Thromboplastic and fibrinolytic activities of cultured human gastric cancer cell lines.

Thromboplastic and fibrinolytic activities of 8 lines of cultured human gastric cancer cells were estimated both in cell lysate and serum-free supernatant fraction. Furthermore, cell lysates with differing levels of thromboplastic activity were injected intravenously into congenitally athymic nude mice and the role of this activity in thrombus formation was examined. Thromboplastic and fibrinolytic activities of the cell lysate and the serum free-supernatant fraction varied from one line to another. There was no apparent correlation between these activities and the degree of histological differentiation of the original tumor. The thromboplastic activity was factor VII-dependent and factor IX-independent, indicating that it was attributable to tissue thromboplastin, although some factor VII-independent thromboplastic activity was also included in the cell lysate of two lines. Intravenous injection of the cell lysate with high thromboplastic activity produced more thrombi in the lung than that with low thromboplastic activity. This suggests that thromboplastic activity of cancer cells might play a significant role in the development of the hypercoagulable state in patients with gastric cancer.