Les thiénopyrimidinones et les thiénofuranes sont considérés comme des structures prometteuses dans le design de molécules bioactives, notamment des composés anti-angiogéniques. L'angiogenèse pathologique est l'un des évènements majeurs dans le développement tumoral. Une des stratégies thérapeutiques étudiée repose donc sur la conception de petites molécules organiques susceptibles d'inhiber l'activité tyrosine kinase du récepteur VEGFR-2, un des acteurs clé du processus angiogénique. Dans ce contexte, nos travaux ont essentiellement porté sur la synthèse d'une nouvelle série de thiénopyrimidinones et thiénofuranes fonctionnalisés à potentiel inhibiteur du VEGFR-2. Pour chacune des nouvelles structures, nous avons étudié, par 3D-QSAR, l'influence sur le potentiel biologique de différentes modulations structurelles (fonctionnalisations et isomérie du noyau central, et structure d’une chaîne latérale). Puis, plusieurs stratégies de synthèse ont été élaborées et discutées afin de pouvoir préparer les molécules cibles. Pour accéder sélectivement à l'un des isomères du thiénofurane, nous avons mis au point une méthode de synthèse chimiosélective à partir de thiophènes 3-O-alkylés judicieusement fonctionnalisés. Ces composés peuvent ensuite être fonctionnalisés pour accéder aux molécules cibles. Parallèlement, la synthèse des thiéno[2,3-d]pyrimidinones a été abordée selon deux stratégies complémentaires : une voie de synthèse convergente permettant d'articuler autour du noyau central les modulations envisagées pour les cibles en série azotée (hétéroatome de jonction), et une voie de synthèse linéaire plus adéquate à la modulation des cibles en séries oxygénée et soufrée / As bioisosteres of quinazolinones and benzofuranes respectively, thienopyrimidinones and thienofuranes can be envisioned as promising precursors for the design of potential bioactive compounds, especially anti-angiogenic molecules. Tumoral angiogenesis plays an important role in the tumor growth and metastasis of cancer. Therefore, one of the most studied anti-cancer strategies implies the design of small kinase inhibitors, targeting more specifically VEGFR-2 (Vascular Endothelial Growth Factor Receptor 2), which is considered as key component in the angiogenic process. In this context, our work has essentially focused on the synthesis of new series of thienopyrimidinone and thienofuran derivatives with potential inhibitory activity of VEGFR-2. For each of the designed structures, we have first studied, by 3D-QSAR, the influence of various modulations of the heterocyclic core (including substitution and isomery of the core, nature of the extending chain) on the predicted activity. Then, we have elaborated several synthetic pathways allowing access to the targeted compounds. Selective synthesis of a choosen thienofuran isomer has been performed through a chemoselective methodology starting from wisely functionalized 3-O-alkylated thiophenes. These molecules could be then further functionalized to access to final compounds. Simultaneously, synthesis of thieno[2,3-d]pyrimidinone derivatives has been carried out according to two strategies : a convergent pathway allowed a direct introduction of some of the envisioned modulations on the central core in nitrogen series (linking heteroatom), while a linear pathway has ensured the desired modulations on oxygen and sulfur series

Temporal and spatial molecular imaging of disease biomarkers using non-invasive MRI with high resolution is largely limited by lack of MRI contrast agents with high sensitivity, high specificity, optimized biodistribution and pharmacokinetics. In this dissertation, I report my Ph. D. work on the development of protein-based MRI contrast agents (ProCAs) specifically targeting different cancer biomarkers, such as grastrin-releasing peptide receptor (GRPR), prostate specific membrane antigen (PSMA), and vascular endothelial growth factor receptor-2 (VEGFR-2). Similar to non-targeted ProCAs, these biomarker-targeted ProCAs exhibit 5 - 10 times higher r1 and r2 relaxivites than that of clinical MRI contrast agents. In addition, these biomarker-targeted ProCAs have high Gd3+ binding affinities and metal selectivities. The highest binding affinity of the three GRPR-targeted contrast reagents obtained by grafting a GRPR ligand binding moiety into ProCA32 for GRPR is 2.7 x 10-9 M. We further demonstrate that GRPR-targeted ProCAs were able to semi-quantitatively evaluate GRPR expression levels in xenograft mice model by MRI. In addition, we have also created a PSMA-targeted ProCA which has a binding affinity to PSMA biomarker of 5.2 x 10-7 M. Further, we developed VEGFR-targeted contrast agent which is able to image VEGFR2 in mice models using T1-weighted and T2-weighted sequences. Moreover, the relaxivities and coordination water numbers of ProCAs can be tuned by protein design of ProCA4. Since disease biomarkers are expressed in various tumors and diseases, our results may have strong preclinical and clinical implications for the diagnosis and therapeutics of cancer and other type of diseases.

