• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 85
  • 63
  • 13
  • 10
  • 8
  • 8
  • 7
  • 7
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 229
  • 229
  • 229
  • 56
  • 56
  • 48
  • 38
  • 37
  • 34
  • 33
  • 32
  • 31
  • 29
  • 28
  • 28
  • 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.
121

Planejamento e relação estrutura-atividade de inibidores da MARK3 em câncer de cabeça e pescoço / Design and structure-activity relationship of inhibitors of MARK3 in head and neck cancer

Volpini, Josiana Garcia de Araujo 29 September 2010 (has links)
O Projeto Genoma Humano do Câncer (PGHC), financiado pela FAPESP e pelo Instituto Ludwig de Pesquisa sobre o câncer, buscou identificar os genes expressos nos tipos mais comuns de câncer no Brasil. Tal projeto conseguiu identificar aproximadamente um milhão de sequências de genes de tumores frequentes no Brasil. A contribuição brasileira foi maior para tumores de cabeça e pescoço, mama e cólon. Uma das iniciativas mais recentes e estimuladas pelo PGHC é o projeto Genoma Clínico, o qual visa desenvolver novas formas de diagnóstico e tratamento do câncer através do estudo de genes expressos. A partir da análise molecular de tecidos saudáveis e neoplásicos em diferentes estágios, é possível identificar marcadores de prognóstico, permitindo escolhas de terapias mais adequadas e eficientes. A proteína MARK3 foi identificada como um desses marcadores, em neoplasias de tecidos de cabeça e pescoço, sendo o objetivo deste estudo a aplicação de técnicas de bioinformática e modelagem molecular no planejamento baseado em estrutura de candidatos a fármacos antineoplásicos que bloqueiem a atividade da proteína MARK3. Após screening virtual em bases de dados de compostos (1.000.000 aproximadamente) com propriedades drug-like, 20 compostos com potencial de inibidor da MARK3 foram selecionados. Os modos de ligação para cada um dos mesmos no sítio ligante da proteína MARK3 foram sugeridos por simulações de docking e apresentaram um bom encaixe espacial com os sítios receptores virtuais calculados pelos campos de interação molecular (MIF). Simulações de dinâmica molecular foram realizadas com o intuito de avaliar a estabilidade dos compostos selecionados, que também foram avaliados quanto à presença de grupamentos toxicofóricos em sua estrutura. / The Brazilian Project Genoma Câncer (PGHC) supported by FAPESP and the Ludwig Institute for Cancer Research, intended to identify the genes involved in the most common cases of cancer in Brazil. In this project about a million of gene sequences were identified. The major contribution was made in breast, colorectal and head and neck cancers. The results obtained stimulated the creation of another project, called Genoma Clínico, which intend to develop new trends in treatments and diagnosis of cancer based on the study of expressed genes. Analyzing healthy and neoplasic tissues in different stages, it is possible to identify molecular markers related to the prognosis of cancer, allowing the use of more efficient therapies. The MARK3 protein was identified as a molecular marker in head and neck cancer, where the objective of this work lies in the application of bioinformatics and molecular modeling strategies by structure-based drug design to identify potential antineoplasic drug candicates that could act against MARK3 protein. After the virtual screening simulations performed with drug-like compound databases, containing approximately 1.000.000 compounds, 20 were selected as potential ligands of MARK3 protein. The binding modes suggested for these compounds, by docking simulations, presented a good spatial fit when compared with the virtual receptor sites calculated by molecular interaction fields (MIF). Molecular dynamics simulations were performed in order to evaluate de stability of the binding modes suggested. The potential ligands were also evaluated to identify toxicophoric features in its chemical structures.
122

A abordagem de high-content screening para identificação de miRs com potencial terapêutico no câncer de cabeça e pescoço / The high-content screening approach for the identification of miRs with therapeutic potential in head and neck cancer

