Procoagulant (Tissue Factor) Activity Is Higher In Cells From Murine Sarcoma Sublines With Lower Metastatic Potential

Abstract

It has been suggested that cancer cell procoagulant activity influences metastasis formation by promoting fibrin deposition around tumors. We have investigated the procoagulant activity of various tumor cell sublines with different metastatic capacity. These were derived from spontaneous lung nodules of mFS6, a benzopyrene-induced sarcoma in C57B1/6 mice. After one in vivo passage by s.c. implantation, the resulting tumor was cultured once in vitro till confluence; cells were then harvested from plastic bottles by trypsin treatment, and washed extensively after trypsin neutralization. Tumor cell procoagulant activity was measured by a one-stage clotting assay using autologous plasma. All the cells tested possessed thromboplastin-like activity since they shortened the recalcification time of normal and factor VUI-deficient plasma to a similar extent but had no activity on factor Vll-deficient plasma.They were, however, heterogeneous as regards the degree of procoagulant activity; the two cell lines with virtually no metastatic capacity showed 6-8 times higher procoagulant activity than the cells from the parent line; in contrast, the procoagulant activity of the two sublines with higher metastatic capacity did not differ significantly from that of the parent line.These findings support the hypothesis that fibrin is part of a defence reaction against cancer cell invasiveness.