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1.
World J Diabetes ; 13(4): 319-337, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35582669

RESUMEN

Insulin, a key pleiotropic hormone, regulates metabolism through several signaling pathways in target tissues including skeletal muscle, liver, and brain. In the brain, insulin modulates learning and memory, and impaired insulin signaling is associated with metabolic dysregulation and neurodegenerative diseases. At the receptor level, in aging and Alzheimer's disease (AD) models, the amount of insulin receptors and their functions are decreased. Clinical and animal model studies suggest that memory improvements are due to changes in insulin levels. Furthermore, diabetes mellitus (DM) and insulin resistance are associated with age-related cognitive decline, increased levels of ß-amyloid peptide, phosphorylation of tau protein; oxidative stress, pro-inflammatory cytokine production, and dyslipidemia. Recent evidence shows that deleting brain insulin receptors leads to mild obesity and insulin resistance without influencing brain size and apoptosis development. Conversely, deleting insulin-like growth factor 1 receptor (IGF-1R) affects brain size and development, and contributes to behavior changes. Insulin is synthesized locally in the brain and is released from the neurons. Here, we reviewed proposed pathophysiological hypotheses to explain increased risk of dementia in the presence of DM. Regardless of the exact sequence of events leading to neurodegeneration, there is strong evidence that mitochondrial dysfunction plays a key role in AD and DM. A triple transgenic mouse model of AD showed mitochondrial dysfunction, oxidative stress, and loss of synaptic integrity. These alterations are comparable to those induced in wild-type mice treated with sucrose, which is consistent with the proposal that mitochondrial alterations are associated with DM and contribute to AD development. Alterations in insulin/IGF-1 signaling in DM could lead to mitochondrial dysfunction and low antioxidant capacity of the cell. Thus, insulin/IGF-1 signaling is important for increased neural processing and systemic metabolism, and could be a specific target for therapeutic strategies to decrease alterations associated with age-related cognitive decline.

2.
Cardiol Rev ; 27(4): 179-181, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31180937

RESUMEN

Multiple strategies have been implemented to increase the donor pool to avoid transplant wait-list mortality. The approval of highly effective direct-acting antiviral regimens for the treatment of hepatitis C virus (HCV) has enabled expansion of the donor pool by allowing the transplantation of organs from HCV-viremic donors to HCV-negative recipients. Multiple centers have recently published data on outcomes of heart transplantation from HCV-viremic heart donors to HCV-negative recipients, with acceptable posttransplant outcomes. However, areas of uncertainty remain, particularly in the long-term risks of intentional HCV transmission, as well as the possibility that sustained virologic response may not be achieved. In this article, we review the literature illustrating both the risks and benefits of transplantation of organs from HCV-viremic donors to HCV-negative recipients. We also present the data collected at our institution regarding this special patient population.


Asunto(s)
Trasplante de Corazón/métodos , Hepacivirus , Hepatitis C/cirugía , Donantes de Tejidos , Receptores de Trasplantes , Viremia/cirugía , Hepatitis C/virología , Humanos , Pronóstico , Viremia/virología
3.
Dis Markers ; 2019: 8761860, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30906485

RESUMEN

Early diagnosis represents the target of contemporary medicine and has an important role in the prognosis and further treatment. Saliva is a biofluid that generated a high interest among researchers due to its multiple advantages over other body fluids. The multitude of components that can act as biomarkers influenced the existing technologies to develop protocols that could allow saliva to become the new noninvasive diagnostic method. Saliva as a diagnostic tool can bring substantial addition to the diagnostic armamentarium, providing important information about oral and general health. The diagnostic applications of saliva extended and had a rapid evolution due to the advancement in salivaomics. The present review summarizes the latest researches in saliva-related studies and explores the information and correlations that saliva can offer regarding the systemic and oral diseases, highlighting its great potential of diagnosis. It is expected that in the future specific guidelines and results regarding the salivary diagnostics are to be available, together with high-sensitivity and specificity tests for multiple systemic and oral diseases.


