Movement of cell-associated matrix during contact competition of cells in mixed cultures

Co-cultured contacting heterotypic cell groups compete with one another for the attachment to the substratum. In the course of this competition one cell group can progressively push another from the substratum. Alterations to the distribution of cell-associated matrix structures in the course of contact competition were examined by immunomorphological methods in the paired cultures of two epithelial lines and those of fibroblasts and epithelia. It was found that matrix structures formed by the retreating cells withdrew from the substratum simultaneously with the cells. These results show that two forms of matrix structures should be distinguished: the usually immovable matrix upon which the cells crawl and the movable matrix that the cells carry with them when they move.