11 resultados para nuclear translocation
Resumo:
While TRAIL is a promising anticancer agent due to its ability to selectively induce apoptosis in neoplastic cells, many tumors, including pancreatic ductal adenocarcinoma (PDA), display intrinsic resistance, highlighting the need for TRAIL-sensitizing agents. Here we report that TRAIL-induced apoptosis in PDA cell lines is enhanced by pharmacological inhibition of glycogen synthase kinase-3 (GSK-3) or by shRNA-mediated depletion of either GSK-3 alpha or GSK-3 beta. In contrast, depletion of GSK-3 beta, but not GSK-3 alpha, sensitized PDA cell lines to TNF alpha-induced cell death. Further experiments demonstrated that TNF alpha-stimulated I kappa B alpha phosphorylation and degradation as well as p65 nuclear translocation were normal in GSK-3 beta-deficient MEFs. Nonetheless, inhibition of GSK-3 beta function in MEFs or PDA cell lines impaired the expression of the NF-kappa B target genes Bcl-xL and cIAP2, but not I kappa B alpha. Significantly, the expression of Bcl-xL and cIAP2 could be reestablished by expression of GSK-3 beta targeted to the nucleus but not GSK-3 beta targeted to the cytoplasm, suggesting that GSK-3 beta regulates NF-kappa B function within the nucleus. Consistent with this notion, chromatin immunoprecipitation demonstrated that GSK-3 inhibition resulted in either decreased p65 binding to the promoter of BIR3, which encodes cIAP2, or increased p50 binding as well as recruitment of SIRT1 and HDAC3 to the promoter of BCL2L1, which encodes Bcl-xL. Importantly, depletion of Bcl-xL but not cIAP2, mimicked the sensitizing effect of GSK-3 inhibition on TRAIL-induced apoptosis, whereas Bcl-xL overexpression ameliorated the sensitization by GSK-3 inhibition. These results not only suggest that GSK-3 beta overexpression and nuclear localization contribute to TNF alpha and TRAIL resistance via anti-apoptotic NF-kappa B genes such as Bcl-xL, but also provide a rationale for further exploration of GSK-3 inhibitors combined with TRAIL for the treatment of PDA.
Resumo:
9 p. : il.
Resumo:
156 p. : graf.
Resumo:
Background: Implantation and growth of metastatic cancer cells at distant organs is promoted by inflammation-dependent mechanisms. A hepatic melanoma metastasis model where a majority of metastases are generated via interleukin-18-dependent mechanisms was used to test whether anti-inflammatory properties of resveratrol can interfere with mechanisms of metastasis. Methods: Two experimental treatment schedules were used: 1) Mice received one daily oral dose of 1 mg/kg resveratrol after cancer cell injection and the metastasis number and volume were determined on day 12. 2) Mice received one daily oral dose of 1 mg/kg resveratrol along the 5 days prior to the injection of cancer cells and both interleukin-18 (IL-18) concentration in the hepatic blood and microvascular retention of luciferase-transfected B16M cells were determined on the 18(th) hour. In vitro, primary cultured hepatic sinusoidal endothelial cells were treated with B16M-conditioned medium to mimic their in vivo activation by tumor-derived factors and the effect of resveratrol on IL-18 secretion, on vascular cell adhesion molecule-1 (VCAM-1) expression and on tumor cell adhesion were studied. The effect of resveratrol on melanoma cell activation by IL-18 was also studied. Results: Resveratrol remarkably inhibited hepatic retention and metastatic growth of melanoma cells by 50% and 75%, respectively. The mechanism involved IL-18 blockade at three levels: First, resveratrol prevented IL-18 augmentation in the blood of melanoma cell-infiltrated livers. Second, resveratrol inhibited IL-18-dependent expression of VCAM-1 by tumor-activated hepatic sinusoidal endothelium, preventing melanoma cell adhesion to the microvasculature. Third, resveratrol inhibited adhesion-and proliferation-stimulating effects of IL-18 on metastatic melanoma cells through hydrogen peroxide-dependent nuclear factor-kappaB translocation blockade on these cells. Conclusions: These results demonstrate multiple sites for therapeutic intervention using resveratrol within the prometastatic microenvironment generated by tumor-induced hepatic IL-18, and suggest a remarkable effect of resveratrol in the prevention of inflammation-dependent melanoma metastasis in the liver.
