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  • 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.
71

Avalia??o do status de zinco e da express?o g?nica de metalotione?nas em pacientes com aterosclerose tratados com rosuvastatina / Evaluation of the zinc status and the metallothionein gene expression in patients with atherosclerosis treated with rosuvastatin

Dias, Paula Cristina Silveira 22 February 2011 (has links)
Made available in DSpace on 2014-12-17T14:16:34Z (GMT). No. of bitstreams: 1 PaulaCSD_DISSERT.pdf: 2575213 bytes, checksum: b1a82c5d30ff9ebaa0fce4e2c1fef958 (MD5) Previous issue date: 2011-02-22 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The study had as objective to evaluate the zinc status by means of dietary intake, zinc in plasma and in erythrocytes and the metallothionein gene expression in patients with atherosclerosis in use of rosuvastatin. The research involved 27 adult and elderly patients of both genders with atherosclerosis that were treated with rosuvastatin (10mg/day) during 4 months. We performed the dosage of lipids, glucose, AST and ALT, ultrasensitive C-reactive protein (hsCRP), plasmatic and erythrocyte zinc and 1 and 2 metallothionein gene expression. The assessment of body mass index (BMI) and abdominal circumference (AC) was performed, besides the analysis of dietary intake of patients. The majority of the evaluated patients presented overweight, before and after the treatment, with no significant difference between the times of the study. It was identified that the AC was significantly reduced in the group (p<0.05) after the intervention. The majority of the patients had intake below the recommendation of calories and fibers and above recommendation of proteins. The mono and polyunsaturated fats were adequate for the majority of the patients, however, the saturated fat and cholesterol were consumed in excess by a great part of the individuals. The intake of zinc was inadequate, being noticed an inadequacy of 100% in the male gender and of 84% in the female. After the treatment with rosuvastatin there was a significant reduction in the total cholesterol (TC) and LDL-c (p<0.01) and no alterations were observed in the HDL-c and triacylglycerols. It was also verified that the reduction of glycemia (p<0.05) and of hsCRP (p<0.01). The analysis did not demonstrate significant differences in the plasmatic and erythrocyte zinc concentration after the treatment. There was, after the treatment, reduction of the MT1F gene (p<0.05) without, however, occurring significant alterations in the MT2A gene. The treatment with rosuvastatin was effective in the reduction of TC and LDL-c, and promoted the reduction of inflammatory marker hsCRP. The zinc in the plasma and erythrocyte was not altered by the use of the medication and there was a reduction in the MT1F gene, possibly due to the reduction of inflammation. The majority of patients presented inadequate intake of zinc and this inadequacy did not have relation with the mineral parameters in plasma and erythrocytes or with the metallothionein gene expression / O estudo teve como objetivo avaliar o status de zinco por meio da ingest?o diet?tica, zinco no plasma e nos eritr?citos e a express?o g?nica das metalotione?nas em pacientes com aterosclerose em uso de rosuvastatina. A pesquisa envolveu 27 pacientes adultos e idosos de ambos os sexos com aterosclerose que foram tratados com rosuvastatina (10mg/dia) durante 4 meses. Foi realizada a dosagem do perfil lip?dico, glicemia, AST e ALT, prote?na C reativa ultrasens?vel (PCRus), zinco plasm?tico e eritrocit?rio e express?o g?nica das metalotione?nas 1 e 2. Realizou-se a avalia??o do ?ndice de massa corporal (IMC) e circunfer?ncia abdominal (CA), al?m da an?lise do consumo alimentar dos pacientes. A maioria dos pacientes avaliados apresentou sobrepeso, tanto antes como ap?s o tratamento, sem diferen?a significativa entre os tempos do estudo. Identificou-se que a CA foi reduzida significativamente no grupo (p<0,05) ap?s a interven??o. A maioria dos pacientes tinha ingest?o abaixo da recomenda??o de calorias e fibras e acima do recomendado de prote?nas. As gorduras mono e poliinsaturadas foram adequadas para a maioria dos pacientes, no entanto, a gordura saturada e colesterol foram consumidos em excesso por grande parte dos indiv?duos. O consumo de zinco foi inadequado, constatando-se 100% de inadequa??o no sexo masculino e 84% no feminino. Ap?s o tratamento com a rosuvastatina houve redu??o significativa do colesterol total (CT) e LDL-c (p<0,01) e n?o foram observadas altera??es no HDL-c e triacilglic?rides. Foi verificada tamb?m a redu??o da glicemia (p<0,05) e da PCRus (p<0,01). As an?lises n?o demonstraram diferen?as significativas nas concentra??es de zinco no plasma nem nos eritr?citos antes e ap?s o tratamento com rosuvastatina. Houve, ap?s o tratamento, redu??o do gene MT1F (p<0,05) sem, no entanto, ocorrer altera??o significativa do gene MT2A. O tratamento com rosuvastatina foi efetivo na redu??o do CT e LDL-c, bem como promoveu a redu??o do marcador inflamat?rio PCRus. O zinco no plasma e nos eritr?citos n?o foi alterado pelo uso da medicamento e houve uma redu??o do gene MT1F, possivelmente em fun??o da redu??o da inflama??o. A maioria dos pacientes apresentou consumo inadequado de zinco e esta inadequa??o n?o teve rela??o com os par?metros do mineral no plasma ou nos eritr?citos nem com a express?o g?nica das metalotione?nas
72

