Spelling suggestions: "subject:"long neoplasias""
71 |
Localization and regulation of peroxiredoxins in human lung and lung diseasesLehtonen, S. (Siri) 13 June 2005 (has links)
Abstract
Reactive oxygen species (ROS) can cause severe damage to cells and organs but they are also important mediators of inflammatory responses and cellular signalling. Due to the significant role of ROS, the cells have evolved a broad antioxidative system to regulate the concentration of these species. Peroxiredoxins (Prxs) are enzymes that participate in the regulation of the cellular redox-homeostasis by detoxifying hydrogen peroxide. Prxs are not classified as conventional antioxidant enzymes and their physiological role, whether protective or regulatory, is still unclear.
The aim of this project was to study the localization and regulation of Prxs in normal human lung and also their role in selected lung disorders (pulmonary sarcoidosis, pleural mesothelioma, lung carcinomas and chronic obstructive disorder, COPD). Additionally the expression of thioredoxin (Trx) and thioredoxin reductase (TrxR) was analysed in the lung of smokers and COPD patients. These enzymes are important reductants in cell and Prxs are one of their targets. Lung is an important organ in the field of ROS and antioxidant research since it is especially vulnerable to exogenous oxidative stress caused by pollutants, cigarette smoke and also by high oxygen pressure.
The results showed that all six human Prxs were expressed in healthy human lung but in a cell-specific manner. The most prominent expression was detected in the epithelium and in macrophages, the cells most prone to oxidative stress. There were also differences in subcellular locations of Prxs.
The expression of Prxs in non-malignant lung diseases (pulmonary sarcoidosis and COPD) and in smoker's lung was very similar with that in normal lung. Higher expression of Prx V and VI was detected in a subpopulation of macrophages sampled from COPD patients' lung. In contrast, Trx expression was induced in the bronchial epithelium of smoker's lung.
Differences in the expression compared to normal lung were seen in lung malignancies (pleural mesothelioma and lung carcinomas). Interestingly, different Prxs were highly expressed in different types of carcinomas. In pleural mesothelioma, all Prxs except Prx IV were highly expressed when compared to normal pleura, in adenocarcinoma Prxs I, II, VI and especially IV, and in squamous cell carcinoma Prxs I, II and IV were upregulated.
Tests performed on cultured cells in vitro revealed only a minor increase in the Prx expression after severe oxidant stress in malignant lung cell line originating from alveolar type II pneumocytes (A549) or non-malignant cell line derived from bronchial epithelium. None of the tested growth factors or cytokines affected Prx expression or oxidation state, but severe oxidant stress influenced remarkably the oxidation state of the Prxs.
|
72 |
Etude des déterminants de l'exposition aux nuisances agricoles et leurs effets sur le cancer du poumon / Occupational exposures in farming and lung cancer riskBoulanger, Mathilde 03 June 2019 (has links)
Contexte. La population agricole française, dans son ensemble, présente un plus faible risque de Cancer BronchoPulmonaire (CBP) par rapport à la population générale. Ce constat, retrouvé au niveau international, s’explique au moins en partie par un tabagisme plus faible notamment chez les plus âgés et chez les femmes ; un effet « protecteur » des endotoxines est également suspecté. Néanmoins le milieu professionnel agricole peut exposer à de nombreux cancérogènes pulmonaires avérés ou suspectés ; malgré cela, à l’exception de certains secteurs d’élevage, il n’existe que très peu de données sur les associations entre expositions ou situations de travail précises en milieu agricole et le risque de CBP. Objectifs. Le premier objectif de ce travail de thèse était d’étudier les associations, au sein de la cohorte AGRICAN (AGRIculture et CANcer), entre (1) CBP et exposition aux activités et tâches de cultures ; (2) CBP et utilisation de pesticides arsenicaux et herbicides dinitroanilines, et de mettre à profit le nombre important de sujets inclus et de cas de CBP pour réaliser ces analyses par sous-type histologique. Le deuxième objectif était d’initier un projet de métrologie de divers aérocontaminants en milieu professionnel agricole. Méthodes. Les analyses ont été menées en utilisant les données de l’étudeAGRICAN et de la matrice culture-exposition aux pesticides PESTIMAT. Nous avons utilisé un modèle de Cox, ajusté sur le sexe, le tabagisme, les élevages bovin et équin. Le projet métrologique AirExpA s’est limité à la Normandie, avec mesures personnelles des poussières totales (en temps réel), endotoxines et 38 mycotoxines (en cumulé), en élevage bovin, lors des foins et des moissons de blé/orge et pois fourrager/féverole. Résultats et discussion. Nous avons retrouvé une