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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.
141

Implication de la glutamine dans l’activation de mTORC1 dans les leucémies aiguës myéloïdes et inhibition ciblée / Involvement in the activation of glutamine mTORC1 in acute myeloid leukemia and targeted inhibition

Willems, Lise 25 October 2012 (has links)
Dans les leucémies aiguës myéloïdes (LAM), l’activation anormale de nombreuses voies de signalisation intracellulaires favorise la croissance et la survie des cellules tumorales. L’amélioration des connaissances biologiques de ces pathologies hétérogènes, dont le pronostic est réservé, devrait permettre le développement de thérapies ciblées. La kinase oncogénique mTOR est présente au sein de deux complexes, parmi lesquels mTORC1, activé constitutivement dans la majorité des blastes primaires de patients porteurs de LAM, qui contrôle la synthèse protéique, et mTORC2 activé constitutivement dans 50% des LAM. Les inhibiteurs allostériques de mTORC1 (la rapamycine et ses dérivés) n’inhibent pas la phosphorylation du répresseur traductionnel 4E-BP1, ne diminuent pas la traduction et induisent peu d’apoptose in vitro dans les LAM. Utilisés en monothérapie, leur effet est décevant. De plus ces inhibiteurs n’agissent pas sur le complexe mTORC2. J’ai étudié l’effet d’un inhibiteur catalytique de mTOR, l’AZD8055, actif sur les deux complexes. In vitro, l’AZD8055 inhibe efficacement la signalisation en aval de mTORC1 et de mTORC2, dont les sites de phosphorylation de 4E-BP1 résistants à la rapamycine, ainsi que la synthèse protéique. Il diminue la prolifération, bloque le cycle cellulaire en phase G0G1 et induit une apoptose caspase-dépendante dans les blastes primaires de LAM. Il diminue également la clonogénicité des progéniteurs leucémiques, sans affecter celle des cellules CD34+ normales. Dans un modèle murin de xéno-transplantation, l’AZD8055 inhibe la croissance tumorale et améliore la survie des souris traitées. Je me suis également intéressée à la régulation de l’activité de mTORC1 par les acides aminés. Dans les cellules de mammifères, l’activation de mTORC1 nécessite la présence de glutamine et de leucine qui agissent en coopération via deux transporteurs membranaires, SLC1A5 et SLC7A5/SLC3A2. J’ai montré que la privation en glutamine, obtenue par l’activité glutaminase de la drogue L-asparaginase ou par l’utilisation de milieux de culture spécifiques dépourvus sélectivement en acides aminés, inhibe l’activation de mTORC1 et induit de l’apoptose dans diverses lignées leucémiques et dans les blastes primaires de LAM. La L-asparaginase inhibe la synthèse protéique et ses effets fonctionnels sont liés à son activité glutaminase. J’ai pu également constater une augmentation de l’expression protéique de la glutamine synthase induite par la Lasparaginase, dont l’inhibition majore l’apoptose induite par la L-asparaginase dans certaines lignées leucémiques. J’ai également étudié l’effet de l’inhibition spécifique par un shARN inductible du transporteur SLC1A5, qui permet l’import de glutamine. L’inhibition de SLC1A5 bloque la réactivation de mTORC1 par l’association leucine/glutamine après privation et induit de l’apoptose dans la lignée leucémique MOLM14. Cette inhibition diminue la croissance tumorale dans un modèle de xénogreffe / Acute myeloid leukaemias (AML) are heterogeneous diseases associated with poor prognosis. In AML, aberrant activation of many signaling pathways enhances proliferation and survival of leukemic blast cells. Understanding the mechanisms underlying survival of tumoral cells should allow the development of targeted therapies. The oncogenic kinase mTOR belongs to two distinct multimeric complexes. MTORC1 that controls protein translation, is constitutively activated in most of primary blast cells at AML diagnosis, while mTORC2 is constitutively activated in about half of AML samples. In AML, some phosphorylation events of the translational repressor 4E-BP1, are resistant to allosteric inhibitors of mTORC1 including rapamycin and its analogs. These first generation inhibitors of mTORC1 have only few effects on AML and do not induce significant apoptosis in vitro. I have tested a second generation mTOR kinase inhibitor active on both mTORC1 and mTORC2 complexes. In vitro, AZD8055 blocked mTORC1 and mTORC2 signaling, including 4E-BP1 rapamycin resistant phosphorylation events and protein synthesis. This compound decreased AML blast cells proliferation and cell cycle progression, reduced the clonogenic growth of leukemic progenitors and induced caspase-dependant apoptosis in leukemic cells but not in normal immature CD34+ cells. Finally, AZD8055 reduced tumor growth and improved survival in xenografted mouse model. In the second part of this work, I have studied the regulation of mTORC1 by amino acids in AML. In mammalian cells, activation of mTORC1 requires the presence of glutamine and leucine acting together via two membrane transporters, SLC1A5 and SLC7A5/SLC3A2. I showed that glutamine deprivation, obtained by L-asparaginase glutaminase activity or specific alpha-MEM use, inhibited mTORC1 and induced apoptosis in AML cell lines and primary AML blasts. L-asparaginase also inhibited protein synthesis and I have observed a correlation between the functional effects of L-asparaginase and its glutaminase activity. L-asparaginase induced an up-regulation of glutamine synthase (GS) protein and shRNA-induced GS inhibition increased L-asparaginase-dependant apoptosis in the MV4-11 AML cell line. I have also studied the effects of SLC1A5 inhibition with an inducible shRNA expressed in MOLM14 cells. Inhibition of this high afffinity transporter for glutamine blocked mTORC1 stimulation by leucine and glutamine after deprivation and induced apoptosis in MOLM-14 cell line. SLC1A5 inhibition reduced tumor growth and improved survival in transplanted mice
142