Sangiorgi, Bruno Braga 10 July 2017 (has links)
Como em diversos tumores sólidos, no câncer de cabeça e pescoço (HNSCC) a presença de metástases é um importante fator de mal prognóstico. Até o momento, estudos indicam que, no microambiente inflamatório tumoral, a estimulação com o Fator de Necrose Tumoral Alpha (TNF-?) leva à ativação de diferentes vias moleculares, como a via do Fator Nuclear Kappa-B (NF-kB) e PI3K/AKT, que inibem GSK3? e consequentemente, promovem a estabilização e translocação nuclear de SNAIL e betacatenina. De um modo geral, em diversos tipos de câncer, enquanto beta-catenina tem ação em promover a proliferação celular, membros da família SNAIL são capazes de induzir o processo de transição epitélio-mesenquimal (EMT). Sabe-se que os eventos de EMT estão envolvidos tanto na iniciação de metástases quanto na geração de célulastronco tumorais (CSCs), que por sua vez estão associadas à falha terapêutica e recidiva, devido à características que lhe conferem resistência aos tratamentos convencionais. Ao silenciar a expressão gênica de modo pós-transcricional, microRNAs (miRs) tem sido associados à regulação tanto da EMT quanto da geração de CSCs. Com uso da abordagem de High-Content Screening (HCS, análise celular multiparamétrica quantitativa por microscopia automatizada), buscamos investigar a capacidade de um grupo de 30 miRs humanos, muitos deles envolvidos em vias inflamatórias e na pluripotência, em modular aspectos relacionados a sobrevivência celular e EMT, em uma linhagem celular derivada de HNSCC (FADU) sob estímulo inflamatório. Inicialmente, avaliamos o potencial do TNF-? em modular parâmetros morfométricos, bem como a presença/localização de proteínas relacionadas com a EMT e capacidade migratória. Posteriormente, avaliamos o efeito de moléculas miméticas dos miRs em suprimir ou potencializar a sobrevivência celular e EMT em células estimuladas com TNF-?, seguido da identificação de transcritos alvos preditos (bem como das vias de sinalização enriquecidas para estes alvos) comumente alvejados por grupos de miRs que levaram a alterações multiparamétricas similares. De modo geral, miRs que alvejaram RELA e AKT2/AKT3 foram responsáveis pela redução na proliferação celular e EMT, enquanto o oposto foi observado em miRs que alvejaram GSK3B e ARHGAP5 (inibidor de RhoA). O silenciamento por siRNAs específicos contra RELA e CTNNB1, causou à redução na sobrevivência celular, enquanto que o silenciamento de AKT1 e CTNNB1 levou à redução na expressão proteica de SNAIL/SLUG. Finalmente, o silenciamento de RELA, AKT1, GSK3B e CTNNB1 levou a redução na sobrevivência celular e indução a apoptose mesmo na ausência de estimulação com TNF-?. Como um todo, nós demonstramos que a abordagem de HCS permitiu a identificação de miRs com efeitos fenotípicos similares (no contexto de proliferação e EMT) e que, a predição de alvos compartilhados por estes miRs, levou à identificação de alvos e vias de sinalização relevantes do ponto de vista terapêutico. / Like many solid cancers, in head and neck cancer (HNC) the presence of metastases is an important factor of poor prognosis. To date, studies indicate that, in the tumor inflammatory microenvironment, stimulation with Tumor Necrosis Factor Alpha (TNF-?) leads to the activation of different molecular pathways, such as the Nuclear Factor-Kappa B (NF-kB) and PI3K/AKT pathway, inhibiting GSK3? and the degradation of SNAIL and beta-catenin, stabilizing them promoting their nuclear translocation. In general, in several types of cancer, while beta-catenin acts to promote cell proliferation, members of the SNAIL family induce the epithelial-mesenchymal (EMT) transition process. It is known that EMT events are involved both in the initiation of metastases and generation of cancer stem cells (CSCs), which in turn are associated with therapeutic failure and relapse, due to its properties that confer resistance to conventional treatments. By silencing gene expression in a post-transcriptional fashion, microRNAs (miRs) have been associated with the regulation of both EMT and CSCs generation. Using the HighContent Screening (HCS) approach, we sought to investigate the ability of a group of 30 human miRs, many of them involved in inflammatory pathways and pluripotency, to modulate aspects related to cell survival and EMT, in a HNSCC-derived cell line (FADU) under inflammatory stimuli. Initially, we evaluated the potential of TNF-? in modulating morphometric parameters, as well as the presence/location of EMT-related proteins and migratory capacity. Subsequently, we evaluated the effect of miRs mimetic molecules on suppressing or potentiating cell survival and EMT in TNF-?-stimulated cells, followed by the identification of predicted target transcripts (as well as signaling pathways enriched for these targets) commonly targeted by groups of miRs that led to similar multiparametric changes. Overall, miRs that targeted RELA and AKT2/AKT3 were responsible for the reduction in cell proliferation and EMT, while the opposite was observed in miRs that targeted GSK3B and ARHGAP5 (RhoA inhibitor). Gene silencing by specific siRNAs against RELA and CTNNB1 caused a reduction in cell survival, while silencing of AKT1 and CTNNB1 led to reduced protein expression of SNAIL/SLUG. Finally, the silencing of RELA, AKT1, GSK3B and CTNNB1 led to a reduction in cell survival and induction of apoptosis even in the absence of TNF-? stimulation. As a whole, we demonstrated that the HCS approach allowed the identification of miRs with similar phenotypic effects (in the context of proliferation and EMT) and that the prediction of targets shared by these miRs led to the identification of relevant targets and signaling pathways from the therapeutic point of view.
123

