipzig, Leipzig, Germany.
authors.forename: Tony
authors.initials: T
authors.lastname: Fischer
authors.affiliation: Institute of Experimental Physics I, Biological Physics Division, Faculty of Physics and Earth Science, University of Leipzig, Leipzig, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Puder
authors.affiliation: Institute of Experimental Physics I, Biological Physics Division, Faculty of Physics and Earth Science, University of Leipzig, Leipzig, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Kunschmann
authors.affiliation: Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.
authors.forename: Birga
authors.initials: B
authors.lastname: Soetje
authors.affiliation: Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Ziegler
mesh_terms: D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D005353:Fibronectins / Q000494:pharmacology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D005353:Fibronectins; D003094:Collagen; D000205:Actomyosin; D051416:Focal Adhesion Protein-Tyrosine Kinases