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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.
91

Evaluating the Social Control of Banking Crimes: An Examination of Anti-Money Laundering Deficiencies and Industry Success

Mulligan, Erin M. 01 January 2015 (has links)
Money laundering is a serious crime with potentially wide ranging consequences that have numerous implications for criminological research. However, criminology rarely explores this crime, nor its potential impact on other more central crimes of interest (e.g. drug trafficking or organized crime). The present study adds to a limited body of literature examining money laundering from a criminological perspective, evaluating aspects of its regulation and social control within the banking industry. Several aspects of regulatory oversight and company dynamics such as fine/settlement size, company size, and the likelihood of non-AML/OFAC violations to predict future AML/OFAC violations were evaluated. These analyses largely supported that banking crimes, and more specifically AML violations, follow the same patterns observed within previous corporate crime research. However, the primary focus of this research was to evaluate the effectiveness of industry success rankings as a form of social control as it pertains to AML violations and to determine whether or not banks that ranked well on industry rankings were also less likely to have banking violations. A variety of rankings including safety, asset-based, and overall performance measures were used to assess their relationship to bank violations, with analyses supporting that these banking industry success markers held little relationship to or acknowledgment of a firm’s previous AML/OFAC violations. Implications are discussed at length including the importance of and numerous directions for future criminological research on money laundering violation within the banking industry, suggested regulatory reforms, and the need for a wider variety and more tailored industry success measures to affect some level of social control.
92

The Role of Colony-stimulating Factor 1 and its Receptor on Acute Myeloid Leukemia

Fateen, Mohammed 25 July 2012 (has links)
Colony-stimulating factor 1 receptor (CSF1R, Fms) is an integral transmembrane glycoprotein with tyrosine specific protein kinase activity that it is found on the mononuclear phagocytes to promote their survival, proliferation and differentiation. Colony-stimulating factor 1 (CSF-1), also known as M-CSF, is a protein ligand that acts on the CSF1R. There is a variable association of Fms with the stem cell marker CD34 on acute myeloid leukemia (AML) cells and this suggests different structures of the AML hierarchy in different patients. Mouse stromal cells (MS-5) were transduced with a plasmid containing human CSF-1 because mouse CSF-1 is inactive on human CSF1R. Results show that AML cells cultured with CSF-1-expressing stroma had a much better growth and survival than the control stroma, suggesting that CSF-1 might be a stimulating factor for the growth of leukemic stem cells.
93

Phosphoproteomic Analysis of Acute Myeloid Leukemia

Durbin, Joshua N. 21 November 2012 (has links)
Acute myeloid leukemia (AML) is a clonal hematopoietic stem cell malignancy, marked by suppressed production of normal terminally differentiated and progenitor hematopoietic cells, and increased cellular proliferation, survival, invasion, and migration of poorly differentiated hematopoietic precursor cells called leukemic blasts. Clinical outcomes vary from good to very poor, and standard therapeutic regiments are only successful in inducing remission for approximately one half of patients. Through the use of phospho tyrosine mass spectrometry, we have identified putative candidate proteins which may be implicated in disease pathogenesis. Our in vitro data suggest a complex within the AML cell lines MOLM-14 and MV4-11 involving tyrosine phosphorylated DAP12, FCER1G, SYK, LYN, and CBL. In addition, we show the ability of high concentrations (µM) of SB203580, a p38α catalytic site inhibitor, to paradoxically sensitize cells to cytarabine while providing a modest proliferative advantage to cells treated with daunorubicin.
94

