Neuron-Specific Enolase (NSE)

The γ-subunit of d-phospho-d-glycerato hydrolyase (EC 4,2,1,11), neuron-specific enolase (NSE) is present in peripheral nerve and neuroendocrine tumors, neuroblastomas, carcinoid, medullary thyroid carcinomas, melanomas, and pheochromo cytomas. NSE may be used as a biological marker of neuroendocrine cells and their tumors. Enolase is a dimeric glycolytic enzyme composed of α and β subunits which are immunologically distinct. The α subunit of enolase is found in adult tissues, and the fetal form the enzyme, β-enolase, is present in smooth muscle. ¹ Recently, it was reported that r-enolase may not be specific for neural structures and that it may exist in other tissues. ² Thomas et al. ³ reported that monoclonal antibody against NSE was slightly less sensitive but more specific than the polyclonal heterologous antiserum. Only 2% of tumors of neural origin stained positively with monoclonal NSE antibody, whereas 20% of tumors were positive with polyclonal NSE antiserum.