Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Sci Total Environ ; 918: 170501, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38307289

RESUMEN

Bio-based fertilizers (BBFs) produced from organic waste have the potential to reduce societal dependence on limited and energy-intensive mineral fertilizers. BBFs, thereby, contribute to a circular economy for fertilizers. However, BBFs can contain plastic fragments and hazardous additives such as phthalate plasticizers, which could constitute a risk for agricultural soils and the environment. This study assessed the exposure associated with plastic and phthalates in BBFs from three types of organic wastes: agricultural and food industry waste (AgriFoodInduWaste), sewage sludge (SewSludge), and biowaste (i.e., garden, park, food and kitchen waste). The wastes were associated with various treatments like drying, anaerobic digestion, and vermicomposting. The number of microplastics (0.045-5 mm) increased from AgriFoodInduWaste-BBFs (15-258 particles g-1), to SewSludge-BBFs (59-1456 particles g-1) and then to Biowaste-BBFs (828-2912 particles g-1). Biowaste-BBFs mostly contained packaging plastics (e.g., polyethylene terephthalate), with the mass of plastic (>10 g kg-1) exceeding the EU threshold (3 g kg-1, plastics >2 mm). Other BBFs mostly contained small (< 1 mm) non-packaging plastics in amounts below the EU limit. The calculated numbers of microplastics entering agricultural soils via BBF application was high (107-1010 microplastics ha-1y-1), but the mass of plastic released from AgriFoodInduWaste-BBFs and SewSludge-BBFs was limited (< 1 and <7 kg ha-1y-1) compared to Biowaste-BBFs (95-156 kg ha-1y-1). The concentrations of di(2-ethylhexyl)phthalate (DEHP; < 2.5 mg kg-1) and phthalate transformation products (< 8 mg kg-1) were low (< benchmark of 50 mg kg-1 for DEHP), attributable to both the current phase-out of DEHP as well as phthalate degradation during waste treatment. The Biowaste-BBF exposed to vermicomposting indicated that worms accumulated phthalate transformation products (4 mg kg-1). These results are overall positive for the implementation of the studied AgriFoodInduWaste-BBFs and SewSludge-BBFs. However, the safe use of the studied Biowaste-BBFs requires reducing plastic use and improving sorting methods to minimize plastic contamination, in order to protect agricultural soils and reduce the environmental impact of Biowaste-BBFs.


Asunto(s)
Dietilhexil Ftalato , Ácidos Ftálicos , Plastificantes/análisis , Plásticos , Fertilizantes , Microplásticos , Suelo , Aguas del Alcantarillado , Dibutil Ftalato
2.
Leg Med (Tokyo) ; 67: 102330, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37802731

RESUMEN

Tape-lifting is a non-destructive method employed in the laboratory to recover and collect trace DNA evidence from crime scene exhibits with porous surfaces. The success of tape-lifting is a balance between capturing the biological material and compatibility with downstream DNA extraction processes to ensure efficient release of the tape-lifted material during DNA extraction. In this study, six commercially available low-, regular- and high-tack adhesive tapes were evaluated. The low-tack S183 tape and the highly adhesive S-Hold tape were compared for DNA recovery efficiency from different materials commonly encountered in casework. All tape-lifts were processed using PrepFiler Express™ BTA and AutoMate Express™ Forensic DNA extraction systems, DNA samples quantitated by Quantifiler TRIO, amplified using Powerplex® 21 and VeriFiler™ PLUS (VFP), and analysed on a 3500xl genetic analyser to evaluate the quality of the resultant STR profiles obtained. The more adhesive S-Hold tape recovered comparable or more DNA than the low-tack S183 tape from the majority of materials tested. However, STR profiles obtained from S183 tape-lifts were of markedly higher quality compared to S-Hold tape-lifts. This was most evident for towel, denim and printed chiffon, where S-Hold samples exhibited severe PCR inhibition, with VFP internal quality markers confirming the presence of inhibitors. The findings suggest that strong adhesion is not necessarily beneficial for tape-lifting, as the low tack S183 tape was able to efficiently recover cellular material from the surface of porous substrates commonly encountered in casework, while avoiding the co-transfer of PCR-inhibitory substances from the sampled material.


