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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

Etude structurale et fonctionnelle d'un domaine intrinsèquement désordonné de l'oncoprotéine BCR-ABL responsable de la leucémie myéloïde chronique / Structural and functional study of an intrinsically disordered domain of the BCR-ABL oncoprotein responsible for chronic myeloid leukemia

Maneville, Stephanie 09 October 2013 (has links)
L'oncoprotéine BCR-ABL est responsable de la physiopathologie de la Leucémie Myéloïde Chronique (LMC). La fusion d'une partie de la protéine ABL et de BCR entraîne une dérégulation de l'activité kinase portée par ABL. Plusieurs domaines contenus dans ces deux protéines jouent un rôle important dans l'activation du pouvoir oncogène. L'un d'entre eux est une région de BCR, située en N-terminal, contenant un domaine de liaison au domaine SH2. Durant ce travail de thèse, j'ai caractérisé, pour la première fois, les propriétés structurales de cette région, à l'aide de plusieurs méthodes biophysiques: le domaine de BCR est intrinsèquement désordonné. En parallèle, j'ai étudié les interactions entre le domaine de liaison de BCR et les domaines SH d'ABL. J'ai identifié de nouveaux sites d'interactions avec ABL sur BCR. Enfin, j'ai évalué l'impact fonctionnel des nouveaux sites d’interactions au sein de l'oncoprotéines BCR-ABL, dans un modèle cellulaire. Les résultats préliminaires montrent que deux nouveaux sites auraient un rôle dans le pouvoir oncogénique de BCR-ABL. Ces résultats offrent la possibilité de développer de nouveaux médicaments complémentaires aux existants, qui cibleraient une nouvelle région de BCR-ABL, ainsi pourraient lutter contre les résistances apparues chez les patients vis-à-vis des traitements actuels. / The BCR-ABL oncoprotein is responsible for the pathogenesis of chronic myelogenous leukemia (CML). The fusion of a part of ABL and BCR leads to deregulation of kinase activity of ABL. Several domains in these two proteins play an important role in the activation of oncogenic properties. One of them is a BCR region, located at the N- terminal part, containing a SH2 domain binding. In this thesis , I have characterized for the first time , the structural properties of this region, using several biophysical methods : the domain of BCR is intrinsically disordered. In parallel, I have studied the interactions between the binding domain of BCR and theSH domains of ABL. I identified new sites of interaction with ABL into BCR. Finally, I evaluated the functional impact of new sites of interaction within the BCR- ABL oncoprotein in a cellular model. Preliminary results show that two new sites have a role in the oncogenic properties of BCR- ABL. These results offer the possibility to develop new drugs complementary to existing , that target a new region of BCR- ABL and could fight against the resistance occurred in patients vis-a-vis current treatments.
72

Caracterização molecular do Epstein-Barr vírus (EBV) em pacientes portadores de HIV, em tratamento, atendidos no sistema hospitalar do sistema penitenciário do Estado de São Paulo. / Molecular characterization of Epstein-Barr virus (EBV) in HIV patients in treatment from the hospitalar system in the penitentiary system from São Paulo State, Brazil.

