title: Inhibition of Class I Histone Deacetylases 1 and 2 Promotes Urothelial Carcinoma Cell Death by Various Mechanisms.
abstract: Class I histone deacetylases HDAC1 and HDAC2 contribute to cell proliferation and are commonly upregulated in urothelial carcinoma. To evaluate whether specific inhibition of these enzymes might serve as an appropriate therapy for urothelial carcinoma, siRNA-mediated knockdown and specific pharmacologic inhibition of HDAC1 and HDAC2 were applied in urothelial carcinoma cell lines (UCC) with distinct HDAC1 and HDAC2 expression profiles. HDACs and response marker proteins were followed by Western blotting and qRT-PCR. Effects of class I HDAC suppression on UCCs were analyzed by viability, colony forming, and caspase-3/7 assays; flow cytometry, senescence and lactate dehydrogenase cytotoxicity assays; and immunofluorescence staining. Whereas single knockdowns of HDAC1 or HDAC2 were impeded by compensatory upregulation of the other isoenzyme, efficient double knockdown of HDAC1 and HDAC2 reduced proliferation by up to 80% and induced apoptosis-like cell death in all UCCs. Clonogenic growth was cell line- and HDAC-dependently reduced, with double knockdown of HDAC1 and HDAC2 being usually most efficient. Class I HDAC-specific inhibitors, especially the more specific HDAC1/2 inhibitors romidepsin and givinostat, significantly reduced proliferation of all UCCs (IC50, 3.36 nmol/L-4.59 μmol/L). Romidepsin and givinostat also significantly inhibited clonogenic growth of UCCs, with minor effects on nontumorigenic controls. Intriguingly, these compounds induced primarily S-phase disturbances and nonapoptotic cell death in UCCs. Thus, although both ways of inhibiting HDAC1/2 share mechanisms and efficaciously inhibit cell proliferation, their modes of action differ substantially. Regardless, combined inhibition of HDAC1/2 appears to represent a promising strategy for urothelial carcinoma therapy. Mol Cancer Ther; 15(2); 299-312. ©2016 AACR.
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Pinkerneil
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: Michèle J
authors.initials: MJ
authors.lastname: Hoffmann
authors.affiliation: Biological and Medical Research Center (BMFZ), Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Deenen
authors.affiliation: Biological and Medical Research Center (BMFZ), Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Köhrer
authors.affiliation: Institute of Forensic Medicine, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Arent
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Schulz
authors.affiliation: Department of Urology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany. Guenter.Niegisch@med.uni-duesseldorf.de.
authors.forename: Günter
authors.initials: G
authors.lastname: Niegisch
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols; D017209:Apoptosis; D002219:Carbamates / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D047630:Depsipeptides / Q000494:pharmacology*; D055785:Gene Knockdown Techniques; D056284:Histone Deacetylase 1 / Q000235:genetics / Q000378:metabolism*; D056464:Histone Deacetylase 2 / Q000235:genetics / Q000378:metabolism*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006801:Humans; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000201:enzymology*
chemical_list: D002219:Carbamates; D047630:Depsipeptides; D056572:Histone Deacetylase Inhibitors; C575255:givinostat; C087123:romidepsin; C110550:HDAC1 protein, human; C533423:HDAC2 protein, human; D056284:Histone Deacetylase 1; D056464:Histone Deacetylase 2