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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.
411

Development and characterization of a mouse model to determine the impact of low dietary folate on spermatogenesis, fertility, and histone methylation

Saint-Phar, Shawna, January 1900 (has links)
Thesis (M.Sc.). / Written for the Dept. of Animal Science. Title from title page of PDF (viewed 2009/07/07). Includes bibliographical references.
412

Initial characterization and determination of the molecular mechanism(s) that control transcription of the human PKC epsilon gene in lung cancer cells

Akinyi, Linnet. January 2004 (has links)
Thesis (M.S.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 52 pages. Includes Vita. Includes bibliographical references.
413

Biomarqueurs épigénétiques de l'atteinte pulmonaire et facteurs responsables de la variabilité phénotypique dans la mucoviscidose / Epigenetic biomarkers of lung disease and factors responsible for phenotypic variability in cystic fibrosis

Pineau, Fanny 26 October 2018 (has links)
Le déclin de la fonction pulmonaire et la destruction progressive des tissus des voies aériennes sont les premières causes de morbidité et de mortalité dans la mucoviscidose (CF). Grâce à un suivi régulier et à des traitements symptomatiques, la qualité de vie et l'espérance de vie des patients CF ont considérablement augmenté. Pour le suivi des patients, les cliniciens utilisent principalement des paramètres cliniques et biologiques. L'objectif principal de ce projet de thèse était d'identifier des biomarqueurs de l'atteinte pulmonaire basés sur la méthylation de l'ADN. Par une approche tout-génome (Infinium 450K), nous avons mesuré la méthylation de l'ADN dans les cellules épithéliales nasales de patients CF et d'individus contrôles sains (cohorte MethylCF, 51 patients, 24 contrôles). Nous avons montré que les profils de méthylation différaient entre patients et contrôles mais aussi entre patients à atteinte pulmonaire modérée et sévère. Les changements de méthylation ont principalement eu lieu dans des régions régulatrices (enhancers) et dans des gènes associés à l'adhésion cellulaire et aux réponses inflammatoire et immunitaire. En combinant données épigénomiques et données cliniques, nous avons sélectionné des potentiels biomarqueurs de sévérité de l'atteinte pulmonaire, et des potentiels biomarqueurs de l'évolution de la fonction pulmonaire. Pour valider les biomarqueurs, nous avons constitué une cohorte longitudinale, MethylBiomark, de 50 patients CF suivis pendant 18 mois. A partir d'échantillons d'expectoration recueillis tous les six mois environ, nous avons mesuré la méthylation de l'ADN des potentiels biomarqueurs par pyroséquençage. Deux biomarqueurs corrélaient avec la sévérité de l'atteinte pulmonaire (VEMS et CVF), et un biomarqueur corrélait avec l'évolution de la fonction pulmonaire (variation de VEMS). Le second objectif de cette thèse était d'étudier l'impact des variations de méthylation d'ADN sur l'expression des gènes, en croisant des données épigénomiques et transcriptomiques générées à partir des mêmes échantillons (sang total, cohorte MethylCF). L'analyse transcriptomique a permis d'identifier (i) des gènes différentiellement exprimés entre patients et contrôles, qui étaient associées aux réponses inflammatoire et immunitaire, et (ii) des modules de co-expression (WGCNA) qui corrélaient fortement avec des paramètres cliniques, dont le diabète. / Lung function decline and progressive destruction or airway tissues are the main causes of morbidity and mortality in cystic fibrosis (CF). Quality of life and life expectancy of CF patients greatly increased over the last decades, because of a regular follow-up and symptomatic treatments. For the follow-up of patients, clinicians usually use clinical or biological parameters. The main goal of this thesis was to identify DNA methylation biomarkers of CF lung disease. We measured genome-wide DNA methylation (with Infinium 450K) in nasal epithelial cells from CF patients and healthy controls (MethylCF cohort, 51 patients, 24 controls). We showed that DNA methylation profiles differed between CF patients and controls, but also between patients with mild and severe lung disease. DNA methylation changes mainly occurred in regulatory regions (enhancers) and in genes associated with cell adhesion and inflammatory and immune responses. By combining epigenomic and clinical data, we selected potential biomarkers of lung disease severity, and potential prognostic biomarkers of the evolution of the lung function. To validate these biomarkers, we built a new longitudinal cohort of 50 CF patients followed for 18 months. We measured the DNA methylation level of the biomarkers by pyrosequencing in sputum samples collected every 6 months. Two biomarkers correlated with lung disease severity (measured by FEV1 and FVC) and one biomarker correlated with the evolution of the lung function (FEV1 variation). The second goal of this thesis was to investigate the impact of DNA methylation changes on gene expression, by combining epigenomic and transcriptomic data from the same samples (whole blood, MethylCF cohort). The transcriptomic analysis revealed (i) differentially expressed genes between patients and controls, that were mainly involved in inflammatory and immune responses, and (ii) co-expression gene modules (WGCNA) highly correlated with clinical parameters, and notably CF-related diabetes.
414

