Morphological and mechanical stability of bladder cancer cells in response to substrate rigidity

• Published in: Biochimica et biophysica acta. General subjects 2019-06, Vol.1863 (6), p.1006-1014
• Main Authors: Lekka, Malgorzata, Pabijan, Joanna, Orzechowska, Barbara
• Format: Article
• Language: English
• Subjects: Acrylic Resins - chemistry; Actin cytoskeleton remodeling; Atomic force microscopy; Basement membrane; Cell Adhesion; Cell Line, Tumor; Cell mechanics; Cytoskeleton - metabolism; Focal Adhesions - metabolism; Focal Adhesions - pathology; Humans; Hydrogels - chemistry; Integrins - metabolism; Laminin; Morphological and mechanical stability; Neoplasm Proteins - metabolism; Tumor environment; Urinary Bladder Neoplasms - metabolism; Urinary Bladder Neoplasms - pathology; Vinculin - metabolism
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/j.bbagen.2019.03.010

Morphology of cells can be considered as an interplay between the accessibility of substrate anchoring sites, cytoskeleton properties and cellular deformability. To withstand tension induced by cell's environment, cells tend to spread out and, simultaneously, to remodel actin filament organization. In this context, the use of polyacrylamide hydrogel substrates with a surface coated with laminin allows to trace remodeling of actin cytoskeleton during the interaction of cells with laminin-rich basement membrane. Reorganization of actin cortex can be quantified by a surface spreading area and deformability of single cells. In our study, we demonstrated that morphological and mechanical alterations of bladder cancer cells in response to altered microenvironment stiffness are of biphasic nature. Threshold-dependent relations are induced by mechanical properties of cell microenvironment. Initially, fast alterations in cellular capability to spread and to deform are followed by slow-rate changes. A switch provided by cellular deformability threshold, in the case of non-malignant cells, triggers the formation of thick actin bundles accompanied by matured focal adhesions. For cancer cells, cell spreading and deformability thresholds switch between slow and fast rate of changes with weak reorganization of actin filaments and focal adhesions formation. The presence of transition region enables the cells to achieve a morphological and mechanical stability, which together with altered expression of vinculin and integrins, can contribute to invasiveness of bladder cancers. Our findings show that morphological and mechanical stability is directly related to actin filament organization used by cancer cells to adapt to altered laminin-rich microenvironment. •Polyacrylamide gels can mimic functional stiffness of bladder.•Cellular response to laminin is related to actin filament organization.•Substrate stiffness induces a biphasic response of bladder cells.•Spreading and deformability thresholds separate between fast- and slow-rate changes.•Cells adapt to altered microenvironment achieving morphological and mechanical stability.