Evaluation of the effects of histone deacetylase inhibitors on cells from canine cancer cell lines.
OBJECTIVE
To determine whether exposure of canine cancer cells to histone deacetylase (HDAC) inhibitors S(+)-N-hydroxy-4-(3-methyl-2-phenyl-butyrylamino)benzamide (OSU-HDAC42) or suberoylanilide hydroxamic acid (SAHA) results in increased histone acetylation and decreased cell viability and whether any changes in viability involve induction of apoptosis or alterations in progression of the cell cycle.


METHODS
9 canine cancer cell lines.


METHODS
Cells from 9 canine cancer cell lines were treated with dimethyl sulfoxide vehicle, OSU-HDAC42, or SAHA, then assays of cell viability were performed. Histone acetylation was assessed by use of western blot analysis. Apoptosis was assessed via ELISA to detect fragmentation of cytoplasmic nucleosomal DNA and western blot analysis to detect cleavage of caspase 3. Cell cycle analysis was performed by use of propidium iodide staining and flow cytometry. RESULTS-Concentrations of OSU-HDAC42 and SAHA required to achieve 50% inhibition of cell viability (IC(50)) were reached in cells of 6 and 4 canine cancer cell lines, respectively, and ranged from approximately 0.4 to 1.3 microM for OSU-HDAC42 and 0.6 to 4.8 microM for SAHA. Cells from T-cell lymphoma, mast cell tumor, osteosarcoma, and histiocytic sarcoma lines were most sensitive to HDAC inhibition, with IC(50)s of < 1 microM for OSU-HDAC42 and < 5 microM for SAHA. Induction of apoptosis was indicated via cleavage of caspase 3 and increases in cytoplasmic nucleosomes and the subG(1) cell population.


CONCLUSIONS
Micromolar concentrations of HDAC inhibitors OSU-HDAC42 and SAHA induced histone acetylation, cytotoxicity, and apoptosis in canine cancer cells. In general, OSU-HDAC42 was more potent than SAHA.
Kisseberth
William C
WC
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
Murahari
Sridhar
S
London
Cheryl A
CA
Kulp
Samuel K
SK
Chen
Ching-Shih
CS
D000107:Acetylation / Q000187:drug effects; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D015153:Blotting, Western / Q000662:veterinary; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D053938:DNA Fragmentation / Q000187:drug effects; D004283:Dog Diseases / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005434:Flow Cytometry / Q000662:veterinary; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D009369:Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*; D010654:Phenylbutyrates / Q000494:pharmacology*; D000077337:Vorinostat
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C529674:OSU-HDAC42 compound; D010654:Phenylbutyrates; D000077337:Vorinostat