Tabagismo, consumo de álcool e câncer de cabeça e pescoço nas regiões Sudeste, Sul e Centro-Oeste do Brasil / Smoking, alcohol consumption and head and neck cancer in Southeast, South and Midwest of Brazil

Suely Aparecida Kfouri Sakaguti 30 April 2013 (has links)
Introdução. Considerando-se a incidência e os reflexos na qualidade de vida, os tumores de cabeça e pescoço constituem-se em relevante problema de saúde pública. A medida de efeito dos principais fatores de risco, tabaco e álcool, no risco de acometimento de cânceres de cabeça e pescoço tem sido pouco relatada no Brasil. Objetivo. Verificar as variações de risco decorrentes do tabagismo e do consumo de bebidas alcoólicas no câncer de cabeça e pescoço nas regiões Sudeste, Sul e Centrooeste do Brasil. Sujeitos e Métodos. Estudo caso-controle de base hospitalar conduzido entre setembro de 1998 e maio de 2003, com base em 1.594 casos diagnosticados com carcinoma espinocelular de cabeça e pescoço, confirmados histologicamente, em hospitais das cidades de São Paulo e Rio de Janeiro (Sudeste), Porto Alegre e Pelotas (Sul), Goiânia (Centro-oeste), e 1.292 controles. Os pacientes foram entrevistados por meio de questionários com informações sobre características e hábitos, bem como dados clínicos e laboratoriais para o diagnóstico de câncer de cabeça e pescoço. A OR (odds ratio) e IC 95 por cento (intervalo com 95 por cento de confiança) para câncer de cabeça e pescoço associados ao tabaco e álcool foram estimados por regressão logística não condicional. O modelo foi ajustado por idade, sexo, escolaridade, consumo de frutas e legumes. Resultados. Na região Centro-oeste observaram-se riscos mais expressivos para tabagismo, ex-fumantes (OR 3,5; IC95 por cento 1,6-7,4) e fumantes (OR 13,6 IC95 por cento 6,4-28,6), com efeito dose-resposta para frequência e tempo de consumo na exposição cumulativa, de 1-9 maços-ano (OR 1,9; IC 95 por cento 0,8-4,4) à 40 maços-ano e mais (OR 8,6; IC95 por cento 4,2-17,5). No consumo de bebidas alcoólicas, observou-se riscos mais elevados para consumidores atuais na região Sul (OR 4,7 IC95 por cento 2,8-7,9); na exposição cumulativa o efeito dose-resposta para frequência de consumo foi nítido a partir da categoria 0-4,99g/ml/dia nas regiões Sudeste, Sul e Centro-oeste. Conclusões. As diferenças que puderam ser observadas no risco para tumores de cabeça e pescoço decorrentes do tabagismo e consumo de bebidas alcoólicas, sugerem diferenças no perfil de consumo nas regiões Sudeste, Sul e Centro-oeste, provavelmente, relacionados ao uso de tipos de preparo do tabaco e consumo de diferentes tipos de bebidas alcoólicas / Introduction. Considering the incidence and reflections on the quality of life, the head and neck tumors constitute an important public health problem. The extent of effect of the main risk factors, tobacco and alcohol, in risk of involvement of head and neck cancers has been rarely reported in Brazil. Objectives. Check the variations the risks caused by smoking and alcohol consumption in head and neck cancer in the Southeast, South and Midwest regions of Brazil. Subjects and Methods. A case-control hospitalbased, conducted between September 1998 and May 2003, based on 1.594 cases diagnosed with squamous cell carcinoma of the head and neck, histologically confirmed, in hospitals in the cities of São Paulo and Rio de Janeiro (Southeast), Porto Alegre and Pelotas (South), Goiania (Midwest), and 1.292 controls. Patients were interviewed using questionnaires with information about characteristics and habits, as well as clinical and laboratory data for the diagnosis of head and neck cancer. The odds ratio (OR) and IC95 per cent (confidence interval 95 per cent ) of head and neck cancer associated with tobacco and alcohol were estimated by unconditional logistic regression. The model was adjusted for age, sex, education, consumption of fruit and vegetables. Results. In the Midwest region we observed more significant risks for smoking, former smokers (OR 3,5; IC95 per cent 1,67,4) and smoking (OR 13,6; IC95 per cent 6,4-28,6), with doseresponse effect for frequency and time consumption in the cumulative exposure, from 1-9 pack-years (OR 1.9, IC95 per cent 0,84,4) to 40 pack-years and more (OR 8,6; IC95 per cent 4,2 17,5). In alcohol consumption was observed increased risks for current consumers in the South (OR 4,7; IC95 per cent 2,8 7,9); in the cumulative exposure dose-response effect for frequency of consumption was clear from the category 0-4,99 g/ml/day in the Southeast, South and Midwest regions. Conclusions. The differences in risk were observed for cancers of the head and neck caused by smoking and alcohol consumption suggest differences in the consumption profile in Southeast, South and Midwest regions, probably related to the use of types of tobacco and consumption of different types of alcoholic beverages
124

Zur regionären Metastasierung der Plattenepithelkarzinome des Oropharynx, Hypopharynx und Larynx