Avaliação da atividade da [delta]-aminolevulinato-desidratase e concentração de metalotioneína em fígado e encéfalo de ratos expostos a cádmio e zinco

Braga, Marcos Martins January 2009 (has links)
É bem conhecido que muitos efeitos tóxicos do cádmio (Cd) resultem da ação da interação com metais essenciais, incluindo zinco (Zn). Sendo um poluente ambiental, a exposição à Cd conduz a distúrbios no conteúdo e atividade de Zn no organismo, representando importante via para o desenvolvimento de sua toxicidade. Evidências suportam que Zn pode reduzir os efeitos do Cd, prevendo ou reduzindo a ação tóxica deste metal, enquanto que a deficiência de Zn pode intensificar a toxicidade de Cd. Com base nisto, este trabalho buscou investigar (1) o efeito da interação Zn-Cd sobre o tecido hepático de ratos adultos, por representar um importante alvo biológico à ação dos metais e (2) se estes efeitos são estendidos ao SNC mesmo protegido pela barreira hemato-encefálica. Através da avaliação de parâmetros bioquímicos, como [delta]-aminolevulinato-desidratase e metalotioneína, os resultados encontrados suportam a sobreposição do efeito tóxico de Cd sobre as funções essenciais de Zn, entretanto existe diferença entre os tecidos quanto ao mecanismo protetivo exercido sobre a toxicidade de Cd. Além disso, obtemos dados sobre os níveis de MT que contrapõem suas funções benéficas previamente descritas. Em resumo, essa dissertação reforça a ação tóxica de Cd por vias biológicas comuns ao Zn e expõe diferenças entre o tecido hepático e o SNC quanto ao mecanismo interativo. / It is well known that many toxic effects of cadmium (Cd) results from the action of the interaction with essential metals, for example zinc (Zn). Cd is an environmental pollutant, which exposure leads to disturbance in the content and atividade of Zn in the body. Evidences indicate that Zn can reduce the effects of Cd for provide or reduce the toxic action of this metal, whereas Zn deficiency can intensify the toxicity of Cd. On account of this, our study aimed investigate (1) the effect of Zn-Cd interaction on the liver tissue of adult rats, which represents important biological target for action of the metals and (2) if these effects are extended to the CNS even protected by the blood-brain barrier. Through the evaluation of biochemical parameters, as [delta]-aminolevulinate-dehydratase ([delta]-ALA-D) and metallothionein (MT), the results support the overlap of the toxic effect of Cd on the essential functions of Zn; however there is difference between the tissues on the protective mechanism exerted on the toxicity of Cd. Furthermore, we obtain data on the levels of MT that contrast to their beneficial functions previously described. In summary, this work reinforces the toxic effect of Cd by biological pathways common to the Zn and explains differences between the liver tissue and CNS in relation to the interactive mechanism.
73

