A quadruple therapy synergistically blocks proliferation and promotes apoptosis of hepatoma cells.
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.
Ganslmayer
Marion
M
Medical Department I, University of Erlangen-Nuernberg, D-91054 Erlangen, Germany.
Ocker
Matthias
M
Zopf
Steffen
S
Leitner
Sandra
S
Hahn
Eckhart G
EG
Schuppan
Detlef
D
Herold
Christoph
C
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
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