Phosphoproteomic Analysis of Acute Myeloid Leukemia

Durbin, Joshua N. 21 November 2012 (has links)
Acute myeloid leukemia (AML) is a clonal hematopoietic stem cell malignancy, marked by suppressed production of normal terminally differentiated and progenitor hematopoietic cells, and increased cellular proliferation, survival, invasion, and migration of poorly differentiated hematopoietic precursor cells called leukemic blasts. Clinical outcomes vary from good to very poor, and standard therapeutic regiments are only successful in inducing remission for approximately one half of patients. Through the use of phospho tyrosine mass spectrometry, we have identified putative candidate proteins which may be implicated in disease pathogenesis. Our in vitro data suggest a complex within the AML cell lines MOLM-14 and MV4-11 involving tyrosine phosphorylated DAP12, FCER1G, SYK, LYN, and CBL. In addition, we show the ability of high concentrations (µM) of SB203580, a p38α catalytic site inhibitor, to paradoxically sensitize cells to cytarabine while providing a modest proliferative advantage to cells treated with daunorubicin.
95

Mutações no gene DNMT3A em pacientes com leucemia mielóide aguda no Rio Grande do Sul, Brasil

Silva, Annelise Martins Pezzi da January 2012 (has links)
Introdução: A Leucemia Mielóide Aguda (LMA) é uma neoplasia complexa e heterogênea do tecido hematopoético, causada por mutações, desregulação da expressão gênica e modificações epigenéticas. Vários marcadores moleculares têm sido descritos para LMA, auxiliando a estratificação dos pacientes em grupos de risco. Recentemente, mutações em DNMT3A foram identificadas em 22.1% dos pacientes com LMA, estando independentemente associadas com pior prognóstico. Objetivos: Determinar a freqüência de mutações somáticas no gene DNMT3A e principais translocações cromossômicas em uma amostra de pacientes com LMA, correlacionando com dados clínicos Métodos: Foram pesquisadas, em 82 amostras de medula óssea de portadores de LMA atendidos no Hospital de Clínicas de Porto Alegre, RS, Brasil, para mutações somáticas no gene DNMT3A por seqüenciamento e principais transcritos de fusão por RT-PCR. Resultados: A freqüência de mutações no gene DNMT3A foi de 8%(6) sendo 3 do tipo R882H. A freqüência relativa dos transcritos de fusão oriundos das translocações t(8;21), t(15;17), t(9;11) e inv16, respectivamente foram: 6,1%(5), 14,6% (12), 0%(0) e 2,4%(2). Conclusão: A descoberta de mutações recorrentes no gene DNMT3A e sua possível implicação prognóstica pode ser um instrumento valioso para a tomada de decisões terapêuticas. Que nos conste, este é o primeiro estudo sobre a presença de mutações somáticas do gene DNMT3A em portadores de LMA no Brasil. Embora em uma amostra relativamente pequena, a freqüência encontrada destas mutações foi inferior à relatada para pacientes caucasianos, sugerindo uma possível variação etnico-geográfica. / Introduction: Acute Myeloid Leukemia (AML) is a complex and heterogeneous neoplasm hematopoietic tissue, caused by mutations, dysregulation of gene expression and epigenetic modifications. Several molecular markers have been described for AML, helping to classify patients into risk groups. Recently, mutations in DNMT3A were identified in 22.1% of patients with AML and these independently associated with poor prognosis. Aims: Determine the frequency of somatic mutations in the gene DNMT3A and major chromosomal translocations in a sample of patients with AML, correlating with clinical data. Methods: We investigated in 82 samples of bone marrow or peripheral blood of patients with AML treated at the Hospital de Clínicas de Porto Alegre, Brazil, for somatic mutations in DNMT3A gene by sequencing and major fusion transcripts by RT-PCR. Results: The frequency of mutations in the DNMT3A gene was 8%(6) 3 being type R882H. The relative frequency of fusion transcripts arising from translocation t(8;21), t(15;17), t(9;11) and inv16, respectively were: 6,1%(5), 14,6% (12), 0%(0) and 2,4%(2). Conclusion: The discovery of recurrent mutations in the DNMT3A gene and its possible prognostic implications can be a valuable tool for making treatment decisions. From what we have recorded, this is the first study on the presence of somatic mutations of the DNMT3A gene in patients with AML in Brazil. Although in a relatively small sample, the frequency of these mutations was found lower than that reported for Caucasian patients and similar to that observed in Asian patients, suggesting a possible ethno-geographic variation.
96