Characterizatin of a Type II Metallothionein from <i>Helianthus annuus</i> Using Recombinant DNA Techniques

Bhogavalli, Sridhar January 2007 (has links)
No description available.
74

Exprese kandidátních genů karcinomu prostaty / Expression of candidate genes for prostate cancer

Krupicová, Daniela January 2013 (has links)
4 Abstract Prostate cancer is one of the major medical problems within the male population in the Czech Republic and in the world. It is on second place among cancer illnesses with respect to mortality in czech male population. Its incidence strongly increases with age. Prostate cells have a unique ability to accumulate zinc in high concentrations compared to other tissues of human body. It is necessary for the proper physiological function of the prostate. There was detected loss of this accumulation ability in prostate cancer cells, which seems to be a condition to carcinogenesis in prostate cells. In this thesis was investigated the expression of four genes involved in the maintenance of homeostasis of zinc in prostate cells. Genes ZIP1 and ZIP7 encode zinc transporters, genes MT1-F and MT2 encode metallothioneins. There was collected 90 biopsy specimens from patients with prostate cancer or with benign prostatic hyperplasia. mRNA was isolated from these samples, cDNA was obtained by RT-PCR. This cDNA was detected by gel electrophoresis and the results were statistically evaluated. Several correlations was found between gene expression and the clinical data of patients. The most important result, there was found lower levels of expression of genes MT1- F and ZIP1 in samples of patients with cancer...
75

Engineering of gene constructs for ectopic expression in transgenic fish.