PLZF et les protéines du groupe Polycomb : interaction et implication dans la différenciation hématopoïétique normale et pathologique / PLZF and Polycomb group proteins : interaction and implication in normal and malignant hematopoiesis

Koubi, Myriam 17 December 2015 (has links)
Les protéines du groupe Polycomb (PcG) sont des facteurs épigénétiques dont le rôle est de maintenir la répression de leurs gènes cibles au niveau de la chromatine via la modification des protéines histones. EZH2 est une protéine clé dans les mécanismes de régulation puisqu’elle catalyse la mise en place de la marque répressive H3K27me3. Dans le cadre de ma thèse, je me suis intéressée au modèle des leucémies aiguës myéloïdes (LAM) dans lesquelles, contrairement à d’autres pathologies myéloïdes, des mutations affectant EZH2 ou des membres Polycomb ne sont retrouvées que très rarement (˂1%). Des études ont montré que dans ce type de leucémies, de nombreux gènes cibles d’EZH2 sont dérégulés bien que son activité répressive soit toujours présente, mettant en évidence d’éventuels défauts de recrutement de cette protéine. Parmi les facteurs de transcription susceptibles de réguler l’association des protéines PcG à la chromatine, se trouve PLZF qui est un candidat intéressant. En effet, le laboratoire a mis en évidence une interaction entre PLZF et la protéine Polycomb BMI-1 et a montré que la distribution génomique de PLZF concorde avec celle de certains composants des Polycomb. L’objectif de mon travail de thèse a donc été de déterminer dans quelle mesure PLZF intervient dans le recrutement ou l’activité d’EZH2. / Polycomb group (PcG) proteins are epigenetic factors which play a major role in maintaining epigenetic silencing via histone modifications at the chromatin level. EZH2 is a key regulator that catalyzes the trimethylation of H3K27, which is a repressive mark. During my PhD, I was interested in the acute myeloid leukemia (AML) model in which, unlike other myeloid malignancies, EZH2 or other PcG protein mutations are very rare (˂1%). Studies have shown that in this type of leukemia, many of EZH2 target genes are deregulated although its repressive activity is still present highlighting possible EZH2 recruitment defects. Among the transcription factors that regulate the association of PcG proteins to chromatin, the transcription factor PLZF is an interesting candidate. Indeed, the laboratory has demonstrated an interaction between PLZF and the Polycomb protein BMI -1 and showed that the genomic distribution of PLZF is consistent with that of some Polycomb components. The aim of my thesis was therefore to determine in which extent PLZF is involved in the recruitment or activity of EZH2.
143

