Effect of C/EBP when 32D cl3 cells are cultured in G-CSF.
C/EBP inhibition leads to apoptosis without differentiation when 32D cl3 cells are cultured in G-CSF. (A) First, 2 × 10432D–KαER-1 (circles) or 32D–KVER-2 (squares) cells were cultured in IL-3 either without 4HT (open) or with 4HT (filled), and viable cell counts were obtained daily. Results of a typical experiment are shown (top). Then, 2 × 105 32D–KαER-1 or 32D–KVER-2 cells were transferred to G-CSF without or with 4HT, and viable cell counts were again obtained daily (bottom). (B) Morphology of 32D–KVER-2 cells in IL-3 and after transfer to G-CSF for 2, 7, or 12 days (G2, G7, G12) with 4HT. Wright-Giemsa stain, original magnification ×100. (C) Morphology of 32D–KαER-1 cells in IL-3, after transfer to G-CSF for 2, 7, or 13 days (G2, G7, G13) without 4HT, or in G-CSF for 1 or 2 days (G1, G2) with 4HT. Wright-Giemsa stain, original magnification ×100. (D) Total cellular RNAs were prepared from 32D–KαER-1 or 32D–KVER-2 cells proliferating in IL-3 or 1 day after transfer to G-CSF, without or with 4HT. These RNAs, 20 μg per lane, were subjected to Northern blot analysis for MPO and β-actin.