January 2001 (has links)
by Yan Hiu Mei, Carol. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 114-126). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Tables --- p.viii / List of Figures --- p.ix / Abbreviations --- p.xii / Chapter CHAPTER 1 --- TRANSGENIC TECHNOLOGY --- p.1 / Chapter 1.1 --- Transgenesis in animals --- p.1 / Chapter 1.2 --- Transgenic fish in toxicology --- p.4 / Chapter 1.2.1 --- Aquatic metal toxicity --- p.4 / Chapter 1.2.2 --- Environmental monitoring of aquatic metal toxicity --- p.5 / Chapter 1.2.3 --- Biomarkers --- p.6 / Chapter 1.3 --- Transgenics in aquaculture --- p.9 / Chapter 1.3.1 --- Revolution is needed in aquaculture --- p.9 / Chapter 1.3.2 --- Aquaculture potential of tilapia in China --- p.10 / Chapter 1.3.3 --- Endocrinology for fish growth --- p.12 / Chapter 1.3.4 --- Growth promotion by exogenous growth hormone in tilapia --- p.14 / Chapter 1.3.5 --- Accelerated growth in transgenic fish --- p.15 / Chapter 1.4 --- General principle in transgenic fish production --- p.16 / Chapter 1.5 --- Project aim --- p.22 / Chapter CHAPTER 2 --- ISOLATION AND CHARACTERIZATION OF ZEBRAFISH METALLOTHIONEIN GENE PROMOTER --- p.23 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.1.1 --- Metallothionein --- p.23 / Chapter 2.1.2 --- Biological functions --- p.24 / Chapter 2.1.3 --- Metallothionein gene regulations --- p.25 / Chapter 2.1.4 --- Metallothionein as biomarker for metal pollution --- p.26 / Chapter 2.2 --- Materials and methods --- p.28 / Chapter 2.2.1 --- General molecular biology techniques --- p.28 / Chapter 2.2.2 --- Sequences of PCR primers used --- p.31 / Chapter 2.2.3 --- Cloning zebrafish MT gene 5-flanking region --- p.31 / Chapter 2.2.4 --- Cloning zebrafish MT gene --- p.32 / Chapter 2.2.5 --- Cloning full length zMT gene --- p.33 / Chapter 2.2.6 --- Cell culture --- p.35 / Chapter 2.2.7 --- Transient transfection assay --- p.37 / Chapter 2.2.8 --- Electrophoretic mobility shift assay --- p.39 / Chapter 2.3 --- Results --- p.42 / Chapter 2.3.1 --- Zebrafish metallothionein gene --- p.42 / Chapter 2.3.2 --- Deletion analysis of zMT promoter by transient transfection assay --- p.48 / Chapter 2.3.3 --- Functional characterization of zebrafish metallothionein promoter --- p.57 / Chapter 2.4 --- Discussions --- p.61 / Chapter 2.4.1 --- Zebrafish MT gene --- p.61 / Chapter 2.4.2 --- Functional characterization of zebrafish MT promoter --- p.61 / Chapter CHAPTER 3 --- PREPARATION OF GENE CONSTRUCTS FOR TRANSFER IN ZEBRAFISH --- p.65 / Chapter 3.1 --- Introduction --- p.65 / Chapter 3.1.1 --- Zebrafish as model in toxicological studies --- p.65 / Chapter 3.1.2 --- Reporter gene system --- p.66 / Chapter 3.1.3 --- Transgenic reporter fish --- p.68 / Chapter 3.1.4 --- Gene transfer by electroporation in zebrafish --- p.68 / Chapter 3.1.5 --- Objective --- p.69 / Chapter 3.2 --- Materials and methods --- p.70 / Chapter 3.2.1 --- Design of gene constructs for ectopic expression in zebrafish --- p.70 / Chapter 3.2.2 --- Testing electroporation conditions for zebrafish --- p.72 / Chapter 3.3 --- Results --- p.73 / Chapter 3.4 --- Discussions --- p.76 / Chapter 3.4.1 --- Engineering gene constructs --- p.76 / Chapter 3.4.2 --- Applications of transgenic zebrafish --- p.79 / Chapter CHAPTER 4 --- GENE TRANSFER EXPERIMENTS ON TILAPIA --- p.82 / Chapter 4.1 --- Introduction --- p.82 / Chapter 4.2 --- Materials and methods --- p.85 / Chapter 4.2.1 --- Isolation of O. aureus growth hormone --- p.85 / Chapter 4.2.2 --- Engineering gene constructs for ectopic expression in tilapia --- p.86 / Chapter 4.2.3 --- Gene transfer in tilapia --- p.87 / Chapter 4.2.4 --- Screening transgenic tilapia --- p.89 / Chapter 4.3 --- Results --- p.91 / Chapter 4.3.1 --- Tilapia growth hormone --- p.91 / Chapter 4.3.2 --- Gene constructs for ectopic expression in tilapia --- p.94 / Chapter 4.3.3 --- Testing electroporation conditions --- p.96 / Chapter 4.3.4 --- PCR screening for transgenic fish --- p.97 / Chapter 4.4 --- Discussions --- p.101 / Chapter 4.4.1 --- Tilapia growth hormone --- p.101 / Chapter 4.4.2 --- Electroporation experiments on of tilapia eggs --- p.101 / Chapter 4.4.3 --- Improvements on gene construct design for tilapia --- p.104 / Chapter 4.4.4 --- Ethical and safety considerations --- p.106 / Chapter CHAPTER 5 --- REFERENCES --- p.114 / APPENDIX --- p.127
76

Estudo da expressão das proteínas metalotioneína, NFkB, ciclina D1 e Cdk4 em linhagens celulares derivadas de carcinoma epidermóide humano / Study of expression of proteins Metalotioneína, NFkB, Ciclina D1 and Cdk4 in cell lines derived from human squamous cell carcinoma

