14-3-2 protein in rat primary and transplanted gliomas and neurinomas and in clonal cell lines

Experimental neurogenic tumors were induced transplacentally in rats by single injections of ethylnitrosourea (ENU). The resulting primary tumors as well as isogenic transplantation tumor lines and clonal cell lines derived therefrom were examined for their content of the brain specific protein 14-3-2 by a quantitative microcomplement fixation assay. The content of S-100 protein in the samples studied is given as well. Some of the tumors of glial or Schwann cell origin did contain 14-3-2 protein ranging from 0.6 to 1.5 mug 14-3-2 per mg total soluble protein. Our experiments also showed that the ability of a tumor to produce this specific protein is transplantable over a series of subcutaneous isogenic transplantations while in the transplantation tumors the content of this protein seemed to be reduced. We were not able so far to find a correlation between the morphology of a tumor and its capability to produce a specific protein. The clonal cell line RN2 of Schwann cell origin which has been previously described in detail contained both the brain specific proteins 14-3-2 and S-100 in comparable amounts ranging from 0.3 to 0.6 and from 0.4 to 1.0 mug specific protein per total soluble protein respectively.