Heints, Daniela 25 February 2013 (has links) (PDF)
Regionäre Metastasten verschlechtern die Prognose von Patienten mit einem Kopf-Hals-Karzinom deutlich. So verringert sich die 5-Jahresüberlebensrate bei einer Metastasierung in die regionären Lymphknoten um etwa 50%. Die Daten von 672 Patienten mit einem Plattenepithelkarzinom des Oropharynx, Hypopharynx oder Larynx der Jahre 2005 bis 2009 wurden retrospektiv ausgewertet. Bei 270 Patienten mit einem Primärtumor der Tonsille (n=82), des Oropharynx (excl. Tonsille) (n=70), des Hypopharynx (n=33), der Supraglottis (n=42) oder der Glottis (n=43) wurde eine ipsilaterale (n=47) oder bilaterale (n=223) Neck dissection im Rahmen der Primärtherapie durchgeführt. Dabei wurden bei 61% der ipsilateralen und 49% der kontralateralen Neck dissections die Level en bloc reseziert und konnten im Falle einer Metastasierung nicht in die levelbezogene Auswertung eingeschlossen werden. Die Level, in welche die Tumoren bevorzugt metastasieren, wurden evaluiert und tumorspezifische Parameter (Tumorlokalisation, pT-Kategorie) auf ihren möglichen Einfluss auf die Parameter der Metastasierung (pN-Kategorie, Seitenlokalisation, Anzahl, Größe und Level der Lymphknotenmetastasen) getestet. In allen untersuchten Tumorlokalisationen lagen die meisten Lymphknotenmetastasen im ipsi- und kontralateralen Level II. Bei Angabe der Sublevel lagen die Metastasen vor allem in Level IIA. Ipsilateral konnten Lymphknotenmetastasen in allen fünf Leveln und kontralateral in den Leveln II, III und V nachgewiesen werden. Verschiedene Metastasierungswege und Levelkombinationen der Lymphknotenmetastasen zeigen, dass die regionäre Metastasierung keinen starren Gesetzmäßigkeiten folgt. Die Metastasierungsrate und die Seitenlokalisation der Lymphknotenmetastasen unterschieden sich signifikant je nach Lokalisation des Primärtumors. Die Anzahl der ipsilateralen histopathologisch nachgewiesenen Lymphknoten zeigte eine statistisch signifikante Korrelation zum Nachweis von Lymphknotenmetastasen. Eine zunehmende Metastasierung mit steigender pT Kategorie wurde bei den Glottistumoren nachgewiesen, nicht aber bei den Tumoren der anderen Lokalisationen. Die Ausdehnung des Primärtumors (pT-Kategorie) lässt keine Rückschlüsse auf die Parameter regionärer Metastasen (Seitenlokalisation, Anzahl, Größe und Level der Lymphknotenmetastasen) zu.
125

Impact of disease and treatment on body weight and eating in patients with head and neck cancer : experiences from a multicenter study

Ottosson, Sandra January 2013 (has links)
Background Nutritional deterioration in patients with head and neck cancer (HNC) has a multifactorial etiology mainly associated with tumor and treatment related factors. The objective of the present thesis was to investigate the impact of the disease and treatment on body weight and eating in patients with HNC treated with radiation therapy (RT) as the single modality treatment or as preoperative RT by analyzing body weight and body mass index (BMI) over time, predictive factors for weight loss and BMI, weight loss and BMI as prognostic factors for survival, and by studying the patients’ own experience of food and eating. Methods ARTSCAN is a randomized prospective multicenter trial conducted between the years of 1998 - 2006. Data were collected during and after RT with a total follow-up time of five years. Nutritional data from the whole study cohort (n = 712), from patients with oropharyngeal cancer (n = 232) and from two of the participating treatment centers (n = 101) were retrospectively analyzed in the present thesis. In addition, interviews (n = 13) were conducted nine months after the termination of RT as part of a care development project. Results On a group level, the patients lost weight during and after RT with a nadir at five months after the termination of RT. Factors related to a higher weight loss were oropharyngeal cancer, a high BMI at the start of RT, post-treatment aspiration, no tube feeding at the start of RT, and larger treated volumes. Furthermore, a high BMI at the start of RT was shown to be significantly related to a better five-year overall survival in patients with oropharyngeal cancer, whereas weight loss was not. The patients’ own narratives showed that all aspects of food, eating and meals were affected by the remaining sequelae, and that the patients found ways to accept and cope with the changes that had to be done to facilitate eating. Conclusions and clinical implications The disease and treatment gave persistent effects on the HNC patients’ weight and BMI which calls for a prolonged nutritional follow-up. The predictive factors found for weight loss can be used during patient history to find patients at risk for nutritional deterioration. In oropharyngeal cancer, patients with a high BMI at the start of RT had the best survival. This finding indicates that patients with a low BMI should be encouraged to gain weight before RT start. All aspects of food, eating and meals were affected during and after RT, and therefore the nutritional treatment should be given with a holistic approach to meet the multifaceted need patients with HNC experience.
126

