Effect of ERK-dependent suppression of hnRNP-E2 on C/EBPα expression and neutrophilic differentiation of Lin⁻ BMC-BCR/ABL^high cells and patient-derived CML-BC^CD34+ progenitors. (A) Levels of hnRNP-E2, C/EBPα, G-CSFR, phospho-ERK1/2, and total ERK1/2 in lineage-negative (Lin⁻) mouse bone marrow cells (BMCs) transduced with the empty vector (Lin⁻BMC-MigRI) or with a p210-BCR/ABL retrovirus and sorted for low and high GFP expression (Lin⁻BMC-BCR/ABL^low and -BCR/ABL^high) (left panel). Effect of MAPK inhibition by U0126 on hnRNP-E2 and C/EBPα expression and/or G-CSF–driven differentiation in Lin⁻ BMC-BCR/ABL^high cells (middle and right panels). May-Grumwald/Giemsa–stained representative microphotographs of Lin⁻ BMC-MigRI, BMC-BCR/ABL^low, untreated, and U0126-treated BMC-BCR/ABL^high cells (right panel). (B) Effect of MAPK inhibition by U0126 and CI-1040 on hnRNP-E2 and C/EBPα expression in primary CD34⁺ human normal bone marrow cells (NBM^CD34+) and CML-BC^CD34+ cells (left panel). May-Grumwald/Giemsa staining of NBM^CD34+ and untreated, U0126-treated, and CI-1040-treated CML-BC^CD34+ cells (right panel).