Polycomb Silencing in MM Figure 3. The expression of H3K27-tri-methylated genes is reactivated by DZNep and LBH589 in MM cell lines. The RPMI 8226 cells (A) and (C), and the U-266-1984 cells (B) and (D) were treated with DZNep (10 mM) or LBH589 (20 nM) for 6, 24, 48 and 72 hours. Fold difference in expression was calculated relative to the untreated cells. GAPDH was used as a reference gene. Error bars represent SD from three independent biological experiments. doi:10.1371/journal.pone.0011483.g003 Figure 4. DZNep and LBH589 deplete EZH2 protein level in MM cell lines. (A) and (B): The RPMI 8226 cells (A) and the U-266-1984 cells (B) were treated with DZNep (10 mM) for 6, 24, 48 and 72 hours. (C) and (D): The RPMI 8226 cells (C) and the U-266-1984 cells (D) were treated with LBH589 (20 nM) for 6, 24, 48 and 72 (RPMI 8226) or 6, 24 and 48 hours (U-266-1984). Western blot was performed using a specific antibody against EZH2. Actin was used to control for equal loading. doi:10.1371/journal.pone.0011483.g004 PLoS ONE | www.plosone.org 5 July 2010 | Volume 5 | Issue 7 | e11483