Differential expression of neuron-specific enolase mRNA in mouse neuroblastoma cells in response to differentiation inducing agents.

1. The mouse neuroblastoma cell line N-115 was used as a model system to study neuronal differentiation induced by treatment of cells with different agents. 2. The extent of morphological differentiation obtained with dibutyryl cyclic AMP (dbc-AMP), dimethyl sulfoxide (DMSO), retinoic acid (RA), and serum-free medium was correlated to the expression of the mRNA for the gamma isoform of the glycolytic enzyme enolase, a recognized neuron-specific marker. 3. A 4-day treatment of the cells with any of the differentiation inducing agents used in this study resulted in the extension of long neurites, though differences in cell body shape were observed depending on the agent used. 4. Northern blot analysis revealed that changes in the level of gamma enolase-specific mRNA correlate with the extent of morphological differentiation, with a 5- to 20-fold increase depending on the differentiation inducing agent used. 5. Finally, we found that a high cell density causes a significative increase in the level of the gamma enolase-specific message in cells maintained in growing conditions.