Effect of C/EBPs in cycloheximide versus actinomycin D on induction of lysozyme and C/EBPε.

Lysozyme and C/EBPε are induced by C/EBPs in cycloheximide but not actinomycin D. The 32D-C/EBPαWT-ER (32D–αWT-ER) or 32D–C/EBPβWT–ER-1 (32D–βWT-ER) cells proliferating in IL-3 were exposed to 1 μM estradiol (Est), 50 μg/mL cycloheximide (CHX), both, or neither for 8 hours. The 32D–C/EBPαWT-ER cells were also cultured with actinomycin D (Act) with and without estradiol. Total cellular RNAs were then isolated and subjected to Northern blotting for lysozyme, C/EBPε, and MPO. An ethidium stain of ribosomal RNAs is also shown as a control for RNA integrity and loading (bottom panels).