• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 187
  • 62
  • 60
  • 27
  • 23
  • 10
  • 10
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 460
  • 182
  • 110
  • 85
  • 78
  • 64
  • 63
  • 63
  • 48
  • 47
  • 44
  • 41
  • 40
  • 37
  • 33
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Novel target genes of ZEB1 and Snail1 in triple-negative human breast cancer.

Kristoffersson, Fredrik January 2016 (has links)
Breast cancer is comprised of several subtypes that are different from one another and thedivergence leads to different outcomes of the disease. There are known prognostic factors andphenotypic distinction in different biological factors and expression patterns, such as theestrogen receptor (ER), progesterone receptor (PR), Ki67, HER2/neu expression (HER2). Ingeneral, there are three breast cancer subtypes with the most recurring subtype being luminalA, and the other two being luminal B and triple negative breast cancer. Triple negative breastcancer is a heterogeneous subtype which is defined by the lack of expression of ERα, PR andHER2. Triple negative breast cancers are also very aggressive and have the worst prognosiscompared to the other two ERα positive tumors. The luminal A subtype can develop into ametastatic cancer thanks to the so-called epithelial-mesenchymal transition (EMT), whichaffects a subpopulation of epithelial cancer cells. EMT is the name of a process that takesplace during the embryonic development, the wound healing and cancer metastasis, where theepithelial cells will transform into mesenchymal cells which have higher invasive andmigratory properties. EMT occurs when epithelial cells lose their apical-basal polarity andthen the adherens- and tight junctions are dissolved. The adherens junction dissolution can beobserved as a downregulation of CDH1 (E-cadherin), which is regularly measured in EMTstudies. Many signaling pathways are associated with the promotion and establishment ofEMT e.g. transforming growth factor β (TGFβ), Notch and Wnt signaling. Bioinformaticscreening was performed to look for mRNA expression levels of ZEB1 and Snail1 indifferent breast cancer cell lines. By using chromatin immunoprecipitation-sequencing (ChIPSeq)in the triple negative (ER-, PR- HER2-) Hs578T breast cancer cell line, a genome-widescreen for ZEB1 and Snail1 binding sites had been performed before the start of the project.The Hs578T cell line expresses many of the EMT transcription factors that are relevant forthe project. Since the signaling of TGFβ is crucial for these genes, manipulation of thissignaling pathway is needed to be able to analyse its importance for the function of thesegenes. To inhibit the activity of TGFβ, the small molecule GW6604 was used to inhibit theTGFβ type I receptor kinase (TβRI) and in that way inhibiting the signaling from thisreceptor. In addition, ZEB1 and Snail1 were knocked out by the use of the transfection andCRISPR/Cas9 knockout technique. By investigating mRNA and protein levels of chosengenes in both control Hs578T cells and ZEB1 and Snail1 knockout Hs578T cells, up or downregulation of some of these genes can be seen with stimulation with TGFβ. The knockout ofSnail1 but not of ZEB1 indicated that the loss of Snail1 generated breast cancer cells thatcould try to revert to epithelial at the phenotypic level.
242

Activin/nodal signalling controls the epigenome and epitranscriptome of human pluripotent stem cells