Patienters upplevelse av att leva med akut myeloisk leukemi / The patients experience of living with acute myeloidleukemia

Petersson, Fanny, Evers, Nadine January 2017 (has links)
Akut myeloisk leukemi (AML) är en invasiv sjukdom som kräver en stor omställning för patienten. Sjuksköterskan har därmed en betydelsefull roll för att kunna bidra till professionell omvårdnad. Syftet med studien var att beskriva patientens upplevelse av att leva med sjukdomen AML. Studien var en litteraturstudie där tio resultatartiklar inkluderades, fem kvalitativa och fem kvantitativa. Innehållsanalys användes som analysmetod, vilket resulterade i tre kategorier: upplevelsen av begränsningar i livet, behovet av stöd och upplevelsen av välbefinnande. I resultatet framkom det att patienter med AML upplever begränsningar i vardagen och vanligtvis är symtomen anledningen till det. Stödet, både professionellt och socialt, har stor betydelse för patienterna. Livskvaliteten hos patienterna kan påverkas både positivt och negativt under sjukdomsförloppet. För att omvårdnaden och bemötandet av patienter med sjukdomen skall förbättras krävs det mer forskning kring ämnet omvårdnad och hur patienternas upplevelse av sjukdomen ser ut. / Acute myeloid leukemia (AML) is an invasive disease that requires a major transformation for the patient. The nurse therefore has an important role in contributing to professional nursing. The purpose of the study was to describe the patients experience of living with the disease AML. The study was a literature study where ten result articles were included, five qualitative and five quantitative. Content analysis was used as an analytical method, which resulted in three categories: experience of life limitations, the need for support and the experience of well-being. It appears that patients with AML feel limited in everyday life, usually the symptoms are the cause of the restrictions. Support, both professionally and socially, is of great importance to patients with AML. The quality of life of patients can be affected both positively and negatively during the disease. In order to improve nursing and treatment of the patients, more research is needed on the subject of nursing and how the patients experience the disease.
144

Feeling the zeros : Modeling individual responses, measured against time, to treatment of chronic myeloid leukemia.

Warnqvist, Anna January 2017 (has links)
In this paper response curves of patients with chronic myeloid leukemia are modeled using one and two-level censored models. Two-level models (also called mixed models) allow random effects and censored models are used to account for the large amount of values too small to be detected. The curves are observed from start of medication to a maximum of 36 months (9 measurement points). The data set is divided into two: "excellent responders" and "other". The "excellent responders" are modeled with a simple cubic censored model, and only one of the background variables measured at time zero ("blasts"), is found to be significant in explaining variation in the change curves, and even this with certain reservations. "Other" are modeled with a cubic two-level censored model and hemoglobin and eosinophile levels, as well as amount of blasts, are significant in explaining variation in this group.
145

Aderência dos pacientes com leucemia mielóide crônica à terapia com inibidores de tirosino quinase / Adherence to tyrosine kinase inhibitors treatment in patients with chronic myeloid leukemia

