Morphological and biochemical study in X-ray- and dibutyryl cyclic AMP-induced differentiated neuroblastoma cells

Abstract

X-irradiation or dibutyryl adenosine 3′:5′-cyclic monophosphate (DBcAMP) induced axon formation in mouse neuroblastoma cells in vitro. The differentiated cells showed morphological maturation, as shown by an increase in the cellular and nuclear size. Neuroblastoma cells in the presence of DBcAMP grew at a slightly reduced rate for 2 days; however, at day 3 they reached plateau phase. The removal of DBcAMP and readdition of fresh growth medium at day 4 did not cause renewal of cell division, indicating that morphological cell differentiation for the most part was irreversible. Na-butyrate, 3′5′ cyclic AMP, 5′ AMP, ATP, ADP, 3′5′ cyclic guanosine monophosphate caused inhibition of cell growth but did not produce morphological differentiation. Acetylcholinesterase activity in both the X-ray- and DBcAMP-induced differentiated cells increased by a factor of 10. Na-butyrate and 3′5′ cyclic AMP which inhibited cell division but did not cause morphological differentiation also increased AChE activity to a similar extent.