Neuron-specific enolase in neuroblastoma and other pediatric tumors: a comparative nude mouse and clinical investigation.

Neuron-specific enolase (gamma-subunit isozyme) in extracts of human neuroblastomas and other tumors in children was measured by means of a radio-immunoassay in order to elucidate the rationale for clinical determination of its serum concentrations in patients. Surgical specimens as well as tumors xenotransplanted in nude mice were studied. The neuron-specific enolase (NSE) concentrations in extracts of xenografted and surgical neuroblastomas were 1,733.2 +/- 677.3 (range; 883-2,659) ng/mg protein and 1,735.3 +/- 941.1 (559-2,933) ng/mg protein, respectively, while other pediatric tumors examined showed much lower levels of NSE: 121.5 +/- 146.1 (22-374) ng/mg protein in xenografts and 17.7-610 ng/mg protein in surgical specimens. Sera of nude mice bearing human neuroblastomas also showed NSE concentrations ranging from 1,102 to 4,400 ng/ml, very much higher than those in sera of nude mice without tumors or with other pediatric tumors. These results tend to confirm the specificity of NSE for neuroblastoma, and the difference in NSE concentrations among five neuroblastoma xenografts is discussed in relation to their cytogenetic characteristics.