Bertero, Alessandro January 2016 (has links)
Human pluripotent stem cells (hPSCs) are an invaluable model for cellular and developmental biology, and hold great potential for translational applications. While great progress has been made in elucidating the signalling pathways regulating pluripotency and differentiation, our mechanistic understanding of the downstream regulations is still incomplete. Moreover, studies aimed at clarifying these aspects are severely impeded by the lack of efficient methods to conditionally modulate gene expression in hPSCs and hPSC-derived cells. In this dissertation I provide new insights into the molecular mechanisms controlled by the Activin/Nodal-SMAD2/3 signalling pathway, whose activity dictates the balance between hPSC pluripotency and differentiation. First, I show that SMAD2/3 modulates the chromatin epigenetic landscape of hPSCs by cooperating with the pluripotency factor NANOG to recruit the DPY30-COMPASS complex and promote histone 3 lysine 4 trimethylation (H3K4me3). This regulation promotes expression of pluripotency genes, while poising developmental regulators for activation during differentiation. Secondly, I describe a novel efficient approach for inducible gene knockdown in hPSCs and hPSC-derived cells. By taking advantage of this technology, I demonstrate that DPY30 is required for early differentiation of hPSCs into certain mesoderm and endoderm derivatives. Finally, I report the first large-scale proteomic identification of SMAD2/3 interacting proteins in both undifferentiated and differentiating hPSCs. This analysis not only confirms that SMAD2/3 interacts with multiple epigenetic modifiers involved in hPSC fate choices, but also implicates SMAD2/3 in several functions other than transcriptional regulation. In particular, I describe how SMAD2/3 physically and functionally interacts with the METTL3-METTL14-WTAP complex to promote the formation of N6-methyladenosine (m6A). This epitranscriptional modification antagonizes the expression of selected mRNAs, including pluripotency factors whose transcription is promoted by SMAD2/3. Therefore, this provides a negative feedback that facilitates rapid exit from pluripotency upon inhibition of Activin/Nodal signalling. Overall, the work presented in this dissertation advances the stem cell field in two ways. First, it demonstrates that the Activin/Nodal-SMAD2/3 pathway finely orchestrates the balance between pluripotency and differentiation by shaping both the epigenome and the epitranscriptome of hPSCs. Secondly, it provides a novel powerful technology to facilitate further studies of the mechanisms that regulate cell fate decisions.
243

Resposta imune celular de portadores de hepa tite C antes e na 12ª semana de tratamento com interferon - alfa e ribavirina