Especificidade de anticorpos antimúsculo liso em portadores de hepatite crônica pelo vírus C

Cabral, Milena Santana 16 June 2011 (has links)
Submitted by Pós graduação Farmácia (ppgfar@ufba.br) on 2017-05-25T20:04:40Z No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / Approved for entry into archive by Patricia Barroso (pbarroso@ufba.br) on 2017-06-01T17:35:33Z (GMT) No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / Made available in DSpace on 2017-06-01T17:35:34Z (GMT). No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / FAPESB e CNPq / A infeção crônica pelo VHC tem como principal característica a associação com diversas manifestações autoimunes. Dentre estas, a aumentada expressão de autoanticorpos não-órgão específicos, como os anticorpos antimúsculo liso, com possível importância na patogênese da doença. Objetivos: (1) Determinar a prevalência de anticorpos antimúsculo liso e sua distribuição conforme o gênero em portadores de HCC; (2) caracterizar a reatividade sorológica dos anticorpos antimúsculo liso usando como referência os padrões de fluorescência previamente determinados; (3) estabelecer as associações entre a reatividade sorológica dos anticorpos antimúsculo liso com os dados clínicos e laboratoriais dos portadores de hepatite C; (4) caracterizar imunoquimicamente os anticorpos frente a antígenos purificados. Pacientes: Foram avaliados 100 portadores de HCC, sem tratamento antiviral prévio, com diagnóstico clínico, sorológico, virológico, e histopatológico, acompanhados no C-HUPES. Métodos: Anticorpos antimúsculo liso e antinúcleo foram pesquisados por imunofluorescência indireta e a especificidade imunoquímica investigada através de imunoblot. Dosagens de fator reumatóide, haptoglobina e IgG foram realizadas por nefelometria. Crioglobulinas foram determinadas por crioprecipitação em tubo e por gel-difusão e a ALT por método cinético. Os dados de genótipo e histopatológico foram obtidos dos prontuários. Resultados: Anticorpos antimúsculo liso foram detectados em 21% dos pacientes (55 homens, 45 mulheres), sendo o padrão de fluorescência AML-v o mais frequentemente observado (81%). A associação de padrões mais prevalente foi AML-v e AML-m (71%). A maioria dos títulos dos autoanticorpos foi baixa, com apenas quatro amostras apresentando títulos superiores a 1/40. Apenas uma amostra apresentou padrão glomerular com título maior que 1/40, e não foi encontrado padrão tubular. Das três proteínas associadas aos AML, os portadores de HCC com AML positivos apresentaram maior frequência de reatividade para a actina-F, ocorrendo em 29% das amostras. A associação entre os AML e este antígeno alvo foi significante (P=0,005). Não houve associação estatisticamente significante entre os antígenos desmina e miosina, com os AML, e a prevalência de reatividade para esses antígenos foi inferior. Com o uso do imunoblot comercial, foi encontrada a presença do autoanticorpo anti-LC1 em 52% das amostras positivas para AML e em 15% das amostras negativas para esse mesmo anticorpo. Foi encontrada também a presença do anti-SLA/LP em 14% das amostras positivas para AML e em 8% das amostras que não apresentavam este autoanticorpo. Os anticorpos AMA-M2 e anti-LKM1 não foram encontrados em nenhum dos grupos avaliados. Conclusões: Uma prevalência de 21% para