RESUMO
Increased expression of thioredoxin (Trx)-1 and matrix metalloproteinase (MMP)-9 associates with malignant breast cancer progression. Here, we describe a functional relationship between Trx-1 and MMP-9 in promoting MDA-MB-231 breast cancer cell invasive behaviour. Trx-1 overexpression stimulated MMP-9 expression, de-regulated the MMP-9/TIMP-1 equilibrium and augmented MMP-9 involvement in a more invasive phenotype. Trx-1 augmented MMP-9 transcription through NF-κB, AP-1 and SP1 elements; stimulated p50/p65 NF-κB activity and recruitment to the MMP-9 promoter; and facilitated MMP-9 promoter-accessibility to NF-κB by preventing HDAC recruitment and maintaining MMP-9 promoter histone acetylation. Our data provide a functional basis for Trx-1 and MMP-9 association in malignant breast cancer and identify Trx-1 and NF-κB as potentially druggable targets for reducing MMP-9 involvement in malignant behaviour.
Assuntos
Neoplasias da Mama/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Metaloproteinase 9 da Matriz/biossíntese , Proteínas de Neoplasias/metabolismo , Tiorredoxinas/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Metaloproteinase 9 da Matriz/genética , Subunidade p50 de NF-kappa B/genética , Subunidade p50 de NF-kappa B/metabolismo , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Elementos de Resposta/genética , Tiorredoxinas/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Transcrição Gênica/genéticaRESUMO
We identify a novel alternative TrkA splice variant, TrkAIII, with deletion of exons 6, 7, and 9 and functional extracellular IG-C1 and N-glycosylation domains, that exhibits expression restricted to undifferentiated early neural progenitors, human neuroblastomas (NBs), and a subset of other neural crest-derived tumors. This NGF-unresponsive isoform is oncogenic in NIH3T3 cells and promotes tumorigenic NB cell behavior in vitro and in vivo (cell survival, xenograft growth, angiogenesis) resulting from spontaneous tyrosine kinase activity and IP3K/Akt/NF-kappaB but not Ras/MAPK signaling. TrkAIII antagonizes NGF/TrkAI signaling, which is responsible for NB growth arrest and differentiation through Ras/MAPK, and its expression is promoted by hypoxia at the expense of NGF-responsive receptors, providing a mechanism for converting NGF/TrkA/Ras/MAPK antioncogenic signals to TrkAIII/IP3K/Akt/NF-kappaB tumor-promoting signals during tumor progression.
Assuntos
Processamento Alternativo/genética , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Receptor trkA/genética , Receptor trkA/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Doxorrubicina/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Hipóxia/genética , Camundongos , Dados de Sequência Molecular , NF-kappa B/metabolismo , Neovascularização Patológica , Fator de Crescimento Neural/metabolismo , Fator de Crescimento Neural/farmacologia , Neuroblastoma/irrigação sanguínea , Neuroblastoma/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfolipase C gama , Ligação Proteica , Receptor trkA/antagonistas & inibidores , Receptor trkA/química , Proteínas Adaptadoras da Sinalização Shc , Transdução de Sinais , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Fosfolipases Tipo C/metabolismoRESUMO
Thioredoxin (Trx) inhibited human HMEC-1 dermal microvascular endothelial cell capillary tubule forming capacity in a Matrigel based assay in vitro. Inhibition of capillary tubule formation was Trx catalytic site and thioredoxin reductase (TrxR) dependent, mediated at the Matrigel matrix level, and associated with a shift from morphological differentiation to continuous proliferation, with enhanced cell spreading resulting in eventual monolayer formation. Soluble complex carbohydrates, which inhibited capillary tubule formation on Matrigel without induction of cell spreading or monolayer formation, failed to impair Trx promotion of cell spreading and mono-layer formation, suggesting a shift away from carbohydrate-mediated cell/matrix adhesive interactions. Laminin peptides YIGRS and SIKVAV, which impaired tubule formation on Matrigel without inducing cell spreading or monolayer formation, partially impaired cell spreading upon Trx-treated Matrigel without restoring tubule formation, consistent with a potential role for laminin in Trx-mediated effects. Trx reduced laminin and destabilised laminin/galectin-3 complexes within Matrigel. Native purified EHS Laminin (also containing galectin-3), but not recombinant galectin-3, restored HMEC-1 capillary tubule formation on Trx-treated Matrigel. These data highlight a novel deregulatory effect of extracellular Trx upon morphological capillary differentiation that appears to depend upon the reduction of laminin and destabilisation of its interaction with galectin-3, possibly leading to galectin-3 neutralisation that shifts cell/matrix adhesive interactions away from being carbohydrate mediated and results in loss of proliferation-inhibiting and differentiation promoting cues from this tumor basement membrane matrix.
