Differentiation of neuroblastoma cells by chick gizzard extract

Cholinergic neuroblastoma NS20Y cells were differentiated by the chicken gizzard extract. They were first inoculated into a glass culture bottle and the aggregated cells which grew in the suspension culture were collected. The aggregated cells (round and immature neuroblastoma cells) were seeded on a polyornithinecoated plastic dish, and the effect of various agents on the differentiation of the neuroblastoma was investigated. When gizzard extract from chicken was added to the culture, many flat cells with neurites emerged around the cell aggregates within 24 h. The flat cells could evoke action potentials with high frequency (in 70% cells). Cyclic GMP levels in the treated cultures were much lower than that in the control culture, and remained continuously lower during 2 days culture. The factor responsible for the differentiation of neuroblastoma cells was rich in the chick gizzard among extracts or conditioned media from various tissues tested. A similar effect was observed by the addition of dibutyryl cyclic AMP or prostaglandin E(1) plus theophylline over a slower time course. The factor in gizzard extract was trypsin-sensitive and heat-labile. The molecular size was estimated to be about 12 s.