Effect of C/EBP inhibition on differentiation in response to exogenous G-CSFR.
Inhibition of C/EBPs blocks and even reverses differentiation in response to exogenous G-CSFR. (A) First, 2 × 10532D-KαER/GR cells were transferred to G-CSF without 4HT (○) or with 4HT (●). Viable cell counts performed daily are shown. (B) Cells from these same cultures were cytospun and subjected to Wright-Giemsa staining. Cells are shown in IL-3, after transfer to G-CSF in the absence of 4HT for 2, 4, or 6 days (G2, G4, G6), or after transfer to G-CSF in the presence of 4HT for 1, 2, 4, or 8 days (G1, G2, G4, G8). Original magnification ×100. (C) The 32D-KαER/GR cells were transferred to G-CSF without or with 4HT. A subset of cells cultured in the absence of 4HT for 3 days were then exposed to 4HT (−/+ d3). Total cellular RNAs prepared on days 0, 1, 2, 3, 4, 5, and 6 were subjected to Northern blot analysis, 20 μg per lane, for MPO, lysozyme (Lys), LF, C/EBPα, C/EBPβ, C/EBPε, and β-actin.