Almeida, Maria Helena de, 1973- 02 April 2013 (has links)
Orientador: Cármino Antonio de Souza / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T09:59:01Z (GMT). No. of bitstreams: 1 Almeida_MariaHelenade_D.pdf: 2031022 bytes, checksum: 4ca81cfeb49f5ad6382582a5201e8b80 (MD5) Previous issue date: 2013 / Resumo: A leucemia mieloide crônica e uma doença clonal, caracterizada por uma translocação recíproca entre os cromossomos 9 e 22. A introdução do tratamento com inibidores de tirosino quinase, administrado por via oral, revolucionou e melhorou drasticamente o tratamento destes pacientes, porem a eficácia deste tratamento esta diretamente relacionada ao uso desta medicação a longo prazo. Pacientes e métodos: 137 pacientes com leucemia mieloide crônica, em uso de inibidores de tirosino quinase, tiveram a sua aderência avaliada em três diferentes momentos: seis meses retrospectivo, seis e doze meses prospectivos. Três diferentes métodos indiretos foram utilizados para a avaliação da aderência: o teste de Morisky, o diário de medicação e o índice de posse da medicação. Resultados: não houve diferença significante quando consideramos os três diferentes momentos em que avaliação foi realizada e o método considerado mais efetivo para a avaliação da aderência foi considerado o índice de posse da medicação (p=0.0001). Considerando as informações acima, o método utilizado para a avaliação da aderência foi o índice de posse da medicação avaliado apos, aproximadamente, 12 meses de analise. A mediana de aderência observada neste estudo foi de 96,5%. Os fatores que influenciaram a aderência foram: nível socioeconômico, qualidade de vida, tempo de uso dos inibidores de tirosino quinase e participação em protocolos de pesquisa clinica. Sendo que pacientes com níveis socioeconômicos mais elevados, com melhor qualidade de vida e que estavam inseridos em protocolos clínicos estavam relacionados com melhores índices de aderência (p=0.01, p=0.007 e p=0.02 respectivamente). Enquanto que pacientes com tempo mais prolongado de uso dos inibidores de tirosino quinase estavam relacionados a piores índices de aderência (p=0.03). Para os pacientes em uso de imatinibe por um período de 24 a 48 meses, em primeira linha de tratamento a aderência foi significativamente melhor em pacientes que apresentavam resposta molecular maior quando comparado ao grupo que não havia atingido este beneficio terapêutico (p=0.04). Apenas 24% da população avaliada mantenve-se completamente aderente no período de avaliação. Conclusões: a manutenção de uma aderência adequado em pacientes com leucemia mieloide crônica em uso de inibidores de tirosino quinase esta relacionado com a obtenção de melhores índices de resposta molecular e consequentemente, melhores resultados terapêuticos. A monitorização continua da aderência nestes pacientes e fundamental para que se atinjam os objetivos x xi terapêuticos. Informações sobre os fatores que podem influenciar a aderência, uma equipe multidisciplinar especializada e treinada para assistir este paciente pode fazer a diferença na obtenção de melhores resultados terapêuticos / Abstract: Chronic myeloid leukemia is a clonal disorder caused by the reciprocal translocation between cromossomes 9 and 22.The introduction of oral tyrosine kinase inhibitors has dramatically revolucioned and improved outcomes in these patients. However, treatment success is directly related to good long-term adherence and questions relating to adherence to prescribed therapy have become an important issue. Patient and Methods: adherence to tyrosine kinase inhibitors therapy was evaluated in 137 chronic myeloid leukemia patients in three different times: six months retrospective, six and twelve month prospectively. Three different methods were used to evaluate adherence: the Morisky Questionnaire, the medication diary and the medication possession ratio. Results: there was no difference between the three different time of evaluation and the medication possession ratio was the most effective method of assessing adherence (p=0.0001); the median adherence was 96.5%. Duration of tyrosine kinase inhibitors treatment was the variable that most impacted adherence (p=0.03); the medication possession ratio was inversely correlated to the duration of therapy. Additionally, participation in clinical trials, better quality of life as reported by patients and higher socioeconomic status were all related to better adherence (p=0.02, p=0.007 and p=0.01, respectively). For patients treated with imatinib for 24 to 48 months (n=22), individuals with major molecular response had a significantly better medication possession ratio than those who failed to achieve MMR (p=0.04). In this group the mean MPR was 87% for the population without apparent molecular response and 96% for those achieving major molecular response, however only 24% of the patients were completely adherent to tirosine kinase inhibitors treatment. Conclusions: higher adherence in chronic myeloid leukemia patients using imatinib is related with best molecular response and therapeutic outcomes. Monitoring the adherence treatment is critical to improving de therapeutics results. A specialized, trained multidisciplinary team that is capable of gaining the trust of patients may persuade them to comply with treatment and detect those who require better monitoring to optimize treatment / Doutorado / Clinica Medica / Doutora em Clínica Médica
146

