RESUMO
Poor prognosis associated with the dysregulated expression of activin A in a number of malignancies has been related to with numerous aspects of tumorigenesis, including angiogenesis. The present study investigated the prognostic significance of activin A immunoexpression in blood vessels and cancer cells in a number of oral squamous cell carcinoma (OSCC) cases and applied in vitro strategies to determine the impact of activin A on angiogenesis. In a cohort of 95 patients with OSCC, immunoexpression of activin A in both blood vessels and tumor cells was quantified and the association with clinicopathological parameters and survival was analyzed. Effects of activin A on the tube formation, proliferation and migration of human umbilical vein endothelial cells (HUVECs) were evaluated in gainoffunction (treatment with recombinant activin A) or lossoffunction [treatment with activin Aantagonist follistatin or by stable transfection with short hairpin RNA (shRNA) targeting activin A] conditions. Conditioned medium from an OSCC cell line with shRNAmediated depletion of activin A was also tested. The profile of pro and antiangiogenic factors regulated by activin A was assessed with a human angiogenesis quantitative PCR (qPCR) array. Vascular endothelial growth factor A (VEGFA) and its major isoforms were evaluated by reverse transcriptionqPCR and ELISA. Activin A expression in blood vessels demonstrated an independent prognostic value in the multivariate analysis with a hazard ratio of 2.47 [95% confidence interval (CI), 1.304.71; P=0.006) for diseasespecific survival and 2.09 (95% CI, 1.074.08l: P=0.03) for diseasefree survival. Activin A significantly increased tubular formation of HUVECs concomitantly with an increase in proliferation. This effect was validated by reduced proliferation and tubular formation of HUVECs following inhibition of activin A by follistatin or shRNA, as well as by treatment of HUVECs with conditioned medium from activin Adepleted OSCC cells. Activin Aknockdown increased the migration of HUVECs. In addition, activin A stimulated the phosphorylation of SMAD2/3 and the expression and production of total VEGFA, significantly enhancing the expression of its proangiogenic isoform 121. The present findings suggest that activin A is a predictor of the prognosis of patients with OSCC, and provide evidence that activin A, in an autocrine and paracrine manner, may contribute to OSCC angiogenesis through differential expression of the isoform 121 of VEGFA.
Assuntos
Ativinas/metabolismo , Neoplasias Bucais/patologia , Neovascularização Patológica/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ativinas/análise , Ativinas/antagonistas & inibidores , Ativinas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Comunicação Autócrina/efeitos dos fármacos , Comunicação Autócrina/genética , Movimento Celular , Proliferação de Células , Feminino , Folistatina/farmacologia , Folistatina/uso terapêutico , Técnicas de Silenciamento de Genes , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa Bucal/patologia , Neoplasias Bucais/irrigação sanguínea , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/mortalidade , Comunicação Parácrina/efeitos dos fármacos , Comunicação Parácrina/genética , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Prognóstico , Isoformas de Proteínas/metabolismo , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/irrigação sanguínea , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidadeRESUMO
PURPOSE: We have shown that GPC3 overexpression in breast cancer cells inhibits in vivo tumor progression, by acting as a metastatic suppressor. GPC3-overexpressing cells are less clonogenic, viable and motile, while their homotypic adhesion is increased. We have presented evidences indicating that GPC3 inhibits canonical Wnt and Akt pathways, while non-canonical Wnt and p38MAPK cascades are activated. In this study, we aimed to investigate whether GPC3-induced Wnt signaling inhibition modulates breast cancer cell properties as well as to describe the interactions among pathways modulated by GPC3. METHODS: Fluorescence microscopy, qRT-PCR microarray, gene reporter assay and Western blotting were performed to determine gene expression levels, signaling pathway activities and molecule localization. Lithium was employed to activate canonical Wnt pathway and treated LM3-GPC3 cell viability, migration, cytoskeleton organization and homotypic adhesion were assessed using MTS, wound healing, phalloidin staining and suspension growth assays, respectively. RESULTS: We provide new data demonstrating that GPC3 blocks-also at a transcriptional level-both autocrine and paracrine canonical Wnt activities, and that this inhibition is required for GPC3 to modulate migration and homotypic adhesion. Our results indicate that GPC3 is secreted into the extracellular media, suggesting that secreted GPC3 competes with Wnt factors or interacts with them and thus prevents Wnt binding to Fz receptors. We also describe the complex network of interactions among GPC3-modulated signaling pathways. CONCLUSION: GPC3 is operating through an intricate molecular signaling network. From the balance of these interactions, the inhibition of breast metastatic spread induced by GPC3 emerges.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Glipicanas/metabolismo , Transdução de Sinais , Comunicação Autócrina/genética , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Progressão da Doença , Feminino , Expressão Gênica , Glipicanas/genética , Humanos , Comunicação Parácrina/genética , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Via de Sinalização WntRESUMO