Angiogenesis is the process of new blood vessel growth from preexisting vessels. This process relies on the activity of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) and occurs in both normal and pathological tissues. Angiogenesis is often dysregulated in diseases such as cancer and many efforts have been made to treat such diseases by targeting the VEGFR-2 pathway. VEGFR-2 is activated upon ligand binding and subsequent autophosphorylation of tyrosine residues in the kinase domain, which leads to endothelial cell survival, proliferation, and growth – all of which are required for angiogenesis to occur. It was previously demonstrated that methylation of VEGFR-2 at Lys1041 enhanced its tyrosine autophosphorylation and is required for VEGFR-2 mediated angiogenesis in zebrafish and tumor growth in mouse. However, the Lysine Methyltransferase (KMT) involved in the methylation of VEGFR-2 remains unknown. This study aimed to identify the KMT involved in the methylation of VEGFR-2. We have identified Enhancer of zeste homolog 2 (EZH2) as the KMT likely responsible for catalyzing methylation of K1041 on VEGFR-2. Over-expression of EZH2 was found to increase phosphorylation of Tyr1054, one of the required phosphorylation sites for VEGFR-2 activation, in whole cell lysates and VEGFR-2 purified by immunoprecipitation. The effect of over-expression of EZH2 in the phosphorylation of VEGFR-2 at Tyr1054 was dose-dependent - increasing concentrations of EZH2 resulted in increasing phosphorylation of VEGFR-2 at Tyr1054. Moreover, we determined that EZH2 physically interacts with VEGFR-2 as demonstrated by co-immunoprecipitation in vitro GST-pulldown assays. The C-terminus of EZH2 (amino acids 371-746), physically interacted with VEGFR-2. Taken together, we have identified EZH2 as a candidate KMT involved in the methylation of Lys1041, which increases phosphorylation of VEGFR-2 at Tyr1054. / 2020-07-03T00:00:00Z

Yes / Extracellular-signal-regulated kinase 5 (ERK5) is critical for normal cardiovascular development. Previous studies have defined a canonical pathway for ERK5 activation, showing that ligand stimulation leads to MEK5 activation resulting in dual phosphorylation of ERK5 on Thr218/Tyr220 residues within the activation loop. ERK5 then undergoes a conformational change, facilitating phosphorylation on residues in the C-terminal domain and translocation to the nucleus where it regulates MEF2 transcriptional activity. Our previous research into the importance of ERK5 in endothelial cells highlighted its role in VEGF-mediated tubular morphogenesis and cell survival, suggesting that ERK5 played a unique role in endothelial cells. Our current data show that in contrast to EGF-stimulated HeLa cells, VEGF-mediated ERK5 activation in human dermal microvascular endothelial cells (HDMECs) does not result in C-terminal phosphorylation of ERK5 and translocation to the nucleus, but instead to a more plasma membrane/cytoplasmic localisation. Furthermore, the use of small-molecule inhibitors to MEK5 and ERK5 shows that instead of regulating MEF2 activity, VEGF-mediated ERK5 is important for regulating AKT activity. Our data define a novel pathway for ERK5 activation in endothelial cells leading to cell survival. / This research was funded by grants from: North West Cancer Research (NWCR): M.J.C. and A.K.M.; Medical Research Council (MRC DiMeN PhD): M.J.C. and K.A.; Biotechnology and Biological Sciences Research Council (BBSRC DTG Studentship): M.J.C., C.E.P.G., B.W. and G.N.N.; and Wellcome Trust Institutional Strategic Fund: M.J.C. and A.K.M.