Asunto(s)
Enfermedades Cardiovasculares/metabolismo , Enfermedades de la Boca/metabolismo , Saliva/metabolismo , Biomarcadores/metabolismo , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/patología , Humanos , Técnicas de Diagnóstico Molecular/métodos , Enfermedades de la Boca/genética , Enfermedades de la Boca/patología
4.
J Immunol Res ; 2018: 7169081, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30406153

RESUMEN

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a glycoprotein belonging to the carcinoembryonic antigen (CEA) family that is expressed on a wide variety of cells and holds a complex role in inflammation through its alternate splicing and generation of various isoforms, mediating intricate mechanisms of modulation and dysregulation. Initially regarded as a tumor suppressor as its expression shows considerable downregulation within the epithelia in the early phases of many solid cancers, CEACAM1 has been linked lately to the progression of malignancy and metastatic spread as various papers point to its role in tumor progression, angiogenesis, and invasion. We reviewed the literature and discussed the various expression patterns of CEACAM1 in different types of tumors, describing its structure and general biologic functions and emphasizing the most significant findings that link this molecule to poor prognosis. The importance of understanding the role of CEACAM1 in cell transformation stands not only in this adhesion molecule's value as a prognostic factor but also in its promising premise as a potential new molecular target that could be exploited as a specific cancer therapy.


Asunto(s)
Antígenos CD/metabolismo , Biomarcadores de Tumor/metabolismo , Moléculas de Adhesión Celular/metabolismo , Células Epiteliales/fisiología , Inflamación/metabolismo , Neoplasias/metabolismo , Empalme Alternativo , Antígeno Carcinoembrionario/metabolismo , Transformación Celular Neoplásica , Humanos , Metástasis de la Neoplasia , Transcriptoma , Proteínas Supresoras de Tumor/metabolismo
5.
Clin Cancer Res ; 24(10): 2276-2284, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29506988

RESUMEN

Purpose: Duligotuzumab is a dual-action antibody directed against EGFR and HER3.Experimental Design: Metastatic colorectal cancer (mCRC) patients with KRAS ex2 wild-type received duligotuzumab or cetuximab and FOLFIRI until progression or intolerable toxicity. Mandatory tumor samples underwent mutation and biomarker analysis. Efficacy analysis was conducted in patients with RAS exon 2/3 wild-type tumors.Results: Of 134 randomly assigned patients, 98 had RAS ex2/3 wild-type. Duligotuzumab provided no progression-free survival (PFS) or overall survival (OS) benefit compared with cetuximab, although there was a trend for a lower objective response rate (ORR) in the duligotuzumab arm. No relationship was seen between PFS or ORR and ERBB3, NRG1, or AREG expression. There were fewer skin rash events for duligotuzumab but more diarrhea. Although the incidence of grade ≥3 AEs was similar, the frequency of serious AEs was higher for duligotuzumab.Conclusions: Duligotuzumab plus FOLFIRI did not appear to improve the outcomes in patients with RAS exon 2/3 wild-type mCRC compared with cetuximab + FOLFIRI. Clin Cancer Res; 24(10); 2276-84. ©2018 AACR.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Camptotecina/análogos & derivados , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Biomarcadores de Tumor , Camptotecina/efectos adversos , Camptotecina/uso terapéutico , Cetuximab/administración & dosificación , Cetuximab/farmacocinética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Femenino , Fluorouracilo/efectos adversos , Fluorouracilo/uso terapéutico , Genes ras , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/farmacología , Leucovorina/efectos adversos , Leucovorina/uso terapéutico , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Mutación , Metástasis de la Neoplasia , Estadificación de Neoplasias , Supervivencia sin Progresión , Retratamiento , Resultado del Tratamiento , Adulto Joven
6.
Medchemcomm ; 8(12): 2258-2262, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30108741

