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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.
111

Small molecule FGF receptor inhibitors block FGFR-dependent urothelial carcinoma growth in vitro and in vivo

Lamont, F.R., Tomlinson, D.C., Cooper, Patricia A., Shnyder, Steven, Chester, J.D., Knowles, M.A. January 2011 (has links)
No / BACKGROUND: Activating mutations of FGFR3 are frequently identified in superficial urothelial carcinoma (UC) and increased expression of FGFR1 and FGFR3 are common in both superficial and invasive UC. METHODS: The effects of inhibition of receptor activity by three small molecule inhibitors (PD173074, TKI-258 and SU5402) were investigated in a panel of bladder tumour cell lines with known FGFR expression levels and FGFR3 mutation status. RESULTS: All inhibitors prevented activation of FGFR3, and inhibited downstream MAPK pathway signalling. Response was related to FGFR3 and/or FGFR1 expression levels. Cell lines with the highest levels of FGFR expression showed the greatest response and little or no effect was measured in normal human urothelial cells or in UC cell lines with activating RAS gene mutations. In sensitive cell lines, the drugs induced cell cycle arrest and/or apoptosis. IC(50) values for PD173074 and TKI-258 were in the nanomolar concentration range compared with micromolar concentrations for SU5402. PD173074 showed the greatest effects in vitro and in vivo significantly delayed the growth of subcutaneous bladder tumour xenografts. CONCLUSION: These results indicate that inhibition of FGFR1 and wild-type or mutant FGFR3 may represent a useful therapeutic approach in patients with both non-muscle invasive and muscle invasive UC.
112

Diseño y síntesis de una quimioteca de sistemas 5,6-dihidropirido[2,3-d]pirimidin-7(8H)-ona no sustituidos en C4 como inhibidores potenciales de tirosina quinasas