association inverse entre l’activité de culture de maïs et le risque de CBP, une association positive entre adénocarcinomes et viticulture, ainsi qu’entre carcinomes à petites cellules et culture de pois fourragers/féveroles. Les éléments de plausibilité d’un lien entre ces secteurs d’activité et le risque de CBP sont encore des hypothèses : la culture de maïs, par le stockage du grain, pourrait exposer aux endotoxines ; à l’inverse, la récolte de pois fourragers a été décrite comme empoussiérante, mais cet élément doit être confirmé par une caractérisation des poussières. Nous n’avons pas retrouvé d’association entre utilisation de pesticides arsenicaux, ni de dinitroanilines, et risque de CBP ; cependant les analyses stratifiées sur le sexe et le statut tabagique, montraient des associations positives chez les non-fumeurs et chez les femmes (en particulier pour les adénocarcinomes). Enfin, le projet AirExpA a permis de documenter un gradient d’exposition aux poussières et endotoxines en fonction de différentes tâches en élevage bovin, et une exposition plus modérée mais réelle, aux endotoxines, lors des activités de culture. Les analyses de mycotoxines sont toutes revenues inférieures aux limites de quantification. L’analyse des pics d’exposition, l’étude d’autres aérocontaminants et d’autres secteurs agricoles, sont des perspectives de ce projet. Conclusion. Notre travail soulève de nouvelles questions de recherche quant à des associations possibles entre certaines expositions professionnelles en milieu agricole (cultures et tâches, utilisation de certains pesticides) et risque de CBP, et contribue à une meilleure connaissance des expositions professionnelles des agriculteurs aux aérocontaminants. / Background. Farmers are at lower risk of lung cancer, compared to the general population, at least partly because of a reduced rate of smoking among the elderly and women. A “protective” effect of endotoxins has also been hypothesized. Even though some of the occupational exposures occurring during farming-related activities are well-known or suspected lung carcinogens, there is scarce data in the literature, about the associations between specific occupational exposures or tasks in farming, and the risk of lung cancer. Objectives.The first aim was to analyse, in the AGRICAN cohort, the associations between lung cancer and (1) occupational exposure to various crops and related tasks; (2) arsenical pesticides and dinitroaniline herbicides use in farming. We also aimed at stratifying our analysis by histological subtypes of lung cancer. The second aim was to initiate a metrological project, to assess farmers’ occupational exposure to various airborne pollutants, in relation with the risk of lung cancer. Methods. We used the data from the French AGRIculture and CANcer cohort (AGRICAN) and from the PESTIcide MATrix project (PESTIMAT), to assess the associations between occupational farming exposures and lung cancer. A Cox model was performed, with adjustment on gender, smoking intensity, cattle and horses breeding. Our metrological project AirExpA was first launched in Normandy and focused on a few exposures – total dusts in real-time ; endotoxins and 38 mycotoxins, cumulative – in cattle breeding, wheat/barley and peas harvesting, and haymaking. Results and discussion. We reported a negative association between lung cancer and corn growing, and positive associations between (1) vineyard growing and adenocarcinoma; (2) peas growing and small cell lung cancer. Corn growing, especially grain handling, might expose to significant levels of endotoxins, thus explaining the inverse association. Peas growing, especially harvesting, is reportedly a dusty task; the AirExpA project will enable us to better characterize the dusts. We found no association between arsenicals use and lung cancer, nor with dinitroaniline herbicides use. However, stratifying on gender and smoking status showed positive associations among women and never-smokers, especially for adenocarcinomas. The AirExpA project showed dust and endotoxins exposure gradients in cattle breeding, depending on the task, and a mild but real exposure to endotoxins in various tasks in crop growing. All samples for mycotoxins were below the limit of quantification. Analysing exposure peaks, extending the project to other breedings/crops and air pollutants are among the perspectives. Conclusion. Our results raise new research questions about possible associations between occupational agricultural exposures and lung cancer, and contribute to a better knowledge and understanding of farmers’ occupational exposure to air pollutants.
|
73 |
Disseminated uveal melanoma : the seeds of metastasesCallejo, Sonia A. January 2006 (has links)
No description available.
|
74 |
Validation of the 60-second chair rise as a measure of physical function in patients with non-small cell lung cancerPereira, Lucy. January 2008 (has links)
No description available.