Factors associated with intensity of end-of-life care for patients with acute myeloid leukemia

Vaughn, Dagny 01 December 2020 (has links)
INTRODUCTION: Older patients with AML (> 60 years) often receive intensive EOL care including hospitalizations and chemotherapy close to death. Intensive EOL care has been shown to increase emotional and financial burdens for patients and families, while often not aligning with patients’ preferences. However, factors associated with the intensity of EOL care in this population are unknown. OBJECTIVES: There is a need to better understand the factors associated with intense EOL care, in hopes of providing more informed, high-quality EOL care in line with patient preferences and decreasing burdens associated with unnecessary healthcare. We aim to describe the associations between the intensity of EOL care, patient demographics, and baseline psychological distress in older patients with AML. METHODS: We conducted a secondary analysis of two supportive care studies including 168 deceased older patients with AML. We assessed patients’ demographics, quality of life (QOL) [Functional Assessment Cancer Therapy-Leukemia], and anxiety and depression symptoms [Hospital Anxiety and Depression Scale (HADS); Patient Health Questionnaire (PHQ-9)] at the time of diagnosis. We used multivariate logistic regression models to examine the association among demographic factors, patient-reported outcomes, and the following EOL care outcomes abstracted from the electronic health record: 1) hospitalizations in the last 7 days of life; 2) receipt of chemotherapy in the last 30 days of life; and 3) hospice utilization. RESULTS: The median age of the cohort was 69 (range 20-100), and the majority were males (63.7% 107/168). Overall, 66.7% (110/165) of patients were hospitalized in the last 7 days of life, 51.8% (71/137) received chemotherapy in the last 30 days of life, and 40.7% (70/168) utilized hospice services. In multivariate models, higher education (OR = 1.54, SE=0.24, P=0.006), and elevated depression symptoms [PHQ-9: OR=1.09, SE=0.04, P=0.028] at the time of diagnosis were associated with higher odds of being hospitalized in the last 7 days of life. In contrast, higher QOL at diagnosis [OR=0.98, SE=0.01, P=0.009] was associated with lower odds of being hospitalized in the last 7 days of life. Depression symptoms at the time of diagnosis as measured by the HADS was the only factor associated with the receipt of chemotherapy in the last 30 days of life [HADS-Depression: OR=1.10, SE=0.05, P=0.042]. Patients factors were not associated with hospice utilization. CONCLUSIONS: Older patients with AML who are more educated and report elevated depression symptoms and lower QOL at the time of diagnosis were more likely to receive intensive EOL care. These findings identify a population at the time of diagnosis of AML who are at higher risk for hospitalizations and chemotherapy use at the EOL and who may benefit from targeted supportive care interventions.
147

Alternative Splicing and Regulation of Innate Immune Mediators in Normal and Malignant Hematopoiesis

Smith, Molly 01 October 2019 (has links)
No description available.
148

MikroRNA v patogenezi AML / MicroRNAs in AML pathogenesis

Koutová, Linda January 2019 (has links)
Acute myeloid leukemia (AML) is a very heterogeneous disease associated with cytogenetic aberrations and genetic mutations. Many of these changes have been revealed and their detection became usual part of the diagnostic process today. However, changes of expression profiles of small, noncoding RNAs, so called microRNAs (miRNAs), are less known and not used for diagnostics yet. These RNAs, 19-24 nucleotides long, take part in the regulation of expression of different genes through complementary base pairing to the 3'non- translated region (3'UTR) of the target messenger RNA (mRNA). They can influence key processes of the cell, like differentiation, proliferation or apoptosis. The changes in expression of different miRNAs are known from different types of cancers. In solid tumors, they are usually detected from bioptic samples; but also plasma samples are now in the center of attention as so called liquid biopsies providing the information about molecular genetic events in the organism. Many studies have revealed deregulated miRNAs in the bone marrow, full blood or isolated progenitor cells (CD34+) of AML patients, only four of them have analyzed plasma samples. We focused on the plasma samples and we targeted on such miRNAs, which levels differ at AML diagnosis and after the chemotherapy. Out of...
149