Berzosa Rodríguez, Xavier 18 June 2010 (has links)
Les Tirosina Cinases (TKs) són un grup de Proteïna Cinases claus en la senyalització cel·lular. Aquestes Cinases estan implicades, entre d'altres, en processos de creixement tumoral, fet que fa que la recerca d'inhibidors de TKs sigui una àrea d'investigació molt important en química mèdica.En aquest context es desenvolupa el present treball en el qual es pretenen sintetitzar inhibidors potencials de Tirosina Cinases amb estructura 4-hidrogenpirido[2,3-d]pirimidínica. Molècules amb aquesta estructura han presentat elevada activitat com inhibidors de TKs pel que en primer lloc s'aborda la síntesis de la 6-(2,6-diclorofenil)-2-(4-(2-(dietilamino)etoxi)fenilamino)-8-metil-5,6-dihidropirido[2,3-d]pirimidin-7(8H)-ona. Aquest compost és anàleg a una de les estructures piridopirimidíniques que ha presentat millors resultats d'activitat inhibidora de TKs. D'altra banda, es desenvolupa un nou procediment per a l'obtenció de sistemes 5,6 dihidropirido[2,3-d]pirimidínics 4-hidrogen substituïts basat en una addició de Michael inusual. S'utilitza com metilè actiu el 3,3-dimetoxipropionitril, no utilitzat prèviament en addicions d'aquest tipus. L'esmenta't nitril, per addició sobre un acrilat de metil 2-aril substituït rendeix èsters 4-cianopentanoics o 4-cianopentenoics en funció de la temperatura de reacció. La posterior reacció d'aquests adductes de Michael amb guanidines desemboca en els sistemes 6 aril-5,6 dihidropirido[2,3-d]pirimidínics 4-hidrogen substituïts desitjats. Aprofitant l'experiència obtinguda amb el 3,3-dimetoxipropionitril es desenvolupa un procediment d'obtenció de pentanodioats substituïts per addició de Michael de 3,3 dimetoxipropionat de metil sobre èsters -insaturats. La posterior reacció d'aquests pentanodioats amb guanidina rendeix 3-(2-amino-1,6-dihidro-6-oxo-pirimidin-5-il)propanoats de metil que poden ser considerats com anàlegs de cadena oberta dels sistemes pirido[2,3-d]pirimídinics. / Las Tirosina Quinasas (TKs) son un grupo de Proteína Quinasas claves en la señalización celular. Dichas quinasas están implicadas, entre otros, en procesos de crecimiento tumoral, por lo que la búsqueda de inhibidores de TKs es un área de investigación muy importante en química médica.En este contexto se desarrolla el presente trabajo en el que se pretenden sintetizar inhibidores potenciales de Tirosina Quinasas con estructura 4-hidrógenopirido[2,3-d]pirimidínica. Moléculas con dicha estructura han presentado elevada actividad como inhibidores de TKs por lo que en primer lugar se aborda la síntesis de la 6-(2,6-diclorofenil)-2-(4-(2-(dietilamino)etoxi)fenilamino)-8-metil-5,6-dihidropirido[2,3-d]pirimidin-7(8H)-ona. Dicho compuesto es análogo a una de las estructuras piridopirimidínicas que ha presentado mejores resultados de actividad inhibidora de TKs.Por otro lado se desarrolla un nuevo procedimiento para la obtención de sistemas 5,6 dihidropirido[2,3-d]pirimidínicos 4-hidrógeno sustituidos basado en una adición de Michael inusual. Se utiliza como metileno activo el 3,3-dimetoxipropionitrilo, no usado previamente en adiciones de este tipo. Dicho nitrilo, por adición sobre un acrilato de metilo 2-aril sustituido rinde ésteres 4-cianopentanoicos o 4-cianopentenoicos en función de la temperatura de reacción. La posterior reacción de estos aductos de Michael con guanidinas desemboca en los sistemas 6 aril-5,6 dihidropirido[2,3-d]pirimidínicos 4-hidrógeno sustituidos deseados.Aprovechando la experiencia obtenida con el 3,3-dimetoxipropionitrilo se desarrolla un procedimiento de obtención de pentanodioatos sustituidos por adición de Michael de 3,3 dimetoxipropionato de metilo sobre ésteres -insaturados. La posterior reacción de dichos pentanodioatos con guanidina rinde 3-(2-amino-1,6-dihidro-6-oxo-pirimidin-5-il)propanoatos de metilo que pueden ser considerados como análogos de cadena abierta de los sistemas pirido[2,3-d]pirimidínicos. / Tyrosine Kinases (TKs) are a group of Protein Kinases key in cell signaling. These kinases are involved in tumor growth processes, so the search for TK inhibitors is a very important research area in medicinal chemistry. Present work is developed in this context, so the aim of the work is to synthesize potential inhibitors of TKs with a 4-unsubstituted pyrido[2,3-d]pyrimidinic structure. Molecules with this structure have presented high activity as TKs inhibitors. Therefore the synthesis of 6-(2,6-dichlorophenyl)-2-(4-(2-(diethylamino)ethoxy)phenylamino)-8-methyl-5,6-dihydropyrido[2,3-d] pyrimidin-7(8H)-one is addressed. This is an analogous compound to a one of the most active pyridopyrimidine systems described as TK inhibitors. On the other hand, a new procedure for obtaining 4-unsubstituted 5,6 dihydropyrido[2,3-d]pyrimidinic systems is described. Such process is based on an unusual addition in which 3,3 dimethoxypropanenitrile is used as an active methylene compound. This compound had not previously been used in this kind of additions. The reaction of this nitrile with methyl 2-arylacrylates yields 4-cyanopentanoic esters or 4-cyanopentenoic esters depending on the reaction temperature. The subsequent reaction of these Michael adducts with guanidines leads to desired 4-unsubstituted 6-aryl-5,6-dihydropyrido[2,3-d]pyrimidine systems. Using the experience obtained with 3,3-dimethoxypropionitrile a procedure for obtaining new substituted alkyl pentanedioates by Michael addition of methyl 3,3 dimethoxypropionate on -unsaturated esters has been developed. The subsequent reaction with guanidine yields methyl 3-(2-amino-1,6-dihydro-6-oxo-pyrimidin-5-yl)propanoates that can be considered as open-chain analogues of pyrido[2,3-d]pyrimidines.
113