RESUMEN

Novel oxazolidin-2-one-linked 1,2,3-triazole derivatives (4a-k) were synthesized by straightforward and versatile azide-enolate (3 + 2) cycloaddition. The series of compounds was screened for antifungal activity against four filamentous fungi as well as six yeast species of Candida spp. According to their efficiency and breadth of scope, they can be ordered as 4k > 4d > 4h > 4a, especially in relation to the activity displayed against Candida glabrata ATCC-34138, Trichosporon cutaneum ATCC-28592 and Mucor hiemalis ATCC-8690, i.e. compounds 4d, 4h and 4k showed excellent activity against C. glabrata (MIC 0.12, 0.25 and 0.12 µg mL-1, respectively), better than that of itraconazole (MIC 1 µg ml-1). The activity of compound 4d (MIC = 2 µg mL-1) was higher than that observed for the standard antifungal drug (MIC = 8 µg mL-1) against Trichosporon cutaneum, while compound 4k displayed an excellent antimycotic activity against Mucor hiemalis (MIC = 2 µg mL-1vs. 4 µg mL-1 for itraconazole). In addition, we describe herein a novel mild and eco-friendly synthetic protocol for obtaining ß-ketosulfones (adducts to afford compounds 4a-k) from α-brominated carbonyls in an aqueous nanomicellar medium at room temperature.

7.
Science ; 349(6245): 309-12, 2015 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-26113639

RESUMEN

Morphinan alkaloids from the opium poppy are used for pain relief. The direction of metabolites to morphinan biosynthesis requires isomerization of (S)- to (R)-reticuline. Characterization of high-reticuline poppy mutants revealed a genetic locus, designated STORR [(S)- to (R)-reticuline] that encodes both cytochrome P450 and oxidoreductase modules, the latter belonging to the aldo-keto reductase family. Metabolite analysis of mutant alleles and heterologous expression demonstrate that the P450 module is responsible for the conversion of (S)-reticuline to 1,2-dehydroreticuline, whereas the oxidoreductase module converts 1,2-dehydroreticuline to (R)-reticuline rather than functioning as a P450 redox partner. Proteomic analysis confirmed that these two modules are contained on a single polypeptide in vivo. This modular assembly implies a selection pressure favoring substrate channeling. The fusion protein STORR may enable microbial-based morphinan production.


Asunto(s)
Bencilisoquinolinas/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Isoquinolinas/metabolismo , Morfinanos/metabolismo , Papaver/enzimología , Proteínas de Plantas/metabolismo , Compuestos de Amonio Cuaternario/metabolismo , Secuencia de Bases , Bencilisoquinolinas/química , Sistema Enzimático del Citocromo P-450/genética , Sitios Genéticos , Isoquinolinas/química , Datos de Secuencia Molecular , Morfinanos/química , Mutación , Oxidación-Reducción , Papaver/genética , Proteínas de Plantas/genética , Compuestos de Amonio Cuaternario/química
8.
J Exp Anal Behav ; 103(2): 349-60, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25766450

RESUMEN

Equivalence class formation by college students was influenced through the prior acquisition of conditional discriminative functions by one of the abstract stimuli (C) in the to-be-formed classes. Participants in the GR-0, GR-1, and GR-5 groups attempted to form classes under the simultaneous protocol, after mastering 0, 1, or 5 conditional relations between C and other abstract stimuli (V, W, X, Y, Z) that were not included in the to-be-formed classes (ABCDE). Participants in the GR-many group attempted to form classes that contained four abstract stimuli and one meaningful picture as the C stimulus. In the GR-0, GR-1, GR-5, and GR-many groups, classes were formed by 17, 25, 58, and 67% of participants, respectively. Thus, likelihood of class formation was enhanced by the prior formation of five C-based conditional relations (the GR-5 vs. GR-0 condition), or the inclusion of a meaningful stimulus as a class member (the GR-many vs. GR-0 condition). The GR-5 and GR-many conditions produced very similar yields, indicating that class formation was enhanced to a similar degree by including a meaningful stimulus or an abstract stimulus that had become a member of five conditional relations prior to equivalence class formation. Finally, the low and high yields produced by the GR-1 and GR-5 conditions showed that the class enhancement effect of the GR-5 condition was due to the number of conditional relations established during preliminary training and not to the sheer amount of reinforcement provided while learning these conditional relations. Class enhancement produced by meaningful stimuli, then, can be attributed to their acquired conditional discriminative functions as well as their discriminative, connotative, and denotative properties.