Role of small RNAs and chromatin in transposable element silencing during global demethylation

Berrens, Rebecca V. January 2017 (has links)
DNA methylation entails the addition of a methyl group to the 5-carbon of the cytosine base of the DNA. This modification is important during many biological processes such as imprinting, X-chromosome inactivation, cell differentiation as well as silencing of transposable elements (TEs). DNA methylation is dynamic during early mammalian development, despite being a more static mark in somatic cells. Global hypomethylation is a hallmark of epigenetic reprogramming in mammalian primordial germ cells (PGCs), the early embryo and in naïve embryonic stem cells (ESCs). Genome integrity is crucial during early development, as the germline DNA needs to be protected for future generations. Therefore, epigenetic reprogramming presents a critical phase for TE defence since presumably alternative silencing pathways need to be employed to limit their activity. In this thesis, I investigate the role of small RNAs to control TEs during global waves of DNA demethylation in cellular reprogramming, naïve pluripotency as well as early mammalian development. Following an introduction to the research questions, in chapter 3 I investigate the mechanism of TE regulation in an in vitro model of Dnmt1 deletion in mouse ES cells to recapitulate in vivo epigenetic reprogramming. I find that certain classes of TEs become transcriptionally upregulated and subsequently resilenced by a mechanism independent of DNA methylation. I identify ARGONAUTE 2 (AGO2) bound siRNAs as the prominent mechanism to control certain classes of TEs, while others appear to be regulated by redistribution of repressive histone modifications. In chapter 4, I construct Dicer constitutive and conditional KO ESCs in the background of the Dnmt1f l/f l ESCs using CRISPR-Cas9. I dissect the role of DNA methylation and of DICER dependent small RNAs on transcriptional changes of ESCs. Additionally, I find that DICER dependent small interfering RNAs (siRNAs) re-silence transcriptionally active TE classes. Finally, in chapter 5, I examine the role of small RNAs in TE silencing in different models of global hypomethylation in vivo and in vitro PGCs, during iPSC reprogramming and in a transition from serum to 2i culturing of mouse ESCs.
415

