The 32D cells expressing dominant-negative STAT3 show differentiation block but normal C/EBPε induction.

(A) Construction of dominant-negative STAT3. (B) Growth curve of 32D/DN-STAT3. Cells were cultured in 25 U/mL IL-3 (○), 50 ng/mL G-CSF (▴), or without cytokines (▪). (C) Morphologic features of 32D/DN-STAT3 cells cultured in IL-3 or G-CSF and stained with Wright-Giemsa stain (original magnification, ×400). (D) Expression of C/EBPε and MPO mRNA in 32D/DN-STAT3 cells. Cells were transferred from IL-3 to G-CSF and subjected to Northern blot analysis at the times indicated.