ADHESION PROPERTIES, INTERMEDIATE FILAMENTS AND MALIGNANT BEHAVIOR OFHEAD AND NECK SQUAMOUS-CELL CARCINOMA-CELLS IN-VITRO

This study compared phenotype and behaviour of seven head and neck squ amous cell carcinoma (HNSCC) cell lines and normal epithelial cells, I ndications were found that in HNSCC cells: 1) loss of the tell-cell ad hesion molecule E-cadherin was correlated with loss of epithelioid cel l morphology but not with loss of cell-cell cohesion; 2) reduced expre ssion of the cell-cell adhesion molecule desmoglein was unrelated to c ell shape or motility; 3) high expression of the cell-substrate adhesi on molecule (alpha 6 beta 4, a receptor for laminin, corresponded with epithelioid colony formation while, in our adhesion assay, low expres sion of alpha 6 beta 4 paradoxically coincided,vith an increased adhes ion to laminin; 4) presence of vimentin intermediate filaments coincid ed with loss of anchorage dependency, We propose that by simultaneous downregulation of E-cadherin, replacement of alpha 6 beta 4 by an aber rant laminin receptor and co-expression of vimentin a malignant phenot ype arises of spindle-shaped, motile, anchorage-independent HNSCC cell s with enhanced laminin-binding capacity.