Enforced expression of miR-125b blocks granulocytic differentiation, enables G-CSF–dependent cell proliferation, and delays cytokine withdrawal–induced cell death. (A) miR-qRT-PCR of mature miR-125b level at the indicated time points; sno-202 served as an endogenous control. (B) Proliferation kinetics of the 32D cells expressing miR-ctrl (circle), miR-125b-1 (star), and miR-125b-2 (triangle) in G-CSF-supplemented suspension cultures. (C) Morphology of 32D derivates (May-Grunwald-Giemsa staining) on day 7 of IL-3 (top panel) and G-CSF (bottom panel) supplemented cell cultures. A 60× magnification of a representative field is shown. (D) Viability of 32D/miR-ctrl and 32D/miR-125b cells after IL-3 deprivation analyzed by trypan blue dye exclusion, and (E) monitoring of GFP⁺ population (left panel), and propidium iodide (PI) and annexin-V stained GFP⁺ fraction (right panel). Mean of at least 3 (panels A,B,D) and representative experiments are shown, respectively. * P < .05 compared with control at corresponding time point of treatment.