Derepression of Glis2 expression in Ring1A/B-deleted MOZ-TIF2 leukemic cells. (A) Hierarchical clustering analysis of gene expression in MOZ-TIF2 leukemic cells from Ring1A^−/−;Ring1B^f/fBM, Ring1A^−/−;Ring1B^Δ/ΔBM, Ring1A^−/−;Ring1B^f/fInk4a/Arf^+/+ FL, Ring1A^−/−;Ring1B^Δ/Δ;Ink4a/Arf^+/+ FL, Ring1A^−/−;Ring1B^f/f;Ink4a/Arf^−/− FL, and Ring1A^−/−;Ring1B^Δ/Δ;Ink4a/Arf^−/− FL. 1, 2, 4, and 5 refer to results obtained from cells cultured for 48 hours in the presence or absence of 4-OHT; 3 refers to results obtained from cells cultured for 7 days. (B) Quantitative RT-PCR analysis of Glis2 expression. RNA was extracted from cells incubated with 4-OHT for 48 hours (mean ± SD, *P < .05, n = 3). (C) Western blot analysis of Ring1B, Glis2, and MOZ-TIF2 expression. Cell lysates were obtained after incubation with 4-OHT for 48 hours. (D) Immunofluorescence staining for Glis2 in MOZ-TIF2 leukemic cells incubated with 4-OHT for 96 hours. Cells were picked from vehicle-treated compact colonies or 4-OHT–treated loose colonies and attached to glass slides by cytospin. Scale bar, 50 μm. FL, fetal liver.