Targeting T-cells to Acute Myeloid Leukemia with a Novel Bispecific Antibody Format

Burke, Alan Austin January 2022 (has links)
Treatment of acute myeloid leukemia, an aggressive hematopoietic malignancy of myeloid progenitors, has remained rather stagnant over the course of several decades. Infusions of cytarabine and anthracycline antibiotics have dominated the landscape of AML therapy, with minor changes to dosing schedule occasionally making slight adjustments to efficacy or tolerability. Improvements in prognosis have been bittersweet, with most progress seen in younger populations less likely to get the disease, and already more likely to achieve remission and to meet survival milestones. Much of this progress is attributed to other factors, such as improved supportive care and availability of hematopoietic stem cell and platelet transfusion. In most patients, occupying the 60-and-above demographic, improvements in survival have not been significant. In turn, the population impact of AML has changed little over time. While accounting for about one-third of total leukemia cases and one percent of total cancer cases, AML accounts for about one half of total leukemia deaths and two percent of total cancer deaths. Most advances straying away from standard treatment have been in important pathways that could be impactful in subsets of the overall AML patient population. Tyrosine kinases are implicated in numerous cancers including AML, with activity-enhancing mutations conferring growth advantages to malignant cells. About one-third of AML patients have mutations in one such kinase, FLT3, and may benefit from inhibitors to tyrosine kinases overall and from FLT3- specific agents. Mutations in isocitrate dehydrogenases highlight another subpopulation, about one-fifth of AML patients, who might benefit from emerging agents that inhibit these pathways from creating a leukemia-favoring environment in the bone marrow. Other pathways similarly implicated in numerous cancers including AML are being targeted with new agents that can benefit some AML patients, such as Hedgehog signaling and apoptotic regulation. Still, breakthroughs are needed that can help most AML patients, particularly in the cases of relapsed leukemia that occurs in most patients within a year or two after remission is achieved. CD33 is among a few molecular targets for AML, though it is just as ubiquitously expressed on healthy myeloid cells. Antibody-drug conjugates like Mylotarg have made progress in this approach, though hematopoietic toxicities have made treatment difficult in older populations. Clever techniques such as ablation of CD33 from healthy myeloid progenitors may be supportive in CD33-based approaches, and immunotherapy involving CD33-targeting is a rapidly growing research focus. This dissertation describes a new type of bispecific antibody that binds CD33 on AML and CD3 on cytotoxic T cells in a proof-of-concept study. Various formats for bifunctional molecules have been created and used clinically, including antibody-drug conjugates and bispecific antibodies that simultaneously engage antigens on two different types of cells. Those like the one described here, bispecific T-cell engagers, have typically taken the form of single-chain fusion proteins containing the variable regions binding to both antigens of interest. Other bispecific antibodies have imitated naturally-occurring immunoglobulin structures, boasting superior pharmacokinetics while facing steep obstacles in large-scale production. The single-chain fusions, easier to produce, can face difficulties in full engagement, with loss of function sometimes seen in fusion partners at the C-terminus. We propose a new format, believed to present two antigen-binding domains in N-terminal positions on a two-chain heterodimeric structure. Capitalizing on an elegantly designed system of hydrophobic cores and hydrogen-bonding networks generating an orthogonal heterodimer, we added an immunoglobulin hinge region to secure a permanently-bound heterodimer, and attached domains binding to CD3 and CD33. We hypothesized that this design, ensured to present its antibody components at N-termini, could bind two antigens at a distance appropriate for facilitating T cell cytotoxicity to AML. After expressing and purifying these proteins in mammalian cells, we demonstrated their ability to persist as a bispecific heterodimer. We showed in vitro that our bispecific heterodimers could bind both CD3+ and CD33+ cells, and that they bolstered T cell cytotoxicity to AML cell lines in a dose-dependent manner. Monomeric components bound only CD3+ or CD33+ cells depending on antibody variable domain present, and had no effect on T cell cytotoxicity. In a mouse model of minimal residual disease, T cells alone did not have a significant effect on the growth of AML, nor did they have an effect on overall survival. T cells with bispecific heterodimer greatly extended survival, and mice of this treatment group were free of leukemia. These findings suggest that this format for bispecific proteins allows for robust simultaneous engagement with both antigens of interest in a manner conducive to T cell cytotoxicity against AML. We believe this presents a compelling modular system for bispecific antibodies, where CD3- and CD33-binding domains can be readily swapped with domains binding to other cancer- or immune cell-specific antigens, and can be further developed into a trispecific system engaging other immune cells or extending half-life with anti-albumin or Fc domains.
150

