57 research outputs found

    Dietary Compounds as Epigenetic Modulating Agents in Cancer

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    Epigenetic mechanisms control gene expression during normal development and their aberrant regulation may lead to human diseases including cancer. Natural phytochemicals can largely modulate mammalian epigenome through regulation of mechanisms and proteins responsible for chromatin remodeling. Phytochemicals are mainly contained in fruits, seeds, and vegetables as well as in foods supplements. These compounds act as powerful cellular antioxidants and anti-carcinogens agents. Several dietary compounds such as catechins, curcumin, genistein, quercetin and resveratrol, among others, exhibit potent anti-tumor activities through the reversion of epigenetic alterations associated to oncogenes activation and inactivation of tumor suppressor genes. In this review, we summarized the actual knowledge about the role of dietary phytochemicals in the restoration of aberrant epigenetic alterations found in cancer cells with a particular focus on DNA methylation and histone modifications. Furthermore, we discussed the mechanisms by which these natural compounds modulate gene expression at epigenetic level and described their molecular targets in diverse types of cancer. Modulation of epigenetic activities by phytochemicals will allow the discovery of novel biomarkers for cancer prevention, and highlights its potential as an alternative therapeutic approach in cancer

    Suppression of cell migration is promoted by miR-944 through targeting of SIAH1 and PTP4A1 in breast cancer cells

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    Background: Aberrant expression of microRNAs has been associated with migration of tumor cells. In this study, we aimed to investigate the biological significance of miR-944 whose function is unknown in breast cancer. Methods: MiR-944 expression in breast cancer cells and tumors was evaluated by Taqman qRT-PCR assays. Transcriptional profiling of MDA-MB-231 cells expressing miR-944 was performed using DNA microarrays. Cell viability, migration and invasion were assessed by MTT, scratch/wound-healing and transwell chamber assays, respectively. The luciferase reporter assay was used to evaluate targeting of SIAH1, PTP4A1 and PRKCA genes by miR-944. SIAH1 protein levels were measured by Western blot. Silencing of SIAH1 gene was performed by RNA interference using shRNAs. Results: Our data showed that miR-944 expression was severely repressed in clinical specimens and breast cancer cell lines. Suppression of miR-944 levels was independent of hormonal status and metastatic potential of breast cancer cells. Gain-of-function analysis indicated that miR-944 altered the actin cytoskeleton dynamics and impaired cell migration and invasion. Genome-wide transcriptional profiling of MDA-MB-231 cells that ectopically express miR-944 showed that 15 genes involved in migration were significantly repressed. Notably, luciferase reporter assays confirmed the ability of miR-944 to bind the 3´UTR of SIAH1 and PTP4A1 genes, but not PRKCA gene. Congruently, an inverse correlation between miR-944 and SIAH1 protein expression was found in breast cancer cells. Moreover, SIAH1 was upregulated in 75 % of miR-944-deficient breast tumors. Finally, SIAH1 gene silencing by RNA interference significantly impaired cell migration of breast cancer cells. Conclusions: Our results pointed out that miR-944 is a novel upstream negative regulator of SIAH1 and PTP4A1 genes and provided for the first time evidence for its functional role in migration and invasion of breast cancer cells. They also suggest that miR-944 restoration may represent a potential strategy for breast cancer therapy

    Pathogenic variant profile in DNA damage response genes correlates with metastatic breast cancer progression-free survival in a Mexican-mestizo population

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    IntroductionMetastatic breast cancer causes the most breast cancer-related deaths around the world, especially in countries where breast cancer is detected late into its development. Genetic testing for cancer susceptibility started with the BRCA 1 and 2 genes. Still, recent research has shown that variations in other members of the DNA damage response (DDR) are also associated with elevated cancer risk, opening new opportunities for enhanced genetic testing strategies.MethodsWe sequenced BRCA1/2 and twelve other DDR genes from a Mexican-mestizo population of 40 metastatic breast cancer patients through semiconductor sequencing.ResultsOverall, we found 22 variants –9 of them reported for the first time– and a strikingly high proportion of variations in ARID1A. The presence of at least one variant in the ARID1A, BRCA1, BRCA2, or FANCA genes was associated with worse progression-free survival and overall survival in our patient cohort.DiscussionOur results reflected the unique characteristics of the Mexican-mestizo population as the proportion of variants we found differed from that of other global populations. Based on these findings, we suggest routine screening for variants in ARID1A along with BRCA1/2 in breast cancer patients from the Mexican-mestizo population

