Adenocarcinoma R-3327 of the Copenhagen rat as a suitable model for immunological studies of prostate cancer.

An experimental animal model for the study of host-prostatic tumor cell interactions has been described. R-3327, a line of prostatic adenocarcinoma of the Copenhagen rat, has been proven to be immunogenic to its syngeneic host as evidenced by two different in vitro cell-mediated immune assays. Specificity of the responses has been ascertained on the basis of absence of response: (a) of nonimmune lymphocytes to the R-3327 tumor antigen(s); (b) of R-3327 immune lymphocytes to several normal tissues including normal prostate; (c) of immune lymphocytes to unrelated squamous cell prostatic carcinoma of the Copenhagen rat. Furthermore, the presence of tumor has an effect in several nonspecific aspects of host response, inducing splenomegaly, heightened responses to nonspecific mitogens in lymphocyte transformation assay, and increased levels of killer cell action. Since there are many histological, biochemical, and functional analogies between this tumor line and human prostate carcinomas, this system appears to be suitable for immunological and possible immunotherapeutic studies of this type of neoplasia.