title: Changes in histone deacetylase (HDAC) expression patterns and activity of HDAC inhibitors in urothelial cancers.
abstract: OBJECTIVE
  To determine histone deacetylase (HDAC) isoenzyme expression patterns in urothelial cancer tissues and cell lines and investigate their potential to predict the efficacy of the HDAC inhibitor vorinostat.
  
  
  METHODS
  Expression of HDAC mRNAs was determined by quantitative RT-PCR in 18 urothelial cancer cell lines (UCC), normal uroepithelial controls (NUC), 24 urothelial cancer tissues, and 12 benign controls. Results were compared with published microarray data. Effects of pan-HDAC inhibitor vorinostat and on UCCs were determined by viability and apoptosis assays, cell cycle analysis, and measurements of p21(CIP1), thymidylate synthase (TS), and EZH2. In addition, protein expression levels of HDACs were investigated in UCCs.
  
  
  RESULTS
  Prominent changes in UCCs were HDAC2 and/or HDAC8 up-regulation in 11 of 18 cell lines and decreased expression of HDAC4, HDAC5, and/or HDAC7 mRNA in 15 of 18 cell lines. In cancer tissues, HDAC8 was likewise significantly up-regulated (P = 0.002), whereas HDAC2 up-regulation was detected only in a subset of tumors (9/24, P = 0.085). Overexpression of HDAC2 and HDAC8 mRNA did not correspond with the protein level. Vorinostat induced G2/M arrest, an increase in the sub-G1 fraction, up-regulation of p21, and down-regulation of TS in all UCC. Effects on EZH2 and PARP cleavage as well as activation of caspase 3/7 differed between cell lines. Associations between the overall sensitivity to the pan-HDACi vorinostat and overexpression of HDAC2 and HDAC8 mRNA were not observed.
  
  
  CONCLUSIONS
  In urothelial cancer, up-regulation of HDAC2 and HDAC8 and down-regulation of HDAC4, HDAC5, and HDAC7 mRNA are common findings. The treatment effect of the pan-HDAC inhibitor vorinostat was variable in UCCs and up-regulation of HDAC2 and HDAC8 was not predictive for treatment response. Whether selective targeting of HDAC2, HDAC8, or other HDACs deregulated in urothelial cancer (e.g., HDAC4, HDAC5, and HDAC7) result in a more consistent treatment response needs further investigation.
authors.affiliation: Department of Urology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany. Electronic address: guenter.niegisch@med.uni-duesseldorf.de.
authors.forename: Günter
authors.initials: G
authors.lastname: Niegisch
authors.forename: Judith
authors.initials: J
authors.lastname: Knievel
authors.forename: Annemarie
authors.initials: A
authors.lastname: Koch
authors.forename: Christiane
authors.initials: C
authors.lastname: Hader
authors.forename: Ute
authors.initials: U
authors.lastname: Fischer
authors.forename: Peter
authors.initials: P
authors.lastname: Albers
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Schulz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000071221:Enhancer of Zeste Homolog 2 Protein; D005260:Female; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006655:Histone Deacetylases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D059467:Transcriptome; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000077337:Vorinostat
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007527:Isoenzymes; D000077337:Vorinostat; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases; D006655:Histone Deacetylases