title: Differential response of p53 and p21 on HDAC inhibitor-mediated apoptosis in HCT116 colon cancer cells in vitro and in vivo.
abstract: We investigated the effect of a novel histone deacetylase inhibitor, A-423378.0, on the colon carcinoma cell line HCT116 and genetically modified derivatives lacking either p21(cip1/waf1) or p53. HCT116 cell lines were incubated with A-423378.0 at different concentrations for 3-120 h. Cell viability, proliferation and apoptosis rates were determined and verified by western blot, detection of mitochondrial membrane potential breakdown DeltaPsi(m), activation of caspases-3, -8 and cytokeratin 18 cleavage. A subcutaneous xenograft model was established in NMRI mice with daily intraperitoneal injections of 10 mg/kg for 14 days. All three HCT116 cell lines responded to A-423378.0 treatment in a dose- and time-dependent manner via induction of apoptosis as measured by breakdown of DeltaPsi(m) and BrdU incorporation. We identified that A-423378.0 induced the expression of TRAIL and TRAIL receptor, especially TRAIL-R2/hDR5, which was up-regulated in HCT116 cells after treatment with A-423378.0. In vivo, a growth inhibitory effect was observed with HDAC-I treatment, which was paralleled by a down-regulation of PCNA and a concomitant induction of apoptosis. Treatment of wild-type or knock-out HCT116 cells with A-423378.0 exerts potent anti-proliferative and pro-apoptotic effects in vitro and in vivo. A-423378.0 was able to induce apoptosis in both p21(WAF1) and p53 deficient tumour cells, which appeared to be mediated by the intrinsic cell death pathway. Interestingly, the effects of A-423378.0 on the extrinsic cell death pathway through activation of TRAIL and its signalling pathway indicate that A-423378.0 may be a potent new therapeutic compound for the treatment of advanced colorectal cancer.
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, D-91054, Erlangen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Zopf
authors.forename: Daniel
authors.initials: D
authors.lastname: Neureiter
authors.forename: Steve
authors.initials: S
authors.lastname: Bouralexis
authors.forename: Tobias
authors.initials: T
authors.lastname: Abt
authors.forename: Keith B
authors.initials: KB
authors.lastname: Glaser
authors.forename: Kinya
authors.initials: K
authors.lastname: Okamoto
authors.forename: Marion
authors.initials: M
authors.lastname: Ganslmayer
authors.forename: Eckhart G
authors.initials: EG
authors.lastname: Hahn
authors.forename: Christoph
authors.initials: C
authors.lastname: Herold
authors.forename: Matthias
authors.initials: M
authors.lastname: Ocker
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D045325:HCT116 Cells; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000032:analysis / Q000235:genetics; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000032:analysis; D013844:Thiazoles / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*; D051028:bcl-2-Associated X Protein / Q000502:physiology
chemical_list: C525713:A-423378.0; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D012333:RNA, Messenger; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D020169:Caspases