Immunocytochemical evidence of neuron specific enolase (NSE) in human adenovirus 12-induced retinoblastoma-like tumor cells in vitro.

Abstract
Retinoblastoma-like tumor cells (EXP-5 cell line) derived from a tumor in an inbred albino rat by human adenovirus 12 have been maintained in culture. We investigated immunocytochemical localization of neuron specific enolase (NSE) and S-100 protein in cultured tumor cells before and after successful differentiation into neuronal and glial-like cells. After the addition of cyclic AMP analog, a neurite-like process developed, and they tended to form a network after 24 hr. Before and after successful differentiation, the cultured cells exhibited simultaneous expression of NSE and S-100 protein. Differentiated cells showed a tendency to express the marker that correlated with their morphology. These results supported the idea that adenovirus 12-induced retinoblastoma-like tumor was derived from bipotential precursor cells.