Epigenetics in leukemia / Epigénétique dans les leucémies

Bagacean, Cristina 15 March 2018 (has links)
Les dérivés de la cytosine sont d’importantes modifications épigénétiques dont le rôle dans l’évolution de la leucémie lymphoïde chronique (LLC) n’est pas totalement exploré. Dans ce contexte, notre première étude vise à examiner le niveau global de la 5-methylcytosine (5-mCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-carboxylcytosine (5-CaCyt) et 5-hydroxymethyluridine (5-hmU) dans des lymphocytes B purifiés de patients LLC (n=56) et d’individus sains (n=17). Les principaux acteurs de la régulation épigénétique (DNMT1/3A/3B, MBD2/4, TET1/2/3, SAT1) ont été évalués par PCR quantitative en temps réel. L’analyse a permis de mettre en exergue trois groupes de patients. En premier lieu, un groupe de patients stables (délai médian de progression [PFS] et délai au premier traitement [TFT] >120 mois), avec un profil épigénétique similaire au groupe contrôle. Deuxièmement, un groupe intermédiaire (PFS=84; TFT=120 mois) qui présente une augmentation de la déméthylation de l’ADN expliquée par l'induction SAT1 / TET2 pendant la progression de la maladie. Troisièmement, un groupe de patients avec une forme active de la maladie (PFS=52; TFT=112 mois) qui présentent une hyperlymphocytose, une réduction du temps de doublement des lymphocytes et des modifications épigénétiques majeures. Au sein de ce groupe, une réduction est observée pour la 5-mCyt, 5-hmCyt, 5-CaCyt et serait associée à une diminution des DNMTs, TETs et MBDs au cours de la progression de la maladie. Les profils épigénétiques mis en évidence sont indépendants du statut mutationnel IGHV mais sont associés avec les anomalies cytogénétiques. Nous nous sommes également intéressés à cette association et nous avons montré dans la deuxième étude que les modifications des dérivées de la cytosine peuvent affiner le pouvoir pronostic des anomalies cytogénétiques. En conclusion, nos résultats suggèrent que les variations de la méthylation ainsi que des intermédiaires de la déméthylation de l’ADN sont impliqués dans la progression de la LLC. / Cytosine derivatives are important epigenetic modifications whose role in the pathogenesis and evolution of chronic lymphocytic leukemia (CLL) is not fully explored. In this context, our first study aims to examine the global DNA level of 5-methylcytosine (5-mCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-carboxylcytosine (5-CaCyt) and 5-hydroxymethyluridine (5-hmU) in purified B lymphocytes of CLL patients (n = 56) and healthy individuals (n = 17). The main actors in epigenetic regulation (DNMT1 / 3A / 3B, MBD2 / 4, TET1 / 2/3, SAT1) were evaluated by quantitative real time PCR. The analysis highlighted three groups of patients. First, a group of patients with stable disease (median time to progression [PFS] and time to first treatment [TFT]> 120 months), with an epigenetic profile similar to the control group. Secondly, an intermediate group (PFS = 84, TFT = 120 months) which shows an increase in DNA demethylation explained by SAT1 / TET2 induction during disease progression. Third, a group of patients with an active form of the disease (PFS = 52, TFT = 112 months) who have hyperlymphocytosis, a short lymphocyte doubling time, and major epigenetic changes. Within this group, a reduction is observed for 5-mCyt, 5-hmCyt, 5-CaCyt which is associated with a decrease in DNMTs, TETs and MBDs during disease progression. The identified epigenetic profiles are independent of IGHV mutational status but are associated with cytogenetic abnormalities. We were also interested in this association and we showed in the second study that modifications of cytosine derivatives levels can refine the prognostic power of cytogenetic abnormalities.In conclusion, our results suggest that methylation variations as well as DNA demethylation intermediates are involved in the progression of CLL.
416

Epigenetic regulation of innate immune responses to infection

Pacis, Alain 03 1900 (has links)
No description available.
417

Análise de metilação de DNA nos genes da citoqueratina 14 (KRT14) e 19 (KRT19) em amostras de pele exposta e não exposta ao sol

