title: Histone deacetylase inhibitors promote apoptosis and differential cell cycle arrest in anaplastic thyroid cancer cells.
abstract: Little information exists concerning the response of anaplastic thyroid carcinoma (ATC) cells to histone deacetylase inhibitors (HDAIs). In this study, the cellular response to the histone deacetylase inhibitors, sodium butyrate and trichostatin A, was analyzed in cell lines derived from primary anaplastic thyroid carcinomas. HDAIs repress the growth (proliferation) of ATC cell lines, independent of p53 status, through the induction of apoptosis and differential cell cycle arrest (arrested in G1 and G2/M). Apoptosis increases in response to drug treatment and is associated with the appearance of the cleaved form of the caspase substrate, poly-(ADP-ribose) polymerase (PARP). Cell cycle arrest is associated with the reduced expression of cyclins A and B, the increased expression of the cyclin-dependent kinase inhibitors, p21(Cip1/WAF1) and p27Kip1, the reduced phosphorylation of the retinoblastoma protein (pRb), and a reduction in cdk2 and cdk1-associated kinase activities. In ATC cells overexpressing cyclin E, drug treatment failed to replicate these events. These results suggest that growth inhibition of ATC cells by HDAIs is due to the promotion of apoptosis through the activation of the caspase cascade and the induction of cell cycle arrest via a reduction in cdk2- and cdk1-associated kinase activities.
authors.affiliation: University of Kentucky, Lucille P. Markey Cancer Center, Department of Immunology & Microbiology, Lexington 40536, USA.
authors.forename: V L
authors.initials: VL
authors.lastname: Greenberg
authors.forename: J M
authors.initials: JM
authors.lastname: Williams
authors.forename: J P
authors.initials: JP
authors.lastname: Cogswell
authors.forename: M
authors.initials: M
authors.lastname: Mendenhall
authors.forename: S G
authors.initials: SG
authors.lastname: Zimmer
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002087:Butyrates / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D019927:Cyclin E / Q000502:physiology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D013964:Thyroid Neoplasms / Q000188:drug therapy* / Q000473:pathology; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
chemical_list: D002087:Butyrates; C493956:CDKN1A protein, human; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D016159:Tumor Suppressor Protein p53; C012589:trichostatin A