Characterization of laminin-stimulated adherence and motility in tumor cells.

Laminin was shown to stimulate attachment, spreading and motility in a line of murine tumor cells. The stimulated cells began to attach and spread within 1 h and remained attached and spread throughout a 48-hour observation period. Pretreatment of the cells with laminin for 24 h beforehand did not interfere with their ability to bind laminin in a second treatment. Laminin-stimulated attachment and spreading occurred in the absence of extracellular Ca2+ or Mg2+, but not in the absence of both divalent cations. A number of cell function inhibitors blocked the adherence response, but were only partially effective even at high concentrations. These characteristics of laminin-stimulated adherence are different from those of the adherence response stimulated by peptide chemotactic factors and phorbol esters.