Silva, Brunno Santos de Freitas 01 July 2008 (has links)
O carcinoma epidermóide por se tratar de uma doença genética, apresenta dificuldades em relação ao seu tratamento. As vias de sinalização celular por controlarem os mecanismos responsáveis pela proliferação e sobrevivência da célula, são de extrema importância nos estudos da biologia do câncer e oncogênese. Aberrações cromossômicas que afetam a estrutura e a expressão de genes e proteínas que regulam componentes das vias de sinalização são diretamente correlacionadas com o desenvolvimento e progressão tumoral. Vários genes e proteínas vêm sendo avaliados na busca de um alvo terapêutico quimioterápico, algo pouco estudado em carcinomas epidermóides bucais. Este trabalho teve como objetivo analisar a influência do quimioterápico 17-AAG e do fator de crescimento epitelial (EGF) nos níveis das proteínas NFkB, Ciclina D1 e Cdk4 nas linhagens de carcinoma epidermóide de cabeça e pescoço (HN6 e HN31) e no queratinócito imortalizado (HaCat). Este trabalho destinou-se também a estudar uma possível inter-relação entre as proteínas Metalotioneína e NFkB e suas interações com as proteínas Ciclina D1 e Cdk4 nas linhagens celulares HN6 , HN31 e (HaCat, para uma maior compreensão de seus efeitos nas vias de sinalização celular e conseqüente progressão do câncer). Para análise a respeito da localização e os níveis das proteínas MT, NFkB, Ciclina D1 e Cdk4 foram utilizados ensaios de imunofluorescência e western blot, respectivamente.Os resultados apontaram um melhor perfil apoptótico da linhagem HN31 frente ao tratamento com 17-AAG, apresentando diminuição significante dos níveis de NFkB e Ciclina D1, além de exibir importante decréscimo nos níveis de Cdk4. A proteína MT parece não sofrer ação do NFkB. A indução de proliferação celular realizada por EGF exerceu um aumento dos níveis das proteínas NFkB e Ciclina D1, sugerindo um papel importante das vias de sinalização estimuladas por EGF (Akt, NFkB e Ciclina D1) na progressão tumoral dessas linhagens.Por fim, a ocorrência de estímulo nos níveis da proteína MT por parte do EGF, sugeriram um importante papel do EGF e da MT na resistência a apoptose nas linhagens estudadas. / Squamous cell carcinomas as a genetic diseases, presents certain difficulties in relation to their treatment. The process of cell signaling for overseeing the mechanisms responsible for cellular proliferation and survival are very important in studies of the biology of cancer and development. Chromosomal alterations affecting the structure and expression of genes and proteins that regulate the process of signaling components are directly correlated with the development and tumor progression. Several genes and proteins are being evaluated in the search for a biological marker that could help in the understanding of cancer as well as in its prognosis, and mainly in search of therapeutic target chemotherapy, something little studied in oral squamous cell carcinoma. This study aimed to examine the influence of chemotherapy 17-AAG and the epithelial growth factor (EGF) in the levels of proteins NFkB, Cyclin D1 and Cdk4 in strains of squamous cell carcinoma of the head and neck (HN6 and HN31) and immortalized in keratinocytes(HaCat). This work is also intended to explore a possible inter-relationship between the Metallothionein and NFkB proteins and their interactions with the proteins Cyclin D1 and Cdk4 in cell lines HN6, HN31 and (HaCat, to a greater understanding of its effects on pathways of cellular signaling and consequent progression of cancer. For analysis regarding the location and levels of the protein MT, NFkB, Cyclin D1 and Cdk4 were used tests of immunofluorescence and western blot. Results showed a better apoptotic profile of HN31 treated with 17-AAG, showing decrease levels of NFkB and Cyclin D1, with a important decrease in the levels of Cdk4. The metallothionin protein does not appear to suffer action of NFkB. The induction of cell proliferation conducted by EGF had increased levels of NFkB and Cyclin D1 proteins, suggesting an important role in the process of signaling stimulated by EGF (Akt, NFkB and Ciclina D1) in tumor progression of oral squamous cell carcinoma. The occurrence to stimulate the levels of metallothionein protein by the EGF, suggest an important role of EGF and MT in resistance to apoptosis in the studied cell lines.
77

