1974 Volume 112 Issue 2 Pages 155-163
RNA was extracted from the spleen cells of the rats or rabbits which had been immunized with Yoshida sarcoma (YS-immune rats or rabbits). Twenty per cent of the recipient rats previously injected with the RNA survived against the inoculation of YS tumor cells. Allogeneic lymphoid cells were incubated with the RNA from the YS-immune rats and then transferred to the recipient rats. Eight days after the transfer, YS tumor cells were inoculated into the peritoneal cavities of the same animals. The survival rate of these recipient rats was 50%. In similar experiments, when the RNA from the YS-immune rabbits was used in the incubation, instead of the rat RNA, the survival rate of the recipient rats was 30%. Splenic RNA from the normal rats and rabbits and from the rabbits sensitized with splenic supernate of normal rats exhibited no antitumor effect. The antitumor effect of RNA derived from the YS-immune rats was lost by treatment with RNAse.