Hétérocycles dérivés de l'imidazoline et de la pyrimidine : nouvelles voies de synthèses et études structurales

Marsura, Alain 23 March 1984 (has links) (PDF)
La première partie de ce travail est consacrée à l'étude et à l'extension de la réaction de Devasia. Un nombre important de structures d'imidazolinones-5 insaturées-4, non accessibles directement par d'autres voies est ainsi réalisé. Le mécanisme de cette réaction et sa catalyse sont étudiés. Les structures des produits sont confirmées par les méthodes spectrométriques et analytiques habituelles. La stéréochimie des composés est déterminée en particulier par R.M.N.1H et 13C. La réactivité des molécules vis-à-vis de plusieurs réactifs est abordée. Au second chapitre nous décrivons une nouvelle voie d'accès à des delta-2-imidazolines polysubstituées et fonctionnalisées originales. La réaction est appliquée aux composés alpha-bromés alpha, bêta-insaturés possédant une fonction carbonylée ou nitrile. L'étude de cette réaction nous a permis de mettre en évidence un mécanisme particulier présentant des intermédiaires non classiques. La structure tridimensionnelle des molécules est déterminée par R.M.N.1H, 13C, dipolmétrie, CNDO-2 et cristallographie. La troisième et dernière partie traite de l'application de la réaction précédente, étendue au cas des amidines non substituées. Elle constitue dans ce cas une nouvelle voie d'accès aux (3H) pyrimidinones-4-disubstituées-2,6. Les structures moléculaires sont déterminées par les méthodes spectroscopiques et analytiques courantes. La réactivité des molécules est alors étudiée vis-à-vis de plusieurs réactifs. En particulier le réarrangement de type Dimroth concernant les (N-éthoxyméthylène et N-formylidène hydrazino)-4 (3H) pyrimidines est abordé et discuté.
114

Efeito da Topologia Molecular no Empacotamento Cristalino de Pirazolo[1,5-a]pirimidinas / Effect of Molecular Topology in Crystal Packing of Pyrazolo[1,5-a]pyrimidines

Tier, Aniele Zolin 27 February 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study shows the influence of the molecular topology of the crystal of a series of 14 pyrazolo[1,5-a]pyrimidines. The topological data were obtained from X-ray diffraction data and energy stabilization were determined by thermal analysis and chemical computations. Topological analysis carried out was Molecular Coordination Number (NCM) using the Voronoi-Dirichlet polyhedra and Hirshfeld surface. The NCM found for the majority of compounds was 14. Furthermore, it was determined contact area and the solid angle between molecules of the first coordination sphere of the cluster. Several correlations between data were performed, where it is possible highlight the correlation between the area of contact of the cluster molecules and the interaction energy and the solid angle and interaction energy were established. These correlations showed that there is a proportionality between the data, showing that the greater the contact area, the greater the interaction energy for a series of pyrazolo[1,5-a]pyrimidine studied in this thesis. As the contact area, solid angle also presents proportionality with the calculated interaction energy. Among the atom-atom contacts present on the surface of the test compounds was observed that contacts C∙∙∙H and C∙∙∙C are key to stabilize the crystals. This result corroborates the hypothesis that the contact surface between the molecules would be the driving force for the crystalline arrangement. / Este trabalho apresenta o estudo da influência da topologia molecular na organização cristalina de uma série de 14 pirazolo[1,5-a]pirimidinas. Os dados topológicos foram obtidos por difratometria de raios-X e os dados de energia de estabilização foram determinados por análises térmicas e cálculos computacionais. Dentre as análises topológicas realizadas destaca-se a determinação do Número de Coordenação Molecular (NCM) usando o Poliedro de Voronoi-Dirichlet e a Superfície de Hirshfeld. O NMC encontrado para a maioria dos compostos foi de 14. Além disso, foi determinada a área de contato, bem como o ângulo sólido entre as moléculas da primeira esfera de coordenação do cluster. Estabeleceu-se uma serie de correlações entre os dados obtidos, entre elas, destaca-se a correlação entre esta área de contato entre as moléculas do cluster e a energia de interação, bem como a correlação ângulo sólido e energia de interação. Ambas correlações mostraram que há uma proporcionalidade entre os dados, mostrando que quanto maior a área de contato, maior a energia de interação para a série de pirazolo[1,5-a]pirimidinas estudadas nesta dissertação. Assim como a área de contato, o ângulo sólido também apresenta uma proporcionalidade com a energia de interação calculada. Dentre os contatos átomo-átomo presentes na superfície dos compostos em estudo, observou-se que os contatos C∙∙∙H e C∙∙∙C são os principais para a estabilização dos cristais estudados. Este resultado corrobora com a hipótese de que a superfície de contato entre as moléculas seria a força motriz para o arranjo cristalino.
115

