Hdac1 knock-down in APL blasts increases mice survival duration. (A-C) APL blasts from 129sv mice were transduced with the indicated vectors, sorted for GFP positivity, and transplanted in wt mice. (A) Analysis of Hdac1 mRNA levels in APL blasts transduced with the indicated retroviral vectors. Values are normalized against GAPDH and referred to CTRL. The graph represents the average and standard deviation of 3 independent experiments. (B) Immunoblot analysis of the expression of Hdac1, 2, and 3 and histone ³H acetylation in GFP⁺ APL blasts transduced as indicated. Histone ³H served as a loading control. (C) Leukemia-free survival curves of mice transplanted with APL blasts transduced with the indicated vectors and then were sorted for GFP expression (CTRL vs HDAC1-KDA or CTRL vs HDAC1-KDB: P < .05). (D) Leukemia-free survival curves of C57Bl/6-Ly5.1 recipient mice transplanted with APL cells derived from the mCG^PR/PR leukemic mouse #1.VPA treatment was started when the blast cells in peripheral blood reached 5% to 10%. CTRL vs VPA: P < .001. Day 0 indicates the start of the treatment.