Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ann Surg Oncol ; 19(2): 443-54, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21761100

RESUMO

BACKGROUND: The understanding of epidermal growth factor receptor (EGFR) deregulation in carcinogenesis remains incomplete. We investigated the implications of EGFR gene status and EGFR nuclear translocation in gallbladder carcinoma (GBCA). METHODS: Subcellular localization of EGFR and phosphorylated EGFR (pEGFR) was analyzed by fractional immunoblotting and confocal immunofluorescence in GBCA cell lines. pEGFR binding to iNOS promoter was assessed by chromatin immunoprecipitation with iNOS promoter activity evaluated by luciferase assay. EGFR, pEGFR, and iNOS were immunohistochemically assessable for localization and level in the training set of 104 GBCAs on tissue microarrays, with 76 cases analyzed for EGFR gene by chromogenic in situ hybridization (CISH) and mutant-enriched PCR targeting exons 19 and 21. The prognostic impact of nuclear pEGFR (N-pEGFR) immunoexpression was reaffirmed on whole sections of 58 GBCAs in the test set. RESULTS: Nuclear expression of EGFR and pEGFR was substantiated in vitro with augmented activity of iNOS promoter elicited by pEGFR binding upon EGF treatment. Despite no mutation, EGFR amplification, identified in 11 cases (15%) by CISH, strongly correlated with cytoplasmic EGFR expression (P < 0.001) but not with disease-specific survival (DSS). Immunoexpression of nuclear EGFR (N-EGFR), cytoplasmic pEGFR, and N-pEGFR was strongly related to that of iNOS (all ≤0.005). N-pEGFR independently predicted worse DSS in both training (P = 0.0468, HR = 2.024) and test sets (P = 0.0223, HR = 5.573). CONCLUSIONS: N-EGFR and N-pEGFR express in GBCA, conferring clinical aggressiveness partly through iNOS transactivation. Lacking response-predicting mutation, EGFR gene status, albeit amplified in 15% of GBCA, is neither related to nuclear EGFR translocation nor prognostically useful.


Assuntos
Adenocarcinoma/metabolismo , Carcinoma Papilar/metabolismo , Núcleo Celular/metabolismo , Receptores ErbB/metabolismo , Neoplasias da Vesícula Biliar/metabolismo , Regulação Neoplásica da Expressão Gênica , Óxido Nítrico Sintase Tipo II/genética , Transporte Ativo do Núcleo Celular , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Idoso , Western Blotting , Carcinoma Papilar/genética , Carcinoma Papilar/mortalidade , Imunoprecipitação da Cromatina , Citoplasma/metabolismo , Receptores ErbB/genética , Feminino , Imunofluorescência , Neoplasias da Vesícula Biliar/genética , Neoplasias da Vesícula Biliar/mortalidade , Humanos , Técnicas Imunoenzimáticas , Hibridização In Situ , Luciferases/metabolismo , Masculino , Mutação/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação , Prognóstico , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Taxa de Sobrevida , Células Tumorais Cultivadas , Regulação para Cima
2.
Ann Surg Oncol ; 17(12): 3212-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20585869

RESUMO

BACKGROUND: The bases of tumorigenesis, progression, and metastasis remain obscure in myxofibrosarcoma. As a member of ezrin-radixin-moesin family, ezrin acts as a link between the cell membrane and actin cytoskeleton to integrate cell adhesion-mediated signaling. It is implicated in tumor progression and metastatic dissemination, and it is associated with adverse outcomes in several cancer types, including pediatric sarcomas. METHODS: Ezrin immunostain could be assessed from tissue microarrays of 78 cases of primary localized myxofibrosarcomas and correlated with clinicopathological factors and patient survival. In two myxofibrosarcoma cell lines, ezrin mRNA expression was measured by real-time reverse transcriptase-polymerase chain reaction and the endogenous expression and activating phosphorylation of ezrin protein analyzed by Western blot test. RESULTS: Ezrin overexpression was significantly associated with remarkable tumor necrosis (P = 0.025), increased histological grades (P = 0.037), advanced American Joint Committee on Cancer stages (P = 0.034), and higher mitotic rate (P < 0.001). Importantly, ezrin overexpression independently predicted inferior metastasis-free survival (P = 0.012, risk ratio = 4.083) and disease-specific survival (P = 0.0337, risk ratio = 4.537). The mRNA and total protein of ezrin in various cells were comparable in the expression level. Despite variation in abundance, phosphorylated ezrin at threonine(567) was detectable in myxofibrosarcoma cell lines but not in fibroblasts. CONCLUSIONS: In primary myxofibrosarcomas, ezrin overexpression correlates with important prognostic elements and independently portends worse outcomes, highlighting the potential prognostic usefulness of ezrin in predicting tumor aggressiveness.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Fibrossarcoma/metabolismo , Mixossarcoma/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Células Cultivadas , Proteínas do Citoesqueleto/genética , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibrossarcoma/patologia , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Mixossarcoma/patologia , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Adulto Jovem
3.
PLoS One ; 5(5): e10718, 2010 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-20502662

