RESUMO
Activation of NF-kappaB has been noted in many tumor types, however only rarely has this been linked to an underlying genetic mutation. An integrated analysis of high-density oligonucleotide array CGH and gene expression profiling data from 155 multiple myeloma samples identified a promiscuous array of abnormalities contributing to the dysregulation of NF-kappaB in approximately 20% of patients. We report mutations in ten genes causing the inactivation of TRAF2, TRAF3, CYLD, cIAP1/cIAP2 and activation of NFKB1, NFKB2, CD40, LTBR, TACI, and NIK that result primarily in constitutive activation of the noncanonical NF-kappaB pathway, with the single most common abnormality being inactivation of TRAF3. These results highlight the critical importance of the NF-kappaB pathway in the pathogenesis of multiple myeloma.
Assuntos
Regulação Neoplásica da Expressão Gênica , Mieloma Múltiplo/genética , Mutação/genética , NF-kappa B/genética , Proteínas de Neoplasias/metabolismo , Adenoviridae , Proteína 3 com Repetições IAP de Baculovírus , Antígenos CD40/genética , Antígenos CD40/metabolismo , Células Cultivadas , Enzima Desubiquitinante CYLD , Ativação Enzimática , Imunofluorescência , Deleção de Genes , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Receptor beta de Linfotoxina/genética , Receptor beta de Linfotoxina/metabolismo , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , NF-kappa B/metabolismo , Subunidade p50 de NF-kappa B/genética , Subunidade p50 de NF-kappa B/metabolismo , Subunidade p52 de NF-kappa B/genética , Subunidade p52 de NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Hibridização de Ácido Nucleico , Plasmídeos , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fator 2 Associado a Receptor de TNF/genética , Fator 2 Associado a Receptor de TNF/metabolismo , Fator 3 Associado a Receptor de TNF/genética , Fator 3 Associado a Receptor de TNF/metabolismo , Transfecção , Proteína Transmembrana Ativadora e Interagente do CAML/genética , Proteína Transmembrana Ativadora e Interagente do CAML/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases , Quinase Induzida por NF-kappaBRESUMO
NFkB activity is critical for survival and proliferation of normal lymphoid cells and many kinds of B-cell tumors, including multiple myeloma (MM). NFkB activating mutations, which are apparent progression events, enable MM tumors to become less dependent on bone marrow signals that activate NFkB. Mutations that activate NFkB-inducing kinase (NIK) protein are the most prevalent among the many kinds of NFkB mutations in MM tumors. NIK is the main activating kinase of the alternative NFkB pathway, although over-expression of NIK also can activate the classical pathway. Two NIK inhibitors and an isomeric control were tested with human myeloma cell lines. These specific NIK inhibitors are selectively cytotoxic for cells with NIK-dependent activation of NFkB. Combination therapy targeting NIK and IKKbeta (as a main kinase of the classical NFkB pathway) represents a promising treatment strategy in MM. NIK inhibitors can also be useful tool for assessing the role of NIK and alternative NFkB pathway in different cells.