Asunto(s)
Dermatoglifia del ADN , Repeticiones de Microsatélite , Humanos , Repeticiones de Microsatélite/genética , Manejo de Especímenes/métodos , ADN/genética , Adhesivos , Reacción en Cadena de la Polimerasa
3.
Transpl Infect Dis ; 26(1): e14182, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37885435

RESUMEN

BACKGROUND: Tixagevimab-cilgavimab (Tix-Cil) was authorized for prophylaxis against COVID-19 in immunocompromised patients from December 2021 through January 2023. Real-world effectiveness for solid organ transplant (SOT) recipients has been unclear. METHODS: We enrolled 911 SOT recipients into a longitudinal COVID-19 serology study, of whom 381 (42%) received ≥1 dose of Tix-Cil. We collected and analyzed data on incident SARS-CoV-2 infections and antibody kinetics for all patients from January 2022 to March 2023, including periods dominated by Omicron BA and BQ subvariants. RESULTS: Over 253 ± 131 days of follow-up, there were 324 new-onset SARS-CoV-2 infections: 117 (31%) in Tix-Cil treated and 207 (39%) in Tix-Cil untreated patients (p = .012). In analyses adjusting for demographic, clinical, and COVID-19 exposure factors, any Tix-Cil treatment was associated with lower infection risk (OR 0.52, 95% CI 0.27-0.96, p = .039) throughout the surveillance period including when more resistant BQ.1 and BQ.1.1 subvariants had emerged (12/1/2022 onwards). Among treated patients, receiving a Tix-Cil dose was associated with substantial and sustained increase in anti-spike IgG antibody and angiotensin-converting enzyme 2 binding inhibition levels (Abbott Architect assay) that together also demonstrated association with lower infection risk (p = .042). During the full surveillance period, the frequency of infections requiring hospitalization was low overall (N = 26, 2.9% of the total cohort) and not significantly different between Tix-Cil recipients (N = 12, 3.2% of treated patients) and non-Tix-Cil recipients (N = 14, 2.6% of untreated patients) with unadjusted p = .31 for between-group difference. CONCLUSION: In a large cohort of SOT recipients, we found that Tix-Cil reduced infection risk even amidst emergent Omicron subvariants. Additionally, the extent of measurable humoral response to Tix-Cil may indicate relative effectiveness. Pre-exposure monoclonal antibody therapy may represent a strategy that will continue to offer clinical benefit for immunocompromised persons who are known to derive limited protection from vaccinations.


Asunto(s)
COVID-19 , Trasplante de Órganos , Humanos , COVID-19/prevención & control , SARS-CoV-2 , Anticuerpos Monoclonales , Trasplante de Órganos/efectos adversos , Receptores de Trasplantes
4.
bioRxiv ; 2023 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-37986929

RESUMEN

Calcium imaging has enabled major biological discoveries. However, the scattering of light by tissue limits the use of standard fluorescent calcium indicators in living animals. To address this limitation, we introduce the first genetically encoded ultrasonic reporter of calcium (URoC). Based on a unique class of air-filled protein nanostructures called gas vesicles, we engineered URoC to produce elevated nonlinear ultrasound signal upon binding to calcium ions. With URoC expressed in mammalian cells, we demonstrate noninvasive ultrasound imaging of calcium signaling in vivo during drug-induced receptor activation. URoC brings the depth and resolution advantages of ultrasound to the in vivo imaging of dynamic cellular function and paves the way for acoustic biosensing of a broader variety of biological signals.

