Determination of three enolase isozymes and S-100 protein in various tumors in children.

Three enolase isozymes (alpha alpha, alpha gamma, and gamma gamma) and S-100 protein in the extract of neuroendocrine tumors (neuroblastoma, ganglioneuroblastoma, ganglioneuroma, and pheochromocytoma) and nonneuroendocrine tumors (Wilms' tumor, rhabdomyosarcoma, and hepatoblastoma) were determined by means of enzyme immunoassay systems. All of the tumors examined showed a high level of alpha alpha-enolase (1.71 to 19.0 micrograms/mg protein). Levels of nervous system-specific enolases (NSE; alpha gamma and gamma gamma) in the neuroendocrine tumors were also rather high (alpha gamma, 1.64 to 7.45 micrograms/mg protein; gamma gamma, 0.052 to 5.56 micrograms/mg protein). However, the NSE concentration in the extract of nonneuroendocrine tumors was low (alpha gamma, less than 0.88 micrograms/mg protein; gamma gamma, 0 microgram/mg protein). The level of S-100 protein was relatively high in ganglioneuroma (greater than 500 ng/mg protein) and ganglioneuroblastoma (greater than 100 ng/mg protein), but low in neuroblastoma (less differentiated neuroendocrine tumor) and nonneuroendocrine tumors. Serum levels of enolase isozymes were also determined in neuroblastoma patients before and after resection of primary tumor or effective chemotherapy. The elevated level of serum NSE (alpha gamma and gamma gamma) was markedly decreased with little change in the alpha alpha level by the treatment.