c-myb silencing effects on CD14⁻ myeloblasts differentiation. (A) Western blot analysis of c-myb expression 24 hours after the last nucleofection. (B) Results of statistical analysis on the percentage of cells in the different cell-cycle phases performed by PI staining 24 hours after nucleofection (mean ± 2 SEM; n = 5). (C) qRT-PCR data (mean ± 2 SEM; n = 3). (D-E) Flow cytometry analysis of CD14 at day 4 after nucleofection: (D) histogram showing a representative experiment and (E) statistical analysis (mean ± 2 SEM; n = 5). *P ≤ .05, **P ≤ .01, and ***P ≤ .001 vs MOCK and NegCTR. Error bars represent SD. (F) Morphological analysis of May-Grunwald-Giemsa–stained cytospins at day 4 after nucleofection (ie, 3 days after ATRA treatment) for both untreated (i-iii) and ATRA-treated (vii-ix) myeloblasts and at day 11 (ie, after 10 days of GCSF treatment) for GCSF-treated cells (iv-vi). The images were captured by Axioskop 40 microscope, by means of AxioCam HRc Digital Camera and Axiovision software 3.1 (all Carl Zeiss MicroImaging Inc). The images were then processed with Adobe Photoshop 7.0 software. Original magnification ×630. n = number of experiments.