Expression of different histone deacetylases and p21WAF1 in untreated and vorinostat-treated MES-SA cells. (a) Immunoblot analyses were used to examine the expression of different HDACs from class I (HDAC 1, 2 and 3) and class II (HDAC7). Note that not all HDACs were equally affected by vorinostat. HDAC2, 3 and 7 were highly deregulated, whereas HDAC1 was not affected. The expression of cyclin-dependent kinase inhibitor p21WAF1 was highly increased in vorinostat-treated MES-SA cells. (b) Western blot data were quantified densitometrically and beta-tubulin was used as a loading control.