|
75 |
Avaliação da função pulmonar e da qualidade de vida em pacientes submetidos à ressecção pulmonar por neoplasia / Assessment of lung function and quality of life in patients submitted to lung resection for cancerLima, Luciana Nunes Titton 10 September 2008 (has links)
Introdução: A ressecção pulmonar pode ser seguramente realizada em pacientes com função pulmonar comprometida se eles forem selecionados apropriadamente, sendo importante determinar o impacto do procedimento cirúrgico no estado funcional e nas atividades de vida diária do paciente. Objetivo: Avaliar as repercussões da ressecção pulmonar sobre a espirometria e sobre a qualidade de vida de pacientes com câncer de pulmão. Métodos: Estudo de coorte transversal que incluiu todos pacientes que realizaram cirurgia com ressecção pulmonar entre Setembro de 2006 e março de 2007, após assinar o termo de consentimento livre e esclarecido. Os pacientes foram avaliados no pré-operatório e após seis meses do procedimento cirúrgico através de espirometria e responderam a dois questionários de qualidade de vida: um geral -The Medical Outcomes Study 36-item Short-Form Health Survey e um específico para sintomas respiratórios - Hospital Saint George. Resultados: Concluíram o estudo 33 pacientes, 14 homens e 19 mulheres com faixa etária entre 39 e 79 anos. Todos os pacientes independentemente de fumantes ou não, apresentaram piora significante da função pulmonar. Na análise de qualidade de vida, observamos valores próximos à população normal, e no questionário específico para doenças respiratórias foi observada redução de 50 a 60% nos vários domínios, em relação a uma população de DPOC. Conclusão: Existe impacto direto da ressecção pulmonar na deterioração da espirometria e na qualidade de vida com ênfase nos aspectos diretamente ligados à função pulmonar. Cabe ressaltar a importância da avaliação da função pulmonar destes pacientes no pré-operatório para se estimar sua evolução pós-cirúrgica / Introduction: Lung resection can be performed safely in patients with compromised lung function if properly selected. It is important to determine the impact of surgical procedure in the functional status and daily life activities, aiming at improving quality of life. Objective: Evaluate the effects of pulmonary resection on spirometry and the impact of surgery for lung cancer on patients quality of life. Methods: Prospective study, conducted between September 2006 and March 2007; all patients who performed pulmonary resection surgery were included after signing a free informed consent term. Patients were evaluated in the pre-operative and after six months of the surgical procedure by spirometry and answered two quality of life questionnaires (The medical Outcomes Study 36-item Short-form Health Survey and Saint George Hospital). Results: 33 patients concluded this study; 14 men and 19 women, age between 39 and 79 years. All patients smokers or not, showed worsening of lung function with statistical significance. General QOL scales showed near normal values, nevertheless, respiratory QOL was 50 to 60% worse than COPD. Conclusions: We observed a direct impact of lung resection on spirometry and QOL. It is important to adequately estimate lung and QOL function before assuming lung resection in cancer patients
|
76 |
Inflamação e câncer hepático e pulmonar em camundongos selecionados para máxima ou mínima resposta inflamatória aguda. / Inverse susceptibility to hepatic and lung cancer in mouse lines selected according to the acute inflammatory response.Carvalho, Lílian Rêgo de 18 March 2013 (has links)
A inflamação é um componente essencial presente no microambiente tumoral, sendo relacionada a muitos tipos de câncer, como o de pulmão e de fígado. O objetivo foi estudar a influência de fatores genéticos relacionados à inflamação no desenvolvimento do câncer através da análise da progressão tumoral em camundongos AIRmax e AIRmin, geneticamente selecionados para máxima ou mínima resposta inflamatória. Os carcinomas foram induzidos pela injeção de Uretana ou DEN. 32 semanas após dose, a maioria dos AIRmax apresentaram tumores hepáticos, enquanto AIRmin foram resistentes. O contrário aconteceu com câncer de pulmão: todos os AIRmin foram acometidos e poucos AIRmax apresentaram pequenas lesões. As proteínas de fase aguda IL-6, TNF<font face=\"Symbol\">a e IL-1<font face=\"Symbol\">b são importantes nesse processo, pois tiveram aumento de produção em órgãos alvo horas após injeção. Esses resultados sugerem que um grupo de loci gênicos controla a resposta inflamatória e a susceptibilidade/resistência a diversos tipos de câncer e ressaltam o papel específico de células locais no controle da imunidade ao tumor. / Inflammatory components are an essential part of the tumor microenvironment being crucial in some types of cancer. Our objective was to study the influence of genetic factors relevant to inflammatory response regulation on cancer development by the comparative analysis of carcinogen-induced liver and lung tumors in AIRmax and AIRmin mouse strains, genetically selected for maximum and minimum inflammatory responsiveness. The carcinomas were induced by the injection of Urethane or DEN. 32 weeks after treatment, most AIRmax had liver tumors whereas AIRmin mice were resistant. The inverse occured in lungs: all AIRmin were affected and the incidence in AIRmax was 27.3%. The acute phase proteins IL-6, TNF<font face=\"Symbol\">a and IL-1<font face=\"Symbol\">b seem to be important in this process, with increased production in target organs hours after drug injection. These results provide a demonstration that a group of genes controls the inflammatory response and susceptibility or resistance to different types of cancers and also highlight the specific role of local cells in the control of tumor immunity.