Asunto(s)
Aprendizaje Discriminativo , Adolescente , Adulto , Formación de Concepto , Condicionamiento Psicológico , Humanos , Persona de Mediana Edad , Estimulación Luminosa , Refuerzo en Psicología , Adulto Joven
9.
Mol Cell Biol ; 33(8): 1621-31, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23401859

RESUMEN

Substrate engagement by F-box proteins promotes NEDD8 modification of cullins, which is necessary for the activation of cullin-RING E3 ubiquitin ligases (CRLs). However, the mechanism by which substrate recruitment triggers cullin neddylation remains unclear. Here, we identify DCNL1 (defective in cullin neddylation 1-like 1) as a component of CRL2 called ECV (elongins BC/CUL2/VHL) and show that molecular suppression of DCNL1 attenuates CUL2 neddylation. DCNL1 via its DAD patch binds to CUL2 but is also able to bind VHL independent of CUL2 and the DAD patch. The engagement of the substrate hypoxia-inducible factor 1α (HIF1α) to the substrate receptor VHL increases DCNL1 binding to VHL as well as to CUL2. Notably, an engineered mutant form of HIF1α that associates with CUL2, but not DCNL1, fails to trigger CUL2 neddylation and retains ECV in an inactive state. These findings support a model in which substrate engagement prompts DCNL1 recruitment that facilitates the initiation of CUL2 neddylation and define DCNL1 as a "substrate sensor switch" for ECV activation.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas Cullin/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Proteínas de Ciclo Celular/genética , Línea Celular , Células HEK293 , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Péptidos y Proteínas de Señalización Intracelular , Mutación , Unión Proteica , Proteínas , Proteínas Proto-Oncogénicas , Interferencia de ARN , ARN Interferente Pequeño
10.
Ciudad Autónoma de Buenos Aires; Ministerio de Salud de la Nación; 2012. 1 p.
No convencional en Español | ARGMSAL, BINACIS | ID: biblio-1554077

RESUMEN

INTRODUCCIÓN El cáncer de mama (CM) es una enfermedad poligénica multifactorial. Debido a variantes polimórficas (VP) en genes que intervienen en la metabolización de sustancias químicas, aumenta el riesgo de desarrollar la enfermedad. OBJETIVOS Estimar las frecuencias alélicas y genotípicas de las VP CYP1B1-Val432Leu, CYP1A1-T6235C y GSTP1-Ile105Val, y analizar su asociación con el desarrollo de CM y el fenotipo tumoral. MÉTODOS Con el método de casos y controles, se llevaron a cabo estudios genéticos moleculares a 170 pacientes con diagnóstico confirmado de CM y 170 controles mediante técnicas de extracción de ADN, amplificación y análisis de polimorfismos en la longitud de los fragmentos de restricción. Los datos obtenidos se analizaron estadísticamente mediante el cálculo de OR. Resultados Se observó que la presencia del alelo Val, en la VP GSTP1-Ile105Val, confiere un efecto protector (OR: 0,67; IC95%: 0,49-0,92; P=0,01) cuando se encuentra en homocigosis en la población de estudio (OR: 0,41; IC95% 0,21-0,82; P=0,009). La VP CYP1B1-Val432Leu no mostró asociación estadísticamente significativa a mayor riesgo de CM en la población de estudio. El análisis de asociación entre VP e histología tumoral no presentó resultados estadísticamente significativos. DISCUSIÓN Los resultados aportan un primer registro de la relación de las frecuencias alélicas y genotípicas de las VP estudiadas en pacientes con CM. Sería importante ampliar el estudio a otras poblaciones de Argentina y de Latinoamérica.


Asunto(s)
Polimorfismo Genético , Neoplasias de la Mama , Factores de Riesgo , Epidemiología Molecular , Compuestos Químicos
11.
Cleve Clin J Med ; 78(9): 585-92, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21885690

RESUMEN

Blood tests are available that measure levels of immunoglobulin E (IgE) against specific allergens such as foods, inhalants, medications, latex, and venoms. These tests can confirm the diagnosis of an allergic disorder, supplementing a clinical history consistent with an immediate allergic reaction. They are particularly useful when skin testing cannot or should not be performed.