Inhibiting KDM6A Demethylase Represses Long Non-Coding RNA Hotairm1 Transcription in MDSC During Sepsis

Bah, Isatou, Youssef, Dima, Yao, Zhi Q., McCall, Charles E., Elgazzar, Mohamed 01 January 2022 (has links)
Myeloid-derived suppressor cells (MDSCs) prolong sepsis by promoting immunosuppression. We reported that sepsis MDSC development requires long non-coding RNA Hotairm1 interactions with S100A9. Using a mouse model that simulates the immunobiology of sepsis, we find that histone demethylase KDM6A promotes Hotairm1 transcription by demethylating transcription repression H3K27me3 histone mark. We show that chemical targeting of KDM6A by GSK-J4 represses Hotairm1 transcription, which coincides with decreases in transcription activation H3K4me3 histone mark and transcription factor PU.1 binding to the Hotairm1 promoter. We further show that immunosuppressive IL-10 cytokine promotes KDM6A binding at the Hotairm1 promoter. IL-10 knockdown repletes H3K27me3 and reduces Hotairm1 transcription. GSK-J4 treatment also relocalizes nuclear S100A9 protein to the cytosol. To support translation to human sepsis, we demonstrate that inhibiting H3K27me3 demethylation by KDM6A ex vivo in MDSCs from patients with protracted sepsis decreases Hotairm1 transcription. These findings suggest that epigenetic targeting of MDSCs in human sepsis might resolve post-sepsis immunosuppression and improve sepsis survival.
116

The microtubule depolymerizing agent CYT997 causes extensive ablation of tumor vasculature in vivo

Burns, C.J., Fantino, E., Powell, A.K., Shnyder, Steven, Cooper, Patricia A., Nelson, S., Christophi, C., Malcontenti-Wilson, C., Dubljevic, V., Harte, M.F., Joffe, M., Phillips, I.D., Segal, D., Wilks, A.F., Smith, G.D. January 2011 (has links)
No / The orally active microtubule-disrupting agent (S)-1-ethyl-3-(2-methoxy-4-(5-methyl-4-((1-(pyridin-3-yl)butyl)amino)pyrimidin-2- yl)phenyl)urea (CYT997), reported previously by us (Bioorg Med Chem Lett 19:4639-4642, 2009; Mol Cancer Ther 8:3036-3045, 2009), is potently cytotoxic to a variety of cancer cell lines in vitro and shows antitumor activity in vivo. In addition to its cytotoxic activity, CYT997 possesses antivascular effects on tumor vasculature. To further characterize the vascular disrupting activity of CYT997 in terms of dose and temporal effects, we studied the activity of the compound on endothelial cells in vitro and on tumor blood flow in vivo by using a variety of techniques. In vitro, CYT997 is shown to potently inhibit the proliferation of vascular endothelial growth factor-stimulated human umbilical vein endothelial cells (IC(50) 3.7 +/- 1.8 nM) and cause significant morphological changes at 100 nM, including membrane blebbing. Using the method of corrosion casting visualized with scanning electron microscopy, a single dose of CYT997 (7.5 mg/kg i.p.) in a metastatic cancer model was shown to cause destruction of tumor microvasculature in metastatic lesions. Furthermore, repeat dosing of CYT997 at 10 mg/kg and above (intraperitoneally, b.i.d.) was shown to effectively inhibit development of liver metastases. The time and dose dependence of the antivascular effects were studied in a DLD-1 colon adenocarcinoma xenograft model using the fluorescent dye Hoechst 33342. CYT997 demonstrated rapid and dose-dependent vascular shutdown, which persists for more than 24 h after a single oral dose. Together, the data demonstrate that CYT997 possesses potent antivascular activity and support continuing development of this promising compound.
117