|
77 |
"Contribuição à avaliação prognóstica de pacientes com adenocarcinoma pulmonar avançado: estudo imunohistoquímico da expressão do fator 1 de transcrição tireoideano e da metaloproteinase 9" / Contribution to the prognostic assessment of patients with advanced lung adenocarcinoma: evaluation by immunohistochemical methods of thyroid transcription factor-1 and matrix metalloproteinase-9Martins, Sandro José 28 April 2005 (has links)
O valor prognóstico da expressão do Fator 1 de Transcrição Tireoideano (TTF-1) e da metaloproteinase-9 (MMP-9) foi avaliado em 51 pacientes com adenocarcinoma pulmonar avançado. Foram fatores de mau prognóstico: baixa capacidade funcional (P = 0,017), baixa expressão do TTF-1 (P = 0,001) e alta expressão da MMP-9 (P = 0,008). Identificaram-se três grupos de risco para mortalidade: baixo risco (TTF-1 > 40% e MMP-9 < 80%; sobrevida: 127,6 semanas), risco intermediário (TTF-1 < 40% ou MMP-9 > 80%; sobrevida: 39,0 semanas) e alto risco (TTF-1 < 40% e MMP-9 > 80%; sobrevida: 16,4 semanas). Com a detecção destes marcadores é possível a identificação de subgrupos de pacientes com prognósticos clinicamente distintos. / The prognostic value of Thyroid Transcription Factor-1 (TTF-1) and Matrix Metalloproteinase-9 (MMP-9) tumor expression was evaluated in 51 patients with advanced lung adenocarcinoma. Poor performance status (P = 0.017), low TTF-1 (P = 0.001), and high MMP-9 (P = 0.008) were independent prognostic factors. There was three risk groups: low risk (TTF-1 > 40% and MMP-9 < 80%; median survival: 127.6 wk), intermediate risk (TTF-1 < 40% or MMP-9 > 80%; median survival: 39.0 wk), and high risk (TTF-1 < 40% and MMP-9 > 80%; median survival: 16.4 wk). Evaluation of TTF-1 and MMP-9 may allow us to identify different, clinically meaningful, prognostic groups of lung adenocarcinoma patients.
|
78 |
Avaliação do potencial carcinogênico de partículas atmosféricas concentradas: estudo experimental em dois modelos diferentes / Evaluation of the potential carcinogenic of concentrated airborne particles: experimental study in two different modelsPedro, Sibelli Silva Cosme 19 March 2014 (has links)
INTRODUÇÃO. Estudos epidemiológicos têm demonstrado que a exposição à poluição atmosférica está associada ao aumento de doenças cardiorrespiratórias. Trabalhos experimentais anteriores, utilizaram uretana para induzir a formação de nódulos pulmonares em camundongos e expor estes animais à poluição de \"mundo real\". Ou seja, os animais foram expostos a gases e partículas da mesma forma com que a população está exposta na cidade de São Paulo. Evidenciou-se então, o papel promotor e dose dependente da atmosfera poluída na progressão dos tumores de pulmão. Sabe-se que substâncias carcinogênicas como hidrocarbonetos policíclicos aromáticos (HPA), metais, ácidos graxos e aldeídos, estão presentes na fração particulada respirável da poluição (material particulado fino - MP 2,5), e a exposição prolongada a este último vem sendo considerada um risco para o desenvolvimento do câncer de pulmão. O objetivo deste estudo é verificar se a exposição crônica ao MP2,5 concentrado, a partir do ar ambiente da cidade de São Paulo, tem potencial carcinogênico. MÉTODOS. Foram utilizados 60 camundongos machos suíços (30g); e 60 AJ (20g), com quatro a seis semanas de vida. Os camundongos suíços foram pré-tratados com um carcinógeno completo, o ácido carbâmico (uretana-U), enquanto que os AJ receberam um carcinógeno iniciador 4-(methylnitrosamino)-1-(3-pyridil)-1-butanona (NNK), por serem pré-dispostos ao desenvolvimento de tumores de pulmão. Em seguida todos os animais foram expostos no Concentrador de Partículas Atmosféricas Harvard ao MP 2,5 diariamente, por 2 horas, durante quatro meses. Cada linhagem foi dividida em quatro grupos (n=15 cada): 2 controles com salina e carcinógeno (CsS e CsU ou CajS e CajNNK) e 2 expostos com salina e carcinógeno (EsS e EsU ou EajS e EajNNK). Foi realizada a análise histopatológica dos pulmões, a contagem e classificação das lesões pulmonares encontradas. Foi feito estudo imunoistoquimico para p53 e PCNA. RESULTADOS. Os animais dos grupos expostos, em ambas as linhagens, apresentaram maior número de lesões neoplásicas. As médias de lesões (nódulos e hiperplasia) obtidas foram: CsU: 1,07( DP+ 1,54), CsSl: 0( DP+ 0), EsU: 2,57 ( DP+ 2,77) e EsS: 0,40 ( DP+ 1,12), com p < 0,001; CajNNK: 4,94( DP+ 3,54), CajS: 0,15( DP+ 0,37), EajNNK: 