Asunto(s)
Pruebas Hematológicas/métodos , Hipersensibilidad Inmediata/sangre , Inmunoglobulina E/sangre , Hipersensibilidad a las Drogas/sangre , Hipersensibilidad a las Drogas/diagnóstico , Hipersensibilidad a los Alimentos/sangre , Hipersensibilidad a los Alimentos/diagnóstico , Pruebas Hematológicas/instrumentación , Humanos , Inmunoensayo/instrumentación , Inmunoensayo/métodos , Inmunoglobulina E/inmunología , Exposición por Inhalación , Mordeduras y Picaduras de Insectos/complicaciones , Medición de Riesgo , Sensibilidad y Especificidad
12.
Haematologica ; 96(10): 1406-14, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21685469

RESUMEN

BACKGROUND: KANK1-PDGFRB is a fusion gene generated by the t(5;9) translocation between KANK1 and the platelet-derived growth factor receptor beta gene PDGFRB. This hybrid was identified in a myeloproliferative neoplasm featuring severe thrombocythemia, in the absence of the JAK2 V617F mutation. DESIGN AND METHODS: KANK1-PDGFRB was transduced into Ba/F3 cells and CD34(+) human progenitor cells to gain insights into the mechanisms whereby this fusion gene transforms cells. RESULTS: Although platelet-derived growth factor receptors are capable of activating JAK2, KANK1-PDGFRß did not induce JAK2 phosphorylation in hematopoietic cells and a JAK inhibitor did not affect KANK1-PDGFRß-induced cell growth. Like JAK2 V617F, KANK1-PDGFRß constitutively activated STAT5 transcription factors, but this did not require JAK kinases. In addition KANK1-PDGFRß induced the phosphorylation of phospholipase C-γ, ERK1 and ERK2, like wild-type PDGFRß and TEL-PDGFRß, another hybrid protein found in myeloid malignancies. We next tested various mutant forms of KANK1-PDGFRß in Ba/F3 cells and human CD34(+) hematopoietic progenitors. The three coiled-coil domains located in the N-terminus of KANK1 were required for KANK1-PDGFRß-induced cell growth and signaling via STAT5 and ERK. However, the coiled-coils were not essential for KANK1-PDGFRß oligomerization, which could be mediated by another new oligomerization domain. KANK1-PDGFRß formed homotrimeric complexes and heavier oligomers. CONCLUSIONS: KANK1-PDGFRB is a unique example of a thrombocythemia-associated oncogene that does not signal via JAK2. The fusion protein is activated by multiple oligomerization domains, which are required for signaling and cell growth stimulation.


Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Janus Quinasa 2/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Factor de Transcripción STAT5/metabolismo , Transducción de Señal , Proteínas Supresoras de Tumor/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Línea Celular Transformada , Proliferación Celular , Proteínas del Citoesqueleto , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Células Madre Hematopoyéticas/metabolismo , Humanos , Trastornos Mieloproliferativos/genética , Trastornos Mieloproliferativos/metabolismo , Proteínas de Fusión Oncogénica/genética , Fosforilación , Multimerización de Proteína , Estructura Terciaria de Proteína , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/genética , Proteínas Supresoras de Tumor/genética
13.
Nat Med ; 17(7): 845-53, 2011 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-21685897

RESUMEN

Chuvash polycythemia is a rare congenital form of polycythemia caused by homozygous R200W and H191D mutations in the VHL (von Hippel-Lindau) gene, whose gene product is the principal negative regulator of hypoxia-inducible factor. However, the molecular mechanisms underlying some of the hallmark abnormalities of Chuvash polycythemia, such as hypersensitivity to erythropoietin, are unclear. Here we show that VHL directly binds suppressor of cytokine signaling 1 (SOCS1) to form a heterodimeric E3 ligase that targets phosphorylated JAK2 (pJAK2) for ubiquitin-mediated destruction. In contrast, Chuvash polycythemia-associated VHL mutants have altered affinity for SOCS1 and do not engage with and degrade pJAK2. Systemic administration of a highly selective JAK2 inhibitor, TG101209, reversed the disease phenotype in Vhl(R200W/R200W) knock-in mice, an experimental model that recapitulates human Chuvash polycythemia. These results show that VHL is a SOCS1-cooperative negative regulator of JAK2 and provide biochemical and preclinical support for JAK2-targeted therapy in individuals with Chuvash polycythemia.


