Neuron-specific enolase in relation to differentiation in human neuroblastoma

The presence of the two forms of enolase, neuron-specific enolase (NSE) and non-neuronal enolase (NNE), have been examined in biopsy material of human neuroblastoma, ganglioneuroblastoma, ganglioneuroma and cultured neuroblastoma cells, after separation with ion exchange chromatography. The enolase activities were inhibited in the presence of NaCl but remained active in KCl, which were used in the chromatographic step. The relative NSE levels in the neuroblastoma tissues were found to be lower than in the histopathologically more differentiated forms of the tumour, i.e. ganglioneuroblastoma and ganglioneuroma. The human neuroblastoma in vitro cell lines SK-N-SH, SH-SY5Y, SK-N-MC and IMR-32 contained considerably lower relative levels of NSE compared to the levels in the neuroblastoma biopsies. After treatment of the cultured cells with nerve growth factor or dibutyryl-cAMP some cells showed morphological differentiation and concomitantly an increase in the NSE levels. The results indicate that NSE might be useful as a marker for differentiation in human neuroblastoma.