5.
Am J Respir Crit Care Med ; 208(1): 49-58, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-36996413

RESUMEN

Rationale: Small trials and professional recommendations support mobilization interventions to improve recovery among critically ill patients, but their real-world effectiveness is unknown. Objective: To evaluate a low-cost, multifaceted mobilization intervention. Methods: We conducted a stepped-wedge cluster-randomized trial across 12 ICUs with diverse case mixes. The primary and secondary samples included patients mechanically ventilated for ⩾48 hours who were ambulatory before admission, and all patients with ICU stays ⩾48 hours, respectively. The mobilization intervention included 1) designation and posting of daily mobilization goals; 2) interprofessional closed-loop communication coordinated by each ICU's facilitator; and 3) performance feedback. Measurements and Main Results: From March 4, 2019 through March 15, 2020, 848 and 1,069 patients were enrolled in the usual care and intervention phases in the primary sample, respectively. The intervention did not increase the primary outcome, patient's maximal Intensive Care Mobility Scale (range, 0-10) score within 48 hours before ICU discharge (estimated mean difference, 0.16; 95% confidence interval, -0.31 to 0.63; P = 0.51). More patients in the intervention (37.2%) than usual care (30.7%) groups achieved the prespecified secondary outcome of ability to stand before ICU discharge (odds ratio, 1.48; 95% confidence interval, 1.02 to 2.15; P = 0.04). Similar results were observed among the 7,115 patients in the secondary sample. The percentage of days on which patients received physical therapy mediated 90.1% of the intervention effect on standing. ICU mortality (31.5% vs. 29.0%), falls (0.7% vs. 0.4%), and unplanned extubations (2.0% vs. 1.8%) were similar between groups (all P > 0.3). Conclusions: A low-cost, multifaceted mobilization intervention did not improve overall mobility but improved patients' odds of standing and was safe. Clinical trial registered with www.clinicaltrials.gov (NCT03863470).


Asunto(s)
Enfermedad Crítica , Unidades de Cuidados Intensivos , Humanos , Enfermedad Crítica/rehabilitación , Cuidados Críticos , Hospitalización , Alta del Paciente
6.
BMC Infect Dis ; 23(1): 97, 2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36797666

RESUMEN

BACKGROUND: Individuals with post-acute sequelae of COVID (PASC) may have a persistence in immune activation that differentiates them from individuals who have recovered from COVID without clinical sequelae. To investigate how humoral immune activation may vary in this regard, we compared patterns of vaccine-provoked serological response in patients with PASC compared to individuals recovered from prior COVID without PASC. METHODS: We prospectively studied 245 adults clinically diagnosed with PASC and 86 adults successfully recovered from prior COVID. All participants had measures of humoral immunity to SARS-CoV-2 assayed before or after receiving their first-ever administration of COVID vaccination (either single-dose or two-dose regimen), including anti-spike (IgG-S and IgM-S) and anti-nucleocapsid (IgG-N) antibodies as well as IgG-S angiotensin-converting enzyme 2 (ACE2) binding levels. We used unadjusted and multivariable-adjusted regression analyses to examine the association of PASC compared to COVID-recovered status with post-vaccination measures of humoral immunity. RESULTS: Individuals with PASC mounted consistently higher post-vaccination IgG-S antibody levels when compared to COVID-recovered (median log IgG-S 3.98 versus 3.74, P < 0.001), with similar results seen for ACE2 binding levels (median 99.1 versus 98.2, P = 0.044). The post-vaccination IgM-S response in PASC was attenuated but persistently unchanged over time (P = 0.33), compared to in COVID recovery wherein the IgM-S response expectedly decreased over time (P = 0.002). Findings remained consistent when accounting for demographic and clinical variables including indices of index infection severity and comorbidity burden. CONCLUSION: We found evidence of aberrant immune response distinguishing PASC from recovered COVID. This aberrancy is marked by excess IgG-S activation and ACE2 binding along with findings consistent with a delayed or dysfunctional immunoglobulin class switching, all of which is unmasked by vaccine provocation. These results suggest that measures of aberrant immune response may offer promise as tools for diagnosing and distinguishing PASC from non-PASC phenotypes, in addition to serving as potential targets for intervention.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Síndrome Post Agudo de COVID-19 , Humanos , Enzima Convertidora de Angiotensina 2 , Anticuerpos Antivirales , COVID-19/prevención & control , Progresión de la Enfermedad , Inmunoglobulina G , Inmunoglobulina M , SARS-CoV-2 , Vacunación , Síndrome Post Agudo de COVID-19/inmunología , Vacunas contra la COVID-19/inmunología
8.
Crit Care Explor ; 3(8): e0512, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34396146