AML foi encontrada neste estudo, com uma relação homem/mulher de 1,1/1. A presença de AML não foi associada a qualquer dos dados demográficos, clínicos e laboratoriais deste grupo de portadores de HCC, nem associada à lesão tecidual. Determinar os padrões de fluorescência e título das amostras é relevante na detecção dos AML. Apenas a minoria dos AML de portadores de HCC reconhecem as proteínas actina-F, desmina e miosina. Foi documentado elevada expressão de anticorpos anti-LC1 neste grupo de portadores de HCC. / The main characteristic in HCV chronic infection is the association with various autoimmune manifestations. Among them, the increased expression of non-organ specific autoantibodies, such smooth muscle antibody, which possible role in HCV pathogenesis. Objectives: (1) Determine the prevalence of smooth muscle antibodies and their distribution according gender in patients with chronic hepatitis C; (2) characterize the serological reactivity of these autoantibodies in accordance with predetermined patterns of fluorescence; (3) establish associations between serologic reactivity of them with clinical and laboratory data from these patients; (4) characterize the antibodies immunochemically with purified antigens. Patients: 100 HCV carriers before treatment had been evaluated, with previous clinical, serological, virological and histopathological diagnosis, from C-HUPES. Methods: Smooth muscle and antinuclear antibodies were performed by indirect immunofluorescence and immunochemical reactivity was determined by immunoblot. Rheumatoid factor, haptoglobin and IgG were quantified by nephelometry. Cryoglobulins were determined by cryoprecipitation in tube and gel-diffusion and the determination of ALT by UV kinetics. Genotype and histophatological data were obtained from medical records. Results: 21% of HCV carriers presented anti-smooth muscle antibodies (55 men, 45 women); with the AML-v pattern the most found (81%). Also, the AML-v and AML-m patterns were the association more prevalent (71%). The titles of most autoantibodies were low, but four samples showed titles above 1/40. Only one sample showed glomeruli pattern with titles greater than 1/40, and no tubular pattern was found. In the imunoblot, the HCV carriers AML positive presented a major reactivity for F-actin (29%), which association with these autoantibody was significant (P=0.005). There was no association between AML with desmin and myosin, which reactivities of the AML to these proteins were low. Autoantibodies anti-LC1 was found in 52% of samples AML positive and in 15% of samples AML negative. It was also found the presence of anti-SLA/LP in 14% of positive samples for AML and in 8% of the negative samples. AMA-M2 antibodies and anti-LKM1 were not found in any of these groups. Conclusions: This study found an AML prevalence of 21%, with 1.1/1 men/women relation. The AML presence was not associated with any of the demographic, clinical and laboratory data from the HCV carries evaluated or associated with tissue lesion. Determine fluorescence patterns and sample titles are relevant to detect these antibodies. Only the minority of the AML from HCV carriers evaluated recognized the proteins F-actin, desmin and myosin. High expression of anti-LC1 antibodies were found in these HCV carries.
97

