[Morphology of epidermoid carcinoma A431 cells spread on immobilized ligands]

Cell interaction with extracellular matrix is a multi-step process characterized by cell attachment to substrata with subsequent cell spreading accompanied by actin cytoskeleton and cellular membrane receptor reorganization. It has been shown elsewhere that epidermoid carcinoma A431 cells, spread on solid substrata coated with fibronectin, laminin-2/4 or antibodies to EGF receptor, form specific actin filament structures typical for each particular ligand. Here quantitative analysis of heterogeneous A431 cell population spread on the above ligands has been reported. Cells were subdivided into morphological classes, according to their shape and actin filament structure, and the relationship among classes under various experimental conditions were quantitatively estimated for every ligand. We studied the influence of cell detachment pattern, short-term and long-term starvation, and cell incubation in suspended state in the medium before plating on the cell population composition. It was possible to recognize the modal morphological class of cells with typical actin cytoskeleton structure dominating for the ligand in the population. Long-term starvation and incubation in suspension before cell spreading are considered as the crucial experimental parameters leading to dramatic changes in cell population.