Rodrigues, Juliana Nogueira Martins 05 December 2008 (has links)
O Epstein-Barr vírus (EBV) é a única espécie humana pertencente ao gênero Lymphocryptovirus. A transmissão ocorre através da saliva contaminada e geralmente ainda na infância. Nosso estudo analisou 165 amostras clínicas de pacientes, portadores de HIV, em tratamento com antiretrovirais, atendidos no Sistema Hospitalar do Sistema Penitenciário do Estado de São Paulo. Nosso enfoque foi pesquisar o EBV nas células mononucleares do sangue periférico, através das técnicas de PCR, Nested-PCR e seqüenciamento de nucleotídeos. Os resultados obtidos, indicaram que 11,51% (19) das amostras analisadas, apresentaram-se positivas para o EBV. Essas 19 amostras, foram seqüenciadas com primers específicos para a região da EBNA-1 (Epstein Barr Nuclear Antigen 1). As amostras foram alinhadas com o auxílio do DNASTAR. Ao alinharmos as amostras, encontramos uma troca de base (de G para A) em 7 amostras e essa troca não alterou a conformação da proteína EBNA-1. Na análise filogenética de nossas sequências com as depositadas no GenBank, foi possível observar dois grupos, que representam tipo 1 e o tipo 2 do EBV. 100% das amostras estudadas por nós foram identificadas como pertencentes ao grupo que caracteriza o tipo 2. Sendo assim, as 7 amostras que apresentaram a troca sugerem a origem um novo subtipo. / The Epstein-Barr Virus (EBV) is the only species to the genus Lymphocriptovirus that infects humans. One of the possible route for its transmission thought by contamined saliva and usually occurs in the childhood. This study analysed 165 clinical samples from HIV infected patients, treated by HARRT, attended in the Hospitalar System in the Penitentiary System from Sao Paulo State. The aim of this study was to search EBV in peripheral blood mononuclear cells by PCR, Nested-PCR and sequencing analysis. The results showed 11,51% of the analysed samples, positive for EBV. This samples, was sequenced with specifics primers from the EBNA-1 (Epstein Barr Nuclear Antigen 1) region. The samples were aligned by DNASTAR program. The aligned sequences showed the base conversion G to A in seven samples. This conversion caused no alteration in the EBNA-1 protein conformation. In the phylogenetic analysis the studied sequences with the sequences from GenBank was possible to observe two groups represented with type 1 and type 2 from EBV. 100% the samples studied was identified with the group characterized by the type 2 to EBV. So the seven samples showed the conversion, suggesting the origin of the one new subtype.
73

Potencial oncogênico de variantes naturais de papilomavírus humano / Oncogenic potential of natural variants of human papillomavirus

Sichero, Laura 19 December 2003 (has links)
O principal fator etiológico da neoplasia do colo do útero é a infecção por HPVs (papilomavírus humano) de alto risco oncogênico, principalmente HPVs 16 e 18. A variabilidade intra-típica de ambos tipos virais tem sido extensivamente estudada. A análise da diversidade genética de isolados oriundos de diferentes regiões dos cinco continentes permitiu traçar a origem e filogenia destes vírus, e sugeriu-se que a evolução destes reflete a relação dos mesmos com seu hospedeiro. Considera-se uma variante molecular de um tipo de HPV um genoma que possui 98% ou mais de identidade nos genes Ll , E6 e E7 com um genoma já descrito. Entretanto, variantes moleculares apresentam aproximadamente 5% de diferença na seqüência da LCR (long contral region). Alguns grupos de pesquisa de diferentes partes do mundo