ACTIVATION OF THE JUN-D GENE DURING TREATMENT OF HUMAN MYELOID-LEUKEMIA CELLS WITH 1-BETA-D-ARABINOFURANOSYLCYTOSINE

The jun-D gene is a member of the c-jun family of early response genes that code for DNA binding proteins. The present studies demonstrate t hat 1-beta-D-arabinofuranosylcytosine (ara-C) increases jun-D expressi on in HL-525 myeloid leukemia cells. This induction by ara-C was maxim al at 6 hr and transient. In contrast, ara-C had no detectable effect on the gene coding for the cAMP-responsive element binding protein 1. Nuclear run-on assays demonstrated that ara-C treatment is associated with an increased rate of jun-D transcription. The results also show t hat jun-D transcripts are stabilized at a posttranscriptional level in ara-C-treated cells. Taken together, these results demonstrate that a ra-C induces expression of the jun-D gene and that this effect is regu lated by transcriptional and posttranscriptional mechanisms.