Immunohistochemical analysis of DNMT1 and DNMT3a expression. HepG2 xenografts were treated with daily i.p. injections of 10 mg/kg panobinostat for 28 days. Untreated controls show a high nuclear expression of both DNMTs, while a significant reduction in expression is observed in treated samples. Bar diagram shows mean percentage of positive cells ± standard deviation of n = 5 in each group. * P < 0.05 vs. untreated controls. Bar represents 20 μm (400× magnification) for overview and 10 μm (1000 x magnification) for detailed areas (marked by a rectangle).