RESUMEN

Prior studies have demonstrated suboptimal adherence to lung protective ventilation among patients with acute respiratory distress syndrome. A common barrier to providing this evidence-based practice is diagnostic uncertainty. We sought to test the hypothesis that patients with acute respiratory distress syndrome due to coronavirus disease 2019, in whom acute respiratory distress syndrome is easily recognized, would be more likely to receive low tidal volume ventilation than concurrently admitted acute respiratory distress syndrome patients without coronavirus disease 2019. DESIGN: Retrospective cohort study. SETTING: Five hospitals of a single health system. PATIENTS: Mechanically ventilated patients with coronavirus disease 2019 or noncoronavirus disease 2019 acute respiratory distress syndrome as identified by an automated, electronic acute respiratory distress syndrome finder in clinical use at study hospitals. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 333 coronavirus disease 2019 patients and 234 noncoronavirus disease 2019 acute respiratory distress syndrome patients, the average initial tidal volume was 6.4 cc/kg predicted body weight and 6.8 cc/kg predicted body weight, respectively. Patients had tidal volumes less than or equal to 6.5 cc/kg predicted body weight for a mean of 70% of the first 72 hours of mechanical ventilation in the coronavirus disease 2019 cohort, compared with 52% in the noncoronavirus disease 2019 cohort (unadjusted p < 0.001). After adjusting for height, gender, admitting hospital, and whether or not the patient was admitted to a medical specialty ICU, coronavirus disease 2019 diagnosis was associated with a 21% higher percentage of time receiving tidal volumes less than or equal to 6.5 cc/kg predicted body weight within the first 72 hours of mechanical ventilation (95% CI, 14-28%; p < 0.001). CONCLUSIONS: Adherence to low tidal volume ventilation during the first 72 hours of mechanical ventilation is higher in patients with coronavirus disease 2019 than with acute respiratory distress syndrome without coronavirus disease 2019. This population may present an opportunity to understand facilitators of implementation of this life-saving evidence-based practice.

9.
Implement Sci ; 16(1): 78, 2021 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-34376233

RESUMEN

BACKGROUND: Behavioral economic insights have yielded strategies to overcome implementation barriers. For example, default strategies and accountable justification strategies have improved adherence to best practices in clinical settings. Embedding such strategies in the electronic health record (EHR) holds promise for simple and scalable approaches to facilitating implementation. A proven-effective but under-utilized treatment for patients who undergo mechanical ventilation involves prescribing low tidal volumes, which protects the lungs from injury. We will evaluate EHR-based implementation strategies grounded in behavioral economic theory to improve evidence-based management of mechanical ventilation. METHODS: The Implementing Nudges to Promote Utilization of low Tidal volume ventilation (INPUT) study is a pragmatic, stepped-wedge, hybrid type III effectiveness implementation trial of three strategies to improve adherence to low tidal volume ventilation. The strategies target clinicians who enter electronic orders and respiratory therapists who manage the mechanical ventilator, two key stakeholder groups. INPUT has five study arms: usual care, a default strategy within the mechanical ventilation order, an accountable justification strategy within the mechanical ventilation order, and each of the order strategies combined with an accountable justification strategy within flowsheet documentation. We will create six matched pairs of twelve intensive care units (ICUs) in five hospitals in one large health system to balance patient volume and baseline adherence to low tidal volume ventilation. We will randomly assign ICUs within each matched pair to one of the order panels, and each pair to one of six wedges, which will determine date of adoption of the order panel strategy. All ICUs will adopt the flowsheet documentation strategy 6 months afterwards. The primary outcome will be fidelity to low tidal volume ventilation. The secondary effectiveness outcomes will include in-hospital mortality, duration of mechanical ventilation, ICU and hospital length of stay, and occurrence of potential adverse events. DISCUSSION: This stepped-wedge, hybrid type III trial will provide evidence regarding the role of EHR-based behavioral economic strategies to improve adherence to evidence-based practices among patients who undergo mechanical ventilation in ICUs, thereby advancing the field of implementation science, as well as testing the effectiveness of low tidal volume ventilation among broad patient populations. TRIAL REGISTRATION: ClinicalTrials.gov , NCT04663802 . Registered 11 December 2020.