Asunto(s)
Janus Quinasa 2/fisiología , Policitemia/etiología , Proteínas Supresoras de la Señalización de Citocinas/genética , Ubiquitina-Proteína Ligasas/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Animales , Modelos Animales de Enfermedad , Humanos , Janus Quinasa 2/antagonistas & inhibidores , Ratones , Mutación/genética , Policitemia/genética , Multimerización de Proteína/genética , Pirimidinas/farmacología , Sulfonamidas/farmacología , Proteína 1 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/fisiología , Ubiquitina-Proteína Ligasas/fisiología , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/fisiología
14.
Artículo en Inglés | MEDLINE | ID: mdl-22649382

RESUMEN

The thrombopoietin receptor (TpoR) is a type I transmembrane protein that mediates the signaling functions of thrombopoietin (Tpo) in regulating megakaryocyte differentiation, platelet formation, and hematopoietic stem cell renewal. We probed the role of each of the four extracellular domain putative N-glycosylation sites for cell surface localization and function of the receptor. Single N-glycosylation mutants at any of the four sites were able to acquire the mature N-glycosylated pattern, but exhibited a decreased Tpo-dependent JAK2-STAT response in stably transduced Ba/F3 or Ba/F3-JAK2 cell lines. The ability of JAK2 to promote cell surface localization and stability of TpoR required the first N-glycosylation site (Asn117). In contrast, the third N-glycosylation site (Asn298) decreased receptor maturation and stability. TpoR mutants lacking three N-glycosylation sites were defective in maturation, but N-glycosylation on the single remaining site could be detected by sensitivity to PNGaseF. The TpoR mutant defective in all four N-glycosylation sites was severely impaired in plasma membrane localization and was degraded by the proteasome. N-glycosylation receptor mutants are not misfolded as, once localized on the cell surface in overexpression conditions, they can bind and respond to Tpo. Our data indicate that extracellular domain N-glycosylation sites regulate in a combinatorial manner cell surface localization of TpoR. We discuss how mutations around TpoR N-glycosylation sites might contribute to inefficient receptor traffic and disease.

15.
EMBO Mol Med ; 1(1): 66-78, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20049704

RESUMEN

Tumour hypoxia promotes the accumulation of the otherwise oxygen-labile hypoxia-inducible factor (HIF)-alpha subunit whose expression is associated with cancer progression, poor prognosis and resistance to conventional radiation and chemotherapy. The oxygen-dependent degradation of HIF-alpha is carried out by the von Hippel-Lindau (VHL) protein-containing E3 that directly binds and ubiquitylates HIF-alpha for subsequent proteasomal destruction. Thus, the cellular proteins involved in the VHL-HIF pathway have been recognized as attractive molecular targets for cancer therapy. However, the various compounds designed to inhibit HIF-alpha or HIF-downstream targets, although promising, have shown limited success in the clinic. In the present study, we describe the bioengineering of VHL protein that removes the oxygen constraint in the recognition of HIF-alpha while preserving its E3 enzymatic activity. Using speckle variance-optical coherence tomography (sv-OCT), we demonstrate the dramatic inhibition of angiogenesis and growth regression of human renal cell carcinoma xenografts upon adenovirus-mediated delivery of the bioengineered VHL protein in a dorsal skin-fold window chamber model. These findings introduce the concept and feasibility of 'bio-tailored' enzymes in the treatment of HIF-overexpressing tumours.


Asunto(s)
Bioingeniería , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Oxígeno/farmacología , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Proteínas Recombinantes de Fusión/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Adenoviridae/genética , Animales , Translocador Nuclear del Receptor de Aril Hidrocarburo/metabolismo , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/terapia , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Transferencia de Gen , Proteínas Fluorescentes Verdes/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/química , Neoplasias Renales/genética , Neoplasias Renales/patología , Neoplasias Renales/terapia , Ratones , Necrosis , Neovascularización Patológica/terapia , Plásmidos/genética , Unión Proteica/efectos de los fármacos , Estructura Terciaria de Proteína , Elementos de Respuesta/genética , Transcripción Genética/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Ann Oncol ; 19(2): 327-31, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18065408