relataram a associação epidemiológica entre variantes específicas de HPVs 16 e 18 e o risco aumentado de infecção persistente e de desenvolvimento de lesão do colo uterino de alto grau. No Brasil foi observada a associação positiva entre variantes não-européias de HPVs 16 e 18 e o risco de lesão do colo uterino em um estudo epidemiológico prospectivo que vem sendo conduzido em São Paulo. Neste estudo foi analisada a atividade transcricional dos promotores P97 e P105 de variantes moleculares de HPVs 16 e 18, respectivamente. A variante asiático-americana de HPV-18, B18-3, apresentou a maior atividade transcricional entre todos os isolados testados. Entre as variantes moleculares de HPV-18, o isolado europeu B18-2 foi o menos ativo transcricionalmente. Entre as amostras de HPV-16, a variante européia B-12 foi a que apresentou a maior atividade transcricional. Foi observado, também, que o promotor P105 de HPV-18 é mais ativo transcricionalmente que o promotor P97. Adicionalmente, foi analisada a capacidade de imortalização de queratinócitos humanos primários por E6/E7 de variantes moleculares de HPV-16. Essas variantes não diferiram muito quanto a eficiência de formação de colônias de queratinócitos crescidos em baixa densidade. Entretanto, a variante asiático-americana gerou um maior número de colônias potencialmente imortalizadas. Esses resultados têm implicações importantes na determinação do risco de desenvolvimento de lesões de colo uterino associadas ao HPV. / Infection by high-risk HPV (human papillomavirus) types, especially HPVs 16 and 18, is the major etiological factor of cervical neoplasia. Intratypic nucleotide variability of both HPV types has been extensively studied. Genetic diversity analyses of isolates from different regions of the five continents permitted to reconstruct the origin and phylogeny of this virus, and suggested that viral evolution reflects the relation between the virus and their host. A molecular variant of HPV possess 98% or more identity in L1, E6 and E7 genes with another viral genome. However, molecular variants have approximately 5% differences within the LCR (long control region). Some research groups from different parts of the world have described the epidemiologic association between specific variants of HPVs 16 and 18 and increased risk of persistent infection and development of squamous intraepithelial lesions. In Brazil, we observed a positive association between non-European variants of HPVs 16 and 18 and risk of cervical lesion in a prospective epidemiologic study that is being conducted in São Paulo. In this study we analyzed P97 and P105 transcriptional activity of molecular variants of HPVs 16 and 18, respectively. The Asian-American variant of HPV-18, B18-3, exhibited the highest transcriptional activity among all isolates tested. Among HPV-18 molecular variants, the B 18-2 European isolate was the less transcriptionally active. Among HPV-16 samples, the B-12 European variant exhibited the highest transcriptional activity. We also observed that the HPV-18 P105 promoter was more active than the HPV-16 P97 promoter. Furthermore, we analyzed the capacity of immortalization of primary human keratinocytes by E6/E7 molecular variants of HPV-16. These variants did not differ much in the efficiency of colony formation by low density keratinocyte plating. However, the Asian-American variant yielded a higher number of colonies potentially immortalized. These results have important implications in the determination of risk for development of HPV -associated cervical lesions.
74