Einfluss höhergradiger akuter Organtoxizität während adjuvanter Radio(chemo)therapie auf die Prognose von Patienten mit lokal fortgeschrittenen Kopf-Hals-Tumoren / Eine retrospektive Analyse / High-grade acute organ toxicity as positive prognostic factor in adjuvant radio(chemo)therapy for locally advanced head and neck cancer

Daldrup, Benjamin 15 May 2013 (has links)
No description available.
127

Functional outcomes of pharyngeal stimulation in patients with dysphagia after surgical treatment for head and neck cancer

Harris, Jennifer Unknown Date
No description available.
128

Galvos ir kaklo srities plokščialąstelinio vėžio atkryčio spindulinio gydymo veiksmingumo ir saugumo tyrimas / Investigation of radiation therapy effectiveness and safety of recurrent head and neck squamous cell carcinoma

Rudžianskas, Viktoras 11 June 2013 (has links)
Po radikalaus gydymo 20–50 proc. pacientų, kuriems nustatytas galvos–kaklo srities vėžys lokoregioninis atkrytis nustatomas per pirmus dvejus metus. Literatūroje paskelbtų tyrimų rezultatai taikant pakartotinę nuotolinę spindulinę terapiją dėl galvos-kaklo vėžio atkryčio prasti: 2-jų metų bendras išgyvenimas siekė 15,2–40 proc., vėlyvųjų 3-4 laipsnio komplikacijų dažnis buvo 1,4–47 proc., 5 laipsnio - 7,6 proc. Retrospektyvinių ir II fazės tyrimų rezultatai naudojant didelės dozės galios brachiterapiją galvos-kaklo srities vėžio atkryčiui gydyti: 2-jų metų bendras išgyvenimas siekė 19–63 proc., vėlyvųjų 3-4 laipsnio komplikacijų dažnis buvo 4–22,2 proc. Tyrimų metu skirtos 3–4 Gy frakcijos iki 30–40 Gy suminės dozės. Iki šiol neatlikti tyrimai lyginantys nuotolinės spindulinės terapijos ir didelės dozės galios brachiterapijos gydymo veiksmingumą ir saugumą. Šioje disertacijoje palyginti skirtingi spindulinio gydymo metodai gydant galvos-kaklo srities vėžio atkrytį: kontrolinei grupei taikytas nuotolinis konforminis spindulinis gydymas (25 frakcijos po 2 Gy, suminė dozė 50 Gy), tiriamajai grupei - hipofrakcionuota didelės dozės galios brachiterapija skiriant naują frakcionavimo režimą – po 2,5 Gy per frakciją po dvi frakcijas per dieną, iki 30 Gy suminės dozės. Toks frakcionavimo režimas pasirinktas siekiant sumažinti spindulinių reakcijų dažnį ir sunkumo laipsnį, o suminė dozė yra biologiškai ekvivalentiška suminėms dozėms, kurios buvo naudotos ankstesniuose tyrimuose. / After radical treatment of head and neck cancer 20–50% of patients are diagnosed with the locoregional recurrence during first two years. In the literature the results of studies, using reirradiation by three-dimensional radiotherapy for head and neck cancer recurrence, according to a 2-year overall survival and toxicity, are poor: overall survival reached 15.2–40%, the grade 3 - 4 toxicity reached 1.4–47% and grade 5 - 7.6%. The results of phase II and retrospective studies using the high-dose-rate brachytherapy for treatment of head and neck cancer relapse were: 2-year overall survival was 19–63%; grade 3 - 4 late toxicity 4–22.2%. In these studies 3–4 Gy per fraction up to 30–40 Gy total dose were administered. So far, the randomized study, comparing the high-dose-rate brachytherapy with the three-dimensional radiotherapy, treating head and neck cancer relapse, hasn’t been conducted. We compared different radiotherapy methods: three-dimensional conformal radiotherapy was administered to the control group (25 fractions of 2 Gy, total dose of 50 Gy); the hypofractionated high-dose-rate brachytherapy was administered to the experimental group, while applying a new regime of fractionation: 2.5 Gy per fraction, two fractions per day, up to 30 Gy total dose. Such fractionation regimen was selected in order to reduce the rate and grade of toxicity, while the total dose is biologically equivalent to the total doses, which have been used in previous studies.
129

