Percorrer por autor "Costa, Raquel"
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- 1-Aryl-3-[ 4-( thieno[3,2-d]pyrimidin-4-yloxy )phenyl]ureas as VEG FR2 inhibitors: synthesis, docking enzymatic and cellular assaysPublication . Peixoto, Daniela; Calhelha, Ricardo C.; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, Raquel; Queiroz, Maria João R.P.A number of thienopyrimidines derivatives have shown potent VEGFR2 (Vascular Endothelium Growth Factor Receptor2) tyrosine kinase inhibition activity.[ll VEGF is a sun·ogate marker of angiogenesis that activates VEGFR2 in endothelial cells. Here we present the synthesis of new 1-aryl-3-[ 4-(thieno[3,2-d]pyrimidin-4- yloxy)phenyl]ureas from the aminodi(hetero)arylether 1, also prepared by us, which was reacted with arylisocyanates to give the corresponding 1,3-diarylureas 2a-c.
- 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 tyrosine kinase inhibitors: Synthesis, biological evaluation, and molecular modelling studiesPublication . Soares, Pedro; Costa, Raquel; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Peixoto, Daniela; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.The Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that is implicated in tumor-associated angiogenesis. In this study novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150-199 nM) in enzymatic assays. The latter promoted also significant inhibition of cell proliferation at low concentrations (0.5-1 µM), not affecting cell viability, of VEGF-stimulated Human Umbilical Vein Endothelial Cells (HUVECs) using the BrdU assay. The determination of the total and phosphorylated (active) VEGFR-2 was performed by western-blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also done and discussed using molecular docking studies.
- 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR2 tyrosine kinase inhibitors: synthesis, docking studies, enzymatic and cellular assaysPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, RaquelA number of thienopyrimidines derivatives have shown potent vascular endothelial growth factor receptor 2 (VEGFR2) inhibition activity. Here, we present the synthesis of new 1-aryl-3-[4-(thieno[3,2-d) pyrimidin-4-yloxy)phenyl]ureas by promoting t he regioselective attack of the hydroxy group of the 4-aminophenol in the chlorine nucleophilic displacement on two 4-chlorinated thieno[3,2-d]pyrimidines, obtaining compounds la and 1b which were reacted with arylisocyanates to give t he corresponding 1,3-diarylureas 2a-f (see scheme). These compounds were evaluated for inhibition of VEGFR2 tyrosine kinase activity using enzymatic assays, and 2a- c showed good inhibition ability with IC50 values in the range of hundreds of nanomolar. The rationale for the inhibition activity is also discussed using docking. To examine the activity of 2a- c in endothelial cells, human umbilical vein endothelial cells (HUVECs) were cultured in the presence or absence of each compound in different concentrations. A decrease in the proliferation of HUVECs was observed by the incorporation of BrdU quantified by ELISA assay. Given the established role of VEGFR2 in proliferation and migration of endothelial cells, these molecules are promising antiangiogenic agents that can be used for therapeutic purposes in pathological conditions where angiogenesis is exacerbated, such as cancer.
- Estudo preliminar de alterações anátomo-histológicas em caprinos intersexuais sem cornos da raça SerranaPublication . Correia, Teresa Montenegro; Valentim, Ramiro; Mendonça, Álvaro; Costa, RaquelEste estudo teve como principal objectivo identificar possíveis alterações anátomo-histológicas em caprinos Serranos, sem cornos e intersexuais, relativamente a caprinos da mesma raça, com cornos e sexualmente normais. Neste sentido, quatro caprinos da raça portuguesa Serrana, ecótipo transmontano, com aproximadamente um ano de idade, foram utilizados na realização deste ensaio. Dois deles tinham cornos e eram sexualmente normais (testemunhas), enquanto os outros dois eram sem cornos e apresentavam fenómenos de intersexualidade. Os dois caprinos intersexuais estudados apresentavam diferentes graus de masculinização do seu tracto genital e eram estéreis. Um deles revelou-se pseudomacho e o outro hermafrodita bilateral.
- Heteroarylether 1,3-diarylureas in the thieno[3,2-d]pyrimidine series as VEGFR2 tyrosine Kinase inhibitors: synthesis, docking studies, enzymatic and cellular assaysPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, RaquelA number of thienopyrimidines derivatives have shown potent YEGFR2 (Vascular Endothelium Growth Factor Receptor2) inhibition activity [ 1]. YEGF is a surrogate marker of angiogenesis that activates VEGFR2 in endothelial cells. VEGF induces proliferation, migration and anastomosis of these cells. Here we present the synthesis of new l-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas, by reaction of 4-aminophenol with 4-chlorothieno[3,2-d]pyrimidine giving compound 1, which was reacted with arylisocyanates to give the corresponding I ,3-diarylureas 2a-c (Scheme).
- New di(heteroaryl)thioethers 1,3-diarylureas in the thieno[3,2-b]pyridine series as VEGFR2 tyrosine kinase inhibitors: docking, synthesis, enzymatic and cellular assaysPublication . Machado, Vera A.; Costa, Raquel; Peixoto, Daniela; Abreu, Rui M.V.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) is a tyrosine kinase receptor, expressed primarily in endothelial cells, and is activated by the specific binding of VEGF, produced and released by the tumor, to the VEGFR2 extracellular regulatory domain, undergoing autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation towards the tumor [!].Small molecules may act as inhibitors by competing for the ATP-binding site of the VEGFR2 intracellular tyrosine kinase domain, thereby preventing the intracellular signaling that leads to angiogenesis [2]. Herein, we report the synthesis using rational design of new 1-aryl-3-[3-thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas (la-c) as VEGFR2 tyrosine kinase inhibitors. The compounds presented, with the arylurea in the meta position to the thioether and with F or a Me group, showed very low !Cso values (11-28 nM) in enzymatic assays as predicted by molecular docking. To examine the activity of compounds 1 in endothelial cells, VEGF-stimulated (60 ng/mL) Human Umbilical Vein Endothelial Cells (HUVECs) were cultured in M199 medium in the absence (C) or presence of each compound at different concentrations. A remarkable reduction in the proliferation of HUVECs using the BrdU incorporation assay was observed for all compounds at I !JM, for compound la being observed a higher antiproliferative effect. Further studies are ongoing to examine whether these molecules affect the expression and activity of VEGFR2 and the signaling pathways, using western blotting assays. Given the established role of VEGFR2 in proliferation and migration of endothelial cells, these molecules are promising anti-angiogenic agents that can be used for therapeutic purposes in pathological conditions where angiogenesis is exacerbated, such as cancer.
