2,253 research outputs found

    Differential Functional Roles of ALDH1A1 and ALDH1A3 in Mediating Metastatic Behavior and Therapy Resistance of Human Breast Cancer Cells

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    Previous studies indicate that breast cancer cells with high aldehyde dehydrogenase (ALDH) activity and CD44 expression (ALDHhiCD44+ ) contribute to metastasis and therapy resistance, and that ALDH1 correlates with poor outcome in breast cancer patients. The current study hypothesized that ALDH1 functionally contributes to breast cancer metastatic behavior and therapy resistance. Expression of ALDH1A1 or ALDH1A3 was knocked down in MDA-MB-468 and SUM159 human breast cancer cells using siRNA. Resulting impacts on ALDH activity (Aldefluor® assay); metastatic behavior and therapy response in vitro (proliferation/adhesion/migration/colony formation/chemotherapy and radiation) and extravasation/metastasis in vivo (chick choroiallantoic membrane assay) was assessed. Knockdown of ALDH1A3 but not ALDH1A1 in breast cancer cells decreased ALDH activity, and knockdown of ALDH1A1 reduced breast cancer cell metastatic behavior and therapy resistance relative to control (p \u3c 0.05). In contrast, knockdown of ALDH1A3 did not alter proliferation, extravasation, or therapy resistance, but increased adhesion/migration and decreased colony formation/metastasis relative to control (p \u3c 0.05). This is the first study to systematically examine the function of ALDH1 isozymes in individual breast cancer cell behaviors that contribute to metastasis. Our novel results indicate that ALDH1 mediates breast cancer metastatic behavior and therapy resistance, and that different enzyme isoforms within the ALDH1 family differentially impact these cell behaviors

    Co-expression of α9β1 integrin and VEGF-D confers lymphatic metastatic ability to a human breast cancer cell line MDA-MB-468LN

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    Introduction and Objectives: Lymphatic metastasis is a common occurrence in human breast cancer, mechanisms remaining poorly understood. MDA-MB-468LN (468LN), a variant of the MDA-MB-468GFP (468GFP) human breast cancer cell line, produces extensive lymphatic metastasis in nude mice. 468LN cells differentially express α9β1 integrin, a receptor for lymphangiogenic factors VEGF-C/-D. We explored whether (1) differential production of VEGF-C/-D by 468LN cells provides an autocrine stimulus for cellular motility by interacting with α9β1 and a paracrine stimulus for lymphangiogenesis in vitro as measured with capillary-like tube formation by human lymphatic endothelial cells (HMVEC-dLy); (2) differential expression of α9 also promotes cellular motility/invasiveness by interacting with macrophage derived factors; (3) stable knock-down of VEGF-D or α9 in 468LN cells abrogates lymphangiogenesis and lymphatic metastasis in vivo in nude mice. Results: A comparison of expression of cyclo-oxygenase (COX)-2 (a VEGF-C/-D inducer), VEGF-C/-D and their receptors revealed little COX-2 expression by either cells. However, 468LN cells showed differential VEGF-D and α9β1 expression, VEGF-D secretion, proliferative, migratory/invasive capacities, latter functions being stimulated further with VEGF-D. The requirement of α9β1 for native and VEGF-D-stimulated proliferation, migration and Erk activation was demonstrated by treating with α9β1 blocking antibody or knock-down of α9. An autocrine role of VEGF-D in migration was shown by its impairment by silencing VEGF-D and restoration with VEGF-D. 468LN cells and their soluble products stimulated tube formation, migration/invasiveness of HMVEC-dLy cell in a VEGF-D dependent manner as indicated by the loss of stimulation by silencing VEGF-D in 468LN cells. Furthermore, 468LN cells showed α9-dependent stimulation of migration/invasiveness by macrophage products. Finally, capacity for intra-tumoral lymphangiogenesis and lymphatic metastasis in nude mice was completely abrogated by stable knock-down of either VEGF-D or α9 in 468LN cells. Conclusion: Differential capacity for VEGF-D production and α9β1 integrin expression by 468LN cells jointly contributed to their lymphatic metastatic phenotype. © 2012 Majumder et al