Oliveira, Isabela Silva de January 2015 (has links)
Submitted by Pós Imunologia (ppgimicsufba@gmail.com) on 2017-02-17T18:25:36Z No. of bitstreams: 1 Tese Isabela.pdf: 1865877 bytes, checksum: cbd1986b7bda4dc09057f53feeaa35b2 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-05-02T12:43:10Z (GMT) No. of bitstreams: 1 Tese Isabela.pdf: 1865877 bytes, checksum: cbd1986b7bda4dc09057f53feeaa35b2 (MD5) / Made available in DSpace on 2017-05-02T12:43:10Z (GMT). No. of bitstreams: 1 Tese Isabela.pdf: 1865877 bytes, checksum: cbd1986b7bda4dc09057f53feeaa35b2 (MD5) / A hepatite C crônica (HCC) é um problema de saúde mundial, sendo uma das principais causas de transplantes de fígado. A maioria dos indivíduos infectados desenvolve a infecção crônica. Muitos trabalhos têm relatado a ocorrência de desregulação na resposta imune durante a infecção pelo HCV, o que implica na persistência viral. Alguns mecanismos de escape foram sugeridos, como: mascaramento de epítopos, interferência viral nas vias de sinalização de IFN e da resposta imune inata, exaustão e anergia de células T, supressão de resposta imune por ação das células T regulatórias ou ação de citocinas. O objetivo deste trabalho foi avaliar a resposta imune celular em portadores de hepatite C crônica antes e na 12ª semana de tratamento com interferon-α mais ribavirina. Este trabalho foi dividido em dois artigos. No primeiro artigo foi investigada a frequência de subpopulações de linfócitos no sangue periférico de portadores de HCC não tratados e após 12 semanas de tratamento antiviral com IFN-α e ribavirina. Uma elevada frequência de células B e frequências baixas de células T CD8+ e células NK foram encontrados nos indivíduos não tratados, mas não houve alteração nas frequências de células T CD4+ e células Tregs. Porém, portadores de HCC que tiveram positividade para crioglobulinas possuíam baixa frequência de células Treg CD4+CD25+FoxP3+ em comparação aos pacientes sem essas manifestações extra-hepáticas. Não houve diferença na frequência das subpopulações de linfócitos entre os portadores de HCC antes e na 12ª semana do tratamento duplo, mas houve aumento da frequência de células NK em pacientes com resposta virológica precoce. No segundo trabalho foi avaliada a produção das citocinas imunorregulatórias (IL-10 e TGF-β) e as relacionadas à resposta antiviral (IL-2 e IFN-γ) por células mononucleares do sangue periférico (CMSP) de portadores de HCC estimuladas com fitohemaglutinina e antígenos do HCV (core, NS3, NS4 e NS5), antes e na 12ª semana de tratamento antiviral com interferon e ribavirina. Foi demonstrado que o estímulo das CMSP desses pacientes com antígeno HCV-core causou um aumento na produção de IL-2, redução na produção de IFN-γ e produção aumentada de IL-10. Antígenos HCV-NS3 e HCV-NS5 estimularam apenas a produção de IL-10. Os antígenos do HCV não estimularam a produção de TGF-β pelas CMSP, e houve uma relação entre os níveis desta citocina e a carga viral do HCV dos pacientes antes do tratamento. Conclui-se que a resposta imune nos portadores de HCC está alterada, demonstrado pela diminuição na frequência de células CD8+ e NK, e pela aumentada produção de IL-10, baixa produção de IL-2 e IFN-γ provocada pelos antígenos virais. / Chronic hepatitis C (HCC) is a global health problem and a cause of liver transplants. Most infected individuals develop chronic infection. Altered immune response to hepatitis C virus (HCV) infection can be demonstrated in patients with chronic hepatitis C (CHC), which implies the viral persistence. Some escape mechanisms have been suggested, such as: masking epitopes, viral interference in the IFN signaling pathway and innate immune response, exhaustion and anergy of T cells response, suppression of immune response by action of regulatory T cells or action of cytokines. The aim of this study was to evaluate the cellular immune response in patients with chronic hepatitis C before and after 12 weeks of treatment with interferon-α plus ribavirin. This study has been divided into two papers. The first paper investigated the frequency of blood lymphocyte subsets in untreated HCV patients and after 12 weeks of antiviral treatment with IFN-α plus ribavirin. A high frequency of B cells and low frequencies of both CD8+ T cells and NK cells were found in untreated patients, but there was no change in the frequency of CD4 + T cells and Treg cells. However, patients with cryoglobulinemia had a lower frequency of CD4+CD25+FoxP3+ Treg cells compared to patients without these extrahepatic manifestations. There was no difference in the frequency of blood lymphocyte subsets among patients with HCC before and after 12 weeks of antiviral treatment, but there was an increase in the frequency of NK cells in patients with early virological response. The second study evaluated the production of immunoregulatory cytokines (IL-10 and TGF-β) and associated antiviral response (IL-2 and IFN-γ) in peripheral blood mononuclear cells (PBMC) from CHC patients stimulated with Phytohemagglutinin (PHA) and HCV antigens (core, NS3, NS4 e NS5), before and at 12 weeks of antiviral treatment with interferon plus ribavirin. It has been shown that stimulation of the PBMC of patients with HCV core antigen caused an increase in IL-2 production, reduction in IFN-γ and increased in IL-10 production. HCV-NS3 e HCV-NS5 antigens only stimulated IL-10 production. The HCV antigens did not stimulate TGF-β production. There was a relationship between the levels of this cytokine and the HCV viremia of the patients before treatment. In conclusion, the immune response in patients with HCC is disrupted, demonstrated by decrease in the frequency of CD8 +T cells and NK cells, and the increased production of IL-10, low IL-2 and IFN-γ production induced by the viral antigens.
244

Roles of ERK1/2 signaling in LMNA-cardiomyopathy / Les rôles de la signalisation ERK1/2 dans la cardiomyopathie liée aux mutations du gène LMNA