Bioensaios com metais (\'CD\', \'CU\' e \'ZN\') e as alterações em biomarcadores do estresse oxidativo, na glutationa S-transferase e na metalotioneína em brânquias, fígado e rim de Oreochromis niloticus / Bioassays with metals (CD\', \'CU\' e \'ZN\') and alterations in oxidative stress biomarkers in kidney, liver and gills of Oreochromis niloticus

Tonissi, Fabiano Botta 11 September 2009 (has links)
Uma das formas de se quantificar os possíveis efeitos de metais sobre o estado de saúde de organismo é analisar os biomarcadores do estresse oxidativo. Bioensaios foram realizados com a tilápia do Nilo (Oreochromis niloticus) com concentrações de cádmio (4,25 \'mü\'g/L), cobre (45,0 \'mü\'g/L ) e zinco (260,0 \'mü\'g/L). Os peixes foram expostos aos metais separados (\'CD\', \'CU\' e \'ZN\'), associados dois a dois (\'CD\'/\'CU\', \'CD\'/\'ZN\' e \'CU\'/\'ZN\') e aos três metais juntos (\'CD\'/\'CU\'/\'ZN\'), por doze dias. Foram retiradas amostras de rim, fígado e brânquias para análise de biomarcadores de estresse oxidativo, a superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx), o efeito da peroxidação de lipídios (HP), a glutationa S-transferase (GST) e a metalotionéina (MT). Pelos reusltados obtidos constatou-se que, mesmo nas baixas concentrações de exposição aos metais, ocorreram alterações no sitema de defesa antioxidante de O. niloticus. A primeira barreira antioxidante, composta pela SOD, não foi suficiente para barrar os efeitos da exposição aos metais. Em brânquias, onde a ativação desta enzima foi proeminente, formação de HP ocorreu. E, mesmo inicialmente em rim e fígado, tecidos onde ocorreu diminuição da atividade da SOD, ocorreu também a formaçao de HP nas etapas seguintes. A CAT e a GPx também atuaram no sentido de tentar evitar o aparecimento de HP, mas não foram bem sucedidas neste processo. A GST, como enzima da fase II de biotransformação pode ter auxiliado no processo de eliminação dos metais, mas como ocorre de forma tardia em relação à defesa antioxidante, acarretando danos celulares. Em relação às enzimas que compõem o sistema de defesa antioxidante não se verificou também especificidade de tecidos nas respostas. No entanto, a brânquia foi o órgão que teve maior intensidade nas respostas (em termos de ativação das enzimas), nos tratamentos de metais combinados dois a dois, evidenciando que este órgão, por estar em contato com a água e ser sede de processos fisiológicos de homeostase, desempenhou papel importante na tentativa de neutralizar os efeitos dos metais. / One way of quantifying metals effects upon organisms\' health state is to analyse oxidative stress biomarkers. Bioassays were conducted with Nile tilapia (Oreochromis niloticus) with cadmium (4,25 \'mü\'g/L), copper (45,0 \'mü\'g/L ) and zinc (260,0 \'mü\'g/L). Fishes were exposed to metals separatelly (\'CD\', \'CU\' e \'ZN\'), associated two by two (\'CD\'/\'CU\', \'CD\'/\'ZN\' e \'CU\'/\'ZN\') and to three metals together (\'CD\'/\'CU\'/\'ZN\'), for twelve days. Gills, liver and kidney samples were taken to analyse oxidative stress biomarkers, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), the effect of lipid peroxidation (HP), an enzyme of phase II biotransformation, glutathione S-transferase (GST) and metallothionein (MT). From results obtained, it was stablished that, even in low concentrations of metals, O. niloticus antioxidant defense system was modified. The first antioxidant barrier, SOD, wasn\'t able to minimize metal exposition effects. In gills, where activaton of this enzyme was prominent, didn\'t avoi HP formation. And even in liver and kidney, tissues where SOD activity decreased, HP formation also occurred. CAT and GPx also acted trying to avoid HP formation, but weren\'t successfull. GST, like a phase I enzyme, could help eliminating metals, but in a late moment in relation to antioxidant defense, leading to cell damage. For antioxidant enzymes no relation to tissue-specificity response was observed. But gills were the organ which had more intense responses (in terms of enzyme activation), mainly in metals combined two by two, evidencing that gills are important like a first organ in antioxidant defense because it is in direct contact with water and determine the main processes in homeostasis, trying to neutralize metals effects.
78