RESUMEN

BACKGROUND: The amount of residual disease after surgery is considered the most important factor influencing the survival of patients with advanced epithelial ovarian cancer (adEOC). In optimally treated patients with adEOC, there are no well-established prognostic factors [excluding International Federation of Gynecology and Obstetrics (FIGO) stage]. The aim of this retrospective study is to analyze the prognostic value of the CA-125 nadir after the completion of an optimal primary treatment. PATIENTS AND METHODS: Patients treated for adEOC were identified from January 1998 to December 2006. INCLUSION CRITERIA: elevated CA-125 at time of diagnosis (>35 kU/l); FIGO stage III-IV treated with optimal primary treatment (residual tumor <1 cm and carboplatin/taxane-based combination chemotherapy); and complete response to optimal primary treatment with normalization of CA-125. RESULTS: Patients, n = 96: 44 group A (< or =10 kU/l); 52 group B (11-35 kU/l). Median progression-free survival (PFS) was 42 and 20 months for groups A and B, respectively (P = 0.0087). Median overall survival (OS) was 84 and 43 months for groups A and B, respectively (P < 0.0001). The Cox model showed a highly significant impact on PFS and OS in relation to CA-125 nadir levels. CONCLUSIONS: The CA-125 nadir value is a strong independent prognostic factor for optimally treated adEOC after achieving a complete response.


Asunto(s)
Antígeno Ca-125/sangre , Invasividad Neoplásica/patología , Neoplasias Glandulares y Epiteliales/sangre , Neoplasias Glandulares y Epiteliales/mortalidad , Neoplasias Ováricas/sangre , Neoplasias Ováricas/mortalidad , Adulto , Anciano , Biomarcadores de Tumor/sangre , Quimioterapia Adyuvante , Estudios de Cohortes , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Glandulares y Epiteliales/terapia , Neoplasias Ováricas/patología , Neoplasias Ováricas/terapia , Ovariectomía/métodos , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Radioterapia Adyuvante , Sistema de Registros , Estudios Retrospectivos , Medición de Riesgo , Segunda Cirugía , Sensibilidad y Especificidad , España , Análisis de Supervivencia , Factores de Tiempo
17.
Mol Cell Biol ; 27(1): 157-69, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17060462

RESUMEN

The product of the von Hippel-Lindau gene (VHL) acts as the substrate-recognition component of an E3 ubiquitin ligase complex that ubiquitylates the catalytic alpha subunit of hypoxia-inducible factor (HIF) for oxygen-dependent destruction. Although emerging evidence supports the notion that deregulated accumulation of HIF upon the loss of VHL is crucial for the development of clear-cell renal cell carcinoma (CC-RCC), the molecular events downstream of HIF governing renal oncogenesis remain unclear. Here, we show that the expression of a homophilic adhesion molecule, E-cadherin, a major constituent of epithelial cell junctions whose loss is associated with the progression of epithelial cancers, is significantly down-regulated in primary CC-RCC and CC-RCC cell lines devoid of VHL. Reintroduction of wild-type VHL in CC-RCC (VHL(-/-)) cells markedly reduced the expression of E2 box-dependent E-cadherin-specific transcriptional repressors Snail and SIP1 and concomitantly restored E-cadherin expression. RNA interference-mediated knockdown of HIFalpha in CC-RCC (VHL(-/-)) cells likewise increased E-cadherin expression, while functional hypoxia or expression of VHL mutants incapable of promoting HIFalpha degradation attenuated E-cadherin expression, correlating with the disengagement of RNA polymerase II from the endogenous E-cadherin promoter/gene. These findings reveal a critical HIF-dependent molecular pathway connecting VHL, an established "gatekeeper" of the renal epithelium, with a major epithelial tumor suppressor, E-cadherin.


Asunto(s)
Cadherinas/biosíntesis , Regulación Neoplásica de la Expresión Génica , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Proteínas del Tejido Nervioso/fisiología , Proteínas de Unión al ARN/fisiología , Factores de Transcripción/fisiología , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/fisiología , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Células Epiteliales/metabolismo , Humanos , Riñón/metabolismo , Regiones Promotoras Genéticas , Interferencia de ARN , ARN Polimerasa II/metabolismo , ARN Interferente Pequeño/metabolismo , Factores de Transcripción de la Familia Snail , Fracciones Subcelulares/metabolismo
18.
Neoplasia ; 8(11): 956-63, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17132228