    HypoxamiRs Profiling Identify miR-765 as a Regulator of the Early Stages of Vasculogenic Mimicry in SKOV3 Ovarian Cancer Cells

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    Vasculogenic mimicry (VM) is a novel cancer hallmark in which malignant cells develop matrix-associated 3D tubular networks with a lumen under hypoxia to supply nutrients needed for tumor growth. Recent studies showed that microRNAs (miRNAs) may have a role in VM regulation. In this study, we examined the relevance of hypoxia-regulated miRNAs (hypoxamiRs) in the early stages of VM formation. Data showed that after 48 h hypoxia and 12 h incubation on matrigel SKOV3 ovarian cancer cells undergo the formation of matrix-associated intercellular connections referred hereafter as 3D channels-like structures, which arose previous to the apparition of canonical tubular structures representative of VM. Comprehensive profiling of 754 mature miRNAs at the onset of hypoxia-induced 3D channels-like structures showed that 11 hypoxamiRs were modulated (FC>1.5; p < 0.05) in SKOV3 cells (9 downregulated and 2 upregulated). Bioinformatic analysis of the set of regulated miRNAs showed that they might impact cellular pathways related with tumorigenesis. Moreover, overall survival analysis in a cohort of ovarian cancer patients (n = 485) indicated that low miR-765, miR-193b, miR-148a and high miR-138 levels were associated with worst patients outcome. In particular, miR-765 was severely downregulated after hypoxia (FC < 32.02; p < 0.05), and predicted to target a number of protein-encoding genes involved in angiogenesis and VM. Functional assays showed that ectopic restoration of miR-765 in SKOV3 cells resulted in a significant inhibition of hypoxia-induced 3D channels-like formation that was associated with a reduced number of branch points and patterned tubular-like structures. Mechanistic studies confirmed that miR-765 decreased the levels of VEGFA, AKT1 and SRC-α transducers and exerted a negative regulation of VEGFA by specific binding to its 3‘UTR. Finally, overall survival analysis of a cohort of ovarian cancer patients (n = 1435) indicates that high levels of VEGFA, AKT1 and SRC-α and low miR-765 expression were associated with worst patients outcome. In conclusion, here we reported a novel hypoxamiRs signature which constitutes a molecular guide for further clinical and functional studies on the early stages of VM. Our data also suggested that miR-765 coordinates the formation of 3D channels-like structures through modulation of VEGFA/AKT1/SRC-α axis in SKOV3 ovarian cancer cells

    Crimen organizado y violencia homicida en ciudades intermedias

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    El presente libro compila un conjunto de investigaciones sobre las diferentes expresiones de la violencia homicida y el crimen organizado en Colombia, en el contexto de los esfuerzos discontinuos de construcción de Paz de la nación. Con perspectiva plural, muestra las distintas problemáticas de la violencia homicida, el conflicto armado y las reacciones de los afectados, así como los distintos impactos en un conjunto de ciudades intermedias. Abarca un conjunto de espacios urbanos diversos dentro del vasto y profundo territorio colombiano. Además de las lógicas de violencia homicida y de las actividades de organizaciones criminales en cada ciudad seleccionada en el libro, los autores exploran, en diversas formas, cuáles son las respuestas de los actores públicos, de la sociedad y los actores ilícitos armados, así como la manera en que las distintas violencias afectan las posibilidades de construcción de paz

    COVID-19 Severity and Cardiovascular Outcomes in SARS-CoV-2-Infected Patients With Cancer and Cardiovascular Disease

