Cyclooxygenase-2 inhibitor and interferon-beta synergistically induce apoptosis in human hepatoma cells in vitro and in vivo.
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.
Nakamoto
Nobuhiro
N
Department of Internal Medicine, School of Medicine, Keio University, Tokyo 160-8582, Japan.
Higuchi
Hajime
H
Kanamori
Hideaki
H
Kurita
Satoshi
S
Tada
Shinichiro
S
Takaishi
Hiromasa
H
Toda
Kyoko
K
Yamada
Takaya
T
Kumagai
Naoki
N
Saito
Hidetsugu
H
Hibi
Toshifumi
T
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
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