Chatzifrangkeskou, Maria 08 November 2016 (has links)
La cardiomyopathie dilatée est l'une des principales causes d'insuffisance cardiaque en Europe. Dans le cadre de la cardiomyopathie liée aux mutations du gène LMNA, en dépit des soins médicaux conventionnels, aucun traitement satisfaisant ne permet de pallier à la dilatation cardiaque progressive et à la perte de la contractilité. Le gène LMNA code pour les lamines nucléaires de type A, qui sont les principaux constituants de la lamina nucléaire. De précédents travaux démontrent que l'activation anormale de ERK 1/2 est impliquée dans la pathophysiologie de la cardiomyopathie dilatée liée aux mutations du gène LMNA. L'inhibition de la voie ERK 1/2 ralentit également la progression de la fibrose myocardique, relativement développée chez l'homme, en cas de cardiomyopathie dilatée. Dans le cadre de ma thèse, j’ai suggéré que l'activité aberrante de la voie TGF-β pourrait participer à l’activation anormale de ERK 1/2 et être impliquée dans la physiopathologie de dysfonction contractile ventriculaire gauche dans la cardiomyopathie liée aux mutations du gène LMNA. Les mécanismes moléculaires sous-jacents à la modulation de la signalisation ERK1/2, causée dans le cœur, par les mutations du gène LMNA, restent totalement incertains. De ce fait, j'ai testé l'hypothèse selon laquelle la modulation anormale de ERK1/2 induirait l'altération des cibles cytosoliques et modifierait le réseau du cytosquelette cardiaque. Mon travail a mis en évidence un nouveau partenaire de la forme active (phosphorylée) d’ERK1/2 : cofiline-1. La cofiline induit la déramification des filaments d'actine. Ce projet met en lumière un rôle inattendu joué par la signalisation ERK1/2 dans la dynamique de l'actine et dans le développement de la dysfonction ventriculaire gauche de la cardiomyopathie liée aux mutations du gène LMNA. / Dilated cardiomyopathy is one of the leading causes of heart failure in Europe. Despite of the conventional medical care, there is no definitive treatment for the progressive cardiac dilatation and loss of contractility in LMNA cardiomyopathy often leading to sudden death or heart transplantation. LMNA gene encodes nuclear A-type lamins, which are the main constituents of the nuclear lamina. Previous studies clearly show that the abnormal ERK1/2 activation is involved in the pathophysiology of LMNA dilated cardiomyopathy. However, its role in the development of cardiac dysfunction remains unclear. Inhibition of ERK1/2 signaling also slows progression of myocardial fibrosis, which is prominent in humans with dilated cardiomyopathy. I suggested that aberrant TGF-β signaling activity could participate to the abnormal ERK1/2 activation and be involved is the pathophysiology of left-ventricular contractile dysfunction in LMNA cardiomyopathy. Given that the understanding of molecular and cellular mechanisms underlying the modulation of ERK1/2 signaling in the heart caused by LMNA mutation remains totally unclear, I tested the hypothesis that ERK1/2 abnormal modulation leads to alteration of cytosolic targets and alter cardiac cytoskeleton network. My work highlighted a novel partner of activated (phosphorylated) ERK1/2, ADF/cofilin-1. Cofilin promotes debranching of actin filaments. I showed that disrupted actin dynamics leads to abnormal sarcomere structure. This project unraveled an unexpected role played by ERK1/2 signaling in actin dynamics and in the development of left-ventricular dysfunction in LMNA cardiomyopathy.
245