9,14 ( DP+ 7,70) e EajS:0,80 ( DP+ 1,93), com p<0,001. Não houve alterações para o p53 em ambas as linhagens e, apenas os grupos AJ controle e exposto NNK apresentaram diferença para o PCNA. CONCLUSÃO. A exposição crônica ao MP 2,5 proveniente da poluição atmosférica da cidade de São Paulo tem potencial para promover tumores em camundongos de duas linhagens diferentes, com ou sem o pré-tratamento por carcinógenos / INTRODUCTION. Epidemiological studies have shown that exposure to air pollution is associated with increased cardiorespiratory diseases. Previous experimental studies, we used urethane to induce lung nodule formation in mice and these animals exposed to pollution from \"real world.\" In these studies, animals were exposed to gases and particles in the same way that the population is exposed in the city of São Paulo. It was evident then, the role of promoter and dose dependent polluted atmosphere in the progression of lung tumors. It is known that carcinogens such as polycyclic aromatic hydrocarbons (PAHs), metals, aldehydes and fatty acids, are present in the respirable fraction particulate pollution (fine particulate matter - PM2.5), and prolonged exposure to the latter has been considered a risk factor for the development of lung cancer. The objective of this study is to verify whether chronic exposure to PM 2.5 concentration from the air of the city of São Paulo, has carcinogenic potential. METHODS. A total of 60 male Swiss mice (30 g) and 60 AJ (20g), with four to six weeks of life. The Swiss mice were pretreated with a carcinogen completed, the carbamic acid (urethane-U), while AJ received a carcinogen primer 4 - (methylnitrosamino) -1 - (3-pyridil)-1-butanone (NNK) as being predisposed to developing lung tumors. Then all the animals were exposed to atmospheric Harvard Particle Concentrator to PM 2.5 daily for two hours for four months. Each strain was divided into four groups (n = 15 each): 2 with saline controls and carcinogen (CsS and CsU or CajS and CajNNK) and 2 exposed to saline and carcinogen (EsS and EsS or EajS and EajNNK). After the exposure time, the animals were anesthetized and euthanized. The lungs were fixed, processed histologically and imunohistochemistry was performed on slides with tumor presence of antibodies to p53 and PCNA. Later, in histopathology of pulmonary nodules made counting and classification of lesions found. RESULTS. The animals exposed groups in both strains showed a high percentage of neoplastic lesions. Mean lesions (nodules and hyperplasia) were obtained: CsU: 1.07 (SD + 1.54), CsS: 0 (DP + 0), EsU: 2.57 (SD + 2.77) and EsS: 0.40 ( + SD 1.12), p < 0.001; CajNNK: 4.94 (SD + 3.54), CajS: 0.15 (SD + 0.37), EajNNK: 9.14 (SD + 7.70) and EajS: 0 , 80 (SD + 1.93), with p < 0.001. There were no changes to the p53 in both strains, and only groups A / J control and exposed to NNK differ PCNA. CONCLUSION. The chronic exposure to PM 2.5 air pollution from the city of São Paulo has the potential to promote tumors in mice of two different strains with or without pretreatment by carcinogens
|
79 |
Lesões em DNA promovidas por produtos de oxidação do β-caroteno: possíveis implicações biológicas / Lesions in DNA caused by oxidation products of -carotene: possible biological implicationsMarques, Sabrina de Almeida 11 May 2005 (has links)
Apesar de diversos estudos in vitro e em populações indicarem um efeito protetor do β-caroteno em sistemas biológicos, estudos epidemiológicos como o \"The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study\" (ATBC) e o \"The Beta-Carotene and Retinol Efficacy Trial\" (CARET) mostraram um aumento na incidência de câncer pulmonar em indivíduos fumantes suplementados com β-caroteno. Essa ação contraditória tem sido chamada na literatura de \"Paradoxo do β-Caroteno\". Sabe-se que este carotenóide sob altas pressões de oxigênio ou na presença de peróxidos pode sofrer oxidação e levar a formação de compostos como aldeídos, epóxidos, etc, que são capazes de se adicionarem covalentemente ao DNA. Estudos, in vitro e in vivo têm demonstrado a possibilidade de os metabólitos do β-caroteno agirem como agentes pró-carcinogênicos. Estes agentes quando ativados quimicamente podem levar à formação de adutos de DNA. Já se sabe que alguns desses adutos encontramse em níveis aumentados em diversas situações de risco de câncer. Diversos grupos, incluindo o nosso, têm demonstrado a formação de