Atomic force microscopy and graph analysis to study the P-cadherin/SFK mechanotransduction signalling in breast cancer cells.

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.

Aproveitamento de soro lácteo na formulação de bebidas com frutas e hortaliças / The use of whey in the formulation of beverages with fruits and vegetables

O uso do soro lácteo como complemento na formulação de alimentos visando ao seu aproveitamento é uma alternativa para a obtenção de novos produtos. Neste trabalho, desenvolveram-se bebidas à base de soro oriundo de queijo coalho tipo A com frutas e hortaliças. Na formulação das bebidas, utilizaram-se diferentes proporções entre soro lácteo, frutas e hortaliças, com adição de 10% de açúcar. Seis bebidas foram formuladas e submetidas a um teste de preferência, e as três primeiras colocadas foram submetidas a um teste de aceitação sensorial. As três preferidas foram as bebidas sabor graviola, morango e goiaba. A bebida sabor graviola obteve aceitação com as melhores notas nos atributos sensoriais cor, sabor, aparência e qualidade global, seguida pela formulação de sabor morango, mas sem diferença significativa (P>0,05). A bebida sabor goiaba teve o diferencial no atributo odor e superou as bebidas sabor graviola e morango (P<0,05). Conclui-se que é viável a elaboração de bebidas à base de soro de queijo coalho com frutas.

The use of whey as complement in food formulation aiming it's an alternative for the attainment of new products. The aim of this work was developed a type A curd cheese whey derived drink with fruits and vegetables. On drink's formulation was used different ratios of whey, fruits and vegetables, with 10% of sugar. Six drinks were formulated and submited to a preference test. The three best drinks were submitted to a acceptance test. The three best drinks were graviola, strawberry and guava flavours. The graviola one had the greater acceptability with best grades in color's sensory attributes, flavor, appearance and overall quality, following the strawberry flavor, but without significant difference (P<0,05). The guava dink had it's differential on scent character, overcoming the graviola and strawberry drinks (P<0,05). In conclusion we can say that whey-based drink with fruits is viable.