title: Cyclooxygenase-2 inhibitor and interferon-beta synergistically induce apoptosis in human hepatoma cells in vitro and in vivo.
abstract: Recent clinical trials have shown that interferon (IFN) is effective for chemoprevention against hepatocellular carcinoma (HCC). However, it remains controversial as to whether IFN exerts direct cytotoxicity against HCC. Cyclooxygenase (COX)-2 also plays a role in hepatocarcinogenesis and may mediate resistance to apoptosis in HCC. Therefore, we aimed to elucidate the combined effect of COX-2 inhibitor, NS-398, and IFN on in vitro growth suppression of HCC using 3 hepatoma cell lines (HepG2, PLC/PRF/5, and Huh7) and in vivo nude mouse xenotransplantation model using Huh7 cells. Only minimal growth inhibition was observed after treatment with IFN-beta alone in the 3 hepatoma cell lines. In contrast, treatment with NS-398 and IFN-beta synergistically inhibited cell proliferation in dose- and time-dependent manner. Apoptosis was identified by 4',6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-beta up-regulated the expression of TRAIL, while NS-398 increased the expression of TRAIL receptors (especially of death receptor 5). Subsequently, activation of caspase-8 and caspase-3 was observed following the treatment with NS-398 and IFN-beta. Blockade of TRAIL with a specific antibody attenuated this apoptosis. Furthermore, we found that IFN-beta up-regulated COX-2 expression in Huh7 cells, and NS-398 might suppress the up-regulated COX-2 activity downstream of IFN signaling. In vivo experiment showed the combined regimen with NS-398 and IFN-beta reduced the growth of xenotransplated HCCs in nude mice. In conclusion, NS-398 is sufficient to overcome IFN resistance in hepatoma cells through the TRAIL/TRAIL receptor pathway, therefore, the combination would appear to be a new therapeutic regimen for HCC.
authors.affiliation: Department of Internal Medicine, School of Medicine, Keio University, Tokyo 160-8582, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nakamoto
authors.forename: Hajime
authors.initials: H
authors.lastname: Higuchi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kanamori
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kurita
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Tada
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Takaishi
authors.forename: Kyoko
authors.initials: K
authors.lastname: Toda
authors.forename: Takaya
authors.initials: T
authors.lastname: Yamada
authors.forename: Naoki
authors.initials: N
authors.lastname: Kumagai
authors.forename: Hidetsugu
authors.initials: H
authors.lastname: Saito
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Hibi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D016899:Interferon-beta / Q000494:pharmacology*; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009578:Nitrobenzenes / Q000494:pharmacology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology*; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D052246:Cyclooxygenase 2 Inhibitors; D008562:Membrane Glycoproteins; D009578:Nitrobenzenes; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D013449:Sulfonamides; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505653:TNFSF10 protein, human; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D016899:Interferon-beta