Functional outcomes of pharyngeal stimulation in patients with dysphagia after surgical treatment for head and neck cancer

Harris, Jennifer 11 1900 (has links)
Head and neck cancer patients often experience swallowing disorders placing them at risk for aspiration and malnutrition. This study examined the effects of electrical stimulation to the pharyngeal wall on swallowing function in post-surgical head and neck cancer patients. Swallowing of liquid, pudding, and cookie consistencies was examined using videofluoroscopy before, and 30 minutes after, a ten minute application of electrical stimulation the pharyngeal wall in 5 male patients experiencing moderate-severe dysphagia. A total of ten measures of swallowing function were obtained from pre- and post-videofluoroscopy studies. Changes were observed post-stimulation in duration of posterior pharyngeal wall to base of tongue contact, total number of swallows, cricopharyngeal opening durations, and pharyngeal transit time. Preliminary findings indicate that electrical stimulation of the pharynx may impact certain features of swallowing in head and neck cancer patients who experience dysphagia. However, further studies are required to confirm the present findings, explore the mechanisms responsible for these changes, and investigate the effect on swallowing function as a result of manipulating stimulus frequencies, intensities and durations. / Speech-Language Pathology
130

Avaliação de marcadores moleculares relacionados ao prognóstico de pacientes com carcinoma epidermóide de cavidade oral e orofaringe