Resumo:
Introducción: La medición de la concentración de hierro hepática (CHH) por RM es una técnica no invasiva de gran utilidad en el diagnóstico de los pacientes con sospecha de sobrecarga férrica en hígado. Objetivo:Validar la eficacia de la RM 1 Tesla en la determinación de la (CHH) en pacientes con sospecha de sobrecarga férrica. Validar su capacidad para diagnosticar o descartar la presencia de una CHH sugestiva de hemocromatosis. Pacientes y métodos:Estudio observacional, transversal, con inclusión prospectiva de pacientes consecutivos. De 2002 a 2010 hemos obtenido la CHH estimada mediante RM 1 Tesla (método Gandon) y de RM 1,5 Tesla (método Alústiza), y mediante BH, en 56 pacientes consecutivos (58RM:35/23). Resultados:Grupo RM 1 Tesla: de acuerdo con CHH en BH, 15 pacientes clasificados como normales (<36µmol/g)-la RM valoró correctamente 7; sobreestimó 8-; 15 grupo hemosiderosis (36-80 µmol/g)-RM valoró correctamente 5, sobreestimó 10-; 5 grupo hemocromatosis (>80 µmol/g)-valoró correctamente las 5-. Existió una correlación entre la determinación de la CHH por BH y RM 1 Tesla con r=0.619. Existieron diferencias estadísticamente significativas (p<0.05) entre CHH media por biopsia (53.43/DE45.67/IC95%37.74 a 69.12) y por RM 1 Tesla (76.14/DE47.31/IC95% 60.46 a 92.97), con sobrevaloración por parte de la RM. Grupo RM 1,5 Tesla: de acuerdo con CHH en BH, normal en 14, hemosiderosis en 6 y hemocromatosis en 3. La RM valoró correctamente 6 y sobreestimó 8 en grupo normal; grupo hemosiderosis, 3 correctamente, 3 sobrevalorados; grupo hemocromatosis, valoró correctamente los 3. La correlación entre CHH por BH y RM 1,5 Tesla fue de r=0.815. La CHH media obtenida por BH (69,34/DE152.1/IC95% 3.57 a 135.1 ) y RM 1,5 Tesla (70.43/DE 57.63/IC95% 45.51 a 95.36) no demostraron diferencias significativas (p>0.05). Conclusiones: La determinación de CHH por RM 1 Tesla (método Gandon) es útil para diagnosticar o descartar hemocromatosis y para diagnosticar CHH normal. Existe una importante tendencia a la sobreestimación en pacientes sin y con sobrecarga férrica en la CHH obtenida por RM 1 Tesla. La determinación de CHH por RM 1,5 Tesla (método Alústiza) es superior a la de RM 1 Tesla, aunque también existe una tendencia a sobreestimar. La CHH media obtenida por BH o RM 1,5 Tesla no tuvieron diferencias significativas. En cambio si existieron entre BH y RM 1 Tesla.
Resumo:
4 p.
Resumo:
[ES]Este trabajo surge de la inquietud del alumno sobre la energía nuclear y mas concretamente sobre la energía de fusión. Esta inquietud se plasma en una recopilación de información sobre los combustibles necesarios , su abundancia y su forma de obtención actual. Analizaremos la posibilidad de implantar alguna de estas plantas de combustible en el País Vasco, junto con un estudio de una posible central nuclear de fusión con la suma de la potencia de cada uno de los reactores de fisión que se encuentran actualmente en funcionamiento en el estado Español. Compararemos las cantidades de combustible necesarias en un año de uranio y el combustible de fusión, así como el coste de construcción de cada una.
Resumo:
EN]This is a document done to try to see the effect of a nuclear power plant accident. In particular, it studies what would be the radiation doses delivered to the people in the close areas around the power plant of Garoña, if it had suffered from a loss of coolant accident during its normal functioning.
Resumo:
In the present study we have investigated the population genetic structure of albacore (Thunnus alalunga, Bonnaterre 1788) and assessed the loss of genetic diversity, likely due to overfishing, of albacore population in the North Atlantic Ocean. For this purpose, 1,331 individuals from 26 worldwide locations were analyzed by genotyping 75 novel nuclear SNPs. Our results indicated the existence of four genetically homogeneous populations delimited within the Mediterranean Sea, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean. Current definition of stocks allows the sustainable management of albacore since no stock includes more than one genetic entity. In addition, short-and long-term effective population sizes were estimated for the North Atlantic Ocean albacore population, and results showed no historical decline for this population. Therefore, the genetic diversity and, consequently, the adaptive potential of this population have not been significantly affected by overfishing.
Resumo:
One of the main problems of fusion energy is to achieve longer pulse duration by avoiding the premature reaction decay due to plasma instabilities. The control of the plasma inductance arises as an essential tool for the successful operation of tokamak fusion reactors in order to overcome stability issues as well as the new challenges specific to advanced scenarios operation. In this sense, given that advanced tokamaks will suffer from limited power available from noninductive current drive actuators, the transformer primary coil could assist in reducing the power requirements of the noninductive current drive sources needed for current profile control. Therefore, tokamak operation may benefit from advanced control laws beyond the traditionally used PID schemes by reducing instabilities while guaranteeing the tokamak integrity. In this paper, a novel model predictive control (MPC) scheme has been developed and successfully employed to optimize both current and internal inductance of the plasma, which influences the L-H transition timing, the density peaking, and pedestal pressure. Results show that the internal inductance and current profiles can be adequately controlled while maintaining the minimal control action required in tokamak operation.