Anomalies d'épissage dans les leucémies aigues myéloblastiques : rôle de WT1 et de DEK et impact clinique / WT1 and DEK-associated missplicing in acute myelogenous leukemias (AML)

Mint Mohamed, Aminetou 27 November 2015 (has links)
Parmi les nombreuses perturbations participant à l'hétérogénéité bioclinique des leucémies aiguës myéloïdes (LAM), les anomalies d'épissage ont récemment pu être identifiées grâce au développement des techniques de microarray et du séquençage à haut débit. Après une revue bibliographique abordant les possible mécanismes et conséquences des perturbation de l'épissage dans les LAM, nous avons dans un deuxième article, analysé les patrons d'épissage associés à l'expression d'oncogènes connus pour interférer avec le splicéosome, l'ARN et la chromatine, ainsi qu'à la résistance aux principales drogues utilisées dans la prise en charge des LAM. Nos résultats identifient des signatures spécifiques et originales, de nombreux évènements concernant des gènes non dérégulés au plan transcriptionnel. Parmi ces perturbation nous avons, dans une troisième étude, évalué l'impact clinique d'une perturbation d'épissage de l'ARN messager de TET2. Les résultats montrent que l'exclusion de l'exon 2 de TET2 défini un facteur pronostic indépendant chez les malades traités par chimiothérapie intensive, en particulier chez les patients au caryotype normal. La dernière étude aborde l'impact des anomalies d‘épissage du transporteur ABCA3 identifiées dans les LAM. In vitro nous trouvons que l'exclusion de l'exon 19 d'ABCA3 favorise la résistance à la daunorubicine et au VP16. Paradoxalement, alors que la résistance liée à cette exclusion d'exon dépasse significativement celle liée à l'expression de la forme sauvage d'ABCA3, l'effet de l'isoforme sans exon 19 sur la rétention cellulaire de daunorubicine apparaît significativement inférieur à celui de l'ABCA3 sauvage. Au plan bioclinique, l'exclusion de l'exon 19 d'ABCA3 réduit les chances de rémission et défini un facteur pronostic indépendant chez les malades traités par chimiothérapie intensive, en particulier chez les patients au caryotype normal / Approximately one-third of expressed genes are misspliced in AML, opening the possibility that additional factors than splicing factor mutations might cause RNA missplicing in these diseases. We performed exon-array analysis and exon-specific PCR (ESPCR) to identify specific landscapes of exon expression that are associated with DEK and WT1 oncogene expression and the resistance of AML cells to AraC, doxorubicin or azacitidine. More than 70% of AEUs identified by exon-array were technically validated through ESPCR. In vitro, 1,130 to 5,868 exon events distinguished the 5 conditions from their respective controls while in vivo 6,560 and 9,378 events distinguished chemosensitive and chemoresistant AML, respectively, from normal bone marrow. Whatever the cause of this effect, 30 to 80% of mis-spliced mRNAs involved genes unmodified at the whole transcriptional level. These AEUs unmasked new functional pathways that are distinct from those generated by transcriptional deregulation. Having identified aberrant TET2 exon 2 and ABCA3 exon 19 expression in, we tested their prognostic impact In a discovery cohort (n=99), TET2 exon 2 skipping (TET2E2S) was found positively associated with a significant reduction in the cumulative incidence of relapse (CIR). Age, cytogenetics, and TET2E2S were independent prognostic factors for disease-free survival (DFS), and favorable effects on outcomes predominated in cytogenetic normal (CN)-AML and younger patients. Using the same cutoff in a validation cohort of 86 CN-AML patients, TET2E2Shigh patients exhibited a significantly lower CIR (p<10-4). TET2E2S and FLT3-ITD, but not age or NPM1 mutation status were independent prognostic factors for DFS and eventfree survival (EFS), while TET2E2S was the sole prognostic factor that we identified for overall survival (OS). In both the intermediate-1 and favorable ELN genetic categories, TET2E2S remained significantly associated with prolonged survival. Regarding ABCA3, we found that skipping of exon 19 (A3S19) triggered resistance to daunorubicine and VP16 in vitro. However such skipping did not significantly modify drug efflux, when compared with wild-type ABCA3. At the clinical level, A3S19 was found negatively correlated with response to IC, OS, DFS, and EFS, independently of age, cytogenetics, FLT3-ITD, and NPM1 mutation. AS19 improved the European LeukemiaNet Risk Classification of AML whereas it possessed no prognostic impact in patients unfit for IC
98

Mutações no gene DNMT3A em pacientes com leucemia mielóide aguda no Rio Grande do Sul, Brasil

