GFA and S 100 protein levels as an index for malignancy in human gliomas and neurinomas.

Human glia-specific proteins S 100 and GFA were quantitated by use of a rocket immunoelectrophoresis technique with monospecific antisera. No relation was found between the S 100 protein content of an astrocytoma and its degree of neoplasia. However, the lower the GFA protein content of the astrocytoma, the more malignant it was. Similarly, the more malignant a neurinoma was, the lower was its S 100 protein content. Therefore, the levels of these proteins might be used as indexes of neoplastic dedifferentiation.