    Propuesta estratégica de mejora en la implementación de los estándares mínimos del Sistema de Gestión de la Seguridad y Salud en el Trabajo (SG- SST) en la empresa Fondar para el segundo semestre del 2019 y principios del 2020

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    Matriz de evaluación del sistema de gestión de seguridad y salud en el trabajo, diagrama de GanttEl presente proyecto comprende el estudio del decreto 1443 del 31 de julio de 2014; que ordeno las directrices de obligatorio cumplimiento para implementar el Sistema de Gestión de la Seguridad y Salud en el Trabajo (SG-SST) el cual debe cumplir la empresa de economía solidaria FONDAR, a partir de ese momento el Fondo de Empleados direcciono un trabajo detallado para cumplir con lo ordenado por el gobierno; teniendo en cuenta la actualización de los estándares mínimos de acuerdo a la resolución No. 0312 del 13 de febrero de 2019, sin embargo al revisar en la práctica el desarrollo de los estándares mínimos que debe cumplir, se evidencio que FONDAR no ha trabajado de la manera correcta el ítem de capacitación en SST y por ende está fallando en el ítem que detalla su plan anual de trabajo. Es por ello que buscamos guiar a la empresa FONDAR para que logre realizar una buena implementación de estos estándares y de esta manera evitar sanciones en la inspección, vigilancia y control que realizará el Ministerio de Trabajo a partir del mes de Noviembre de 2019; aunque la empresa ya tiene un gran porcentaje del trabajo realizado, es importante en este momento hacer un proceso de seguimiento y plan de mejora de acuerdo a lo que ellos ya tienen planteado, proceso que se ha llevado a cabo generando una autoevaluación conforme a los estándares mínimos y en el cual se observó la problemática anteriormente descrita y de acuerdo a esta misma se generará un plan de mejora para solventar esta situación, es muy importante para la consecución de esta actividad poder contar con todos los colaboradores de FONDAR y para ello se elaborará una propuesta que brinde un cronograma de capacitación el cual se pueda ejecutar y que permita cumplir con el plan anual del Sistema de Gestión de SST. Para alcanzar este proyecto es necesario plantear el problema observado, revisar sus antecedentes y analizar de forma cualitativa que está generando esta falencia, así como también analizar el marco teórico y legal, mostrando una metodología de investigación cualitativa la cual se llevara a cabo de acuerdo al análisis que se realizó de la implementación inicial del SG - SST en la empresa, la implementación de la tabla de valores y calificación de los estándares mínimos de SG -SST, de acuerdo a la matriz utilizada para tal fin logrando describir como fue la transición de la empresa desde el decreto 1443 a la nueva resolución 0312, obteniendo de esta manera un análisis detallado de los resultados obtenidos y generando con estos un plan de mejora y los diferentes cronogramas con los que debe trabajar la empresa para alcanzar a un 100% la implementación y evaluación de su Sistema de Gestión de la Seguridad y Salud en el Trabajo (SG-SST) para ser aplicado a partir del mes de Noviembre, evitando sanciones y demás perjuicios para la organización.This project includes the study of Decree 1443 of July 31, 2014; I order the mandatory compliance guidelines to implement the Occupational Health and Safety Management System (SG-SST) which must be met by the solidarity economy company FONDAR, from that moment the Employee Fund directed a detailed work to comply with the orders of the government; taking into account the update of the minimum standards according to resolution No. 0312 of February 13, 2019, however, when reviewing in practice the development of the minimum standards that must be met, it was evidenced that FONDAR has not worked on the Correctly, the training item in OSH and therefore is failing in the item that details your annual work plan. That is why we seek to guide the company FONDAR to achieve a good implementation of these standards and thus avoid sanctions in the inspection, surveillance and control that will be carried out by the Ministry of Labor from the month of November 2019; Although the company already has a large percentage of the work done, it is important at this time to carry out a monitoring process and improvement plan according to what they have already proposed, a process that has been carried out generating a self-assessment according to the standards minimum and in which the above-described problem was observed and according to this one an improvement plan will be generated to solve this situation, it is very important for the achievement of this activity to be able to count on all the employees of FONDAR and for this it will be prepared a proposal that provides a training schedule which can be executed and that allows to comply with the annual plan of the OSH Management System. To achieve this project it is necessary to raise the observed problem, review its background and analyze in a qualitative way that this flaw is generating, as well as analyze the theoretical and legal framework, showing a qualitative research methodology which will be carried out according to the analysis that was carried out of the initial implementation of the SG-SST in the company, the implementation of the table of values ​​and qualification of the minimum standards of SG-SST, according to the matrix used for this purpose managing to describe how the transition of the company from decree 1443 to the new resolution 0312, thus obtaining a detailed analysis of the results obtained and generating with them an improvement plan and the different schedules with which the company must work to achieve 100% implementation and evaluation of its Occupational Health and Safety Management System (SG-SST) to be applied as of the month November, avoiding penalties and other damages for the organization