Barroso, Haline 27 February 2015 (has links)
Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-05T14:37:36Z No. of bitstreams: 1 arquivototal.pdf: 798401 bytes, checksum: 41671bb8b384bd28413ef4c5851e99ce (MD5) / Made available in DSpace on 2017-09-05T14:37:36Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 798401 bytes, checksum: 41671bb8b384bd28413ef4c5851e99ce (MD5) Previous issue date: 2015-02-27 / It is well established that solar UV radiation can cause mutations in DNA and increase the risk of developing skin cancer. However, little is known about the ability of UV radiation to cause epigenetic changes in the skin. DNA methylation, characterised by the addition of a methyl group in cytosines within CpG dinucleotides, can modify gene transcription, leading to decreased expression or even silencing of a gene. Epigenetic changes could represent an important pathway by which environmental factors influence aging and disease risks, with a tissue-specific manner. Epithelial keratins are called cytokeratins, the main function of cytokeratins is to maintain the integrity and mechanical stability through cell-cell contacts with epithelial tissue. The aim of this study was to investigate the sun exposure influence on DNA methylation status in the cytokeratin 14 (KRT14) and 19 (KRT19) genes of skin cells of subjects whithout history of skin disease. Skin biopsies were obtained by punch of sun-exposed (outer forearm) and sun-protected areas (inner arm) from 30 corpses of the Brazilian Services of Death Investigation. The KRT14 gene DNA methylation analysis was performed using Methylation-Specific PCR (MSP), and the KRT19 gene DNA methylation analysis was performed using Methylation-Sensitive Restriction Enzymes (MSRE) of sun-exposed and sun-protected skin areas. Statistical analysis showed no significant differences between sun-protected and sun-exposed areas and the most frequently methylated condition for CpG studied for KRT14 and KRT19 genes (p> 0.05; McNemar). We conclude that sun exposure does not induce changes in DNA methylation status in the KRT14 and KRT19 genes. / Pesquisas tem mostrado que a radiação UV do sol pode causar mutações no DNA e aumentar o risco para o desenvolvimento de câncer de pele. Entretanto, ainda pouco se sabe sobre a capacidade da radiação UV em causar alterações epigenéticas na pele. A metilação do DNA é caracterizada pela adição do grupo metil em uma citosina precedida por uma guanina (dinucleotídeo CpG), o que pode alterar a transcrição gênica, diminuindo a expressão ou silenciando um gene. Alterações epigenéticas podem representar um importante caminho de como os fatores ambientais influenciam no envelhecimento e no desenvolvimento de certas doenças de maneira tecido específica. Queratinas epiteliais são chamadas de citoqueratinas, e sua principal função é manter a integridade e estabilidade mecânica do tecido epitelial. Neste trabalho investigamos se há influência da exposição solar sobre o perfil de metilação de DNA nos genes das citoqueratinas 14 (KRT14) e (KRT19), em células da pele de indivíduos sem histórico de doenças de pele. Biopsias de pele foram obtidas através de um Punch circular da de área exposta e não exposta ao sol de 30 cadáveres do Serviço de Verificação de Óbito. A análise de metilação do gene KRT14 foi realizada pelo método de PCR Específica para Metilação (MSP), e para o gene KRT19 foi realizado o método de Restrição Enzimática Sensível à Metilação (MSRE) das áreas expostas e protegidas do sol. A análise estatística mostrou que não há diferenças significativas entre as regiões exposta e não exposta ao sol, sendo a condição metilada a mais frequente tanto para o gene KRT14 quanto para o gene KRT19 (p>0,05; McNemar). Assim, concluímos que não há influência da exposição solar no perfil de metilação de DNA nos genes KRT14 e KRT19.
418

Identificação de SNPs em sítios CpG localizados em regiões genômicas relacionadas à produção em bovinos / Identification of SNPs in CpG sites located in genomic regions related to production in cattle