- Synthesis, antiangiogenesis evaluation and molecular docking studies of 1-aryl-3-[(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas: Discovery of a new substitution pattern for type II VEGFR-2 Tyr kinase inhibitorsPublication . Machado, Vera A.; Peixoto, Daniela; Costa, Raquel; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.The synthesis and biological evaluation of novel 1-aryl-3-[2-, 3- or 4-(thieno[3,2-b]pyridin-7-ylthio)phenyl] ureas 3, 4 and 5 as VEGFR-2 tyrosine kinase inhibitors, are reported. The 1-aryl-3-[3-(thieno[3,2-b]- pyridin-7-ylthio)phenyl]ureas 4a–4h, with the arylurea in the meta position to the thioether, showed the lowest IC50 values in enzymatic assays (10–206 nM), the most potent compounds 4d–4h (IC50 10– 28 nM) bearing hydrophobic groups (Me, F, CF3 and Cl) in the terminal phenyl ring. A convincing rationalization was achieved for the highest potent compounds 4 as type II VEGFR-2 inhibitors, based on the simultaneous presence of: (1) the thioether linker and (2) the arylurea moiety in the meta position. For compounds 4, significant inhibition of Human Umbilical Vein Endothelial Cells (HUVECs) proliferation (BrdU assay), migration (wound-healing assay) and tube formation were observed at low concentrations. These compounds have also shown to increase apoptosis using the TUNEL assay. Immunostaining for total and phosphorylated (active) VEGFR-2 was performed by Western blotting. The phosphorylation of the receptor was significantly inhibited at 1.0 and 2.5 lM for the most promising compounds. Altogether, these findings point to an antiangiogenic effect in HUVECs.
- Synthesis, docking, enzymatic and cellular assays of thieno[3,2-b]pyridine-thioether-1,3-diarylureas as VEGFR2 inhibitorsPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Calhelha, Ricardo C.; Abreu, Rui M.V.; Froufe, Hugo J.C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, RaquelVascular endothelial growth factor receptor 2 (VEGFR2) is a class of tyrosine kinase receptors, expressed primarily in endothelial cells , and is activated by the specific binding of VEGF to the VEGFR2 extracellular regulatory domain, undergoing autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation and subsequent angiogenesis.111 Small molecules may actas inhibitors by competing for the ATP-binding si te of the VEGFR2 intracellular tyrosine kinase domain, thereby preventing the intracellular signaling that leads to angiogenesisYl Herein, we report the synthesis of nove! nine 1-aryl-3-[2-, 3- or 4-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas as VEGFR2 inhibitors. The compounds presented below, with the arylurea in the meta position to the thioether, showed the lowest IC50 values (0.4-0.9 ]lM) in enzymatic assays. Using molecular docking (A) and molecular dynamics simulations, a convincing rationalization was achieved to explain the highest potency of these compounds.
- Synthesis, molecular Docking and biological evaluation of new 1-Aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenylureas as Potent Type II VEGFR-2 Tyrosine Kinase inhibitorsPublication . Machado, Vera A.; Peixoto, Daniela; Costa, Raquel; Calhelha, Ricardo C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.The vascular endothelial growth factor receptor 2 (VEGFR-2) is a tyrosine kinase receptor, expressed primarily in endothelial cells, and is activated by the specific binding of VEGF to the VEGFR-2 extracellular regulatory domain. Once activated, VEGFR-2 undergoes autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation and subsequent angiogenesisY1 Small molecules may act as inhibitors by competing for the ATP-binding s'1te of the VEGFR-2 intracellular tyrosine kinase domain, thereby preventing the intracellular signa ling that leads to angiogenesis. [ZJ Here, we present the synthesis of new 1-aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas la-c, as potent type 11 VEGFR-2 inhibitors based on molecular docking (Figure A) and biological evaluation including enzymatic assays using the VEGFR-2 tyrosine kinase domain (ICso=l0-28 nM) and studies in human umbilical vein endothelial cells (HUVECs). The latter included cell viability (MTS), proliferation (BrdU) and Western blot for total and phosphorylated VEGFR-2 (Figure B). The predicted docked poses were analyzed in detail and a plausible explanation for compounds 1 potency was obtained base9 on the simultaneous presence of a S-linker and the arylurea moiety in the meta position as a new substitution pattern for the type 11 VEGFR-2 inhibitors. These chemical features place the thieno[3,2-b]pyridine and the terminal aryl ring in close superimposition to a pyrrolo[3,2-d]pyrimidine derivative. The presence of hydrofobic substituents (F and Me) in the terminal aryl ring is also important. For these compounds a significant inhibition in HUVECs proliferation upon VEGF stimulation was observed at low concentrations (0.5-1.0 IJ.M) without affecting cell viability. Westernblot analysis demonstrated that compounds 1 significantly the inhibited VEGFR-2 phosphorylation at 1.0 jlM, thus confirming their anti-angiogenic potential.