RESUMO

BACKGROUND: Outbreaks of white spot disease have had a large negative economic impact on cultured shrimp worldwide. However, the pathogenesis of the causative virus, WSSV (whit spot syndrome virus), is not yet well understood. WSSV is a large enveloped virus. The WSSV virion has three structural layers surrounding its core DNA: an outer envelope, a tegument and a nucleocapsid. In this study, we investigated the protein-protein interactions of the major WSSV structural proteins, including several envelope and tegument proteins that are known to be involved in the infection process. PRINCIPAL FINDINGS: In the present report, we used coimmunoprecipitation and yeast two-hybrid assays to elucidate and/or confirm all the interactions that occur among the WSSV structural (envelope and tegument) proteins VP51A, VP19, VP24, VP26 and VP28. We found that VP51A interacted directly not only with VP26 but also with VP19 and VP24. VP51A, VP19 and VP24 were also shown to have an affinity for self-interaction. Chemical cross-linking assays showed that these three self-interacting proteins could occur as dimers. CONCLUSIONS: From our present results in conjunction with other previously established interactions we construct a 3D model in which VP24 acts as a core protein that directly associates with VP26, VP28, VP38A, VP51A and WSV010 to form a membrane-associated protein complex. VP19 and VP37 are attached to this complex via association with VP51A and VP28, respectively. Through the VP26-VP51C interaction this envelope complex is anchored to the nucleocapsid, which is made of layers of rings formed by VP664. A 3D model of the nucleocapsid and the surrounding outer membrane is presented.


Assuntos
Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Modelos Moleculares , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/metabolismo , Vírus da Síndrome da Mancha Branca 1/metabolismo , Nucleocapsídeo/química , Nucleocapsídeo/metabolismo , Ligação Proteica , Multimerização Proteica , Estrutura Terciária de Proteína , Reprodutibilidade dos Testes , Vírus da Síndrome da Mancha Branca 1/ultraestrutura
4.
J Virol ; 82(24): 12555-64, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18829765

RESUMO

In this study, we characterize a novel white spot syndrome virus (WSSV) structural protein, VP51A (WSSV-TW open reading frame 294), identified from a previous mass spectrometry study. Temporal-transcription analysis showed that vp51A is expressed in the late stage of WSSV infection. Gene structure analysis showed that the transcription initiation site of vp51A was 135 bp upstream of the translation start codon. The poly(A) addition signal overlapped with the translation stop codon, TAA, and the poly(A) tail was 23 bp downstream of the TAA. Western blot analysis of viral protein fractions and immunoelectron microscopy both suggested that VP51A is a viral envelope protein. Western blotting of the total proteins extracted from WSSV virions detected a band that was close to the predicted 51-kDa mass, but the strongest signal was around 72 kDa. We concluded that this 72-kDa band was in fact the full-length VP51A protein. Membrane topology assays demonstrated that the VP51A 72-kDa protein is a type II transmembrane protein with a highly hydrophobic transmembrane domain on its N terminus and a C terminus that is exposed on the surface of the virion. Coimmunoprecipitation, colocalization, and yeast two-hybrid assays revealed that VP51A associated directly with VP26 and indirectly with VP28, with VP26 acting as a linker protein in the formation of a VP51A-VP26-VP28 complex.


Assuntos
Proteínas do Capsídeo/metabolismo , Proteínas do Envelope Viral/metabolismo , Vírus da Síndrome da Mancha Branca 1/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas do Capsídeo/genética , Microscopia Imunoeletrônica , Dados de Sequência Molecular , Peso Molecular , Penaeidae , Ligação Proteica , Transcrição Gênica/genética , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/ultraestrutura , Vírion/metabolismo , Vírus da Síndrome da Mancha Branca 1/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...