Mechanical tension across focal adhesion protein vinculin in normal and tumoral human breast cells

MARINA CUENCA; LÍA I PIETRASANTA; LORENA SIGAUT

San Miguel de Tucumán

Congreso; III Latin American Federation of Biophysical Societies (LAFeBS) / IX IberoAmerican Congress of Biophysics / XLV Reunión Anual SAB 2016; 2016

Latin American Federation of Biophysical Societies and Sociedad Argentina de Biofísica

Mechanical forces play an important role in the organization, growth, maturation, and function of living tissues. Cells sense the extracellular environment using transient macromolecular assemblies, called focal adhesions (FAs) that physically connect the extracellular matrix to the actin cytoskeleton through integrin receptors. FAs exhibit mechanosensitive properties, they respond to internal and external mechanical stresses. In particular, it has been seen, that the FA protein vinculin is crucial for the ability of cells to transmit forces and to generate cytoskeletal tension1, and is involved in regulating cell adhesion and motility2.In this work we use a FRET (Förster resonance energy transfer)-based force/tension sensor that reports changes in tension-induced strain within the FA protein vinculin3. Employing this sensor we investigated the tension across vinculin within individual FA in two different human breast epithelial cell lines: MCF10A, normal-like breast cells and MCF7 breast tumor cells. In order to quantify and characterize FA tension, we developed and implemented a FA segmentation routine combining OTSU threshold method, with the watershed method to optimize automatic single FA individualization. Statistical analysis reveals the existence of FA subpopulations exhibiting high and low levels of vinculin tension in both cell lines. We found that non tumoral cell line, MCF10A, presents a larger subpopulation of low tension FA, while the high tension FA subpopulation is greater in MCF7, tumorigenic cell line.Acknowledgements: CONICET, ANPCyT and UBA. References: 1 Danowski, B.A. et al., J. Cell Biol. 1992; 118:1411. Alenghat, F.J. et al., Biochem. Biophys. Res. Commun. 2000; 277:93. 2 Xu, W. et al., J. Cell Sci. 1998; 111:1535. Rodriguez Fernandez, J.L. et al., J. Cell Biol 1993; 122:1285. 3 Grashoff, C. et al., Nature. 2010; 466(7303):263.