Expressão imuno-histoquímica de TGF Β1 em pacientes com adenomiose

Jacobo, Andréia January 2016 (has links)
Introdução: Proteínas da Superfamília do fator transformador de crescimento β (TGF-β) estão implicadas na regulação de diversas funções biológicas. Embora alguns estudos revelaram a sua presença no endométrio ectópico de portadoras de adenomiose, a sua função na etiopatogenia da doença permanece pouco conhecida. Objetivo: o estudo visa comparar a expressão imuno-histoquímica de TGF-β1 no endométrio ectópico de portadoras de adenomiose com o endométrio tópico de pacientes sem essa condição. Método: Estudo de caso-controle utilizando imuno-histoquímica em amostras uterinas (blocos de parafina) do Hospital de Clínicas de Porto Alegre. A amostra contém 28 casos de adenomiose e 21 controles. Resultados: Não encontramos associação entre tabagismo e adenomiose (P = 0,75), abortos e adenomiose (P = 0,29), gestações e adenomiose (P = 0,85), curetagens e adenomiose (P = 0,81), dor pélvica e adenomiose (P = 0,72) e presença de mioma e adenomiose (P = 0,15). Além disso encontramos relação entre sangramento uterino anormal (SUA) e adenomiose (P = 0,02) e cesarianas prévias e adenomiose (P = 0,02) . A expressão imuno-histoquímica de TGF-β1 no endométrio ectópico de portadoras de adenomiose não teve diferença significativa quando comparado com a expressão dessa proteína no endométrio tópico de pacientes sem adenomiose (P = 0,86). Conclusão: Nosso estudo foi um dos primeiros a comparar a expressão de TGF-β1 no endométrio de pacientes com e sem adenomiose. Em nossa análise não obtivemos diferença significativa entre os grupos, resultado diferente do encontrado em outros dois estudos. Mais estudos são necessários para investigar o papel da superfamília TGF no desenvolvimento e manutenção da adenomiose. / Background: Proteins of transforming growth factor β superfamily (TGF-β) are implicated in the regulation of various biological functions. Although some studies have revealed their presence in ectopic endometrium of women with adenomyosis, their role in the pathogenesis of the disease remains largely unknown. Objective: The study aims to compare the immunohistochemical expression of TGF- β1 in ectopic endometrium of women with adenomyosis with the topic endometrium of patients without this condition. Methods: Casecontrol study using immunohistochemistry in uterine samples (paraffin blocks) obteined from Hospital de Clínicas de Porto Alegre. The sample contained 28 adenomyosis cases and 21 controls. Results: We found no significant difference between smoking and adenomyosis (P = 0.75), abortions and adenomyosis (P = 0.29), pregnancies and adenomyosis (P = 0.85), curettage and adenomyosis (P = 0.81), pelvic pain and adenomyosis (P = 0.72) and presence of myoma and adenomyosis (P = 0.15). We did find a relationship between adenomyosis and abnormal uterine bleeding (AUB) (P = 0.02) and previous cesarean section and adenomyosis (P = 0.02). Immunohistochemical expression of TGF-β1 in ectopic endometrium of women with adenomyosis did not have significant difference when compared with the expression of this protein in the topic endometrium of patients without adenomyosis (P = 0.86). Conclusion: Our study was one of the first to compare the TGF-β1 expression in the endometrium of patients with and without adenomyosis. In our analysis we have not had significant difference between the groups, unlike observed in two other studies. More studies are needed to investigate the role of TGF superfamily in the development and maintenance of adenomyosis.
246

Expressão imuno-histoquímica de TGF Β1 em pacientes com adenomiose

Jacobo, Andréia January 2016 (has links)
Introdução: Proteínas da Superfamília do fator transformador de crescimento β (TGF-β) estão implicadas na regulação de diversas funções biológicas. Embora alguns estudos revelaram a sua presença no endométrio ectópico de portadoras de adenomiose, a sua função na etiopatogenia da doença permanece pouco conhecida. Objetivo: o estudo visa comparar a expressão imuno-histoquímica de TGF-β1 no endométrio ectópico de portadoras de adenomiose com o endométrio tópico de pacientes sem essa condição. Método: Estudo de caso-controle utilizando imuno-histoquímica em amostras uterinas (blocos de parafina) do Hospital de Clínicas de Porto Alegre. A amostra contém 28 casos de adenomiose e 21 controles. Resultados: Não encontramos associação entre tabagismo e adenomiose (P = 0,75), abortos e adenomiose (P = 0,29), gestações e adenomiose (P = 0,85), curetagens e adenomiose (P = 0,81), dor pélvica e adenomiose (P = 0,72) e presença de mioma e adenomiose (P = 0,15). Além disso encontramos relação entre sangramento uterino anormal (SUA) e adenomiose (P = 0,02) e cesarianas prévias e adenomiose (P = 0,02) . A expressão imuno-histoquímica de TGF-β1 no endométrio ectópico de portadoras de adenomiose não teve diferença significativa quando comparado com a expressão dessa proteína no endométrio tópico de pacientes sem adenomiose (P = 0,86). Conclusão: Nosso estudo foi um dos primeiros a comparar a expressão de TGF-β1 no endométrio de pacientes com e sem adenomiose. Em nossa análise não obtivemos diferença significativa entre os grupos, resultado diferente do encontrado em outros dois estudos. Mais estudos são necessários para investigar o papel da superfamília TGF no desenvolvimento e manutenção da adenomiose. / Background: Proteins of transforming growth factor β superfamily (TGF-β) are implicated in the regulation of various biological functions. Although some studies have revealed their presence in ectopic endometrium of women with adenomyosis, their role in the pathogenesis of the disease remains largely unknown. Objective: The study aims to compare the immunohistochemical expression of TGF- β1 in ectopic endometrium of women with adenomyosis with the topic endometrium of patients without this condition. Methods: Casecontrol study using immunohistochemistry in uterine samples (paraffin blocks) obteined from Hospital de Clínicas de Porto Alegre. The sample contained 28 adenomyosis cases and 21 controls. Results: We found no significant difference between smoking and adenomyosis (P = 0.75), abortions and adenomyosis (P = 0.29), pregnancies and adenomyosis (P = 0.85), curettage and adenomyosis (P = 0.81), pelvic pain and adenomyosis (P = 0.72) and presence of myoma and adenomyosis (P = 0.15). We did find a relationship between adenomyosis and abnormal uterine bleeding (AUB) (P = 0.02) and previous cesarean section and adenomyosis (P = 0.02). Immunohistochemical expression of TGF-β1 in ectopic endometrium of women with adenomyosis did not have significant difference when compared with the expression of this protein in the topic endometrium of patients without adenomyosis (P = 0.86). Conclusion: Our study was one of the first to compare the TGF-β1 expression in the endometrium of patients with and without adenomyosis. In our analysis we have not had significant difference between the groups, unlike observed in two other studies. More studies are needed to investigate the role of TGF superfamily in the development and maintenance of adenomyosis.
247