Santos, Marcelo 29 August 2014 (has links)
Made available in DSpace on 2016-08-29T15:34:42Z (GMT). No. of bitstreams: 1 tese_7863_Tese_Marcelo dos Santos.pdf: 3192836 bytes, checksum: 0f6dcd43e2d9f2f7922c37d18da58333 (MD5) Previous issue date: 2014-08-29 / O câncer de cabeça e pescoço é o quarto em incidência e o quinto em mortalidade na lista das neoplasias mais frequentes no mundo. Para o ano de 2014, são estimados pouco mais de 15 mil novos casos de câncer oral e de orofaringe no Brasil. Assim como outros tumores, o câncer oral e de orofaringe é uma doença multifatorial decorrente de fatores ambientais e genéticos, envolvendo diversas alterações em mecanismos moleculares importantes para a homeostase celular. A investigação de marcadores moleculares envolvidos nesses mecanismos tem sido o objeto de estudo de muitos grupos de pesquisa, uma vez que, apesar do crescente avanço em técnicas terapêuticas, a sobrevida desses pacientes pouco tem aumentado nas ultimas décadas. É sabido que a progressão do tumor depende de que suas células adquirem algumas competências, como por exemplo, evasão da apoptose mediada pelo sistema imunológico, disfunção no controle da proliferação celular, proliferação celular facilitada pela ativação angiogênica, adaptações celulares como resposta à hipóxia tumoral, ativação do mecanismo de sobrevivência celular e modificações epigenéticas dependentes de hipóxia. Considerando sua atuação nesses mecanismos, o presente trabalho teve o objetivo de avaliar o potencial das proteínas FAS, FASL, FGFR4, LEPR, HIF1-a, NDRG1 e JMJD1a e os polimorfismos Gly388Arg no gene FGFR4 e Gln223Arg no gene LEPR, como possíveis marcadores moleculares para as características clinicopatológicas e o prognóstico de pacientes com o carcinoma epidermóide oral e de orofaringe. Nossos resultados mostraram a expressão HIF1-alpha relacionada com a recidiva local da doença e sobrevida livre de doença local nos pacientes submetidos à radioterapia pósoperatória, sendo também relacionada com a microdensidade vascular tumoral. Adicionalmente, a expressão NDRG1 foi diferente quando comparadas as amostras de tecido tumoral e margem cirurgica não tumoral, também mostrando relação com a sobrevida da doença. Com relação ao FGFR4, a expressão e o polimorfismo Gly388Arg mostraram relação com a ocorrência do óbito e com a sobrevida da doença. Contudo, apenas a expressão FGFR4 mostrou relação com com a metástase linfonodal e a ocorrência de recidiva. O perfil FGFR4 proposto mostrou relação com a sobrevida da doença. Sobre o sistema FAS/FASL, ambas expressões mostraram relação com a ocorrência do óbito e o perfil FAS/FASL proposto foi significantemente relacionado com a sobrevida da doença. O polimorfismo Gln223Arg no gene LEPR mostrou relação com a sobrevida livre de doença e da doença específica, enquanto que a expressão LEPR mostrou relação com a metástase linfonodal. Á respeito da proteína JMJD1A, tanto a