Silva, Annelise Martins Pezzi da January 2012 (has links)
Introdução: A Leucemia Mielóide Aguda (LMA) é uma neoplasia complexa e heterogênea do tecido hematopoético, causada por mutações, desregulação da expressão gênica e modificações epigenéticas. Vários marcadores moleculares têm sido descritos para LMA, auxiliando a estratificação dos pacientes em grupos de risco. Recentemente, mutações em DNMT3A foram identificadas em 22.1% dos pacientes com LMA, estando independentemente associadas com pior prognóstico. Objetivos: Determinar a freqüência de mutações somáticas no gene DNMT3A e principais translocações cromossômicas em uma amostra de pacientes com LMA, correlacionando com dados clínicos Métodos: Foram pesquisadas, em 82 amostras de medula óssea de portadores de LMA atendidos no Hospital de Clínicas de Porto Alegre, RS, Brasil, para mutações somáticas no gene DNMT3A por seqüenciamento e principais transcritos de fusão por RT-PCR. Resultados: A freqüência de mutações no gene DNMT3A foi de 8%(6) sendo 3 do tipo R882H. A freqüência relativa dos transcritos de fusão oriundos das translocações t(8;21), t(15;17), t(9;11) e inv16, respectivamente foram: 6,1%(5), 14,6% (12), 0%(0) e 2,4%(2). Conclusão: A descoberta de mutações recorrentes no gene DNMT3A e sua possível implicação prognóstica pode ser um instrumento valioso para a tomada de decisões terapêuticas. Que nos conste, este é o primeiro estudo sobre a presença de mutações somáticas do gene DNMT3A em portadores de LMA no Brasil. Embora em uma amostra relativamente pequena, a freqüência encontrada destas mutações foi inferior à relatada para pacientes caucasianos, sugerindo uma possível variação etnico-geográfica. / Introduction: Acute Myeloid Leukemia (AML) is a complex and heterogeneous neoplasm hematopoietic tissue, caused by mutations, dysregulation of gene expression and epigenetic modifications. Several molecular markers have been described for AML, helping to classify patients into risk groups. Recently, mutations in DNMT3A were identified in 22.1% of patients with AML and these independently associated with poor prognosis. Aims: Determine the frequency of somatic mutations in the gene DNMT3A and major chromosomal translocations in a sample of patients with AML, correlating with clinical data. Methods: We investigated in 82 samples of bone marrow or peripheral blood of patients with AML treated at the Hospital de Clínicas de Porto Alegre, Brazil, for somatic mutations in DNMT3A gene by sequencing and major fusion transcripts by RT-PCR. Results: The frequency of mutations in the DNMT3A gene was 8%(6) 3 being type R882H. The relative frequency of fusion transcripts arising from translocation t(8;21), t(15;17), t(9;11) and inv16, respectively were: 6,1%(5), 14,6% (12), 0%(0) and 2,4%(2). Conclusion: The discovery of recurrent mutations in the DNMT3A gene and its possible prognostic implications can be a valuable tool for making treatment decisions. From what we have recorded, this is the first study on the presence of somatic mutations of the DNMT3A gene in patients with AML in Brazil. Although in a relatively small sample, the frequency of these mutations was found lower than that reported for Caucasian patients and similar to that observed in Asian patients, suggesting a possible ethno-geographic variation.
99

Mutações no gene DNMT3A em pacientes com leucemia mielóide aguda no Rio Grande do Sul, Brasil

