Modified adhesion behavior after in vitro passage of two related murine mammary adenocarcinomas with different metastasizing ability.

The effect of purified extracellular matrix components (EMC) as mediators of cell attachment was studied in vitro using two related murine mammary adenocarcinomas with different metastasizing ability. Freshly harvested cells from M3, the less metastatic tumor, exhibited a similar low affinity for fibronectin, laminin, type IV collagen and the control protein albumin, while the highly metastatic MM3 cells attached preferentially to fibronectin. On the other hand an enhancement of the spreading and adhesion rate to the EMC was observed after primary culture. MM3 cultured cells showed almost the same affinity for all EMC while M3 cells specially attached to fibronectin and type I collagen. The data indicate that in vitro passage can modify the adhesion behavior of these metastatic adenocarcinoma cells to EMC.