lesões em DNA a partir de aldeídos e epóxidos exógenos ou gerados endogenamente. O presente trabalho mostra que a reação do β-caroteno e dois de seus produtos de oxidação, retinal e β-apo-8\'-carotenal, com 2\'-desoxiguanosina e DNA leva à formação de adutos. Dentre os adutos formados, foi caracterizado o aduto 1,N2eteno-2\'-desoxiguanosina (1 ,N2-εdGuo). Os níveis de outro aduto de DNA, a 8-oxo-7,8-dihidro-2\'-deoxiguanosina (8-oxodGuo), também foram monitoradas para estudo comparativo. A formação dos adutos também foi verificada em fibroblastos normais de pulmão humano (linhagem IMR-90) expostos ao β-caroteno e aos seus produtos de oxidação. Experimentos com ratos suplementados com β-caroteno e expostos à fumaça de cigarro em períodos de 7, 30 e 180 dias, mostraram níveis aumentados de 1,N2-εdGuo nos animais suplementados com o carotenóide comparado ao grupo veículo. Aumento no nível de 8-oxodGuo também foi verificado nos tratamentos de 7 e 180 dias. Um aumento significativo no nível do eteno aduto também foi verificado nos animais suplementados com β-caroteno e expostos à fumaça de cigarro, comparado ao grupo apenas exposto à fumaça após 7 e 180 dias de exposição. Nestes mesmos grupos, o aumento do 8-oxodGuo só foi observado no tratamento por 180 dias. Sabendo que estas lesões são comprovadamente mutagênicas, nossos estudos podem contribuir para o esclarecimento dos mecanismos envolvidos na formação de câncer em fumantes suplementados ou não com β-caroteno. / Despite several studies performed in vitro and in population indicate a protector effect of β-carotene, the epidemiological studies \"The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study\" (ATBC) and \"The Beta-Carotene and Retinol Efficacy Trial\" (CARET) showed a relative risk for lung cancer in smokers supplemented with β-carotene. It is well known that this carotenoid is able to oxidize in high oxygen tension or in the presence of peroxides yielding to aldehydes, epoxides, and other compounds that are capable to bind to DNA. lhe possibility that β-carotene oxidation products can act as pro carcinogenic agents is under investigation. Lhese products can be activated by peroxides, ar by enzymes such as cytochromr P450, leading to DNA adducts formation. Several groups, like ours, showed the formation of DNA adducts from aldehydes or epoxides generated by endogenous or exogenous sources. We investigated here the reactions of β-carotene, and two of its oxidation products, retinal and β-apo-8\'-carotenal, with 2\'-deoxyguanosine to evaluate their DNA damaging potential. A known mutagenic adduct, 1,N2-etheno-2\'-deoxyguanosine (1 ,N2 edGuo) was isolated and characterized on the basis of its spectroscopic features. After treatment of calf thymus DNA with β-carotene or β-carotene oxidation products, significantly increased levels of the etheno adduct were detected and quantified in DNA by a sensitive LC/ESI/MS-MS technique. For comparative purposes, levels of 8-oxo7,8-dihydro-2\'-deoxyguanosine were also evaluated (8-oxodGuo). Levels of these lesions were also increased. Exposure of human lung cells (IMR 90) to the carotenoids also leads to increased levels of the two adducts. As the main noteworthy result, rats supplemented with β-carotene for 7, 30, and 180 days showed significantly higher lung DNA concentrations of the 1,N2-εdGuo adduct than those of the control group. lhe level of 8-oxodGuo was also increased after 7 and 180 days in the group supplemented with the carotenoid. Rats supplemented with β-carotene and exposed to cigarette smoke for 7 and 180 days also showed significantly increased levels of the adduct 1,N2-εdGuo when compared with the group exposed to cigarette smoke. In the same groups level of 8-oxodGuo was only increased after 180 days of treatment. These DNA lesions are confirmed mutagenic, so our data could contribute to the elucidation of the mechanisms responsible for the association between β-carotene and lung cancer in smokers.
|
80 |
