title: Cyld inhibits tumor cell proliferation by blocking Bcl-3-dependent NF-kappaB signaling.
abstract: Mutations in the CYLD gene cause tumors of hair-follicle keratinocytes. The CYLD gene encodes a deubiquitinase that removes lysine 63-linked ubiquitin chains from TRAF2 and inhibits p65/p50 NF-kappaB activation. Here we show that mice lacking Cyld are highly susceptible to chemically induced skin tumors. Cyld-/- tumors and keratinocytes treated with 12-O-tetradecanoylphorbol-13 acetate (TPA) or UV light are hyperproliferative and have elevated cyclin D1 levels. The cyclin D1 elevation is caused not by increased p65/p50 action but rather by increased nuclear activity of Bcl-3-associated NF-kappaB p50 and p52. In Cyld+/+ keratinocytes, TPA or UV light triggers the translocation of Cyld from the cytoplasm to the perinuclear region, where Cyld binds and deubiquitinates Bcl-3, thereby preventing nuclear accumulation of Bcl-3 and p50/Bcl-3- or p52/Bcl-3-dependent proliferation. These data indicate that, depending on the external signals, Cyld can negatively regulate different NF-kappaB pathways; inactivation of TRAF2 controls survival and inflammation, while inhibition of Bcl-3 controls proliferation and tumor growth.
authors.affiliation: Department of Molecular Medicine, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
authors.forename: Ramin
authors.initials: R
authors.lastname: Massoumi
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Chmielarska
authors.forename: Katharina
authors.initials: K
authors.lastname: Hennecke
authors.forename: Alexander
authors.initials: A
authors.lastname: Pfeifer
authors.forename: Reinhard
authors.initials: R
authors.lastname: Fässler
mesh_terms: D000818:Animals; D000081242:B-Cell Lymphoma 3 Protein; D002273:Carcinogens / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000502:physiology*; D000074749:Deubiquitinating Enzyme CYLD; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology; D047992:TNF Receptor-Associated Factor 2 / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014466:Ultraviolet Rays
chemical_list: D000081242:B-Cell Lymphoma 3 Protein; C000631344:BCL3 protein, human; C000631345:Bcl3 protein, mouse; D002273:Carcinogens; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D047992:TNF Receptor-Associated Factor 2; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; C409984:CYLD protein, human; C511601:CYLD protein, mouse; D000074749:Deubiquitinating Enzyme CYLD; D003546:Cysteine Endopeptidases; D013755:Tetradecanoylphorbol Acetate