Conception et réalisation de microdispositifs électrochimiques, pour l'analyse de l'activité bioénergétique de mitochondries isolées, dans le cadre de la mise au point de traitements innovants des leucémies aiguës myéloïdes / Design manufacturing of electrochemical microdevices, for the analysis of the bioenergetic activity of isolated mitochondria, in the frame of the development of innovative therapies of acute myeloid leukemia

Lemercier, Gabriel 23 May 2018 (has links)
La mitochondrie est restée longtemps cantonnée au rôle de centrale énergétique cellulaire. On sait désormais qu'elle est aussi la principale source d'espèces réactives oxygénées, impliquées dans le stress oxydant et la signalisation inter- cellulaire. Le dérèglement de l'activité mitochondriale est ainsi susceptible d'être la cause de l'apparition et de la progression de maladies associées au vieillissement, comme le cancer et les maladies neurodégénératives. Dans le cadre de la leucémie aiguë myéloïde, des études menées par l'équipe dirigée par Jean-Emmanuel Sarry du Centre de Recherche en Cancérologie de Toulouse, ont montré qu'il est possible de sensibiliser les cellules jusqu'alors résistantes à la chimiothérapie, en ciblant préalablement la fonction mitochondriale. C'est dans ce contexte que s'inscrit le sujet de cette de thèse, portant sur la conception et la réalisation de micro-capteurs électrochimiques dédiées à l'analyse du métabolisme mitochondrial, à l'échelle de la mitochondrie isolée. La fabrication des microsystèmes s'est déroulée dans la salle blanche du Laboratoire d'Analyse et d'Architecture des Systèmes de Toulouse, sous l'encadrement des chercheurs Jérôme Launay et Pierre Temple-Boyer, spécialisés dans la conception de capteurs pour la détection d'espèces en phase liquide. Finalement, un système complet assurant le couplage à la microscopie et à la gestion des fluides a été fabriqué, validé, et breveté. Les résultats obtenus nous permettent d'envisager l'analyse à l'échelle de la mitochondrie unique par une approche parallélisée, ce qui n'a encore jamais été réalisé. / The role of mitochondria have been restricted to oxidative phosphorylation for a long time. Now it is clear that they are also the main sources of reactive oxygen species, implied in oxidative stress and cell-to-cell signaling. Thus, mitochondrial malfunction is potentially the cause of the appearance and the progression of diseases linked to ageing like cancers and neurodegenerative troubles. In the frame of acute myeloid leukemia, studies governed by Jean-Emmanuel Sarry of the Cancer Research Center of Toulouse, showed that it is possible to improve the efficacy of current chemotherapies by targeting mitochondria's function. In this context, the objective of the thesis presented here consist in the design and the manufacturing of electrochemical micro-sensors, dedicated to the analysis of the metabolic activity of isolated mitochondria. The manufacturing occurred in the clean room facilities of the Laboratory for Analysis and Architecture of Systems of Toulouse under the supervision of Jérôme Launay and Pierre Temple-Boyer, researchers specialized in the development of solutions aiming the detection of species diluted in solution. Finally, a complete system ensuring the coupling with microscopy and fluidics have been realized, validated, and patented. The results obtained allow us to consider the analysis at the scale of the single mitochondrion with a parallelized approach, thing that have never been made.

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