Predictive biomarkers of the efficacy of epidermal growth factor receptor tyrosine kinase Inhibitors in treating advanced non-small cell lung cancer: a systematic review of randomized controlled trials = 表皮生长因子受体酪氨酸激酶抑制剂治疗晚期非小细胞肺癌的疗效预测生物标志物 : 随机对照试验的系统综述. / 表皮生长因子受体酪氨酸激酶抑制剂治疗晚期非小细胞肺癌的疗效预测生物标志物: 随机对照试验的系统综述 / Predictive biomarkers of the efficacy of epidermal growth factor receptor tyrosine kinase Inhibitors in treating advanced non-small cell lung cancer: a systematic review of randomized controlled trials = Biao pi sheng zhang yin zi shou ti luo an suan ji mei yi zhi ji zhi liao wan qi fei xiao xi bao fei ai de liao xiao yu ce sheng wu biao zhi wu : sui ji dui zhao shi yan de xi tong zong shu. / Biao pi sheng zhang yin zi shou ti luo an suan ji mei yi zhi ji zhi liao wan qi fei xiao xi bao fei ai de liao xiao yu ce sheng wu biao zhi wu: sui ji dui zhao shi yan de xi tong zong shuJanuary 2014 (has links)
目的: 尽管过去几十年癌症的化疗取得了很大进步,但晚期非小细胞肺癌的预后仍然较差。表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor tyrosine kinase inhibitors,EGFR TKIs)给晚期非小细胞肺癌的患者带来了新的希望。然而,EGFR TKIs的总体效果有限,且不良反应较多,价格也较昂贵。如果能找到EGFR TKIs的疗效预测因子,则该治疗就可以只给予那些最有可能从中获益的人,从而提高成本效果,并使治疗变得更加个体化。 / 已有单组研究在接受EGFR TKIs治疗的患者中对有或没有某个标志物的人的预后进行了比较,发现EGFR基因突变、EGFR基因拷贝数增加、EGFR蛋白表达和KRAS基因突变这4个生物标志物可能能够预测EGFR TKIs的疗效。然而,此类研究的方法学是有缺陷的。要确定以上生物标志物是否有预测作用,应该在评估EGFR TKIs疗效的随机对照试验中作亚组分析,对该治疗在有某个生物标志物及没有某个生物标志物的患者中的疗效进行比较,检测治疗与生物标记物的交互作用。 / 但是,现有的随机对照试验通常样本量较小,统计效能不足,难以从中得到确定的结论。因此,我们做了一个随机对照试验的系统综述,以总结现有的最佳证据,对EGFR TKIs与上述4个生物标志物的交互作用进行评估。 / 方法: 我们检索了PubMed,EMBASE,考科蓝图书馆,中国生物医学文献数据库(中文),万方数据库(中文),美国临床肿瘤学会和欧洲肿瘤学会的会议摘要,以及相关原始研究、系统综述与Meta分析、临床指南、共识及专家意见的参考文献。检索时间截至2012年6月。合格研究为非重复、提供了具体数据且符合下列所有条件的研究:1)研究对象:晚期非小细胞肺癌患者;2)干预措施:EGFR TKIs单药治疗或联合其他药物治疗;3)对照措施:安慰剂对照,空白对照或化疗,或者它们任一种加上干预组的基线治疗;4)结局指标:无进展生存期和/或总生存期;5)研究设计:随机对照试验;6)根据上述任一种或多种生物标志物的状态作了亚组分析。 / 两名研究者平行独立地从合格研究中提取了患者特征、治疗方案、结局、生物标志物分析和方法学质量等方面的资料。对每一个研究,我们都根据生物标志物阳性亚组的风险比(hazard ratio)和阴性亚组的风险比计算了一个风险比之比(ratio of hazard ratios)来测量该标志物对疗效的预测能力或者说治疗与该生物标志物的交互作用。然后,采用随机效应模型对来自不同研究的风险比之比进行Meta分析;采用Cochran Q检验和I²评估研究间的异质性;通过敏感性分析考察原始研究的方法学质量等因素对结果的影响;采用Begg漏斗图和Egger检验来检测发表偏倚存在的可能性。 / 结果: 共有18个合格研究入选。可用于各个生物标志物分析的患者数量从1763到3246不等。原始研究普遍对关于方法学质量的信息报告得不够充分;有的研究可能存在重要偏倚。与安慰剂相比,EGFR TKIs可以有效延长无进展生存期和总生存期,但对总生存期的效果相对较小。除了在EGFR基因突变的患者中EGFR TKIs延长无进展生存期的效果明显好于化疗外,其它情形下,不管是无进展生存期还是总生存期,EGFR TKIs与化疗的效果均相当。 / 以无进展生存期为结局的风险比之比,在EGFR基因突变状态不同的亚组间(野生型亚组为参照)为0.37(95% 置信区间[CI]:0.22-0.60,P < 0.0001),EGFR基因拷贝数状态不同的亚组间(未增加的亚组为参照)为0.72(95% CI:0.52-0.99,P = 0.04),EGFR蛋白表达状态不同的亚组间(无表达的亚组为参照)为0.99(95% CI:0.78-1.26,P = 0.93),KRAS基因突变状态不同的亚组间(野生型亚组为参照)为1.35(95% CI:1.02-1.80,P = 0.04)。这些结果提示EGFR TKIs治疗与EGFR基因突变,EGFR基因拷贝数及KRAS基因突变之间可能存在交互作用。以总生存期为结局的风险比之比,在EGFR基因突变、EGFR基因拷贝数、EGFR蛋白表达及KRAS基因突变状态不同的亚组间分别为0.84(95% CI:0.64-1.11,P = 0.22)、0.92(95% CI:0.69-1.23,P = 0.57)、0.86(95% CI:0.70-1.05,P = 0.14)和1.37(95% CI:0.89-2.10,P = 0.15)。 / 就统计学显著性、异质性和稳定性而言,关于其它3个生物标志物的结果不如EGFR基因突变的相关结果确定,关于总生存期的结果不如无进展生存期的相关结果确定。没有证据表明本研究中存在发表偏倚。 / 结论: EGFR基因突变可用于确定哪些患者更有可能从EGFR TKIs治疗中获益。EGFR基因拷贝数增加和KRAS基因突变可能也有类似用途,但它们与治疗的交互作用是独立存在的还是由于它们与EGFR基因突变的相关性而获得的,目前尚不清楚。在EGFR野生型的患者中,选择化疗似乎比EGFR TKIs更好,因为它的副作用相对较少,且更为便宜。 / 本研究的结果为当前的临床指南提供了全面的证据支持。其它3个标志物在EGFR野生型患者中的预测价值可能还值得进一步的探讨,但我们更建议未来的研究在探讨治疗与生物标志物的交互作用时进行多因素分析。 / Objective: Despite the many new progresses in chemotherapy, the prognosis of advanced non-small cell lung cancer (NSCLC) remains poor. The introduction of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) seems to offer new promises for advanced NSCLC patients. However, EGFR TKIs have a limited overall efficacy, clear adverse events and large costs. It has become particularly appealing to identify, through new biomarkers, patients who are more likely to benefit from the treatment so that the treatment can be more personalized and effective. / EGFR mutations, EGFR gene copy number gain, EGFR protein expression and KRAS mutations were indicated as potential predictive biomarkers for the efficacy of the treatment in single-arm studies that compared survival of treated patients with and without a biomarker. However, such comparisons are flawed and the appropriate study design to evaluate the value of a biomarker in predicting efficacy which is known as interaction in epidemiology is the randomized controlled trial with stratified analysis that compared the efficacy of EGFR TKIs between patients with and without the biomarker. / As trials in this field are usually small in sample size and insufficiently powered for drawing a robust conclusion, we conducted this systematic review to summarize the evidence from all relevant randomized controlled trials that have data for investigating the interaction between EGFR TKIs and the 4 biomarkers. / Methods: PubMed, EMBASE, the Cochrane Library, Chinese Biomedical Literature Database (in Chinese), Wanfang Data (in Chinese), the abstracts of conferences of the American Society of Clinical Oncology and