Maldonado, Mariângela Bueno Cordeiro [UNESP] 22 August 2017 (has links)
Submitted by Mariângela Bueno Cordeiro Maldonado null (maribuenocordeiro@hotmail.com) on 2017-09-01T02:02:20Z No. of bitstreams: 1 TESE DE DOUTORADO 2017 - Mariangela Maldonado .pdf: 1446039 bytes, checksum: 2e08a41374d1ed14783e9142f58bdec8 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-09-01T13:59:09Z (GMT) No. of bitstreams: 1 maldonado_mbc_dr_araca.pdf: 1446039 bytes, checksum: 2e08a41374d1ed14783e9142f58bdec8 (MD5) / Made available in DSpace on 2017-09-01T13:59:09Z (GMT). No. of bitstreams: 1 maldonado_mbc_dr_araca.pdf: 1446039 bytes, checksum: 2e08a41374d1ed14783e9142f58bdec8 (MD5) Previous issue date: 2017-08-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo desse estudo foi identificar polimorfismos de nucleotídeo único (SNPs) potencialmente sujeitos a controle epigenético exercido por metilação do DNA via seus envolvimentos na criação, remoção ou deslocamento de sítios CpG (meSNPs) e a partir de tal identificação criar um banco de dados para meSNPs, bem como determinar a possível associação desses marcadores com ilhas CpG (CGIs) e com o perfil metilacional de tecidos submetidos ao ensaio de recuperação de ilhas CpG metiladas combinado com plataformas de sequenciamento de nova geração (MIRA-seq) em bovinos. Usando as variantes anotadas para os SNPs identificados no Run5 do projeto 1000 Bull Genomes e a sequência genômica bovina de referência UMD3.1.1, identificamos e anotamos 12.836.763 meSNPs de acordo com o padrão de variação criado por cada SNP em um sítio CpG. Também analisamos a distribuição genômica desses meSNPs, sendo a maioria deles localizados em regiões intergênicas (68,00%) e intrônicas (26,32%). Globalmente, os meSNPs representam 22,53% dos 56.969.697 SNPs descritos na base de dados e 12,35% deles estão localizados em CGIs. Comparando o número observado com o número esperado de meSNPs nas CGIs e nos tecidos submetidos ao MIRA-seq, verificamos um enriquecimento médio (P<0,01) para meSNPs de 2,47 vezes em CGIs relaxadas e 1,90 vezes em CGIs rigorosas. Nos tecidos, o enriquecimento foi de 1,52 vezes em longissimus dorsi e 2,09 vezes em intestino delgado. Dez meSNPs com metilação diferencial, sendo 1 em longissimus dorsi e 9 em intestino delgado, causaram uma alteração na sequência genômica, a qual está associada ao fenótipo de eficiência alimentar em bovinos. / The aim of this study was to identify single nucleotide polymorphisms (SNPs) potentially subject to epigenetic control exerted by DNA methylation via their involvement in creating, removing or displacement CpG sites (meSNPs) and from this identification create a database for meSNPs, as well as to determine its possible association with CpG islands (CGIs) and the methylation profile of tissues submitted to the methylated-CpG island recovery assay combined with next generation sequencing platforms (MIRA-seq) in cattle. Using the variant annotations for SNPs identified in Run5 of the 1000 bull genomes project and the UMD3.1.1 bovine reference genome sequence assembly, we identified and classified 12,836,763 meSNPs according to the pattern of variation caused at the CpG site. We have also analyzed the genomic distribution of the meSNPs, with the majority being located in intergenic regions (68.00%) and then in introns (26.32%) and the remainder distributed among proximal promoters (3.93%), coding regions (1.27%), untranslated regions (UTRs) (0.29%), non-coding RNAs (0.11%) and splice regions (0.08%). Overall, meSNPs represent 22.53% of 56,969,697 SNPs described in the database of which 12.35% are located in CGIs. Comparing the observed number with the expected number of meSNPs in the CGIs and tissues submitted to the MIRAseq we found a mean enrichment (P<0.01) for meSNPs of 2.47 times in the relaxed CGIs and 1.90 times in the strict CGIs. In the tissues the enrichment was of 1.52 times in ribeye and 2.09 times in small intestine. Ten meSNPs, differing in methylation status, 1 in ribeye and 9 in small intestine, caused an alteration in the genomic sequence which is associated with a feed efficiency phenotype in cattle. / FAPESP: 2015/20557-5 / FAPESP: 2016/07584-6
419

Expressão de RNAs não codificadores intrônicos longos em linhagens celulares humanas e o seu controle epigenético por metilação do DNA / Long intronic noncoding RNA expression in human cell lines and its DNA methylation epigenetic control