Silva, Annelise Martins Pezzi da January 2012 (has links)
Introdução: A Leucemia Mielóide Aguda (LMA) é uma neoplasia complexa e heterogênea do tecido hematopoético, causada por mutações, desregulação da expressão gênica e modificações epigenéticas. Vários marcadores moleculares têm sido descritos para LMA, auxiliando a estratificação dos pacientes em grupos de risco. Recentemente, mutações em DNMT3A foram identificadas em 22.1% dos pacientes com LMA, estando independentemente associadas com pior prognóstico. Objetivos: Determinar a freqüência de mutações somáticas no gene DNMT3A e principais translocações cromossômicas em uma amostra de pacientes com LMA, correlacionando com dados clínicos Métodos: Foram pesquisadas, em 82 amostras de medula óssea de portadores de LMA atendidos no Hospital de Clínicas de Porto Alegre, RS, Brasil, para mutações somáticas no gene DNMT3A por seqüenciamento e principais transcritos de fusão por RT-PCR. Resultados: A freqüência de mutações no gene DNMT3A foi de 8%(6) sendo 3 do tipo R882H. A freqüência relativa dos transcritos de fusão oriundos das translocações t(8;21), t(15;17), t(9;11) e inv16, respectivamente foram: 6,1%(5), 14,6% (12), 0%(0) e 2,4%(2). Conclusão: A descoberta de mutações recorrentes no gene DNMT3A e sua possível implicação prognóstica pode ser um instrumento valioso para a tomada de decisões terapêuticas. Que nos conste, este é o primeiro estudo sobre a presença de mutações somáticas do gene DNMT3A em portadores de LMA no Brasil. Embora em uma amostra relativamente pequena, a freqüência encontrada destas mutações foi inferior à relatada para pacientes caucasianos, sugerindo uma possível variação etnico-geográfica. / Introduction: Acute Myeloid Leukemia (AML) is a complex and heterogeneous neoplasm hematopoietic tissue, caused by mutations, dysregulation of gene expression and epigenetic modifications. Several molecular markers have been described for AML, helping to classify patients into risk groups. Recently, mutations in DNMT3A were identified in 22.1% of patients with AML and these independently associated with poor prognosis. Aims: Determine the frequency of somatic mutations in the gene DNMT3A and major chromosomal translocations in a sample of patients with AML, correlating with clinical data. Methods: We investigated in 82 samples of bone marrow or peripheral blood of patients with AML treated at the Hospital de Clínicas de Porto Alegre, Brazil, for somatic mutations in DNMT3A gene by sequencing and major fusion transcripts by RT-PCR. Results: The frequency of mutations in the DNMT3A gene was 8%(6) 3 being type R882H. The relative frequency of fusion transcripts arising from translocation t(8;21), t(15;17), t(9;11) and inv16, respectively were: 6,1%(5), 14,6% (12), 0%(0) and 2,4%(2). Conclusion: The discovery of recurrent mutations in the DNMT3A gene and its possible prognostic implications can be a valuable tool for making treatment decisions. From what we have recorded, this is the first study on the presence of somatic mutations of the DNMT3A gene in patients with AML in Brazil. Although in a relatively small sample, the frequency of these mutations was found lower than that reported for Caucasian patients and similar to that observed in Asian patients, suggesting a possible ethno-geographic variation.
100

Identification de nouvelles cibles pro-apoptotiques dans les leucémies aiguës myéloblastiques / New pro-apoptotic targets in acute myeloid leukaemia