Em roedores, o aumento da permeabilidade vascular, a transformação decidual, e angiogênese são eventos cruciais para o sucesso da gestação. O fator endotelial vascular (VEGF) é um mitogênico para células endoteliais e um indutor de angiogênese. O VEGF age via dois receptores da família das tirosina quinases: VEGFR1 e VEGFR2. O objetivo deste estudo foi investigar usando o método imunohistoquímico, a expressão espacial e temporal do VEGF e os receptores VEGFR1 e VEGFR2 em células endometriais de camundongo entre o 4º e 8º dias de gestação. No 4º dia de gestação, VEGF, VEGFR1 e VEGFR2 foram expressos pelo epitélio luminal e glandular e fracamente pelo estroma endometrial. Do 5º ao 8º dias de gestação, o VEGF foi expresso nas células deciduais mesometriais. VEGFR1 e VEGFR2 foram expresso pelas células do epitélio luminal e glandular e mostraram uma marcação diferencial na decídua mesometrial e antimesometrial. Os receptores VEGFR1 e VEGFR2 foram intensamente expressos pelas células endoteliais dos capilares sinusóides mesometriais e pelas células Nk uterinas. / In rodents, increase of vascular permeability, decidual cell transformation, and uterine angiogenesis are crucial events for the success of pregnancy. Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells and an inducer of angiogenesis. VEGF acts via two tyrosine kinase family receptors: VEGFR1 and VEGFR2. The aim of this study was to investigate using the immunohistochemical method, the spatiotemporal expression of VEGF and its receptors VEGFR1 e VEGFR2 by mouse endometrial cells on days 4 to 8 of pregnancy. On day 4, VEGF, VEGFR1 and VEGFR2 were expressed mostly by the luminal and glandular epithelium. Stromal cells showed a very weak labeling. On days 5-8, VEGF and its receptors showed an increased labeling throughout the mesometrial decidua. The expression of VEGF, VEGFR1, and VEGFR2 were differentially expressed in the mesometrial cells and in the predecidual cells of the antimesometrial decidua. VEGFR1 and VEGF R2 were highly expressed by endothelial cells of the mesometrial sinusoids, and Nk uterine cells.

Em roedores, o aumento da permeabilidade vascular, a transformação decidual, e angiogênese são eventos cruciais para o sucesso da gestação. O fator endotelial vascular (VEGF) é um mitogênico para células endoteliais e um indutor de angiogênese. O VEGF age via dois receptores da família das tirosina quinases: VEGFR1 e VEGFR2. O objetivo deste estudo foi investigar usando o método imunohistoquímico, a expressão espacial e temporal do VEGF e os receptores VEGFR1 e VEGFR2 em células endometriais de camundongo entre o 4º e 8º dias de gestação. No 4º dia de gestação, VEGF, VEGFR1 e VEGFR2 foram expressos pelo epitélio luminal e glandular e fracamente pelo estroma endometrial. Do 5º ao 8º dias de gestação, o VEGF foi expresso nas células deciduais mesometriais. VEGFR1 e VEGFR2 foram expresso pelas células do epitélio luminal e glandular e mostraram uma marcação diferencial na decídua mesometrial e antimesometrial. Os receptores VEGFR1 e VEGFR2 foram intensamente expressos pelas células endoteliais dos capilares sinusóides mesometriais e pelas células Nk uterinas. / In rodents, increase of vascular permeability, decidual cell transformation, and uterine angiogenesis are crucial events for the success of pregnancy. Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells and an inducer of angiogenesis. VEGF acts via two tyrosine kinase family receptors: VEGFR1 and VEGFR2. The aim of this study was to investigate using the immunohistochemical method, the spatiotemporal expression of VEGF and its receptors VEGFR1 e VEGFR2 by mouse endometrial cells on days 4 to 8 of pregnancy. On day 4, VEGF, VEGFR1 and VEGFR2 were expressed mostly by the luminal and glandular epithelium. Stromal cells showed a very weak labeling. On days 5-8, VEGF and its receptors showed an increased labeling throughout the mesometrial decidua. The expression of VEGF, VEGFR1, and VEGFR2 were differentially expressed in the mesometrial cells and in the predecidual cells of the antimesometrial decidua. VEGFR1 and VEGF R2 were highly expressed by endothelial cells of the mesometrial sinusoids, and Nk uterine cells.

