Fig. 2.

HDAC inhibition and histone acetylation in AM-treated HT29 cells. (A) Whole-cell extracts from human HT29 colon cancer cells were treated directly with the test agents and assayed for HDAC activity (BioMol kit). The IC₅₀ for AM and TSA was 20 μM and 5 nM, respectively. Data = mean ± SD, n = 3, *P < 0.05. (B) HT29 cells were treated with AM (0.5, 1 and 2 mM) or TSA (0.1 and 0.2 μM) for selected times, from 10 min to 72 h, and whole-cell extracts were tested for HDAC activity. Data = mean ± SD, n = 3, *P < 0.05. (C) In the same cell lysates as (B), acetylated histones H3 and H4 were analyzed by immunoblotting. At each time point, acetylated histone expression was normalized to the corresponding non-acetylated histone, and this ratio was assigned an arbitrary value of 1.0 for the vehicle controls. Data are from a single experiment and are representative of findings from experiments repeated at least twice for each time point.