Interactions cellule-matrice associées au remodelage et au vieillissement vasculaires

Bouvet, Céline January 2007 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
248

Avaliação dos polimorfismos nos genes das citocinas IL 6 (RS 1800795) e TGF- β (RS 1982073) e RS 1800471) e suas relações com o grau de lesão cervical em pacientes infectados pelo Papillomavírus humano

Ferreira de Lima Júnior, Sérgio 31 January 2012 (has links)
Made available in DSpace on 2014-06-12T15:02:36Z (GMT). No. of bitstreams: 2 arquivo9594_1.pdf: 387191 bytes, checksum: 6e165c4c1d5b7a1de372a0305283d68c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O câncer cervical (CC) é o segundo tipo de câncer mais comum a afetar mulheres em todo mundo. O Papillomavírus humano (HPV) é encontrado em 99% dos casos de CC e a infecção por esse vírus é considerado um fator de risco para o desenvolvimento do câncer. Muitos estudos tem demonstrado uma relação entre polimorfismos nos genes de citocinas e doenças infecciosas. Polimorfismos nos genes da Interleucina-6 (IL-6) e o Fator de Crescimento Transformador (TGF) β1, importantes mediadores do sistema imunológico, tem sido associados com níveis séricos elevados destas citocinas e no desenvolvimento de muitas doenças e tipos de cânceres. O objetivo desse estudo foi verificar se o SNP -174G/C do gene da IL-6 e T869C e G915C do gene do TGF-β1 estão relacionados com o desenvolvimento de Neoplasias Intraepiteliais Cervicais (NIC). 115 amostras de pacientes saudáveis e 115 de pacientes com lesões foram analisadas. As análises dos SNP foram realizadas através do sequenciamento automático de DNA utilizando o MEGABACE 1000 . Os genótipos do polimorfismo -174G/C da IL-6 que possuem pelo menos um alelo C parecem estar envolvidos no desenvolvimento de NIC induzida pelo HPV (p=0.05232). Nenhuma diferença significativa foi encontrada entre as frequências alélicas e genotípicas dos polimorfismos da TGF-β1 nos dois grupos analisados. Além disso, polimorfismos nos genes da IL-6 e TGF-β1 não estão envolvidos na progressão do CIN. Este estudo sugere que o polimorfismo -174G/C do gene da IL-6 pode ser usado como um gene marcador da susceptibilidade a infecção pelo HPV, mas não como um marcador de progressão de NIC na população Pernambucana
249

Valor prognóstico dos polimorfismos funcionais nos genes da PON1, TNF-a e TGF-ß no carcinoma de células escamosas oral e orofaríngeo / Prognostic value of functional polymorphisms in PON1, TNF-α and TGF-β genes in oral and oropharyngeal squamous cell carcinoma