    Ambition meets reality:Achieving GHG emission reduction targets in the livestock sector of Latin America

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    Livestock production is a very relevant source of income and agricultural greenhouse gas (GHG) emissions in Colombia, Brazil, Argentina, Costa Rica, Uruguay, Mexico, and Peru. Several management and technological options with enteric methane mitigation potential have been evaluated and their scaling is anticipated to contribute toward achieving GHG emission reduction targets in the framework of the Paris Agreement. Yet, widespread adoption of promising mitigation options remains limited, raising questions as to whether envisaged emission reduction targets are achievable. Using findings from local studies, we explore the mitigation potentials of technologies and management practices currently proposed to mitigate enteric methane emissions from cattle production systems in the higher emitting countries of Latin America. We then discuss barriers for adopting innovations that significantly reduce cattle-based enteric methane emissions and the major shifts in policy and practice that are needed to raise national ambitions in the high emitting countries. Using the latest science and current thinking, we provide our perspective on an inclusive approach and re-imagine how the academic, research, business and public policy sectors can support and incentivize the changes needed to raise the level of ambition and achieve sustainable development goals (SDG), considering actions from the farm to the national scale

    COX-2 Induces Breast Cancer Stem Cells via EP4/PI3K/AKT/NOTCH/WNT Axis

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    Cancer stem-like cells (SLC) resist conventional therapies, necessitating searches for SLC-specific targets. We established that cyclo-oxygenase(COX)-2 expression promotes human breast cancer progression by activation of the prostaglandin(PG)E-2 receptor EP4. Present study revealed that COX-2 induces SLCs by EP4-mediated NOTCH/WNT signaling. Ectopic COX-2 over-expression in MCF-7 and SKBR-3 cell lines resulted in: increased migration/invasion/proliferation, epithelial-mesenchymal transition (EMT), elevated SLCs (spheroid formation), increased ALDH activity and colocalization of COX-2 and SLC markers (ALDH1A, CD44, β-Catenin, NANOG, OCT3/4, SOX-2) in spheroids. These changes were reversed with COX-2-inhibitor or EP4-antagonist (EP4A), indicating dependence on COX-2/EP4 activities. COX-2 over-expression or EP4-agonist treatments of COX-2-low cells caused up-regulation of NOTCH/WNT genes, blocked with PI3K/AKT inhibitors. NOTCH/WNT inhibitors also blocked COX-2/EP4 induced SLC induction. Microarray analysis showed up-regulation of numerous SLC-regulatory and EMT-associated genes. MCF-7-COX-2 cells showed increased mammary tumorigenicity and spontaneous multiorgan metastases in NOD/SCID/IL-2Rγ-null mice for successive generations with limiting cell inocula. These tumors showed up-regulation of VEGF-A/C/D, Vimentin and phospho-AKT, down-regulation of E-Cadherin and enrichment of SLC marker positive and spheroid forming cells. MCF-7-COX-2 cells also showed increased lung colonization in NOD/SCID/GUSB-null mice, an effect reversed with EP4-knockdown or EP4A treatment of the MCF-7-COX-2 cells. COX-2/EP4/ALDH1A mRNA expression in human breast cancer tissues were highly correlated with one other, more marked in progressive stage of disease. In situ immunostaining of human breast tumor tissues revealed co-localization of SLC markers with COX-2, supporting COX-2 inducing SLCs. High COX-2/EP4 mRNA expression was linked with reduced survival. Thus, EP4 represents a novel SLC-ablative target in human breast cancer. Stem Cells 2016;34:2290–2305

