Directional motility in strongly malignant murine tumor cells.

Laminin, fibronectin and 12-O-tetradecanoyl phorbol acetate (TPA) were examined for their ability to induce biological responses (cell-to-substrate adherence and motility) in a series of strongly malignant and weakly malignant murine fibrosarcoma cells. All three agents caused increased cell-to-substrate attachment of the cell lines. Laminin and fibronectin induced a slow but sustained response, whereas with TPA the response was rapid and transient. The 3 agents also stimulated motility in the same cells. Random motility was seen with all of the cells but directional motility was observed primarily in the strongly malignant cells. With TPA, the response was chemotactic but laminin and fibronectin induced cell migration by haptotaxis. Since laminin and fibronectin are constituents of the extracellular matrix and since malignant tumor cells must cross the extracellular space during invasion, those properties of cells which allow for migration across a substrate containing these materials may contribute to the expression of malignancy.