Cyclic AMP-induced differentiated neuroblastoma cells: changes in total nucleic acid and protein contents

The total DNA contents of neuroblastoma cells “differentiated” by dibutyryl cyclic AMP, prostaglandin E₁ and 4-(-3-butoxy-4-methoxybenzyl)-2-imidazolidinone treatment was about 50 percent that of control cells, indicating that cells were accumulated in the G₁-phase of the cell cycle. Sodium butyrate-treated cells were also accumulated in the G₁-phase; however, the expression of “differentiated” phenotype did not occur indicating that inhibition of cell division is not sufficient for morphological differentiation. A marked increase in RNA and protein contents of cyclic AMP-induced “differentiated” cells is consistent with an increase in the size of soma and nucleus.