Osteoblast differentiation is controlled by transcription factor RUNX2 which temporally activates or represses several bone-related genes, including those encoding extracellular matrix proteins or factors that control cell-cell, and cell-matrix interactions. Cell-cell communication in the many skeletal pericellular micro-niches is critical for bone development and involves paracrine secretion of growth factors and morphogens. This paracrine signaling is in part regulated by "A Disintegrin And Metalloproteinase" (ADAM) proteins. These cell membrane-associated metalloproteinases support proteolytic release ("shedding") of protein ectodomains residing at the cell surface. We analyzed microarray and RNA-sequencing data for Adam genes and show that Adam17, Adam10, and Adam9 are stimulated during BMP2 mediated induction of osteogenic differentiation and are robustly expressed in human osteoblastic cells. ADAM17, which was initially identified as a tumor necrosis factor alpha (TNFα) converting enzyme also called (TACE), regulates TNFα-signaling pathway, which inhibits osteoblast differentiation. We demonstrate that Adam17 expression is suppressed by RUNX2 during osteoblast differentiation through the proximal Adam17 promoter region (-0.4 kb) containing two functional RUNX2 binding motifs. Adam17 downregulation during osteoblast differentiation is paralleled by increased RUNX2 expression, cytoplasmic-nuclear translocation and enhanced binding to the Adam17 proximal promoter. Forced expression of Adam17 reduces Runx2 and Alpl expression, indicating that Adam17 may negatively modulate osteoblast differentiation. These findings suggest a novel regulatory mechanism involving a reciprocal Runx2-Adam17 negative feedback loop to regulate progression through osteoblast differentiation. Our results suggest that RUNX2 may control paracrine signaling through regulation of ectodomain shedding at the cell surface of osteoblasts by directly suppressing Adam17 expression.
Assuntos
Proteína ADAM17/genética , Proteína Morfogenética Óssea 2/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Retroalimentação Fisiológica , Osteoblastos/metabolismo , Osteogênese/genética , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAM10/genética , Proteína ADAM10/metabolismo , Proteína ADAM17/metabolismo , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Sítios de Ligação , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular , Linhagem Celular , Linhagem Celular Tumoral , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Osteoblastos/citologia , Comunicação Parácrina/genética , Regiões Promotoras Genéticas , Ligação Proteica , Ratos , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
IL-6 is a pleiotropic cytokine with multiple pathophysiological functions. As a key factor of the senescence secretome, it can not only promote tumorigenesis and cell proliferation but also exert tumor suppressive functions, depending on the cellular context. IL-6, as do other cytokines, plays important roles in the function, growth and neuroendocrine responses of the anterior pituitary gland. The multiple actions of IL-6 on normal and adenomatous pituitary function, cell proliferation, angiogenesis and extracellular matrix remodeling indicate its importance in the regulation of the anterior pituitary. Pituitary tumors are mostly benign adenomas with low mitotic index and rarely became malignant. Premature senescence occurs in slow-growing benign tumors, like pituitary adenomas. The dual role of IL-6 in senescence and tumorigenesis is well represented in pituitary tumor development, as it has been demonstrated that effects of paracrine IL-6 may allow initial pituitary cell growth, whereas autocrine IL-6 in the same tumor triggers senescence and restrains aggressive growth and malignant transformation. IL-6 is instrumental in promotion and maintenance of the senescence program in pituitary adenomas.
Assuntos
Adenoma/genética , Senescência Celular/genética , Interleucina-6/genética , Neovascularização Patológica/genética , Adeno-Hipófise/metabolismo , Neoplasias Hipofisárias/genética , Adenoma/metabolismo , Adenoma/patologia , Animais , Comunicação Autócrina/genética , Ciclo Celular/genética , Proliferação de Células , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Regulação da Expressão Gênica , Humanos , Interleucina-6/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Comunicação Parácrina/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Adeno-Hipófise/patologia , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismoRESUMO
BACKGROUND: New vessels are formed in response to stimuli from angiogenic factors, a process in which paracrine signaling is fundamental. OBJECTIVE: To investigate the cooperative paracrine signaling profile in response to Vascular Endothelial Growth Factor (VEGF) gene therapy in patients with coronary artery disease (CAD) and refractory angina. METHOD: A cohort study was conducted in which plasma was collected from patients who underwent gene therapy with a plasmid expressing VEGF 165 (10) and from surgical procedure controls (4). Blood samples were collected from both groups prior to baseline and on days 3, 9 and 27 after the interventions and subjected to systemic analysis of protein expression (Interleukin-6, IL-6; Tumor Necrosis Factor-α, TNF-α; Interleukin-10, IL-10; Stromal Derived Factor-1 α, SDF-1α; VEGF; Angiopoietin-1, ANGPT-1; and Endothelin-1, ET-1) using the enzyme-linked immunosorbent assay (ELISA). RESULTS: Analysis showed an increase in proinflammatory IL-6 (p=0.02) and ET-1 (p=0.05) on day 3 after gene therapy and in VEGF (p=0.02) on day 9. A strong positive correlation was found between mobilization of endothelial progenitor cells and TNF-α on day 9 (r=0.71; p=0.03). Furthermore, a strong correlation between ß-blockers, antiplatelets, and vasodilators with SDF-1α baseline in the group undergoing gene therapy was verified (r=0.74; p=0.004). CONCLUSION: Analysis of cooperative paracrine signaling after VEGF gene therapy suggests that the immune system cell and angiogenic molecule expression as well as the endothelial progenitor cell mobilization are time-dependent, influenced by chronic inflammatory process and continuous pharmacological treatment.