O fator de crescimento vascular endotelial (VEGF) desempenha um papel importante na angiogênese, induzindo a proliferação da célula endotelial, migração e sobrevivência. Com o intuito de promover a formação de novos vasos, e obter uma melhora na circulação colateral, VEGF tem sido utilizado para o tratamento de áreas de isquemia cardíaca, na doença cardiovascular. A manutenção da vitalidade pulpar com VEGF pode melhorar o prognóstico dos dentes que sofreram avulsão, prevenindo a perda precoce do dente. O propósito deste estudo foi desenvolver um modelo para se estudar o processo de revascularização da polpa dentária e avaliar o efeito do VEGF- 165 na angiogênese da polpa humana e na apoptose. Fatias de dente humano foram mantidas in vitro (cultura) com e sem VEGF (50ng/ml) durante 7 dias. Coloração de imuno-histoquímica para o Fator de Von Willebrand (Fator VIII) foi utilizada para quantificar o número de vasos sangüíneos no tecido pulpar. O número de vasos sangüíneos foi significantemente mais alto no grupo do VEGF (média -67.87) comparado ao grupo controle (média- 46.25, p< .05). O teste do Tunel foi usado para determinar o número de células apoptóticas nos grupos com e sem VEGF. Análises da expressão de VEGFR-2 por RT-PCR foram realizadas nas células endoteliais da microvasculatura da derme humana (HDMECs), células pulpares indiferenciadas (OD-21), células tipo odontoblasto de camundongo (MDPC-23) e macrófagos. A expressão de VEGFR-2 foi detectada nas HDMECs, mas não nas outras 3 linhas celulares. Quatro fatias de dente humano por camundongo imunodeprimido foram implantadas na região dorsal, subcutaneamente, pelo período de 7 dias. A vitalidade pulpar foi determinada pelas análises microscópica e imuno-histoquímica. O teste do Tunel foi usado para determinar o número de células apoptóticas. O modelo de angiogênese pulpar utilizando camundongos imunodeprimidos (SCID mouse model of pulp angiogenese) demonstrou ser um modelo viável para se estudar o processo de revascularização da polpa dentária humana. Levando-se em consideração os resultados obtidos neste estudo, sugere-se que o VEGF possa ter um efeito positivo na revascularização de dentes avulsionados. E que o modelo de angiogênese pulpar desenvolvido nesta pesquisa possa ser útil para responder a inúmeras novas questões experimentais na área de Endodontia. / The Vascular endothelial growth factor (VEGF) plays na important role in angiogenesis by inducing endothelial cell proliferation, migration, and survival. To promote new vessel formation and improve collateral circulation, VEGF has been used to treat ischemic heart areas in cardiovascular disease. Maintenance of pulp vitality with VEGF may improve the outcomes of avulsed teeth, preventing premature tooth loss. The purpose of this study was to develop a model system to study the process of dental pulp revascularization, and assess the effect of VEGF-165 in the human pulp angiogenesis and apoptosis. Human tooth slices were maintained in vitro for 7 days +/- VEGF (50ng/mL). Immunohistochemistry staining for Von Willebrand?s factor (Factor VIII) was used to quantify the number of vessels in pulp tissues. There was a significantly higher number of blood vessels in the VEGF group (67.8 Mean) compared to the control group (46.2 Mean, p<0.05). Tunel Assay was used to determine the number of apoptotic cells in +/- VEGF groups. RTPCR analyses of VEGFR-2 transcripts were used on human dermal microvascular endothelial cells (HDMECs), undifferentiated pulp cells (OD-21), mouse odontoblast-like cells (MDPC-23), and macrophages. VEGFR-2 expression was detected in HDMECs but not in the other 3 cell lines. Four tooth slices per mouse were subcutaneously implanted in the dorsal region for 7 days. Pulp vitality was determined by histological and immunohistochemical analysis. Also, Tunel Assay was used to determine the number of apoptotic cells. SCID mouse model of pulp angiogenesis demonstrated to be a good model system to study revascularization of human dental pulps. Taking into account the findings of this study, it is suggested that VEGF could have a positive effect in the revascularization of avulsed teeth. It is hoped that this pulp angiogenesis model be useful to answer a number of new experimental questions in the area of Endodontics.

O fator de crescimento vascular endotelial (VEGF) desempenha um papel importante na angiogênese, induzindo a proliferação da célula endotelial, migração e sobrevivência. Com o intuito de promover a formação de novos vasos, e obter uma melhora na circulação colateral, VEGF tem sido utilizado para o tratamento de áreas de isquemia cardíaca, na doença cardiovascular. A manutenção da vitalidade pulpar com VEGF pode melhorar o prognóstico dos dentes que sofreram avulsão, prevenindo a perda precoce do dente. O propósito deste estudo foi desenvolver um modelo para se estudar o processo de revascularização da polpa dentária e avaliar o efeito do VEGF- 165 na angiogênese da polpa humana e na apoptose. Fatias de dente humano foram mantidas in vitro (cultura) com e sem VEGF (50ng/ml) durante 7 dias. Coloração de imuno-histoquímica para o Fator de Von Willebrand (Fator VIII) foi utilizada para quantificar o número de vasos sangüíneos no tecido pulpar. O número de vasos sangüíneos foi significantemente mais alto no grupo do VEGF (média -67.87) comparado ao grupo controle (média- 46.25, p< .05). O teste do Tunel foi