Piedfer, Marion 12 November 2012 (has links)
Les leucémies aiguës myéloblastiques (LAM) sont des maladies hématopoïétiques caractérisées par une prolifération incontrôlée de précurseurs myéloïdes bloqués à divers stades de différenciation. Le pronostic des LAM reste sombre à cause de la résistance aux traitements et des rechutes après rémission. En conséquence, des thérapies moins intensives et mieux tolérées doivent être développées ; ceci nécessite le développement de stratégies combinatoires associant des molécules avec des modes d’action différents pour augmenter l’efficacité des traitements. Plusieurs approches sont en cours d’étude préclinique et clinique [inhibiteurs des voies de signalisation PI3K/Akt/mTOR, anticorps monoclonaux couplés à une drogue (Mylotarg®), inhibiteurs du protéasome (bortezomib)…] Des travaux récents ont relancé l’intérêt de l’étude des molécules d’origine naturelle pour le traitement des cancers. Ainsi, l’acide flavone-8-acétique (FAA) a suscité de nombreux espoirs au vu de son action sur les tumeurs greffées chez la souris ; il s’est néanmoins révélé inactif chez l’homme du fait d’une métabolisation différente de celle de la souris. L’objectif de ma thèse a été d’étudier les effets d’anticorps monoclonaux dirigés contre l’antigène tumoral CD13 (aminopeptidase-N) et de deux dérivés de FAA, la 2’,3-Dinitroflavone-8-acétique (DNFAA ; inhibiteur de l’activité enzymatique de CD13) et la 3,3’-Diamino-4’-méthoxyflavone (DD1) dans les LAM. Mon étude a montré que DNFAA n’affecte ni la prolifération ni la survie des cellules de LAM (lignées et cellules primaires). Cependant, le traitement de ces cellules par les anticorps anti-CD13, (MY7, SJ1D1, WM15 ; reconnaissant ou non le site enzymatique) induit l’apoptose en activant les voies extrinsèque et intrinsèque. Dans la voie intrinsèque, les anti-CD13 régulent négativement l’expression des protéines anti-apoptotiques Bcl-2 et Mcl-1 et positivement l’expression de la protéine pro-apoptotique Bax. De plus, l’activation de la voie PI3K/Akt apparaît associée au processus apoptotique. Mon étude sur les effets du 3,3’-Diamino-4’-méthoxyflavone dans les cellules de LAM montre une induction d’apoptose résultant de la convergence de l’inhibition du protéasome et de l’activation des voies extrinsèque et intrinsèque. Les cibles de DD1 sont le protéasome, la kinase p70S6K (kinase en aval de mTOR), et les protéines pro-apoptotiques Bad et Bax. De plus, j’ai mis en évidence la dégradation de p70S6K sous l’action de la caspase 3, par le traitement avec DD1, nouvelle propriété partagée par DD1 et le bortezomib. En conclusion, mon travail a permis de mettre en évidence les capacités à induire in vitro des voies d’apoptose déficientes dans les cellules de LAM, d’anticorps monoclonaux anti-CD13 et de la flavone originale, 3,3’-Diamino-4’-methoxyflavone, en tant que nouvel inhibiteur du protéasome. Les propriétés de ces agents pro-apoptotiques méritent d’être analysées de façon plus approfondie. / Acute Myeloid Leukaemia (AML) is a deadly disease characterized by the clonal expansion and accumulation of hematopoietic stem cells arrested at various stages of development. Clinical research efforts are currently focusing on targeted therapies that induce apoptosis in AML cells such as PI3K/Akt/mTOR pathway inhibitors, monoclonal antibodies (Mylotarg®), proteasome inhibitor (bortezomib)… Natural products such as flavonoids have been reported as anticancer agents due to their antioxidant properties as well as to their possible interactions with signalling cascades. Therefore, flavone-8-acetic acid (FAA) has raised considerable attention since the discovery of its exceptional activity on several murine solid tumours. Unfortunately, these promising properties were not confirmed on human due to differential metabolization between human and mouse. The aim of my PhD was to study effects of monoclonal antibody against aminopeptide-N/CD13 and FAA derivatives, 2’,3-Dinitroflavone-8-acetic (DNFAA ; APN/CD13 inhibitor) and 3,3’-Diamino-4’-methoxyflavone (DD1) on acute myeloid leukaemia cells. My studies have shown that DNFAA does not modify proliferation or survival of LAM primary and cell lines. However, treatment of these cells by CD13 antibodies (MY7, SJ1D1 and WM15) induces apoptosis by triggering extrinsic and intrinsic apoptotic pathways. Regarding the intrinsic pathway, anti-CD13 down-regulate anti-apoptotic proteins Bcl-2 and Mcl-1 and up-regulate the pro-apoptotic protein Bax. Morever, PI3K/Akt signalling pathway seems to be associated with this apoptosis. My study about 3,3’-Diamino-4’-methoxyflavone effects on LAM cells has shown that DD1 induces apoptosis by proteasome inhibition and intrinsic and extrinsic pathways induction. DD1 targets p70S6 kinase (a downstream kinase of mTOR) and pro-apoptotic proteins Bad and Bax. Moreover, I have shown p70S6K degradation by caspase 3 during DD1 treatment, a new characteristic shared by DD1 and Bortezomib. As a conclusion, my works demonstrated that CD13 antibodies and a new synthetic flavone are able to induce apoptosis signalling pathway normally impaired on AML cells. Characteristics of these agents deserve to be more deeply analyzed.

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