Primary (Methylcholanthrene-induced) Fibrosarcomas and Glycopro- tein Synthesis1

Paper-strip electrophoretic studies using tris(hydroxymethyl)aminomethane-ethylene diaminetetraacetic acid-boric acid buffer were carried out on the serum of rats bearing primary methylcholanthrene-induced fibrosarcomas as well as 1st and 2nd transplant generation autografts and isografts of such tumors. It was found that, though bearing histologically similar tumors, serum of different rats produced characteristic and differentiat ing electrophoretic patterns. The differentiating component, not detectable immunoelectrophoretically in normal rat serum, was a specific glycoprotein with alpha-2-globulin mobility (a-2-GP). Heterogeneity of the serum glycoprotein patterns permitted classification of these neoplasms into Strong secretors, Weak secretors, and Non-secretors. That production of a-2-GP was donor-graft associated rather than a nonspecific host response to neoplastic growth was indicated by the stability and heritability of the electrophoretic pattern characterizing each primary tumor in subsequent transplant generations and by the observa tions that different primary tumors arising in the same general area produced different patterns in the same host. Comparative chemical determinations made on the protein-bound carbohy drate in the serum of blood taken from the tumor-efferent vessels and heart blood of the same tumor-bearing animal revealed not only that the heart blood of rats bearing strong-secreting tumors contained more protein-bound hexose than that of rats bearing weakor non-secreting tumors but also that there was a signifi cantly greater concentration in tumor-efferent blood compared with heart blood in the same animal when it was bearing a strongsecreting tumor. The indication of serum a-2-GP levels as a specific host-response to the biologic activity of particular cell types making up certain neoplasms of connective tissue origin adds another parameter to the differentiation of these histologi cally similar tumors and raises the question of tumor-host rela tionship, especially since animals bearing strong-secreting tumors