Santana, Ingrede Tatiane Serafim 28 February 2018 (has links)
Oral and oropharyngeal squamous cell carcinoma (OOSCC) is a malignant neoplasm of epithelial origin that accounts for 90 to 95% of tumors in oral cavity. Alcohol and tobacco consumption are main risk factors, but the formation of reactive oxygen species (ROS) and presence of chronic inflammatory processes have been shown to favor the carcinogenesis process. Human serum paraoxonase 1 (PON1) is a protein with an important antioxidant action and prevents oxidative stress induced by ROS, in turn, high levels of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) are commonly found in inflammatory processes, and changes in these proteins have been related to development of different neoplasms. Present study aims to investigate the prognostic value of functional polymorphisms in PON1, TNF-α and TGF-β genes in OOSCC. This is a prospective cohort study with patients attended at the Advanced Oncology Center of the North-Riograndense League against Cancer. Data collection of clinical variables was done through the form: gender, age, tumor site, TNM (primary tumor, regional nodule and distant metastasis) classification, clinical stage; and through interview: smoking habits and alcohol intake by the patient. A total of 163 samples from patients with OOSCC and 146 control samples were genotyped by real-time PCR. It was observed that 76.1% of the population was males, 84% older than 52 years, with a more frequent intra-oral clinical presentation (53.4%), in the tongue region (21.5%), tumors greater than 4cm (56.45%), presence of nodal involvement (58.9%) and stages III and IV (79.15%). There was a positive association between drinking and smoking habits in patients with OOSCC and between clinical stage and tumor site (p <0.05). The polymorphisms were in Hardy-Weinberg equilibrium, with exception of rs662 of PON1. TNF-α wild-type GG homozygous genotype (rs1800629) was associated with intra-oral lesions, clinical stage of the most advanced disease (III and IV), and decreased overall disease survival, whereas the polymorphic AA genotype was associated with lip lesion, clinical stage I and II and a longer overall disease survival (p <0.05). It was observed association of TGF-β polymorphic AG and AA genotypes (rs1800469) with larger diameter tumors (T3 and T4) (p <0.05). Finally, the polymorphic TT genotype of PON1 (rs662) in recessive model was associated with a shorter disease survival time within threshold of significance (p = 0.05). In view of the findings, it is suggested that wild-type GG homozygous genotype of TNF-α rs1800629 and TGF-β rs1800469 polymorphic AG and AA genotypes may exert an influence on more aggressive biological behavior of OOSCC and that AG genotype of TNF-α rs1800629 and TT genotype of PON1 rs662 could be prognostic markers in OOSCC. In the clinical practice of oncology, these genotypes can be used to perform early diagnosis, knowledge of the biological behavior of the tumor and choice of appropriate individualized therapy / O carcinoma de células escamosas oral e orofaríngeo (CCEO) é uma neoplasia maligna de origem epitelial que representa 90 a 95% dos tumores da cavidade oral. O consumo de álcool e de tabaco são os principais fatores de risco, mas a formação de espécies reativas de oxigênio (EROs) e a presença de processos inflamatórios crônicos têm-se mostrado favorável ao processo de carcinogênese. A paraoxonase de soro humano 1 (PON1) é uma proteína com importante ação antioxidante e previne o estresse oxidativo induzido pelas EROs, por sua vez, elevados níveis do fator de necrose tumoral-alfa (TNF-α) e do fator de crescimento transformante-beta (TGF-β) são comumente encontrados em processos inflamatórios, e alterações nessas proteínas têm sido relacionadas com o desenvolvimento de diferentes neoplasias. O presente estudo tem por objetivo investigar o valor prognóstico dos polimorfismos funcionais nos genes da PON1, TNF-α e TGF-β no CCEO. Trata-se de um estudo coorte prospectivo com pacientes atendidos no Centro Avançado de Oncologia da Liga Norte-Riograndense contra o Câncer. Realizou-se a coleta de dados das variáveis clínicas por meio de formulário: gênero, idade, localização do tumor, classificação TNM (Tumor primário, nódulo regional e metástase à distância), estadiamento clínico (EC); e por meio de entrevista: hábitos de fumo e ingestão alcoólica pelo paciente. Foram genotipadas 163 amostras de pacientes com CCEO e 146 amostras controle por meio de PCR em tempo real. Observou-se que 76,1% da população era do gênero masculino, sendo 84% com mais de 52 anos, com apresentação clínica mais frequente intra-oral (53,4%), na região da língua (21,5%), tumores maiores que 4cm (56,45%), presença de envolvimento nodal (58,9%) e em estágios III e IV (79,15%). Evidenciou-se associação positiva entre os hábitos de beber e fumar com pacientes portadores de CCEO e entre o EC e a localização do tumor (p<0,05). Os polimorfismos encontravam-se em equilíbrio de Hardy-Weinberg, com exceção do rs662 da PON1. O genótipo homozigoto selvagem GG do TNF-α (rs1800629) associou-se com lesões intra-orais, EC da doença mais avançado (III e IV) e menor sobrevida global da doença, enquanto o genótipo AA polimórfico associou-se a lesão de lábio, EC I e II e maior sobrevida global da doença (p<0,05). Observou-se associação dos genótipos AG e AA polimórfico do TGF-β (rs1800469) com tumores de maior diâmetro (T3 e T4) (p < 0,05). Por fim, o genótipo TT polimórfico da PON1 (rs662) no modelo recessivo apresentou associação com menor tempo de sobrevida da doença dentro do limiar de significância (p=0,05). Diante dos achados, sugere-se que o genótipo GG selvagem do rs1800629 do TNF-α e os genótipos AG e AA polimórfico do rs1800469 do TGF-β podem exercer influência no comportamento biológico mais agressivo do CCEO e que o genótipo AG do rs1800629 do TNF-α e o genótipo TT polimórfico do rs662 da PON1 poderiam ser marcadores com valor prognóstico no CCEO. Na prática clínica da oncologia, esses genótipos podem ser utilizados para realização de diagnóstico precoce, conhecimento do comportamento biológico do tumor e escolha da terapêutica individualizada adequada. / Lagarto, SE
250