    Strategies to achieve the GHG Mitigation Goals of the livestock sector in Latin America

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    Livestock production is a fundamental source of income and greenhouse gas (GHG) emissions in Latin American countries. 20 percent of the region's emissions come from agriculture, 70 percent of which comes from livestock. There are several management and technology options with enteric methane mitigation potential that have been evaluated and their scale is expected to contribute to achieving the GHG emission reduction targets under the Paris Agreement. These technologies include management of the animal diet, reproductive control, administration of supplements, and reduction of the age at slaughter, among others. However, widespread adoption of promising mitigation options remains limited, raising questions about whether the planned emission reduction targets are achievable. Using the results of local studies, we have explored the mitigation potentials of currently proposed management technologies and practices to mitigate enteric methane emissions from livestock production systems in Latin American countries with the highest emissions. We then discuss the barriers to adopting innovations that significantly reduce enteric methane emissions from livestock and the main changes in policies and practices necessary to raise national ambitions in high-emission countries. Drawing on today's latest science and thought, we take our perspective to an inclusive approach and reimagine how the academic, research, business and public policy sectors can support and incentivize the changes necessary to raise the level of ambition and achieve goals of sustainable development, taking into account actions from the farm to the national scale. Some improvements identified and that need to be made are improving access to information through effective technology transfer plans, access to financial products by small producers, and establishing seed multiplication systems for fodder materials

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Co-Expression of α9β1 Integrin and VEGF-D Confers Lymphatic Metastatic Ability to a Human Breast Cancer Cell Line MDA-MB-468LN

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    INTRODUCTION AND OBJECTIVES: Lymphatic metastasis is a common occurrence in human breast cancer, mechanisms remaining poorly understood. MDA-MB-468LN (468LN), a variant of the MDA-MB-468GFP (468GFP) human breast cancer cell line, produces extensive lymphatic metastasis in nude mice. 468LN cells differentially express α9β1 integrin, a receptor for lymphangiogenic factors VEGF-C/-D. We explored whether (1) differential production of VEGF-C/-D by 468LN cells provides an autocrine stimulus for cellular motility by interacting with α9β1 and a paracrine stimulus for lymphangiogenesis in vitro as measured with capillary-like tube formation by human lymphatic endothelial cells (HMVEC-dLy); (2) differential expression of α9 also promotes cellular motility/invasiveness by interacting with macrophage derived factors; (3) stable knock-down of VEGF-D or α9 in 468LN cells abrogates lymphangiogenesis and lymphatic metastasis in vivo in nude mice. RESULTS: A comparison of expression of cyclo-oxygenase (COX)-2 (a VEGF-C/-D inducer), VEGF-C/-D and their receptors revealed little COX-2 expression by either cells. However, 468LN cells showed differential VEGF-D and α9β1 expression, VEGF-D secretion, proliferative, migratory/invasive capacities, latter functions being stimulated further with VEGF-D. The requirement of α9β1 for native and VEGF-D-stimulated proliferation, migration and Erk activation was demonstrated by treating with α9β1 blocking antibody or knock-down of α9. An autocrine role of VEGF-D in migration was shown by its impairment by silencing VEGF-D and restoration with VEGF-D. 468LN cells and their soluble products stimulated tube formation, migration/invasiveness of HMVEC-dLy cell in a VEGF-D dependent manner as indicated by the loss of stimulation by silencing VEGF-D in 468LN cells. Furthermore, 468LN cells showed α9-dependent stimulation of migration/invasiveness by macrophage products. Finally, capacity for intra-tumoral lymphangiogenesis and lymphatic metastasis in nude mice was completely abrogated by stable knock-down of either VEGF-D or α9 in 468LN cells. CONCLUSION: Differential capacity for VEGF-D production and α9β1 integrin expression by 468LN cells jointly contributed to their lymphatic metastatic phenotype
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