Induction of transplantation immunity to rat colon carcinoma isografts by implantation of intact fetal colon tissue.

The objective of this study was to demonstrate whether intact fetal colon tissue can induce immunity to large-bowel cancer isografts. Adult rats were immunized against fetal antigens by implantation of mitomycin-C-treated intact fetal colon tissue beneath the renal capsule. Control animals received implants of pieces of intact adult colon tissue. Kidneys containing the implants were removed after 3 or 5 weeks and the rats were challenged with isografts of a 1,2-dimethylhydrazin (DMH)-induced colon carcinoma. Significant inhibition of tumor growth was observed in immunized groups compared to controls. The present results indicate that some embro-fetal antigens expressed in intact colon tissue of 13 to 15-day-old fetuses are also expressed in colon carcinoma cells and can act as transplantation antigens.