Enolase isoenzymes in human cerebral metastasis

gamma-Enolase [one of the three possible subunits of the dimeric enzyme enolase (EC 4.2.1.11)] has been reported as a marker for human neurons, neuroendocrine cells and tumors derived from these cells. In recent years, however, its presence has been reported in nonneuronal tumors. For employment in the histopathologic diagnosis of tumors of the nervous system, exact knowledge of the enolase isoenzyme patterns occurring in these tumors is a prerequisite. In human gliomas, the presence of varying quantities of gamma-enolase has been demonstrated. The present study examines the enolase isoenzyme pattern in human cerebral metastases of various primary progeny, using electrophoresis of tumor tissue extracts as well as immunohistochemistry. Additionally, a number of primary tumors of nonneuroepithelial tissue was examined by immunohistochemistry. The presence of gamma-enolase was demonstrated in a significant number of brain metastases. A relation between enolase isoenzyme pattern and survival after operation for brain metastasis could not be found. For histopathologic diagnosis of tumors of the adult human central nervous system, analysis of the enolase isoenzyme pattern is not reliable.