title: Atomic force microscopy and graph analysis to study the P-cadherin/SFK mechanotransduction signalling in breast cancer cells.
abstract: Physical forces mediated by cell-cell adhesion molecules, as cadherins, play a crucial role in preserving normal tissue architecture. Accordingly, altered cadherins' expression has been documented as a common event during cancer progression. However, in most studies, no data exist linking pro-tumorigenic signaling and variations in the mechanical balance mediated by adhesive forces. In breast cancer, P-cadherin overexpression increases in vivo tumorigenic ability, as well as in vitro cell invasion, by activating Src family kinase (SFK) signalling. However, it is not known how P-cadherin and SFK activation impact cell-cell biomechanical properties. In the present work, using atomic force microscopy (AFM) images, cell stiffness and cell-cell adhesion measurements, and undirected graph analysis based on microscopic images, we have demonstrated that P-cadherin overexpression promotes significant alterations in cell's morphology, by decreasing cellular height and increasing its area. It also affects biomechanical properties, by decreasing cell-cell adhesion and cell stiffness. Furthermore, cellular network analysis showed alterations in intercellular organization, which is associated with cell-cell adhesion dysfunction, destabilization of an E-cadherin/p120ctn membrane complex and increased cell invasion. Remarkably, inhibition of SFK signaling, using dasatinib, reverted the pathogenic P-cadherin induced effects by increasing cell's height, cell-cell adhesion and cell stiffness, and generating more compact epithelial aggregates, as quantified by intercellular network analysis. In conclusion, P-cadherin/SFK signalling induces topological, morphological and biomechanical cell-cell alterations, which are associated with more invasive breast cancer cells. These effects could be further reverted by dasatinib treatment, demonstrating the applicability of AFM and cell network diagrams for measuring the epithelial biomechanical properties and structural organization.
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
authors.forename: A S
authors.initials: AS
authors.lastname: Ribeiro
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: F A
authors.initials: FA
authors.lastname: Carvalho
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Figueiredo
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Carvalho
authors.affiliation: IST-ISR, Lisbon, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Mestre
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Monteiro
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: A F
authors.initials: AF
authors.lastname: Guedes
authors.affiliation: IST-ISR, Lisbon, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Fonseca
authors.affiliation: IST-ISR, Lisbon, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Sanches
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal and Medical Faculty of the University of Porto, Porto, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Seruca
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: N C
authors.initials: NC
authors.lastname: Santos
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. jparedes@ipatimup.pt and Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal and Medical Faculty of the University of Porto, Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Paredes
mesh_terms: D001943:Breast Neoplasms; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D006801:Humans; D061986:MCF-7 Cells; D040542:Mechanotransduction, Cellular; D018625:Microscopy, Atomic Force; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D015820:Cadherins; D019061:src-Family Kinases