expressão nuclear quanto a citoplasmática mostraram relação com a metastase linfonodal. Contudo, apenas a expressão nuclear JMJD1A mostrou relação com a ocorrência de recidiva e com a sobrevida da doença. Em conclusão, nossos resultados sugerem que as proteínas e polimorfismos avaliados podem ser utilizados como marcadores moleculares para auxiliar na predição prognóstica de pacientes com carcinoma epidermóide oral e de orofaringe. / Head and neck cancer is the fourth in incidence and the fifth in mortality among the most frequent malignancies worldwide. For 2014, there has been estimated over 15 thousand new oral and oropharynx cancers in Brasil. Similar to other tumors, oral and oropharynx cancer is a multifactorial disease, caused by multiple environmental and genetic factors, involving alterations in molecular pathways and cellular homeostasis. The investigation of molecular markers involved in this process has been the object of my studies, especially because in spite of great advances in the molecular aspects of cancer, little progress has been made in the clinical outcome during the last decades. It is known that tumor progression depends on cellular aquisition of competences, such as apoptosis evasion, cell proliferation disregulation, angiogenic activation, cellular adaptation to hipoxia, cell survival mechanism activation and hypoxia dependent epigenetic changes. Therefore, the present work had the purpose to evaluate the potential of proteins FAS, FASL, FGFR4, LEPR, HIF1-a, NDRG1 and JMJD1a, as well as polymorphisms FGFR4 Gly388Arg and LEPR Gln223Arg, as putative molecular markers for clinicopathological tumor features or oral and oropharynx squamous cell carcinoma. Our results show that HIF1-1 expression was associated with local disease relapse and local disease-free survival in patients who undertook pos-operative radiotherapy and were also related to tumor vascular microdensity. In addition, NDRG1 expression was different in tumor tissue and non tumoral margins, but also showing an association with disease survival. FGFR4 polymorphism and expression showed a relation with death and disease survival. However, FGFR4 expression alone showed an association with lymph node metastasis and relapse. FGFR4 profile showed a relation with disease survival. FAS/FASL expression showed a correlation with death and its proposed profise was related with disease survival. LEPR Gln223Arg polymorphism was realted with disease free survival and disease specific survival, whereas LEPR expression was realted with lymph node metastasis. JMJD1A nuclear and cytoplasmic expression were related with lymph node metastasis. However, only nuclear expression was related with relapse and disease survival. In conclusion, our results suggest that proteins ans polymorphisms can be used as molecular markers to help predict prognosis in oral and oropharynx squamous cell carcinoma.

Page generated in 0.0692 seconds