Mutations, dysregulation, and dysbalance of epigenetic regulators are especially frequent in urothelial carcinoma (UC) compared to other malignancies. Accordingly, targeting epigenetic regulators may provide a window of opportunity particularly in anticancer therapy of UC. In general, these epigenetic regulators comprise DNA methyltransferases and DNA demethylases (for DNA methylation), histone methyltransferases, and histone demethylases (for histone methylation) as well as acetyl transferases and histone deacetylases (for histone and non-histone acetylation).As epigenetic regulators target a plethora of cellular functions and available inhibitors often inhibit enzymatic activity of more than one isoenzyme or may have further off-target effects, analysis of their functions in UC pathogenesis as well as of the antineoplastic capacity of according inhibitors should follow a multidimensional approach.Here, we present our standard approach for the analysis of the cellular and molecular functions of individual HDAC enzymes, their suitability as treatment targets and for the evaluation of isoenzyme-specific HDAC inhibitors regarding their antineoplastic efficacy. This approach may also serve as prototype for the preclinical evaluation of other epigenetic treatment approaches.
Keywords: Epigenetics; Histone deacetylase inhibitors; Histone deacetylases; Targeted therapy; Urothelial carcinoma.