Relationship between fibrin clot retraction and tumorigenesis in C3H/10T1/2 cells.

Fibrin clot retraction (FCR) was studied in C3H/10T1/2 murine fibroblasts. These cells were able to induce FCR with high efficiency during resting phase as well as during active growth. C3H/10/T1/2 cells which became tumorigenic after X-irradiation lacked FCR activity. Non-tumorigenic revertant clones regained the capacity to induce FCR, while revertants which progressively back-reverted to the neoplastic state showed intermediate FCR activity. These unstable revertants, when again fully tumorigenic, completely lost FCR activity.