Asunto(s)
Unidades de Cuidados Intensivos , Respiración Artificial , Mortalidad Hospitalaria , Humanos , Pulmón , Volumen de Ventilación Pulmonar
10.
Ann Am Thorac Soc ; 18(2): 300-307, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33522870

RESUMEN

Rationale: Prone positioning reduces mortality in patients with severe acute respiratory distress syndrome (ARDS), a feature of severe coronavirus disease 2019 (COVID-19). Despite this, most patients with ARDS do not receive this lifesaving therapy.Objectives: To identify determinants of prone-positioning use, to develop specific implementation strategies, and to incorporate strategies into an overarching response to the COVID-19 crisis.Methods: We used an implementation-mapping approach guided by implementation-science frameworks. We conducted semistructured interviews with 30 intensive care unit (ICU) clinicians who staffed 12 ICUs within the Penn Medicine Health System and the University of Michigan Medical Center. We performed thematic analysis using the Consolidated Framework for Implementation Research. We then conducted three focus groups with a task force of ICU leaders to develop an implementation menu, using the Expert Recommendations for Implementing Change framework. The implementation strategies were adapted as part of the Penn Medicine COVID-19 pandemic response.Results: We identified five broad themes of determinants of prone positioning, including knowledge, resources, alternative therapies, team culture, and patient factors, which collectively spanned all five Consolidated Framework for Implementation Research domains. The task force developed five specific implementation strategies, including educational outreach, learning collaborative, clinical protocol, prone-positioning team, and automated alerting, elements of which were rapidly implemented at Penn Medicine.Conclusions: We identified five broad themes of determinants of evidence-based use of prone positioning for severe ARDS and several specific strategies to address these themes. These strategies may be feasible for rapid implementation to increase use of prone positioning for severe ARDS with COVID-19.


Asunto(s)
COVID-19/terapia , Posicionamiento del Paciente/normas , Brechas de la Práctica Profesional , Mejoramiento de la Calidad , Síndrome de Dificultad Respiratoria/terapia , Adulto , Práctica Clínica Basada en la Evidencia , Femenino , Humanos , Ciencia de la Implementación , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Posicionamiento del Paciente/métodos , Posición Prona , Investigación Cualitativa , SARS-CoV-2
11.
Microbiol Resour Announc ; 9(34)2020 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-32816975

RESUMEN

This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants.

12.
Epilepsia ; 50(11): 2390-6, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19563346

RESUMEN

PURPOSE: To determine the effects of long-term use of felbamate (FBM) on weight, complete blood count, liver function tests, and seizure control, and also to determine the effect of age on FBM clearance. METHODS: A computerized prospective database was used to identify all subjects who had FBM listed as one of their antiepileptic drugs (AEDs) during their most recent clinic visit. Medical records from each patient were then reviewed for inclusion criteria [treatment >2 years, FBM initiated at the study clinic, data for pre-FBM (Time-1; T1), one-year exposure to FBM (Time-2; T2), and the latest visit (Time-3; T3)]. Clinical information was abstracted from clinic charts. RESULTS: Seventy-seven patients (F = 41, M = 36; ages 10-69 years) met entry criteria. Mean treatment time was 7.4 years, with the longest 20.3 years. Significant weight loss (mean 5.1 kg; p < 0.001) occurred from T1 to T2, but weight was regained by T3. No clinically significant changes in laboratory parameters occurred. Older age was associated with a significant decrease in FBM clearance (p = 0.01). Significant reduction in generalized tonic-clonic seizures was seen at both T2 (p < 0.001) and T3 (p < 0.001) compared with seizure frequency at T1. DISCUSSION: Our results suggest that long-term FBM use is associated with persistent decrease of seizures and no clinically significant changes in major laboratory parameters. Older age correlated with reduced apparent clearance of FBM. The patient population described in this study were long-term users of FBM who were continuing to use the drug, and thus this study does not constitute an "intent to treat" study.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Fenilcarbamatos/uso terapéutico , Glicoles de Propileno/uso terapéutico , Convulsiones/tratamiento farmacológico , Adolescente , Adulto , Factores de Edad , Anciano , Anticonvulsivantes/farmacocinética , Niño , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Felbamato , Femenino , Humanos , Cuidados a Largo Plazo , Masculino , Registros Médicos , Tasa de Depuración Metabólica , Persona de Mediana Edad , Fenilcarbamatos/farmacocinética , Glicoles de Propileno/farmacocinética , Estudios Prospectivos , Resultado del Tratamiento
13.
Biochem Biophys Res Commun ; 331(4): 984-92, 2005 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-15882975

