title: The pan-deacetylase inhibitor panobinostat affects angiogenesis in hepatocellular carcinoma models via modulation of CTGF expression.
abstract: Post-translational modifications of chromatin components are significantly involved in the regulation of tumor suppressor gene and oncogene expression. Connective tissue growth factor (CTGF) is an epigenetically regulated growth factor with functions in angiogenesis and cell-matrix interactions and plays a pivotal role in hepatocellular carcinoma (HCC). The pharmacologic inhibition of histone and protein deacetylases represents a new approach to interfere with pathways of apoptosis and angiogenesis. We investigated the effect of the pan-deacetylase inhibitor panobinostat (LBH589) on human HCC cell lines HepG2 (p53wt) and Hep3B (p53null) and in a subcutaneous xenograft model and explored the influence on angiogenesis. Specimens were characterized by quantitative real-time PCR. Protein was separated for western blotting against CTGF, VEGF, VEGF receptor-1 (VEGFR-1/FLT-1), VEGF receptor-2 (VEGFR-2/KDR), MAPK and phospho-MAPK. In vivo, HepG2 cells were xenografted to NMRI mice and treated with daily i.p. injections of 10 mg/kg panobinostat. After 1, 7 and 28 days, real-time PCR was performed. Immunohistochemistry and western blotting were examined after 28 days. An increased significant expression of CTGF was only seen after 24 h treatment with 0.1 µM panobinostat in HepG2 cells and Hep3B cells, whereas after 72 h treatment CTGF expression clearly decreased. In the xenografts, treatment with panobinostat showed a minimal CTGF expression after 1 day and 4 weeks, respectively. In vitro as well as in vivo, VEGF was not affected by panobinostat treatment at any time. In conclusion, panobinostat influences extracellular signaling cascades via CTGF-dependent pathways.
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Gahr
authors.affiliation: Laboratory for Tumour Biology and Experimental Therapies, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Mayr
authors.affiliation: Laboratory for Tumour Biology and Experimental Therapies, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kiesslich
authors.affiliation: Institute of Pathology, Salzburger Landeskliniken, Paracelsus Private Medical University, Salzburg, Austria.
authors.forename: Romana
authors.initials: R
authors.lastname: Illig
authors.affiliation: Institute of Pathology, Salzburger Landeskliniken, Paracelsus Private Medical University, Salzburg, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Neureiter
authors.affiliation: Institute of Pathology, Salzburger Landeskliniken, Paracelsus Private Medical University, Salzburg, Austria.
authors.forename: Beate
authors.initials: B
authors.lastname: Alinger
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Ganslmayer
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Wissniowski
authors.affiliation: Institute for Surgical Research, Phillips University Marburg, Marburg, Germany.
authors.forename: Pietro Di
authors.initials: PD
authors.lastname: Fazio
authors.affiliation: Institute for Surgical Research, Phillips University Marburg, Marburg, Germany.
authors.forename: Roberta
authors.initials: R
authors.lastname: Montalbano
authors.affiliation: Klinikum Nuernberg, Department of Respiratory Medicine, Allergology and Sleep Medicine, Nuremberg, Germany.
authors.forename: Joachim H
authors.initials: JH
authors.lastname: Ficker
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ocker
authors.affiliation: Department of Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Quint
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage* / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D055513:Connective Tissue Growth Factor / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D056945:Hep G2 Cells; D056572:Histone Deacetylase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D006877:Hydroxamic Acids / Q000008:administration & dosage* / Q000494:pharmacology; D007211:Indoles / Q000008:administration & dosage* / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D000077767:Panobinostat; D015398:Signal Transduction / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; C526317:CCN2 protein, human; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007211:Indoles; D055513:Connective Tissue Growth Factor; D000077767:Panobinostat