Lymphokine-induced migration inhibition of murine tumor cells derived from solid neoplasms.

We have previously described a noncytotoxic lymphokine, tumor migration inhibition factor, with the capacity of inhibiting the in vitro migration of a variety of tumor cells maintained by animal passage in ascitic form. In the present study, we demonstrate that it is possible to prepare viable, motile tumor cell suspensions from solid tumors and that those cells migrate better than cells that had been propagated in ascitic form. Such preparations derived from solid tumors are inhibited by tumor migration inhibition factor to a degree comparable to that achieved with cells from ascitic tumors. Comparative studies utilizing a methylcholanthrene-induced fibrosarcoma as well as solid and ascitic forms of P815 mastocytoma and Ehrlich tumor demonstrate that responsiveness to tumor migration inhibition factor is not merely a property conferred upon tumor cells by prior animal passage in suspension. These results provide a further suggestion that the capacity for lymphokine-induced migration inhibition is a general property of tumor cells. This in turn raises the possibility that this capacity might vary in a predictable manner with malignant potential.