Assuntos
Angina Pectoris , Doença da Artéria Coronariana , Células Progenitoras Endoteliais/imunologia , Terapia Genética , Neovascularização Fisiológica , Comunicação Parácrina , Fator A de Crescimento do Endotélio Vascular , Idoso , Angina Pectoris/genética , Angina Pectoris/imunologia , Angina Pectoris/terapia , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/imunologia , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neovascularização Fisiológica/genética , Neovascularização Fisiológica/imunologia , Comunicação Parácrina/genética , Comunicação Parácrina/imunologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/imunologiaRESUMO
The IGF-binding proteins (IGFBPs) play a dual role in the regulation of the activity and bioavailability of IGFs in different tissues. Diverse evidence has shown that IGFBPs can inhibit and/or potentiate IGF actions. In this study, igfbp1, 2, 3, 4, 5, and 6 were isolated in the fine flounder, a flat fish species that shows slow growth and inherent Gh resistance in muscle. Subsequently, the expression of all igfbps was assessed in the skeletal muscle of flounder that underwent different nutritional statuses. igfbp1 was not expressed in muscle during any of the nutritional conditions, whereas igfbp3 and igfbp5 were the lowest and the highest igfbps expressed respectively. A dynamic expression pattern was found in all the igfbps expressed in skeletal muscle, which depended on the nutritional status and sampling period. During the fasting period, igfbp2, 4, and 5 were downregulated, whereas igfbp3 was upregulated during part of the fasting period. The restoration of food modulated the expression of the igfbps dynamically, showing significant changes during both the long- and short-term refeeding. igfbp3 and igfbp6 were downregulated during short-term refeeding, whereas igfbp5 was upregulated, and igfbp2 and igfbp4 remained stable. During long-term refeeding, the expression of igfbp2, 4, 5, and 6 increased, while igfbp3 remained unchanged. In conclusion, this study shows for the first time the isolation of all igfbps in a single fish species, in addition to describing a dynamic nutritional and time-dependent response in the expression of igfbps in the skeletal muscle of a nonmammalian species.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Proteínas de Peixes/genética , Linguado/genética , Perfilação da Expressão Gênica , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Músculo Esquelético/metabolismo , Sequência de Aminoácidos , Animais , Comunicação Autócrina/genética , Análise por Conglomerados , Ingestão de Alimentos/fisiologia , Jejum/fisiologia , Proteínas de Peixes/classificação , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 6 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/classificação , Dados de Sequência Molecular , Comunicação Parácrina/genética , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Fatores de TempoRESUMO
FGF2 (Fibroblast Growth Factor 2), o fundador da família FGF, tem funções regulatórias na mitogênese, diferenciação, morfogênese e reparo tecidual. Diversas espécies moleculares de FGF2 compartilham uma seqüência C-terminal comum de 155 aminoácidos, pois se originam de diferentes sítios de iniciação de leitura de um único mRNA. O menor, o FGF2-18kDa, é liberado extracelularmente para se ligar a receptores específicos (FGFRs) para disparar as funções parácrinas e autócrinas pelas quais este fator é conhecido. Por outro lado, as espécies maiores (FGF2-21, 22, 22,5 e 34kDa) são intracelulares se ligam a parceiros moleculares desconhecidos para exercer funções intrácrinas ainda indefinidas. O objetivo desta tese foi produzir espécies recombinantes do FGF2-18 e FGF2-22,5, na forma de proteínas de fusão, para analisar funções biológicas e mecanismos de sinalização. Nas células malignas Y1 de camundongo, os recombinantes de FGF2-18kDa (FGF2-18, His-FGF2-18 e His-FGF2-18-ProA) dispararam uma resposta antagônica estimulando as vias de sinalização mitogênica, mas bloqueando o ciclo celular. Nos fibroblastos não tumorigênicos Balb3T3, estes mesmos recombinantes de FGF2-18kDa dispararam apenas a resposta mitogênica clássica. Todos os efeitos biológicos destes recombinantes de FGF2-18kDa foram bloqueados pelo inibidor específico da proteína quinase de tirosina dos FGFRs, PD173074, demonstrando que são respostas intermediadas pelos FGFRs. Portanto, os domínios estruturais adicionados aos recombinantes de FGF2-18kDa não impediram que estas proteínas se ligassem e ativassem os FGFRs. Por outro lado, o recombinante His-FGF2-22,5 dispara apenas as vias de sinalização mitogênica em ambas as células Y1 e 3T3, mas este efeito biológico não é inibido por PD173074. Estes resultados sugerem que a seqüência N-terminal de 55 resíduos, rica em aminoácidos básicos, impede que o FGF2-22,5kDa se ligue e/ou ative os FGFRs. Entretanto, o recombinante His-FGF2-22,5ProA dispara a resposta...