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    BACKGROUND: Data regarding outcomes among patients with cancer and co-morbid cardiovascular disease (CVD)/cardiovascular risk factors (CVRF) after SARS-CoV-2 infection are limited. OBJECTIVES: To compare Coronavirus disease 2019 (COVID-19) related complications among cancer patients with and without co-morbid CVD/CVRF. METHODS: Retrospective cohort study of patients with cancer and laboratory-confirmed SARS-CoV-2, reported to the COVID-19 and Cancer Consortium (CCC19) registry from 03/17/2020 to 12/31/2021. CVD/CVRF was defined as established CVD RESULTS: Among 10,876 SARS-CoV-2 infected patients with cancer (median age 65 [IQR 54-74] years, 53% female, 52% White), 6253 patients (57%) had co-morbid CVD/CVRF. Co-morbid CVD/CVRF was associated with higher COVID-19 severity (adjusted OR: 1.25 [95% CI 1.11-1.40]). Adverse CV events were significantly higher in patients with CVD/CVRF (all CONCLUSIONS: Co-morbid CVD/CVRF is associated with higher COVID-19 severity among patients with cancer, particularly those not receiving active cancer therapy. While infrequent, COVID-19 related CV complications were higher in patients with comorbid CVD/CVRF. (COVID-19 and Cancer Consortium Registry [CCC19]; NCT04354701)

    Biodiversity recovery of Neotropical secondary forests

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    Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes. Copyright © 2019 The Authors, some rights reserved

    Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

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    Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

    Evaluación de patologías presentes en pavimentos flexibles de la vía Ibagué- Rovira en el tramo comprendido entre el k05+000 hasta el k06+000 del departamento del Tolima

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    En el departamento del Tolima, específicamente entre el corregimiento del Totumo y la vereda Carmen de Bulira, se realizó una inspección técnica y analítica de las fallas que presenta la superficie del pavimento en el tramo de investigación (k05+000-k06+000), observándose patologías como desprendimiento de material asfáltico, fisuras, ahuellamiento, ojo de pescado, piel de cocodrilo, entre otras.In the department of Tolima, specifically between the corregimiento of Totumo and the Carmen de Bulira village, a technical and analytical inspection of the faults presented by the surface of the pavement in the research section (k05 + 000-k06 + 000) was carried out, observing pathologies such as detachment of asphaltic material, fissures, collapse, fish eye, crocodile skin, among others.1. Introducción. -- 2. Justificación. -- 3. Objetivos. -- 3.1 objetivo general . -- 3.2 objetivos específicos. -- 4. Marco de referencia. -- 4.1 pavimento. -- 4.2 características de un pavimento. -- 4.3 pavimento flexible. -- 4.4 procedimiento para el registro de daños. -- 4.5 capacidad de una vía. -- 4.6 nivel de servicio de una vía . -- 5. Marco geográfico. -- 5.1 localización geográfica. -- 6. Metodología. -- 7. Resultados . -- 7.1 reconocimiento y georreferenciación de la malla vial . -- 7.2 implementación de aforo. -- 7.3 calculo con el software cns97. -- 7.4 identificación de patologías. -- 7.5 estado del drenaje. -- 7.6 utilización de software arcgis. -- 7.7 técnicas de rehabilitación. -- 8. Conclusiones. -- Bibliografía. -- Anexos [email protected]@[email protected]

    Caracterización del estilo de vida de fisioterapeutas de instituciones adscritas a los programas académicos de campo de la Universidad del Rosario

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    Estudio descriptivo exploratorio de corte transversal efectuado a fisioterapeutas del área asistencial. Se aplicó el cuestionario FANTASTIC, a 23 fisioterapeutas del área asistencial, entre los meses de febrero a abril de 2004. La edades de los profesionales se encontraron entre los 20 y 51 años. Se utilizó el paquete estadístico SPSS para realizar un análisis simple y cruzado de variables. Se buscaron las frecuencias de presentación más representativas para las variables sociodemográficas y del instrumento. El estudio arrojo que a mayor estrés, más se afectan las relaciones interpersonales y se presenta a medida que aumenta el tiempo de ejercicio profesional, afectando la satisfacción laboral. Con relación al ejercicio, se observó que a medida que se aumenta la frecuencia de práctica, mejora la nutrición. Los hábitos más saludables identificados en esta población se encuentran dentro de las esferas social, familiar, cuidado nutricional y consumo de tabaco, toxinas y alcohol y trabajo. Por el contrario, los menos saludables fueron aquellos relacionados con la parte personal del individuo
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