Figure 4.

MLN4924 stabilizes β-catenin and p27, activates the cell-cycle checkpoint protein CHK1 and induces DNA damage in Ph+ leukemia cells. (a) Immunoblot analysis for β-catenin, p27 and phospho-CHK1 (ser317) levels in BV173 and SUPB15 Ph+ leukemia cells treated for 24 hours with MLN4924 at indicated concentrations. The β-catenin blot was used to control for loading. (b) Immunofluorescent γH2AX staining in BV173 cells treated overnight with DMSO (vehicle) or 400 nM MLN4924, with our without Q-VD-OPh. (c) Bar graphs showing percent of cells with >10 γH2AX foci in BV173 and SUPB15 treated as indicated. For each condition, at least 6 non-overlapping images were captured with a 40x magnification objective and scored manually (on average approximately 120 cells per condition). Means ± SEM are shown. Asterisks indicate statistically significant differences (*p < 0.05; ** p < 0.01, *** p < 0.001, One-way ANOVA).