Aiming to identify protein co-factors contributing to eIF4E’s oncogenic potential

Ndreu, Elma 08 1900 (has links)
No description available.
75

Potencial oncogênico de variantes naturais de papilomavírus humano / Oncogenic potential of natural variants of human papillomavirus

Laura Sichero 19 December 2003 (has links)
O principal fator etiológico da neoplasia do colo do útero é a infecção por HPVs (papilomavírus humano) de alto risco oncogênico, principalmente HPVs 16 e 18. A variabilidade intra-típica de ambos tipos virais tem sido extensivamente estudada. A análise da diversidade genética de isolados oriundos de diferentes regiões dos cinco continentes permitiu traçar a origem e filogenia destes vírus, e sugeriu-se que a evolução destes reflete a relação dos mesmos com seu hospedeiro. Considera-se uma variante molecular de um tipo de HPV um genoma que possui 98% ou mais de identidade nos genes Ll , E6 e E7 com um genoma já descrito. Entretanto, variantes moleculares apresentam aproximadamente 5% de diferença na seqüência da LCR (long contral region). Alguns grupos de pesquisa de diferentes partes do mundo relataram a associação epidemiológica entre variantes específicas de HPVs 16 e 18 e o risco aumentado de infecção persistente e de desenvolvimento de lesão do colo uterino de alto grau. No Brasil foi observada a associação positiva entre variantes não-européias de HPVs 16 e 18 e o risco de lesão do colo uterino em um estudo epidemiológico prospectivo que vem sendo conduzido em São Paulo. Neste estudo foi analisada a atividade transcricional dos promotores P97 e P105 de variantes moleculares de HPVs 16 e 18, respectivamente. A variante asiático-americana de HPV-18, B18-3, apresentou a maior atividade transcricional entre todos os isolados testados. Entre as variantes moleculares de HPV-18, o isolado europeu B18-2 foi o menos ativo transcricionalmente. Entre as amostras de HPV-16, a variante européia B-12 foi a que apresentou a maior atividade transcricional. Foi observado, também, que o promotor P105 de HPV-18 é mais ativo transcricionalmente que o promotor P97. Adicionalmente, foi analisada a capacidade de imortalização de queratinócitos humanos primários por E6/E7 de variantes moleculares de HPV-16. Essas variantes não diferiram muito quanto a eficiência de formação de colônias de queratinócitos crescidos em baixa densidade. Entretanto, a variante asiático-americana gerou um maior número de colônias potencialmente imortalizadas. Esses resultados têm implicações importantes na determinação do risco de desenvolvimento de lesões de colo uterino associadas ao HPV. / Infection by high-risk HPV (human papillomavirus) types, especially HPVs 16 and 18, is the major etiological factor of cervical neoplasia. Intratypic nucleotide variability of both HPV types has been extensively studied. Genetic diversity analyses of isolates from different regions of the five continents permitted to reconstruct the origin and phylogeny of this virus, and suggested that viral evolution reflects the relation between the virus and their host. A molecular variant of HPV possess 98% or more identity in L1, E6 and E7 genes with another viral genome. However, molecular variants have approximately 5% differences within the LCR (long control region). Some research groups from different parts of the world have described the epidemiologic association between specific variants of HPVs 16 and 18 and increased risk of persistent infection and development of squamous intraepithelial lesions. In Brazil, we observed a positive association between non-European variants of HPVs 16 and 18 and risk of cervical lesion in a prospective epidemiologic study that is being conducted in São Paulo. In this study we analyzed P97 and P105 transcriptional activity of molecular variants of HPVs 16 and 18, respectively. The Asian-American variant of HPV-18, B18-3, exhibited the highest transcriptional activity among all isolates tested. Among HPV-18 molecular variants, the B 18-2 European isolate was the less transcriptionally active. Among HPV-16 samples, the B-12 European variant exhibited the highest transcriptional activity. We also observed that the HPV-18 P105 promoter was more active than the HPV-16 P97 promoter. Furthermore, we analyzed the capacity of immortalization of primary human keratinocytes by E6/E7 molecular variants of HPV-16. These variants did not differ much in the efficiency of colony formation by low density keratinocyte plating. However, the Asian-American variant yielded a higher number of colonies potentially immortalized. These results have important implications in the determination of risk for development of HPV -associated cervical lesions.
76