FGF2 (Fibroblast Growth Factor 2), the founder of the FGF family, has regulatory functions in mitogenesis, differentiation, morphogenesis and tissue repair. Multiple FGF2 molecular species, sharing a C-terminal sequence of 155 amino acids, are translated from different iniciation sites of the same mRNA. The smaller, the FGF2-18kD, is extracellularly released to bind to specific membrane receptors (FGFRs), performing paracrine and autocrine functions. On the other hand, the larger FGF2s (21, 22, 22.5 and 34kDa) are intracellular species that bind to unknown partners to play still undefined intracrine roles. The aim of this thesis was to produce recombinant species of FGF2-18kDa and FGF2-22,5kDa, in the form of fusion proteins, to analyze functions and signaling mechanisms. In mouse Y1 malignant cells, FGF2-18kD recombinants (FGF2-18kDa and His-FGF2-18kDaProA) triggered an antagonistic response activating mitogenic signaling pathways, but blocking the cell cycle. However, in non tumorigenic Balb3T3 fibroblasts, these same FGF2-18kD recombinants only elicited the classical mitogenic response. All biological effects of these FGF2-18kD recombinants were blocked by the specific inhibitor of FGFR-protein-tyrosine-kinases, PD173074, demonstrating that these responses are mediated by FGFRs. Therefore, the new peptide domains added to FGF2-18kD did not prevent these recombinant fusion proteins to bind and activate FGFRs. Conversely, the recombinant His-FGF2-22,5kDa triggered only mitogenic signaling pathways in both Y1 and Balb3T3 cells, a biological effect not inhibited by PD173074. These results suggested that the additional basic-rich N-terminal sequence of 55 amino acid residues, found in FGF2-22,5kDa, prevents this FGF2 species from binding and / or activate FGFRs. However, surprisingly, the recombinant His-FGF2-22kDaProA triggered the antagonistic response characteristic of FGF2-18kDa. These results imply that the ProA-domain added to the C-terminal end...
Assuntos
Comunicação Parácrina/genética , Fatores de Crescimento de Fibroblastos/ultraestrutura , Técnicas In Vitro , Fenômenos Biológicos , Bioquímica , Estruturas Celulares , ProteínasRESUMO
The neurotensin (NT) produced in the hypothalamus and in pituitary gonadotrophs and thyrotrophs participates in neuroendocrine regulation. Recently, the involvement of this peptide in normal and neoplastic cell proliferation has been postulated. In the present study, we evaluated the expression of NT and its receptors (NTR1, 2 and 3) in a series of 50 pituitary adenomas [11 growth hormone (GH)-, eight prolactin (PRL)-, four adrenocorticotrophic hormone (ACTH)- and 27 nonfunctioning adenomas]. NT mRNA expression was significantly higher in functioning compared to nonfunctioning adenomas and with normal pituitary. Nonfunctioning pituitary adenomas showed lower expression of NT mRNA than normal pituitary. In the immunohistochemical study of functioning adenomas, NT was colocalised with GH, PRL and ACTH secreting cells. In nonfunctioning adenomas, the NT immunoreactivity intensity was variable among the samples. NTR3 mRNA expression was observed in all examined samples and was higher in the adenomas, both functioning and nonfunctioning, compared to normal pituitary. By contrast, NTR1 and NTR2 mRNA were not detected in either pituitary adenomas or normal tissue. The higher expression of NTR3, as well as the expression of NT by tumoural corticotrophs, lactotrophs and somatotrophs, which are cells types that do not express this peptide in the normal pituitary, suggests that NT autocrine and/or paracrine stimulation mediated by NTR3 may be a mechanism associated with the tumourigenesis of functioning adenomas.