Estudo da expressão das proteínas metalotioneína, NFkB, ciclina D1 e Cdk4 em linhagens celulares derivadas de carcinoma epidermóide humano / Study of expression of proteins Metalotioneína, NFkB, Ciclina D1 and Cdk4 in cell lines derived from human squamous cell carcinoma

Brunno Santos de Freitas Silva 01 July 2008 (has links)
O carcinoma epidermóide por se tratar de uma doença genética, apresenta dificuldades em relação ao seu tratamento. As vias de sinalização celular por controlarem os mecanismos responsáveis pela proliferação e sobrevivência da célula, são de extrema importância nos estudos da biologia do câncer e oncogênese. Aberrações cromossômicas que afetam a estrutura e a expressão de genes e proteínas que regulam componentes das vias de sinalização são diretamente correlacionadas com o desenvolvimento e progressão tumoral. Vários genes e proteínas vêm sendo avaliados na busca de um alvo terapêutico quimioterápico, algo pouco estudado em carcinomas epidermóides bucais. Este trabalho teve como objetivo analisar a influência do quimioterápico 17-AAG e do fator de crescimento epitelial (EGF) nos níveis das proteínas NFkB, Ciclina D1 e Cdk4 nas linhagens de carcinoma epidermóide de cabeça e pescoço (HN6 e HN31) e no queratinócito imortalizado (HaCat). Este trabalho destinou-se também a estudar uma possível inter-relação entre as proteínas Metalotioneína e NFkB e suas interações com as proteínas Ciclina D1 e Cdk4 nas linhagens celulares HN6 , HN31 e (HaCat, para uma maior compreensão de seus efeitos nas vias de sinalização celular e conseqüente progressão do câncer). Para análise a respeito da localização e os níveis das proteínas MT, NFkB, Ciclina D1 e Cdk4 foram utilizados ensaios de imunofluorescência e western blot, respectivamente.Os resultados apontaram um melhor perfil apoptótico da linhagem HN31 frente ao tratamento com 17-AAG, apresentando diminuição significante dos níveis de NFkB e Ciclina D1, além de exibir importante decréscimo nos níveis de Cdk4. A proteína MT parece não sofrer ação do NFkB. A indução de proliferação celular realizada por EGF exerceu um aumento dos níveis das proteínas NFkB e Ciclina D1, sugerindo um papel importante das vias de sinalização estimuladas por EGF (Akt, NFkB e Ciclina D1) na progressão tumoral dessas linhagens.Por fim, a ocorrência de estímulo nos níveis da proteína MT por parte do EGF, sugeriram um importante papel do EGF e da MT na resistência a apoptose nas linhagens estudadas. / Squamous cell carcinomas as a genetic diseases, presents certain difficulties in relation to their treatment. The process of cell signaling for overseeing the mechanisms responsible for cellular proliferation and survival are very important in studies of the biology of cancer and development. Chromosomal alterations affecting the structure and expression of genes and proteins that regulate the process of signaling components are directly correlated with the development and tumor progression. Several genes and proteins are being evaluated in the search for a biological marker that could help in the understanding of cancer as well as in its prognosis, and mainly in search of therapeutic target chemotherapy, something little studied in oral squamous cell carcinoma. This study aimed to examine the influence of chemotherapy 17-AAG and the epithelial growth factor (EGF) in the levels of proteins NFkB, Cyclin D1 and Cdk4 in strains of squamous cell carcinoma of the head and neck (HN6 and HN31) and immortalized in keratinocytes(HaCat). This work is also intended to explore a possible inter-relationship between the Metallothionein and NFkB proteins and their interactions with the proteins Cyclin D1 and Cdk4 in cell lines HN6, HN31 and (HaCat, to a greater understanding of its effects on pathways of cellular signaling and consequent progression of cancer. For analysis regarding the location and levels of the protein MT, NFkB, Cyclin D1 and Cdk4 were used tests of immunofluorescence and western blot. Results showed a better apoptotic profile of HN31 treated with 17-AAG, showing decrease levels of NFkB and Cyclin D1, with a important decrease in the levels of Cdk4. The metallothionin protein does not appear to suffer action of NFkB. The induction of cell proliferation conducted by EGF had increased levels of NFkB and Cyclin D1 proteins, suggesting an important role in the process of signaling stimulated by EGF (Akt, NFkB and Ciclina D1) in tumor progression of oral squamous cell carcinoma. The occurrence to stimulate the levels of metallothionein protein by the EGF, suggest an important role of EGF and MT in resistance to apoptosis in the studied cell lines.
79

