title: Anti-adult T-cell leukemia effects of brown algae fucoxanthin and its deacetylated product, fucoxanthinol.
abstract: Adult T-cell leukemia (ATL) is a fatal malignancy of T lymphocytes caused by human T-cell leukemia virus type 1 (HTLV-1) infection and remains incurable. Carotenoids are a family of natural pigments and have several biological functions. Among carotenoids, fucoxanthin is known to have antitumorigenic activity, but the precise mechanism of action is not elucidated. We evaluated the anti-ATL effects of fucoxanthin and its metabolite, fucoxanthinol. Both carotenoids inhibited cell viability of HTLV-1-infected T-cell lines and ATL cells, and fucoxanthinol was approximately twice more potent than fucoxanthin. In contrast, other carotenoids, beta-carotene and astaxanthin, had mild inhibitory effects on HTLV-1-infected T-cell lines. Importantly, uninfected cell lines and normal peripheral blood mononuclear cells were resistant to fucoxanthin and fucoxanthinol. Both carotenoids induced cell cycle arrest during G(1) phase by reducing the expression of cyclin D1, cyclin D2, CDK4 and CDK6, and inducing the expression of GADD45alpha, and induced apoptosis by reducing the expression of Bcl-2, XIAP, cIAP2 and survivin. The induced apoptosis was associated with activation of caspase-3, -8 and -9. Fucoxanthin and fucoxanthinol also suppressed IkappaBalpha phosphorylation and JunD expression, resulting in inactivation of nuclear factor-kappaB and activator protein-1. Mice with severe combined immunodeficiency harboring tumors induced by inoculation of HTLV-1-infected T cells responded to treatment with fucoxanthinol with suppression of tumor growth, showed extensive tissue distribution of fucoxanthinol, and the presence of therapeutically effective serum concentrations of fucoxanthinol. Our preclinical data suggest that fucoxanthin and fucoxanthinol could be potentially useful therapeutic agents for patients with ATL.
authors.affiliation: Division of Molecular Virology and Oncology, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Ishikawa
authors.forename: Senji
authors.initials: S
authors.lastname: Tafuku
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadekaru
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sawada
authors.forename: Mariko
authors.initials: M
authors.lastname: Tomita
authors.forename: Taeko
authors.initials: T
authors.lastname: Okudaira
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Nakazato
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Toda
authors.forename: Jun-Nosuke
authors.initials: JN
authors.lastname: Uchihara
authors.forename: Naoya
authors.initials: N
authors.lastname: Taira
authors.forename: Kazuiku
authors.initials: K
authors.lastname: Ohshiro
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yasumoto
authors.forename: Takao
authors.initials: T
authors.lastname: Ohta
authors.forename: Naoki
authors.initials: N
authors.lastname: Mori
mesh_terms: D000107:Acetylation; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D015368:Human T-lymphotropic virus 1 / Q000187:drug effects; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D000459:Phaeophyceae / Q000737:chemistry*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014407:Tumor Cells, Cultured; D024341:Xanthophylls / Q000494:pharmacology / Q000627:therapeutic use*; D023041:Xenograft Model Antitumor Assays; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000970:Antineoplastic Agents; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D024341:Xanthophylls; D019207:beta Carotene; C025164:fucoxanthin; C483031:fucoxanthinol; D020169:Caspases