Lauren Camargo 27 September 2012 (has links)
Estudos recentes têm revelado que uma fração significativa do transcriptoma de eucariotos é composta por RNAs não codificadores longos (lncRNAs). Este trabalho investigou o padrão de expressão de um conjunto de lncRNAs originados a partir de regiões intrônicas de genes codificadores de proteínas em três linhagens celulares tumorais humanas utilizando microarranjos de DNA customizados. Realizamos uma série de análises in silico com a perspectiva de identificar propriedades globais desses transcritos, tais como a abundância relativa em diferentes tecidos, características evolutivas, estruturais e regulatórias, além de possíveis funções celulares. Avaliamos também a contribuição da metilação do DNA, um mecanismo de silenciamento epigenético da expressão de genes codificadores de proteínas, na regulação da expressão de lncRNAs intrônicos. Observamos que uma fração dos lncRNAs intrônicos detectados nas linhagens estudadas são conservados evolutivamente, tem padrão de expressão tecido específico, e está enriquecida em elementos regulatórios na sua extremidade 5\'. Foram identificados subconjuntos de lncRNAs intrônicos possivelmente atuando sobre genes associados a vias regulatórias importantes para o controle do desenvolvimento de organismos e ciclo celular. Comparativamente a mRNAs, uma menor proporção de lncRNAs intrônicos possui ilhas CpGs (CGIs) na vizinhança de seu início de transcrição. Apesar disso, observamos que um subconjunto desses transcritos teve sua expressão sensível ao tratamento com o agente desmetilante de DNA 5-AZA, demonstrando que lncRNAs intrônicos transcritos podem estar sujeitos a regulação transcricional mediada por metilação do DNA. Dentre os lncRNAs intrônicos regulados por metilação do DNA, destaca-se o lncRNA AS-APP, cuja expressão aumentou em 25 a 80 vezes nas linhagens celulares DU-145 e HEK293, respectivamente, após tratamento com 5-AZA. Este lncRNA possui uma CGI metilada e um promotor ativo a cerca de 4 kb de distância do seu início de transcrição conhecido. O aumento da transcrição do lncRNA AS-APP após desmetilação do DNA correlacionou-se a uma diminuição significativa dos níveis de expressão do mRNA do gene APP. Este resultado sugere uma possível ação regulatória em cis do lncRNA AS-APP no locus APP, um importante gene envolvido na doença de Alzheimer e com expressão associada ao prognóstico de alguns tipos de câncer. Os resultados obtidos neste trabalho reforçam a ideia de que lncRNAs intrônicos constituem unidades transcricionais independentes que se encontram sobre controle regulatório nos diferentes tipos celulares. Foi gerado também um catálogo de lncRNAs intrônicos regulados por metilação que permitirá a seleção de candidatos com maior potencial de relevância funcional para caracterização detalhada. / Recent studies have revealed that a significant fraction of the eukaryotic transcriptome is composed of long noncoding RNAs (lncRNAs). This work investigated the expression pattern in three human tumor cell lines of a set of lncRNAs originated from intronic regions of protein coding RNAs, using custom DNA oligoarrays. In silico analyses were performed to identify global properties of these transcripts such as relative abundance in different human tissues, regulatory, evolutionary and structural aspects, as well as their possible cellular functions. In addition, we evaluated the contribution of DNA methylation, an important epigenetic mechanism that control the expression of protein coding genes, in the regulation of intronic lncRNAs expression. We found that a fraction of the intronic lncRNAs detected in the cell lines are evolutionarily conserved, show a tissue specific expression pattern, and is enriched in regulatory elements at their 5\' end region. Subsets of intronic lncRNAs possibly acting on genes associated to important regulatory pathways controlling organism development and cell cycle were identified. A smaller proportion of intronic lncRNAs relative to mRNAs displayed CpG islands (CGI) in the vicinity of the transcription start site. Notwithstanding, we observed that a subset of these transcripts responded to treatment with the DNA demethylation agent 5-AZA, demonstrating that intronic lncRNAs may be under transcriptional regulation mediated by DNA methylation. Among intronic lncRNAs regulated by DNA demethylation, stands out AS-APP lncRNA, which was up regulated 25 to 80 times in DU-145 and HEK293 cell lines following 5-AZA treatment, respectively,. This lncRNAs has a methylated CGI and an active promoter at 4-kb upstream from its known transcription start site. Increased AS-APP lncRNA transcription following DNA demethylation correlated with a significant decrease of APP gene messenger RNA levels. This finding suggests a possible cis-regulatory action of the lncRNA AS-APP in the APP locus, an important gene involved in Alzheimer disease and whose expression is associated with prognosis of different cancer types. The results obtained in this study reinforce the idea that intronic lncRNAs constitute independent transcriptional units under regulatory control in the different cell types. It was generated a catalog of intronic lncRNAs regulated by DNA methylation that will allow the selection of candidates with higher potential of functional relevance for detailed characterization
420

Estudo genético e epigenético no prognóstico do câncer cervical por meio da verificação de HPV de baixo e alto risco e da metilação e não metilação dos genes RARβ, TIMP3, CDH1 E MGMT / Study genetic and epigenetic on prognosis of cervical cancer by means of verification of HPV of low and high risk and methylation and unmethylation genes RARβ, TIMP3, CDH1 E MGMT