Caracterização molecular do Epstein-Barr vírus (EBV) em pacientes portadores de HIV, em tratamento, atendidos no sistema hospitalar do sistema penitenciário do Estado de São Paulo. / Molecular characterization of Epstein-Barr virus (EBV) in HIV patients in treatment from the hospitalar system in the penitentiary system from São Paulo State, Brazil.

Juliana Nogueira Martins Rodrigues 05 December 2008 (has links)
O Epstein-Barr vírus (EBV) é a única espécie humana pertencente ao gênero Lymphocryptovirus. A transmissão ocorre através da saliva contaminada e geralmente ainda na infância. Nosso estudo analisou 165 amostras clínicas de pacientes, portadores de HIV, em tratamento com antiretrovirais, atendidos no Sistema Hospitalar do Sistema Penitenciário do Estado de São Paulo. Nosso enfoque foi pesquisar o EBV nas células mononucleares do sangue periférico, através das técnicas de PCR, Nested-PCR e seqüenciamento de nucleotídeos. Os resultados obtidos, indicaram que 11,51% (19) das amostras analisadas, apresentaram-se positivas para o EBV. Essas 19 amostras, foram seqüenciadas com primers específicos para a região da EBNA-1 (Epstein Barr Nuclear Antigen 1). As amostras foram alinhadas com o auxílio do DNASTAR. Ao alinharmos as amostras, encontramos uma troca de base (de G para A) em 7 amostras e essa troca não alterou a conformação da proteína EBNA-1. Na análise filogenética de nossas sequências com as depositadas no GenBank, foi possível observar dois grupos, que representam tipo 1 e o tipo 2 do EBV. 100% das amostras estudadas por nós foram identificadas como pertencentes ao grupo que caracteriza o tipo 2. Sendo assim, as 7 amostras que apresentaram a troca sugerem a origem um novo subtipo. / The Epstein-Barr Virus (EBV) is the only species to the genus Lymphocriptovirus that infects humans. One of the possible route for its transmission thought by contamined saliva and usually occurs in the childhood. This study analysed 165 clinical samples from HIV infected patients, treated by HARRT, attended in the Hospitalar System in the Penitentiary System from Sao Paulo State. The aim of this study was to search EBV in peripheral blood mononuclear cells by PCR, Nested-PCR and sequencing analysis. The results showed 11,51% of the analysed samples, positive for EBV. This samples, was sequenced with specifics primers from the EBNA-1 (Epstein Barr Nuclear Antigen 1) region. The samples were aligned by DNASTAR program. The aligned sequences showed the base conversion G to A in seven samples. This conversion caused no alteration in the EBNA-1 protein conformation. In the phylogenetic analysis the studied sequences with the sequences from GenBank was possible to observe two groups represented with type 1 and type 2 from EBV. 100% the samples studied was identified with the group characterized by the type 2 to EBV. So the seven samples showed the conversion, suggesting the origin of the one new subtype.
77

