title: Experimental therapy using interferon-gamma and anti-Fas antibody against oral malignant melanoma cells.
abstract: The Fas/FasL signalling system plays an important role in chemotherapy-induced apoptosis in several different cell types. After interferon-gamma (IFN-gamma) treatment, we have previously reported a significant increase in Fas expression in oral malignant melanoma cell lines (MMN9, PMP, MAA, HMG) in vitro, and combination therapy using IFN-gamma and anti-Fas antibody (CH-11) has shown a synergistic anti-proliferative effect in MMN9 cells. There have been several in-vitro studies using CH-11, but there are few reports of its anti-tumour effect in vivo. In this study, we investigated experimental therapy using anti-Fas antibody against MMN9 in vivo in a mouse model, and histologically examined tumour tissue removed from BALB/c nude mice. Animals that received both IFN-gamma and CH-11 showed a 53.8% increase in anti-tumour effect (P=0.0018) 20 days after the first administration. In the histological study, the combined administration group tested positive in terminal deoxynucleotidyl transferase-mediated nick end labelling staining, and showed significantly increased levels of Fas expression on immunostaining compared with the vehicle group. These results show the efficacy of anticancer therapy using IFN-gamma and anti-Fas antibody via the modulation of Fas-mediated apoptosis. Moreover, inhibition of IFN-gamma/CH-11-induced apoptosis with a general caspase inhibitor (benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone) reduced cell death significantly in vitro. Bcl-2 cleavage did not occur under these conditions, suggesting a relationship between caspase activation and Bc1-2 cleavage in MMN9 cells.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Mie University, Japan. t-kamei@clin.medic.mie-u.ac.jp
authors.forename: Takahiko
authors.initials: T
authors.lastname: Kamei
authors.forename: Madoka
authors.initials: M
authors.lastname: Inui
authors.forename: Minoru
authors.initials: M
authors.lastname: Nakase
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Nakamura
authors.forename: Kenya
authors.initials: K
authors.lastname: Okumura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hiramoto
authors.forename: Toshiro
authors.initials: T
authors.lastname: Tagawa
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D007371:Interferon-gamma / Q000494:pharmacology*; D008545:Melanoma / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009062:Mouth Neoplasms / Q000628:therapy*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D019014:fas Receptor / Q000276:immunology
chemical_list: D000906:Antibodies; C481004:CH-11 anti-fas antibody, human; D019253:Proto-Oncogene Proteins c-bcl-2; D019014:fas Receptor; D007371:Interferon-gamma