RESUMEN

ECV is an E3 ubiquitin ligase complex, which is composed of elongins B and C, Rbx1, Cul2, and the substrate-conferring von Hippel-Lindau (VHL) tumor-suppressor protein that targets the catalytic alpha subunit of hypoxia-inducible factor (HIF) for oxygen-dependent ubiquitin-mediated destruction. Mutations in VHL that compromise proper HIFalpha regulation through ECV have been documented in the majority of renal cell carcinomas, underscoring the significance of the VHL-HIF pathway in renal epithelial oncogenesis. Recent evidence has shown that the modification of Cul2 by the ubiquitin-like molecule NEDD8 increases the activity of ECV to ubiquitylate HIFalpha. However, the underlying mechanism responsible for the NEDD8-mediated induction of ECV function is unknown. Here, we demonstrate that oxygen-dependent recognition of HIFalpha by VHL triggers Rbx1-dependent neddylation of Cul2, which preferentially engages the E2 ubiquitin-conjugating enzyme UbcH5a. These events establish a central role for the neddylation of Cul2 in a previously unrecognized, temporally coordinated activation of ECV with the recruitment of its substrate HIFalpha.


Asunto(s)
Proteínas Cullin/fisiología , Ubiquitina-Proteína Ligasas/química , Ubiquitinas/fisiología , Proteínas Portadoras/metabolismo , Dominio Catalítico , Línea Celular , Proteínas Cullin/metabolismo , Humanos , Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Proteínas de Unión a Hierro/metabolismo , Modelos Biológicos , Mutación , Proteína NEDD8 , Oxígeno/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Enzimas Ubiquitina-Conjugadoras/metabolismo , Ubiquitinas/metabolismo
19.
Am J Physiol Renal Physiol ; 287(1): F1-6, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15180922

RESUMEN

The majority of kidney cancers are caused by the mutation of the von Hippel-Lindau (VHL) tumor suppressor gene. VHL protein (pVHL) is part of an E3 ubiquitin ligase complex called VEC that is composed of elongin B, elongin C, cullin 2, NEDD8, and Rbx1. VEC targets a hypoxia-inducible factor (HIF) transcription factor for ubiquitin-mediated destruction selectively in the presence of oxygen. In the absence of wild-type pVHL, as in VHL patients or in the majority of sporadic clear cell renal cell carcinomas, HIF-responsive genes are inappropriately activated even under normoxia. Recent insights into the molecular mechanisms regulating the function of pVHL, and thereby HIF, in the context of kidney cancer are the focus of this review.


Asunto(s)
Carcinoma de Células Renales/genética , Carcinoma de Células Renales/fisiopatología , Hipoxia de la Célula , Neoplasias Renales/genética , Neoplasias Renales/fisiopatología , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/farmacología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/farmacología , Enfermedad de von Hippel-Lindau/genética , Genes Supresores de Tumor , Humanos , Mutación , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau , Enfermedad de von Hippel-Lindau/fisiopatología
20.
Rev Lat Am Enfermagem ; 10(1): 21-7, 2002.
Artículo en Portugués | MEDLINE | ID: mdl-12080584

RESUMEN

This study aimed at analyzing the conformation of the Epidemiological Surveillance Service in Ribeirão Preto Municipal Health Secretariat under the orientation of the principles established by the Unified Health System and the perspective of Health Surveillance in face of the health care municipalization process occurring in the 1990s through the following dimensions: territory; problems; intersectoriality based on positive health concepts and on the paradigm of social health production. By means of a qualitative approach, bibliographical and documentation sources as well as 17 semi-structured interviews were used. Data were analyzed through the thematic analysis technique by which the following themes were identified: from "Monitoring" to "Educating and Preventing": practice in Epidemiological Surveillance--a proposal to work in the territory. It was concluded that the potentiality of actions related to Epidemiological Surveillance is associated with the perspective of working in the territory for the construction of Health Surveillance in order to assure the technical content of those actions as well as the participation of different professional categories in the same work project, which will not necessarily be performed by all professionals in the same health production process, territory or time.


Asunto(s)
Vigilancia de la Población , Enfermería en Salud Pública , Brasil , Agencias Gubernamentales , Humanos
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