usado para determinar o número de células apoptóticas nos grupos com e sem VEGF. Análises da expressão de VEGFR-2 por RT-PCR foram realizadas nas células endoteliais da microvasculatura da derme humana (HDMECs), células pulpares indiferenciadas (OD-21), células tipo odontoblasto de camundongo (MDPC-23) e macrófagos. A expressão de VEGFR-2 foi detectada nas HDMECs, mas não nas outras 3 linhas celulares. Quatro fatias de dente humano por camundongo imunodeprimido foram implantadas na região dorsal, subcutaneamente, pelo período de 7 dias. A vitalidade pulpar foi determinada pelas análises microscópica e imuno-histoquímica. O teste do Tunel foi usado para determinar o número de células apoptóticas. O modelo de angiogênese pulpar utilizando camundongos imunodeprimidos (SCID mouse model of pulp angiogenese) demonstrou ser um modelo viável para se estudar o processo de revascularização da polpa dentária humana. Levando-se em consideração os resultados obtidos neste estudo, sugere-se que o VEGF possa ter um efeito positivo na revascularização de dentes avulsionados. E que o modelo de angiogênese pulpar desenvolvido nesta pesquisa possa ser útil para responder a inúmeras novas questões experimentais na área de Endodontia. / The Vascular endothelial growth factor (VEGF) plays na important role in angiogenesis by inducing endothelial cell proliferation, migration, and survival. To promote new vessel formation and improve collateral circulation, VEGF has been used to treat ischemic heart areas in cardiovascular disease. Maintenance of pulp vitality with VEGF may improve the outcomes of avulsed teeth, preventing premature tooth loss. The purpose of this study was to develop a model system to study the process of dental pulp revascularization, and assess the effect of VEGF-165 in the human pulp angiogenesis and apoptosis. Human tooth slices were maintained in vitro for 7 days +/- VEGF (50ng/mL). Immunohistochemistry staining for Von Willebrand?s factor (Factor VIII) was used to quantify the number of vessels in pulp tissues. There was a significantly higher number of blood vessels in the VEGF group (67.8 Mean) compared to the control group (46.2 Mean, p<0.05). Tunel Assay was used to determine the number of apoptotic cells in +/- VEGF groups. RTPCR analyses of VEGFR-2 transcripts were used on human dermal microvascular endothelial cells (HDMECs), undifferentiated pulp cells (OD-21), mouse odontoblast-like cells (MDPC-23), and macrophages. VEGFR-2 expression was detected in HDMECs but not in the other 3 cell lines. Four tooth slices per mouse were subcutaneously implanted in the dorsal region for 7 days. Pulp vitality was determined by histological and immunohistochemical analysis. Also, Tunel Assay was used to determine the number of apoptotic cells. SCID mouse model of pulp angiogenesis demonstrated to be a good model system to study revascularization of human dental pulps. Taking into account the findings of this study, it is suggested that VEGF could have a positive effect in the revascularization of avulsed teeth. It is hoped that this pulp angiogenesis model be useful to answer a number of new experimental questions in the area of Endodontics.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This work deals with radiochemistry and new approaches to develop novel PET tracers labelled with the radionuclide 11C. Two methods for the synthesis of 11C-labelled acrylamides have been explored. First, [1-11C]-acrylic acid was obtained from a palladium(0)-mediated 11C-carboxylation of acetylene with [11C]carbon monoxide; this could be converted to the corresponding acyl chloride and then combined with benzylamine to form N-benzyl[carbonyl-11C]acrylamide. In the second method, the palladium(0)-mediated carbonylation of vinyl halides with [11C]carbon monoxide was explored. This latter method, yielded labelled acrylamides in a single step with retention of configuration at the C=C double bond, and required less amine compared to the acetylene method. The vinyl halide method was used to synthesize a library of 11C-labelled EGFr-inhibitors in 7-61% decay corrected radiochemical yield via a combinatorial approach. The compounds were designed to target either the active or the inactive form of EGFr, following computational docking studies. The rhodium(I)-mediated carbonylative cross-coupling of an azide and an amine was shown to be a very general reaction and was used to synthesize a library of dual VEGFr-2/PDGFrβ inhibitors that were 11C-labelled at the urea position in 38-78% dc rcy. The angiotensin II AT1 receptor antagonist eprosartan was 11C-labelled at one of the carboxyl groups in one step using a palladium(0)-mediated carboxylation. Autoradiography shows specific binding in rat kidney, lung and adrenal cortex, and organ distribution shows a high accumulation in the intestines, kidneys and liver. Specific binding in frozen sections of human adrenal incidentalomas warrants further investigations of this tracer. Three angiotensin II AT2 ligands were 11C-labelled at the amide group in a palladium(0)-mediated aminocarbonylation in 16-36% dc rcy. One of the compounds was evaluated using in vitro using autoradiography, and in vivo using organ distribution and animal PET. The compound was metabolized fast and excreted via urine. High radioactivity was also found in the liver, meaning that more metabolically stable compounds are desirable for future development.