European Society of Medical Oncology, the reference list of relevant original studies, systematic reviews and meta-analyses, guidelines, consensus, and expert opinions were searched up to June 2012. / Eligible studies had to be non-duplicate, extractable studies meeting all the following criteria: 1) Population: patients with advanced NSCLC; 2) Intervention: EGFR TKIs alone or EGFR TKIs plus other treatments; 3) Control: placebo, no treatment, or chemotherapy, with or without the baseline treatments in the intervention arm; 4) Outcome: progression-free survival and/or overall survival; 5) Study design: randomized controlled trial; 6) Subgroup analyses were conducted according to the status of one or more of the 4 biomarkers. / Data on patients’ characteristics, treatment protocols, outcomes, biomarker analysis and methodological quality were extracted by two researchers independently. Within a study, we defined the measure of the value of a biomarker in predicting efficacy or biomarker-treatment interaction as the hazard ratio in patients with the biomarker relative to that in those without the marker. The ratio of hazard ratios from relevant studies was then combined by using the random-effect model. / Heterogeneity among studies was assessed by the Cochran’ Q test and I². Sensitivity analyses were conducted to examine the impact of factors such as methodological quality on the results. Begg’s funnel plots and Egger’s tests were used to examine the possibility of publication bias. / Results: Eighteen studies were included. The number of patients available for analyses on different biomarkers varied from 1,763 to 3,246. Data on the methodological quality of included studies are generally under-reported. Some studies seemed to have important biases. EGFR TKIs are in general effective in increasing progression-free and overall survival as compared with placebo although the effect size is smaller for overall survival than for progression free survival. EGFR TKIs are comparable to chemotherapy in their effect in prolonging both progression-free and overall survival, except in EGFR mutation group in which EGFR TKIs seem much more effective than chemotherapy in prolonging progression-free survival. / Importantly, for progression-free survival, the summary ratio of hazard ratios was 0.37 (95% confidence interval [CI]: 0.22-0.60, P < 0.0001) for EGFR mutations (versus wild-type), 0.72 (95% CI: 0.52-0.99, P = 0.04) for EGFR gene copy number gain (versus no gain), 0.99 (95% CI: 0.78-1.26, P = 0.93) for EGFR protein expression (versus negative), and 1.35 (95% CI: 1.02-1.80, P = 0.04) for KRAS mutations (versus wild-type), indicating interaction may exist between EGFR TKIs and EGFR mutation, EGFR gene copy number and KRAS mutations. For overall survival, the summary ratio of hazard ratios for EGFR mutations, EGFR gene copy number gain, EGFR protein expression and KRAS mutations was 0.84 (95% CI: 0.64-1.11, P = 0.22), 0.92 (95% CI: 0.69-1.23, P = 0.57), 0.86 (95% CI: 0.70-1.05, P = 0.14) and 1.37 (95% CI: 0.89-2.10, P =0.15), respectively. / In general, the results on EGFR gene copy number gain, KRAS mutations and EGFR protein expression were less certain than those on EGFR mutations in terms of statistical significance, consistency and robustness, and the results on overall survival were less certain than those on progression-free survival. Publication bias did not seem present in the study. / Conclusions: EGFR mutations and possibly EGFR-GCN and KRAS mutations can help identify who are more likely to benefit from EGFR TKIs treatment. However, it is not clear whether the interaction with EGFR-GCN and KRAS mutations are independent or obtained through their relation with EGFR mutations. Furthermore, in EGFR wild-type patients, given that chemotherapy is cheaper and of fewer side effects, chemotherapy seems clearly a better choice than EGFR TKIs. / Our findings provided the most comprehensive evidence for the recommendations of current guidelines. Although the predictive value of the other 3 biomarkers in wild-type EGFR patients may be worth further investigation, we suggest that multivariate analyses are explored in future studies of biomarker-treatment interactions. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yang, Zuyao. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 88-104). / Abstracts also in Chinese. / Yang, Zuyao.
|
Page generated in 0.1051 seconds