Effect of immunisation with cancer procoagulant on the growth of Walker 256 carcinosarcoma cells in rats.

The effect of preimmunisation with cancer procoagulant (CP) on the growth of Walker 256 carcinosarcoma cells in Wistar Lew/Han/IMP rats in vivo has been analysed. One group of rats was immunised with CP purified from human amnion-chorion membranes. The rest of the animals (control groups) were injected with 0.9% NaCl in Freund’s adjuvant or were not immunised at all. When the presence of polyclonal anti-CP antibody was detected in CP-immunised rats’ serum, all (CP-immunised and control) animals were injected i.p. with 4.8x105 Walker 256 cells per rat. After 5 days ascitic fluid was collected and viable cells were counted. The complete lack of viable Walker 256 carcinosarcoma cells in 24% of the CP-immunised rats was observed. However, the viable neoplastic cells were present in all control (NaCl-injected and nonimmunised) animals. It seems possible that CP plays an important role in tumour progression, so immunisation with CP can reduce the risk of development of malignant disease. [ABSTRACT FROM AUTHOR]