Resposta inflamatória cardiovascular associada ao sistema renina-angiotensina e à dieta hiperlipídica. / Cardiovascular inflammatory response associated to renin-angiotensin system and to high-fat diet.

André Bento Chaves Santana 30 January 2014 (has links)
Este trabalho avaliou o efeito da dieta hiperlipídica em camundongos para o estudo da inflamação cardiovascular. Camundongos C57Bl/6 machos com 8 semanas de vida foram utilizados nos ensaios, sendo divididos nos grupos dieta controle e dieta hiperlipídica. Após 8 semanas foram avaliados: o ganho de peso, a porcentagem de tecido adiposo, pressão arterial sistólica, frequência cardíaca, perfil lipídico e glicêmico séricos. A partir de cortes histológicos de aortas e corações corados com picrossirius foram feitas análises morfométricas. Em cortes histológicos de aorta foram realizadas a análise fibras elásticas e colágenas usando a coloração de Weigert-Van Gieson. Também foram realizadas a quantificação de fibras colágenas em aortas, usando a coloração de picrossirius. Nos tecidos aórticos e cardíacos foram feitos: 1) Ensaios de atividade enzimática para ECA e MPO. 2) Ensaios de Immunoblotting para a detecção proteíca para ECA e TGF-b. Também foram feitos ensaios de imuno-histoquímica para marcação e localização de ECA e TGF-b no tecido aórtico. / This work evaluated the effect of high-fat diet in mice for the study of cardiovascular inflammation. C57BL / 6 mice at 8 weeks of age were used in the tests were divided in groups control diet and high fat diet. After 8 weeks were evaluated: weight gain, percentage of fat, systolic blood pressure, heart rate, serum lipids and glucose levels. From histological aortas and hearts stained with picrosirius morphometric analyzes. Histological sections of the aorta were performed to analyze elastic and collagen fibers using Weigert-Van Gieson staining. Also the quantification of collagen fibers in aortas using picrosirius staining. In aortic and cardiac tissues were made: 1) Enzymatic activity assays for ACE and MPO. 2) Immunoblotting assays to detect proteinous for ACE and TGF-b. Also were peformed Immunohistochemistry assays for marking and localization of ACE and TGF- b in the aortic tissue.

Page generated in 0.0784 seconds