Ethanol teratogenicity : the aetiological importance of zinc and metallothionein / by Luke Charles Carey.

Carey, Luke Charles January 2002 (has links)
"August 2002" / Bibliography: leaves 141-176. / ix, 179 leaves : ill. (some col.) ; 30 cm / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Changes in maternal-foetal zinc homeostasis resulting in a foetal deficiency may be an important contributing factor in ethanol-realted teratogenicity. Ethanol induces expression of hepatic metallothionein, causing zinc transfer from the plasma to the liver. Rodent studies show that changes in plasma zinc correlate with a high incidence of abnormal fetuses in MT+/+ mice. Demonstrates a clear link between maternal hepatic MT induction, decreased foetal zinc supply, and teratogenicity, which has major implications for binge alcohol consumption in early pregnancy. The demonstration that zinc treatment is effective in preventing teratogenicity indicates potential treatment strategies. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 2003
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Structure-function relationships in cellular copper control

Zhang, Limei 09 June 2009
X-ray absorption spectroscopy and computational chemistry have been used to probe the structure of biomolecules involved in cellular copper homeostasis. X-ray absorption spectroscopy shows that copper chaperones involved in cytochrome c oxidase assembly bind Cu(I) with trigonal coordination environments in poly-copper thiolate clusters, but the number of coppers in these clusters remains unclear. X-ray absorption spectroscopy of the metal-sensing transcription factor-1 from Drosophila melanogaster and metallothionein from Saccharomyces cerevisiae with stoichiometries of four or less shows a tetracopper cluster in an all-or-none manner in these molecules. These results suggest that cooperative binding of copper to form tetracopper clusters may be a common mechanism employed by copper control molecules. The active site structure of the novel copper-sensitive repressor CsoR in Mycobacterium tuberculosis binds copper in a trigonal coordination geometry with two sulfur and one nitrogen donors according to X-ray absorption spectroscopy results. Molecular dynamics simulations of both apo- and Cu-bound CsoR reveal local conformational changes in CsoR upon copper binding, which suggests multiple possible mechanisms of Cu-dependent transcriptional regulation by CsoR. Finally, X-ray absorption spectroscopy and X-ray fluorescence imaging have been used to understand the molecular basis of a promisng new treatment for Wilsons disease (a genetic disorder of Cu homeostasis) using tetrathiomolybdate. Overall, the results presented provide an essential structural basis for understanding copper homeostasis in living cells.

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