D'Alessandro, Aline Almeida Barbaresco 08 April 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-01-29T17:16:37Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Aline Almeida Barbaresco D'Alessandro - 2014.pdf: 3202318 bytes, checksum: bef7dce7cab9c3b56900a9c2d14f4a49 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-01-29T17:41:21Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Aline Almeida Barbaresco D'Alessandro - 2014.pdf: 3202318 bytes, checksum: bef7dce7cab9c3b56900a9c2d14f4a49 (MD5) / Made available in DSpace on 2015-01-29T17:41:21Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Aline Almeida Barbaresco D'Alessandro - 2014.pdf: 3202318 bytes, checksum: bef7dce7cab9c3b56900a9c2d14f4a49 (MD5) Previous issue date: 2014-04-08 / The human papillomavirus (HPV) is a major etiologic factor in the development of cervical cancer, DNA virus primarily infects the epithelium and may induce benign and malignant lesions of the mucous membranes and skin. Carcinogenesis is a multistep process that involves both changes genetic and epigenetic. The two changes epigenetic most studied are DNA methylation and histone acetylation. DNA methylation may be related development to cancer, and their presence or absence can affect the prognosis. The objective of this study was to evaluate the prognosis of patients with cervical cancer in stages I and II through the verification of HPV high and low risk, and the presence and absence of genes methylated and unmethylated RARβ, TIMP3, CDH1 and MGMT. We analyzed 129 records and samples of paraffin embedded biopsies of patients with cervical cancer in stages I and II. Detection of HPV - DNA was performed by PCR for HPV DNA of low and high oncogenic risk and MSP-PCR to detect the genes methylated or not, RARβ, TIMP3, CDH1 and MGMT. The calculation of survival used the Kaplan-Meier method and the log-hank test to compare means of survival between the prognostic factors for cervical cancer. The overall survival at 60 months of patients with the presence of RARβ, TIMP3, CDH1 and MGMT methylated or not were: 100%, 90.0%, 85.7%, 92.5%, respectively, and survival free of disease were 100%, 85.7%, 100%, 100%, respectively. The presence and absence of genes did not affect the overall and disease-free survival. The prevalence of HPV of low risk patients was 45% (58/129) and the high-risk HPV was 76% (98/129). Regarding the analysis to evaluate the existence of statistical relationships between the presence and absence of genes methylated or not, RARβ, TIMP3, CDH1 and MGMT with variables clinical and HPV, it was found that there were no significant differences in the presence and the absence of genes the methylated or not in relation to the distribution of variables. The study demonstrated that the absence and presence of genes methylated or not, RARβ, TIMP3, CDH1 and MGMT, did not influence the prognosis of patients suffering from cervical cancer in stages I and II. / O papilomavírus humano (HPV) é um importante fator etiológico no desenvolvimento do câncer cervical, o DNA viral infecta principalmente o epitélio e pode induzir lesões benignas e malignas das membranas de mucosa e pele. A carcinogênese é um processo de múltiplas etapas que envolvem tanto mudanças genéticas quanto epigenéticas. As duas mudanças epigenéticas mais estudadas são a metilação do DNA e acetilação das histonas. A metilação do DNA pode estar relacionada com o desenvolvimento do câncer, e a sua presença e ausência pode afetar no prognóstico. O objetivo deste estudo foi avaliar o prognóstico das pacientes portadoras de câncer cervical nos estádios I e II por meio da verificação de HPV de baixo e alto risco e da presença e ausência dos genes metilados e não metilados RARβ, TIMP3, CDH1 e MGMT. Foram analisados 129 prontuários e amostras de biópsias parafinizadas das pacientes portadoras de câncer cervical nos estádios I e II. A detecção do DNA – HPV foi realizada por PCR para detectar o DNA do HPV de baixo e alto risco oncogênico e a MSP-PCR para detectar os genes metilados ou não, RARβ, TIMP3, CDH1 e MGMT. O cálculo de sobrevida utilizou-se o método de Kaplan-Meier e o teste de log-hank para comparação das médias de sobrevida entre os fatores prognósticos para câncer cervical. As sobrevidas globais aos 60 meses das pacientes com a presença de RARβ, TIMP3, CDH1 e MGMT metilado ou não foram de: 100%, 90,0%, 85,7%, 92,5%, respectivamente, e as sobrevidas livre de doença foram de 100%, 85,7%, 100%, 100%, respectivamente. A presença e ausência dos genes não interferiram nas sobrevidas global e livre de doença. A prevalência de HPV de baixo risco das pacientes foi de 45 % (58/129) e o HPV de alto risco foi de 76 % (98/129). Em relação as análises para avaliar a existência de relações estatísticas entre a presença e a ausência dos genes metilados ou não, RARβ, TIMP3, CDH1 e MGMT com as variáveis clínicas e do HPV, verificou-se que não houveram diferenças significativas com a presença e a ausência dos genes metilados ou não em relação com as distribuições das variáveis. O estudo demonstrou que a ausência e presença dos genes metilados ou não, RARβ, TIMP3, CDH1 e MGMT, não influenciaram no prognóstico das pacientes portadoras do câncer cervical nos estádios I e II.

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