RESUMEN

Although leptin is known to induce proliferative response in gastric cancer cells, the mechanism(s) underlying this action remains poorly understood. Here, we provide evidence that leptin-induced gastric cancer cell proliferation involves activation of STAT and ERK2 signaling pathways. Leptin-induced STAT3 phosphorylation is independent of ERK2 activation. Leptin increases SHP2 phosphorylation and enhances binding of Grb2 to SHP2. Inhibition of SHP2 expression with siRNA but not SHP2 phosphatase activity abolished leptin-induced ERK2 activation. While JAK inhibition with AG490 significantly reduced leptin-induced ERK2, STAT3 phosphorylation, and cell proliferation, SHP2 inhibition only partially reduced cancer cell proliferation. Immunostaining of gastric cancer tissues displayed local overexpression of leptin and its receptor indicating that leptin might be produced and act locally in a paracrine or autocrine manner. These findings indicate that leptin promotes cancer growth by activating multiple signaling pathways and therefore blocking its action at the receptor level could be a rational therapeutic strategy.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Leptina/fisiología , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Neoplasias Gástricas/patología , Transactivadores/metabolismo , Proliferación Celular , Activación Enzimática , Humanos , Fosforilación , Factor de Transcripción STAT3 , Transducción de Señal , Neoplasias Gástricas/enzimología , Neoplasias Gástricas/metabolismo
14.
Cleve Clin J Med ; 71 Suppl 2: S25-37, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15379297

RESUMEN

Most women with epilepsy today can conceive and bear normal, healthy children, but their pregnancies present an increased risk for complications. Pregnancy can exacerbate seizure frequency in some women with epilepsy, and both maternal epilepsy and in utero exposure to antiepileptic drugs can increase the risk of adverse outcomes in children born to women with epilepsy. These outcomes include fetal loss and perinatal death, congenital malformations and anomalies, neonatal hemorrhage, low birth weight, developmental delay, and childhood epilepsy. After reviewing these risks, this article concludes with practical recommendations for reducing these risks and optimizing the management of pregnant women with epilepsy.


Asunto(s)
Anomalías Inducidas por Medicamentos/prevención & control , Anticonvulsivantes/efectos adversos , Anticonvulsivantes/uso terapéutico , Epilepsia/tratamiento farmacológico , Complicaciones del Embarazo/tratamiento farmacológico , Lactancia Materna , Epilepsia/fisiopatología , Epilepsia/terapia , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/fisiopatología , Complicaciones del Embarazo/terapia , Resultado del Embarazo , Riesgo
15.
Mol Biol Cell ; 15(5): 2156-63, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15004225

RESUMEN

Colorectal cancer is often lethal when invasion and/or metastasis occur. Tumor progression to the metastatic phenotype is mainly dependent on tumor cell invasiveness. Secondary bile acids, particularly deoxycholic acid (DCA), are implicated in promoting colon cancer growth and progression. Whether DCA modulates beta-catenin and promotes colon cancer cell growth and invasiveness remains unknown. Because beta-catenin and its target genes urokinase-type plasminogen activator receptor (uPAR) and cyclin D1 are overexpressed in colon cancers, and are linked to cancer growth, invasion, and metastasis, we investigated whether DCA activates beta-catenin signaling and promotes colon cancer cell growth and invasiveness. Our results show that low concentrations of DCA (5 and 50 microM) significantly increase tyrosine phosphorylation of beta-catenin, induce urokinase-type plasminogen activator, uPAR, and cyclin D1 expression and enhance colon cancer cell proliferation and invasiveness. These events are associated with a substantial loss of E-cadherin binding to beta-catenin. Inhibition of beta-catenin with small interfering RNA significantly reduced DCA-induced uPAR and cyclin D1 expression. Blocking uPAR with a neutralizing antibody significantly suppressed DCA-induced colon cancer cell proliferation and invasiveness. These findings provide evidence for a novel mechanism underlying the oncogenic effects of secondary bile acids.


Asunto(s)
Neoplasias del Colon/metabolismo , Proteínas del Citoesqueleto/metabolismo , Ácido Desoxicólico/farmacología , Transducción de Señal , Transactivadores/metabolismo , Bioensayo , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular , Neoplasias del Colon/patología , Ciclina D1/genética , Ciclina D1/metabolismo , Ácido Desoxicólico/metabolismo , Regulación de la Expresión Génica , Humanos , Invasividad Neoplásica , Fosforilación/efectos de los fármacos , ARN Interferente Pequeño/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Tirosina/efectos de los fármacos , Activador de Plasminógeno de Tipo Uroquinasa/genética , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo , beta Catenina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...