1-beta-D-Arabinofuranosylcytosine stimulates ceramide and diglyceride formation in HL-60 cells.

The effect of 1-beta-D-arabinofuranosylcytosine (ara-C) on phospholipid metabolism was investigated in HL-60 cells. Treatment of cells with ara-C resulted in a time- and dose-dependent increase in the mass of ceramide and diglyceride. When cells were treated with 10 microM ara-C, an increase in the mass of ceramide and diglyceride was detectable at 5 min and reached a plateau at 30 min with a 2-fold increase compared to control cells. Treatment of cells with 10 microM ara-C resulted in the activation of neutral sphingomyelinase with a peak at 30 min that represented a 2-fold increase in specific activity. ara-C also increased expression of the transcription factor NF-kappa B which is related to the control of monocyte differentiation. These findings suggest that ara-C activates phospholipid hydrolytic pathways to generate second messengers that control gene expression and differentiation in the HL-60 cell line.