Coopération entre les inducteurs de l’EMT (EMT-TF/miRNA) et les altérations oncogéniques dans la tumorigenèse mammaire / Cooperation between EMT inductors (EMT-TFs/miRNA) and oncogenic alterations in human mammary transformation

Ruiz, Emmanuelle 22 May 2015 (has links)
Les cellules cancéreuses sont capables de réactiver la transition Epithélio-Mésenchymateuse (EMT), mécanisme embryonnaire, pour acquérir une mobilité et une capacité de dédifférenciation. L'EMT conduit à une reprogrammation génétique avec la réactivation d'inducteurs de l'EMT, qui sont en majorité des facteurs de transcription (EMT-TF), et conduit à l'inhibition de miARN. Par ailleurs des stress oncogéniques sont essentiels à la progression tumorale. Le but de mon projet de thèse était de comprendre comment les événements de reprogrammation génétique survenant au cours de l'EMT coopèrent avec des stress oncogéniques dans la transformation tumorale mammaire.Premièrement, un criblage basé sur la coopération oncogénique en soft agar assay, entre les EMT-TFs et les stress oncogénique a été réalisé. Suite à une analyse bioinformatique, différentes signatures d'EMT-TF associés à un stress oncogénique ont été identifiées. Ainsi, par exemple, l'expression de l'EMT-TF Zeb1 et l'EMT-TF GSC sont associés à la délétion du gène suppresseur de tumeur PTEN pour transformer des cellules mammaires immortalisées. Une analyse en immuno-histochimie sur un set de 558 tumeurs du sein triple négatives a validé in vivo la présence d'une corrélation entre l'expression de GSC et l'expression de PTEN. Cependant cette association semble être plus complexe. En effet, l'expression de GSC est négativement associée à l'expression nucléaire de PTEN tandis qu'elle est positivement associée à l'expression de PTEN cytoplasmique. Enfin une analyse sur des métadonnées publiques de cancers telles que le TCGA ou le METABRIC est en cours pour valider ces signatures in vitro et plus largement pour déterminer comment l'EMT ou les signatures associées aux EMT-TF se corrèlent avec les voies oncogéniques classiques. Deuxièmement, une analyse in silico à partir d'algorithmes prédictifs de cibles de miARN, a été réalisée pour sélectionner les miARN capables d'inhiber l'expression de plusieurs EMT-TF. Deux miARN (miR-495 et 590-3p) ont été identifiés ciblant plusieurs membres des 4 principales familles d'EMT-TF (FoxC, Snail, bHLH et ZEB). Des tests in vitro ont été réalisés pour valider ces régulations identifiant Slug comme une cible de miR-590-3p. De plus, l'expression de ces miARN dans des lignées cellulaires mammaires est négativement associée à l'expression des EMT-TF et des marqueurs de l'EMT. Un traitement au TGF, inducteur de l'EMT, diminue leur expression, signifiant potentiellement que ces miARN peuvent négativement réguler l'EMT. En parallèle, plusieurs EMT-TF sont capables de réprimer l'expression de miR-590-3p, agissant directement sur son promoteur, créant ainsi des boucles de régulation. Des études fonctionnelles utilisant des vecteurs d'expression stable de miR-590-3p sembleraient montrer un rôle secondaire de ce miARN dans la régulation de l'EMT car mir-590-3p dérégule des marqueurs secondaires de l'EMT comme la N-cadhérine. Des études de restauration de fonctions sont envisagées pour déterminer quelle est l'importance de ces boucles de régulation dans la progression tumorale mammaire. Plus largement, l'expression des miARN identifiés va être corrélée avec les signatures associées aux EMT-TF et aux voies oncogéniques classiques pour déterminer le lien entre ces trois composants dans la tumorigenèse mammaire. Mes travaux de thèse ont montré qu'il existait un intéractome entre des inducteurs de l'EMT, des stress oncogéniques et des miARNs au cours de la transformation mammaire humaine / Cancer cells are able to reactivate the Epithelio-Mesenchymal Transition (EMT), an embryonic mechanism, to acquire mobility and dedifferentiation capacities. EMT leads to a genetic reprogramming with the reactivation of EMT inductors, mainly transcription factors (EMT-TF) and the inhibition of miRNA. Otherwise, oncogenic stresses are essentials to tumor progression. The aim of my thesis project was to have a better understanding about the cooperation between events of genetic reprogramming occurring during EMT and oncogenic stresses during mammary tumor transformation. First, a screening based on oncogenic cooperation in soft agar assay, between EMT-TFs and oncogenic stresses was performed. Following a bioinformatics analysis, different EMT-TFs signatures associated with an oncogenic stress were identified. Thus, for example, the expression of EMT-TF ZEB1 and GSC were associated with the deletion of tumor suppressor gene PTEN to transform immortalized mammary epithelial cells. An immunohistochemistry analysis on a set of 558 triple negative breast cancers validated in vivo the presence of a correlation between the expressions of GSC and PTEN. However, this association seems to be more complex. Indeed, the expression of GSC is negatively associated with the nuclear expression of PTEN while it’s positively associated with the cytoplasmic expression of PTEN. Finally, an analysis of public metadata on cancer samples as TCGA or METABRIC is ongoing to validate these in vitro signatures and wider to determine how EMT or EMT-TFs associated signatures correlate with classical oncogenic pathways.Secondly, an in silico analysis, from predictive algorithms of miRNA targets, was performed to select miRNA able to inhibit the expression of several EMT-TFs. Two miRNA (miR-495 and miR-590-3p) were identified targeting several members of four principal’s families of EMT-TFs (FOXC, Snail, bHLH and ZEB). In vitro tests were realized to validate these regulations identifying Slug as a target of miR-590-3p. Moreover, these miRNAs expression in mammary cell lines is negatively correlated with EMT-TFs expression and EMT markers. A treatment with TGF-, a major EMT inductor, decreases their expression, potentially meaning that these miRNA can negatively regulate EMT. In parallel, several EMT-TFs are able to repress the expression of miR-590-3p, acting directly on its promotor, thus creating feedback loops. Functional studies using stable expression vector of miR-590-3p suggest a secondary role of this miRNA in the regulation of EMT because miR-590-3p deregulates EMT secondary markers as N-Cadherin. Functions restauration studies are planned to determine how important these feedback loops in mammary tumor progression are. To open the project, expression of these identified miRNA will be correlated with EMT-TF associated signatures and with classical oncogenic pathways to determine the link between these three components in mammary tumorigenesis. My thesis works are shown that there is an interactome between EMT inductors, oncogenic stresses and miRNA during human mammary transformation
78

