title: A quadruple therapy synergistically blocks proliferation and promotes apoptosis of hepatoma cells.
abstract: Effective therapy for advanced hepatocellular carcinoma (HCC) is lacking. Conventional chemotherapy was judged to be ineffective. We previously demonstrated that the histone deacetylase inhibitor Trichostatin A (TSA) blocks growth of HCC cells in vitro. The anti-tumoral effect of a combination of more than 2 classes of drugs remains unexplored. Four hepatoma cell lines were incubated with increasing concentrations of Tamoxifen (TAM), 9-cis retinoic acid (CRA), the methioninaminopeptidase inhibitor TNP-470 and TSA as single agents and in combination. Anti-proliferative and pro-apoptotic effects were assessed using BrdU-incorporation, FACS analysis and immunocytochemistry. Central pro- and anti-apoptotic proteins were measured by semi-quantitative Western blotting and substrate assays. All single substances inhibited proliferation and induced apoptosis in HCC cells only at high concentrations. The combination of TAM/CRA/TNP/TSA multiplied the anti-tumoral effects, reaching up to 93% inhibition of proliferation and 63% induction of apoptosis after 24 h in Hep1B cells. Pro-apoptotic factors bax and caspase 3 were highly increased with quadruple therapy, while anti-apoptotic bcl-2 decreased to undetectable levels. Fibroblasts remained largely unaffected. While the single substances were not effective on hepatoma cells in tolerable doses, their combination significantly increases anti-tumoral efficacy. Combination therapy with biomodulators is a promising treatment option for HCC.
authors.affiliation: Medical Department I, University of Erlangen-Nuernberg, D-91054 Erlangen, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Ganslmayer
authors.forename: Matthias
authors.initials: M
authors.lastname: Ocker
authors.forename: Steffen
authors.initials: S
authors.lastname: Zopf
authors.forename: Sandra
authors.initials: S
authors.lastname: Leitner
authors.forename: Eckhart G
authors.initials: EG
authors.lastname: Hahn
authors.forename: Detlef
authors.initials: D
authors.lastname: Schuppan
authors.forename: Christoph
authors.initials: C
authors.lastname: Herold
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D003510:Cyclohexanes; D004247:DNA / Q000096:biosynthesis; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D004965:Estrogen Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology* / Q000627:therapeutic use; D007155:Immunologic Factors / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D000077609:O-(Chloroacetylcarbamoyl)fumagillol; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D012717:Sesquiterpenes / Q000494:pharmacology* / Q000627:therapeutic use; D013629:Tamoxifen / Q000494:pharmacology* / Q000627:therapeutic use; D014212:Tretinoin / Q000494:pharmacology* / Q000627:therapeutic use; D051028:bcl-2-Associated X Protein
chemical_list: D000970:Antineoplastic Agents; C494826:BAX protein, human; C494827:Bax protein, mouse; C494828:Bax protein, rat; C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D003510:Cyclohexanes; D004791:Enzyme Inhibitors; D004965:Estrogen Antagonists; D006877:Hydroxamic Acids; D007155:Immunologic Factors; D019253:Proto-Oncogene Proteins c-bcl-2; D012717:Sesquiterpenes; D051028:bcl-2-Associated X Protein; D013629:Tamoxifen; C012589:trichostatin A; D014212:Tretinoin; D004247:DNA; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D000077609:O-(Chloroacetylcarbamoyl)fumagillol