Navegando por Palavras-chave "Receptor do fator de crescimento epidérmico"
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- ItemSomente MetadadadosÓxido nítrico e cGMP ativam a via de Ras-MAP quinase estimulando fosforilação de tirosina em proteínas intracelulares e proliferação em células endoteliais de aorta de coelho(Universidade Federal de São Paulo (UNIFESP), 2001) Oliveira, Carlos Jorge Rocha [UNIFESP]; Monteiro, Hugo Pequeno [UNIFESP]Fosforilacao de residuos de tirosina em proteinas intracelulares representa um papel essencial no controle e no caminho da sinalizacao celular, no controle mitogenico e na transformacao oncogenica. Recentes achados mostram que especies reativas de oxigenio e oxido nitrico (NO) mediam eventos da sinalizacao dependentes de fosforilacao. NO especificamente e um efetivo transdutor e estimula a enzima guanilil ciclase, a oncoproteina p21 Ras e a fosforilacao de residuos de tirosina de proteinas. P21 Ras representa um ponto de convergencia dentro das celulas por direcionar a cascata de sinalizacao. Para isto demonstramos que o NO estimula diretamente a atividade de p21Ras dependente de cGMP. No presente estudo, usamos celulas endoteliais de aorta de coelho (Raec). Demonstramos que substancias geradoras de NO, (SNP) nitroprussiato de sodio e S-nitroso-N-acetil-penicilamina (SNAP) e o analogo de cGMP o 8 BrcGMP estimulam a atividade de p21Ras. Tambem e aumentada a fosforilacao de tirosina em proteinas citosolicas e, a producao intracelular de cGMP indica que a fosforilacao de tirosina pelo par NO/cGMP dependentes, estimula o caminho da sinalizacao celular com provavel associacao pela ativacao de p21 Ras. O par NOIcGMP ativa p21 Ras, resultando na asossiacao da oncoproteina ao dominio de ligacao de Raf-1 quinase. A incubacao de Raec com FPT II, potente e seletivo inibidor de p21 Ras, previni a fosforilacao de tirosina NO dependente. ODQ, um potente inibidor da forma soluvel da guanilil ciclase, inibiu o sinal. Para esclarecer o papel de p21 Ras no caminho da sinalizacao para fosforilacao de tirosina estimulada por NO, Raec foram...(au)
- ItemAcesso aberto (Open Access)Protein expression of VEGF, IGF-1 and FGF in retroocular connective tissues and clinical correlation in Graves' ophthalmopathy(Conselho Brasileiro de Oftalmologia, 2008-08-01) Matos, Kimble [UNIFESP]; Manso, Paulo Gois [UNIFESP]; Marback, Eduardo [UNIFESP]; Furlanetto, Reinaldo [UNIFESP]; Alberti, Gustave Nosé; Nosé, Vania [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal da Bahia; Tufts University Medical Center; Brigham and Women's Hospital Department of PathologyPURPOSE: To investigate the immunohistochemical expression (IGF-1, EGFr, EGF, c-erbB-2/HER-2/neu, PDGF-A, PDGF-B, FGF and VEGF) in patients with Graves' ophthalmopathy. METHODS: Twenty-four samples (Graves' ophthalmopathy patients) underwent lateral rectus muscle and surrounding fibrous and adipose tissue biopsy. The control group was obtained by strabismus surgery. Correlation between clinical- ophthalmologic, endocrinological, ultrasonographic findings, and immunohistochemical expression was performed. RESULTS: IGF-1: There were 7 positive cases (29.2%). There was a direct relation with higher CAS (clinical activity score) in all of them and if only CAS equal or higher than 5 was considered, this was 54.5%. FGF: There was expression in 5 cases (20.8%) with a direct relation in all those with higher CAS (>5) (45.4%). VEGF: There were two positive cases (8.3%) for VEGF in endothelial cells, in these cases the patients also presented CAS higher than 5. There was no expressions of all growth factors in the control group. CONCLUSIONS: All patients, except one, with positive expression of FGF, IGF-1 and VEGF showed CAS greater than 5, suggesting in this way an important role of these growth factors in the pathogenesis and severity of Graves' ophthalmopathy. However, statistical analysis revealed only significant association between IGF-1 and male sex (P=0.034). Low ultrasound reflectivity and endocrine status may not correlate directly with disease activity or with immunoexpression of growth factors and c-erbB-2/HER-2/neu.
- ItemAcesso aberto (Open Access)Reações cutâneas secundárias ao uso dos inibidores do receptor de fator de crescimento epidérmico: relato de dois casos(Sociedade Brasileira de Dermatologia, 2009-12-01) Rodarte, Camila Martins; Abdallah, Omar Ali; Barbosa, Nadyesda Fagundes; Koch, Ludmila De Oliveira [UNIFESP]; Resende, Uirá Maira; Hospital Geral de Goiânia Clínica Médica; Hospital Geral de Goiânia Serviço de Oncologia; Universidade Federal de São Paulo (UNIFESP); Instituto de Hemoterapia de Goiânia Centro de OncologiaAn increase in the expression of epidermal growth factor receptors (EGFR) is involved in the stimulation of tumor development. EGFR inhibitors have shown efficacy in the treatment of neoplasms of the head, neck, colon and lung. EGFR when inhibited can cause cutaneous reactions in more than 50% of the patients. They are usually reversible, but when severe, limit the use of the drug. Papulopustulars lesions in the face and upper torso are the most common, as well as xerosis, hair and nail changes. There is a direct relationship between the degree of cutaneous toxicity and the antitumoral response. An adequate dermatologic approach is necessary for an effective therapy against cancer.