Nuclear HDAC activity, class I HDACs mRNA and protein expressions in RASFs after TNFα treatment. RASFs (n = 3) were treated with TNFα (10 ng/ml) and total nuclear protein was extracted at the indicated time points. (a) Nuclear HDAC activity was elevated significantly at 6 h. The data were plotted as means ± SE. * = P < 0.001 versus time 0 h, 24 h. (b) The expression of HDAC1 in RASFs was increased after TNFα treatment, while the expressions of other class I HDACs were not elevated. The increase of mRNA in HDAC1 at 24 h was significantly greater than that in other class I HDACs. For real-time PCR analysis, levels of mRNA were normalized against actin expression and compared with 0 h. * = P < 0.05 versus HDAC2, 3, 8. (c) Quantitative results of Western blot analysis of nuclear class I HDACs protein expression in RASFs. The band intensity of class I HDACs was measured by Image J software. For analysis, levels of protein expression were normalized by lamin A and compared with 0 h. * = P < 0.05 versus HDAC3 and HDAC8 at 48 h.