Resveratrol modulates interleukin-1beta-induced phosphatidylinositol 3-kinase and nuclear factor kappaB signaling pathways in human tenocytes

Busch, F., Mobasheri, A., Shayan, P., Lueders, C., Stahlmann, R., Shakibaei, M. January 2012 (has links)
No / Resveratrol, an activator of histone deacetylase Sirt-1, has been proposed to have beneficial health effects due to its antioxidant and anti-inflammatory properties. However, the mechanisms underlying the anti-inflammatory effects of resveratrol and the intracellular signaling pathways involved are poorly understood. An in vitro model of human tenocytes was used to examine the mechanism of resveratrol action on IL-1beta-mediated inflammatory signaling. Resveratrol suppressed IL-1beta-induced activation of NF-kappaB and PI3K in a dose- and time-dependent manner. Treatment with resveratrol enhanced the production of matrix components collagen types I and III, tenomodulin, and tenogenic transcription factor scleraxis, whereas it inhibited gene products involved in inflammation and apoptosis. IL-1beta-induced NF-kappaB and PI3K activation was inhibited by resveratrol or the inhibitors of PI3K (wortmannin), c-Src (PP1), and Akt (SH-5) through inhibition of IkappaB kinase, IkappaBalpha phosphorylation, and inhibition of nuclear translocation of NF-kappaB, suggesting that PI3K signaling pathway may be one of the signaling pathways inhibited by resveratrol to abrogate NF-kappaB activation. Inhibition of PI3K by wortmannin attenuated IL-1beta-induced Akt and p65 acetylation, suggesting that p65 is a downstream component of PI3K/Akt in these responses. The modulatory effects of resveratrol on IL-1beta-induced activation of NF-kappaB and PI3K were found to be mediated at least in part by the association between Sirt-1 and scleraxis and deacetylation of NF-kappaB and PI3K. Overall, these results demonstrate that activated Sirt-1 plays an essential role in the anti-inflammatory effects of resveratrol and this may be mediated at least in part through inhibition/deacetylation of PI3K and NF-kappaB.
118

Imatinib radiosensitizes bladder cancer by targeting homologous recombination

Qiao, B., Kerr, M., Groselj, B., Teo, M.T., Knowles, M.A., Bristow, R.G., Phillips, Roger M., Kiltie, A.E. January 2013 (has links)
No / Radiotherapy is a major treatment modality used to treat muscle-invasive bladder cancer, with patient outcomes similar to surgery. However, radioresistance is a significant factor in treatment failure. Cell-free extracts of muscle-invasive bladder tumors are defective in nonhomologous end-joining (NHEJ), and this phenotype may be used clinically by combining radiotherapy with a radiosensitizing drug that targets homologous recombination, thereby sparing normal tissues with intact NHEJ. The response of the homologous recombination protein RAD51 to radiation is inhibited by the small-molecule tyrosine kinase inhibitor imatinib. Stable RT112 bladder cancer Ku knockdown (Ku80KD) cells were generated using short hairpin RNA technology to mimic the invasive tumor phenotype and also RAD51 knockdown (RAD51KD) cells to show imatinib's pathway selectivity. Ku80KD, RAD51KD, nonsilencing vector control, and parental RT112 cells were treated with radiation in combination with either imatinib or lapatinib, which inhibits NHEJ and cell survival assessed by clonogenic assay. Drug doses were chosen at approximately IC40 and IC10 (nontoxic) levels. Imatinib radiosensitized Ku80KD cells to a greater extent than RAD51KD or RT112 cells. In contrast, lapatinib radiosensitized RAD51KD and RT112 cells but not Ku80KD cells. Taken together, our findings suggest a new application for imatinib in concurrent use with radiotherapy to treat muscle-invasive bladder cancer. Cancer Res; 73(5); 1611-20. (c)2012 AACR.

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