CORRELATION OF DIFFERENCES IN ANTIGENICITY OF 4 3-METHYLCHOLANTHRENE-INDUCED TUMORS IN SYNGENEIC MICE WITH SUSCEPTIBILITY OF TUMORS TO AN IMMUNOPOTENTIATOR, PS-K

  • 1 January 1978
    • journal article
    • research article
    • Vol. 69  (2) , 223-228
Abstract
Eleven syngeneic tumors were induced by 3-methylcholanthrene in DDD mice. Their antigenicity in vivo was examined by measuring growth inhibition of transplanted tumors in mice immunized by implanting tumors into their tails and then cutting off the tail. Four tumors with different antigenicity were selected from them for study. The growth-suppressive effect of an immunotherapeutic agent, PS-K [coriolus versicolor protein bound polysaccharide] on the 4 tumors was examined. The growth of highly antigenic tumors in mice was inhibited by PS-K, but that of weakly antigenic tumors was not, and a close correlation was found between the antigenicity of tumors and the antitumor activity of PS-K against them. No similar correlation was found between antigenicity and sensitivity to a mitotic poison, 6-mercaptopurine. The antitumor effect of an immunopotentiator depends on the antigenicity of tumors.