Analyse des propriétés oncogéniques de cIAP1 : contribution de ses partenaires cdc42 et E2F1 / cIAP1 oncogenic properties analysis : contribution of its partners cdc42 and E2F1

Berthelet, Jean 04 November 2014 (has links)
La protéine cIAP1 (cellular Inhibitor of Apoptosis Protein-1) de la famille des IAP (Inhibitor of Apoptosis Protein) est un oncogène avec une activité E3 ubiquitine ligase. Au cours de la différenciation de nombreux modèles cellulaires (macrophages, cellules dendritiques, cellules épithéliales du colon, cellules souches hématopoïetiques, cardiomyocytes), cIAP1 sort du noyau pour se relocaliser dans le cytoplasme, cette relocalisation étant associée à un arrêt de prolifération. La plupart des fonctions connues de cIAP1 sont liées à sa localisation cytoplasmique où il est un régulateur important des voies de signalisation des récepteurs du TNF-a et de NF-?B. Cependant, cIAP1 est principalement exprimée dans le noyau de différents types cellulaires ce qui n’est pas en accord avec son rôle dans la signalisation cellulaire. Mon travail de thèse a permis d’identifier un rôle de cIAP1 dans la prolifération cellulaire. cIAP1 interagit avec le facteur de transcription E2F1 et favorise son recrutement sur les promoteurs des Cycline E et A impliquées dans les transitions G1/S et G2 du cycle cellulaire, ce qui augmente l’expression des transcrits et des protéines de ces deux cibles. Il semblerait que par cette activité, cIAP1 régule la prolifération des cellules et soit important dans l’équilibre entre la prolifération et la différenciation, deux mécanismes cellulaires étroitement liés. Dans un second travail, nous avons montré que cAIP1 est déterminant dans le remodelage du cytosquelette d’actine en réponse au TNF-a. Dans les fibroblastes, le TNF-a induit la formation de fines protrusions membranaires riches en actine appelées filipodes, cette formation étant régulée par cdc42. Mes travaux ont montrés que cIAP1, associé à son partenaire historique TRAF2, régule la formation de ces filipodes. Il est capable d’interagir directement avec la RhoGTPase Cdc42 et de contrôler son activation après un traitement par le TNF- a, mais aussi par l’EGF. De plus, cIAP1 régule également la transformation oncogénique par HRas en augmentant les propriétés invasives et migratoires des cellules. Ces nouvelles fonctions de cIAP1 pourraient contribuer à ses propriétés oncogéniques. / The inhibitor of apoptosis protein cIAP1 (cellular inhibitor of apoptosis protein-1) from the IAP family (Inhibitor of Apoptosis Protein) is an oncogene with an E3 ubiquitin ligase activity. cIAP1 is relocalized from the nucleus to the cytoplasm during the differentiation of many kind of cellular models (macrophages, dendritic cells, colon epithelial cells, hematopoietic stem cells, cardiomyocytes) and this relocalization is associated with a proliferation arrest. The well-known functions of cIAP1 are associated with its cytoplasmic localization, where it regulates the TNFa receptors and NF-?B signaling pathways. However, cIAP1 is mainly expressed in the nucleus on many cell types which is not in accordance with its cell signalling activity. My work identifies a function of cIAP1 in proliferation regulation. cIAP1 interacts with E2F1 transcription factor and favors its recruitment on Cyclins E and A promoters, both involved in G1/S and G2 phases of the cell cycle, which leads to high level of transcript and protein expression of these two targets. It seems that cIAP1 regulates the cellular proliferation and is important for the balance between proliferation and differentiation, two mechanisms tightly connected in cells. In a second work, we showed that cIAP1 is critical for actin cytoskeleton modification upon TNF-a treatment. In fibroblasts, TNF-a induce filipodia formation, a process regulated by cdc42. Our work showed that cIAP1, when associated with its partner TRAF2, interact and control cdc42 activation, a member of Rho GTPases protein family. We also observed that cIAP1 regulates HRas driven oncogenic transformation and increases the motility and invasiveness of the cells. These new functions of cIAP1 in the control of transcription factor and cell cytoskeleton could be important for its oncogenic properties.
79

The role of PI4KB in cellular localization of small GTPases

Sadrpour, Parisa 30 August 2022 (has links)
No description available.
80

Preparation, Characterization, and Delivery of Antibodies Binding to a Model Oncogenic RNA, Human Initiator tRNA

Archer, Jennifer 01 January 2014 (has links)
Non-coding RNAs (ncRNAs) account for a higher percent of the genome than coding mRNAs, and are implicated in human disease such as cancer, neurological, cardiac and many others. While the majority of ncRNAs involved in disease were originally attributed to a class of RNAs called micro RNAs (miRNAs) with a small size of only about 19 -24 base pairs, emerging research has now demonstrated a class of long non-coding RNAs (lncRNAs) that have a size of over 200 base pairs to be responsible for gene regulation and other functional roles and have also found to contribute to pathogenesis in humans. The increased size and structural complexity require novel tools to study their interactions beyond RNA interference. Synthetic antibodies are classic tools and therapeutics utilized to study and treat proteins involved in human disease. Likewise we hypothesize that structured RNAs can also take advantage of synthetic antibodies to probe their functions and be utilized as therapeutics. Currently, antibodies have been raised against microbial riboswitches and other structured RNAs of single-celled organisms, and only one human structured RNA to the best of our knowledge. However, no one has yet to create a synthetic antibody capable of behaving as a therapeutic against a structured RNA. We therefore sought to raise an antibody Fab against a structured RNA, human initiator tRNA, a model oncogenic non-coding RNA and demonstrate its efficacy in vitro. We then characterized the antibody and explored delivery options in cancer cells including the use of nanoparticle delivery systems. With the emerging transcriptome revealing new ncRNAs implicated in human disease, our research has begun to address a new therapeutic strategy, laying down the foundation for the future of structured RNA-targeted therapies.

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