RESUMEN
BACKGROUND: Educational attainment is important in shaping young people's life prospects. To investigate whether being born with orofacial cleft (OFC) affects school performance, we compared school test results between children born with and without OFC. METHODS: Using record-linked datasets, we conducted a population-based cohort study of children liveborn in Western Australia 1980-2010 with a diagnosis of OFC on the Register of Developmental Anomalies, and a random sample of 6603 children born without OFC. We compared odds ratios for meeting national minimum standards in five domains (reading, numeracy, writing, spelling, grammar and punctuation), and adjusted OR (aOR) for children with cleft lip only (CLO), cleft lip and palate (CL + P) and cleft palate only (CPO) for each domain. RESULTS: Results from two testing programs (WALNA and NAPLAN) were available for 3238 (89%) children expected to participate. Most met the national minimum standards. Compared with children without OFC, children with CPO were less likely to meet minimum standards for NAPLAN reading (aOR 0.57 [95%CI 0.34, 0.96]) grammar and punctuation (aOR 0.49 [95%CI 0.32, 0.76]), WALNA writing (aOR 0.66 [95%CI 0.47, 0.92]), and WALNA and NAPLAN numeracy (aOR 0.64 [95%CI 0.43, 0.95] and aOR 0.47 [95%CI 0.28, 0.82]), respectively. Children with CL + P had significantly lower odds for reaching the spelling standard in NAPLAN tests (aOR 0.52 [95%CI 0.29, 0.94]). Children with CLO had similar odds for reaching all minimum standards. CONCLUSION: Children born with OFC, particularly children with CPO, should be monitored to identify learning difficulties early, to enable intervention to maximize school attainment.
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Labio Leporino/psicología , Fisura del Paladar/psicología , Escolaridad , Discapacidades para el Aprendizaje/etiología , Niño , Labio Leporino/epidemiología , Fisura del Paladar/epidemiología , Estudios de Cohortes , Femenino , Humanos , Discapacidades para el Aprendizaje/epidemiología , Masculino , Registro Médico Coordinado , Instituciones Académicas , Clase Social , Australia Occidental/epidemiologíaRESUMEN
In our earlier studies, Semliki Forest virus vector VA7 completely eliminated type I interferon (IFN-I)-unresponsive human U87-luc glioma xenografts, whereas interferon-responsive mouse gliomas proved refractory. Here, we describe in two clones of CT26 murine colon carcinoma, opposed patterns of IFN-I responsiveness and sensitivity to VA7. Both CT26WT and CT26LacZ clones secreted biologically active interferon in vitro upon virus infection but only CT26WT cells were protected. Focal infection of CT26WT cultures was self-limiting but could be rescued using IFN-I pathway inhibitor Ruxolitinib or antibody against IFNß. Whole transcriptome sequencing (RNA-Seq) and protein expression analysis revealed that CT26WT cells constitutively expressed 56 different genes associated with pattern recognition and IFN-I signaling pathways, spanning two reported anti-RNA virus gene signatures and 22 genes with reported anti-alphaviral activity. Whereas CT26WT tumors were strictly virus-resistant in vivo, infection of CT26LacZ tumors resulted in complete tumor eradication in both immunocompetent and severe combined immune deficient mice. In double-flank transplantation experiments, CT26WT tumors grew despite successful eradication of CT26LacZ tumors from the contralateral flank. Tumor growth progressed uninhibited also when CT26LacZ inoculums contained only a small fraction of CT26WT cells, demonstrating dominance of IFN responsiveness when heterogeneous tumors are targeted with interferon-sensitive oncolytic viruses.
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Neoplasias del Colon/terapia , Viroterapia Oncolítica , Virus Oncolíticos/genética , Virus de los Bosques Semliki/genética , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Efecto Espectador , Línea Celular Tumoral , Neoplasias del Colon/inmunología , Neoplasias del Colon/patología , Vectores Genéticos , Proteínas Fluorescentes Verdes/biosíntesis , Interferón Tipo I/farmacología , Interferón Tipo I/uso terapéutico , Interferón beta/metabolismo , Ratones Endogámicos BALB C , Necrosis , Trasplante de Neoplasias , Factor de Transcripción STAT1/metabolismo , Transfección , Resultado del TratamientoRESUMEN
The use of oncolytic viruses (OV) to precisely target and eliminate tumors ('virotherapy') is a rapidly evolving therapeutic approach to treating cancer. A major obstacle in virotherapy, especially for systemic administration, is the host's immune response towards the OV. In the case of measles virus (MeV), most individuals have been immunized against this agent leading to pre-existing neutralizing antibodies that can impair OV delivery to the tumor. These antibodies predominantly target the hemagglutinin (H) and fusion (F) envelope glycoproteins displayed at the particle's surface. Here, we introduce a novel and versatile pseudotyping platform for rapid envelope exchange of oncolytic MeV that allows for engineering of chimeric viruses invulnerable to pre-existing anti-MeV antibodies. Using this system, we have successfully exchanged the MeV F and H proteins with the glycoprotein G of vesicular stomatitis virus (VSV) and the surface proteins of Newcastle disease virus (NDV) or canine distemper virus (CDV), all of which are not endemic in the general human population. While the MeV-VSV and MeV-NDV pseudotypes were non-functional, the MeV-CDV pseudotype was successfully propagated to high-titer virus stocks. This study describes the successful generation of a robust envelope exchange platform for oncolytic MeV while also highlighting its intricate pseudotyping tolerance.
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Viroterapia Oncolítica , Virus Oncolíticos , Animales , Anticuerpos Neutralizantes , Virus del Sarampión/genética , Virus Oncolíticos/genética , Virus de la Estomatitis Vesicular IndianaRESUMEN
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 µm diameter hot core.
RESUMEN
Interferons are circulating factors that bind to cell surface receptors, activating a signaling cascade, ultimately leading to both an antiviral response and an induction of growth inhibitory and/or apoptotic signals in normal and tumor cells. Attempts to exploit the ability of interferons to limit the growth of tumors in patients has met with limited results because of cancer-specific mutations of gene products in the interferon pathway. Although interferon-non-responsive cancer cells may have acquired a growth/survival advantage over their normal counterparts, they may have simultaneously compromised their antiviral response. To test this, we used vesicular stomatitis virus (VSV), an enveloped, negative-sense RNA virus exquisitely sensitive to treatment with interferon. VSV rapidly replicated in and selectively killed a variety of human tumor cell lines even in the presence of doses of interferon that completely protected normal human primary cell cultures. A single intratumoral injection of VSV was effective in reducing the tumor burden of nude mice bearing subcutaneous human melanoma xenografts. Our results support the use of VSV as a replication-competent oncolytic virus and demonstrate a new strategy for the treatment of interferon non-responsive tumors.
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Efecto Citopatogénico Viral , Neoplasias Experimentales/terapia , Neoplasias Experimentales/virología , Virus de la Estomatitis Vesicular Indiana/patogenicidad , Animales , Médula Ósea/virología , Humanos , Leucemia Mieloide Aguda/virología , Melanoma Experimental/terapia , Melanoma Experimental/virología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Células Tumorales Cultivadas/virología , Virus de la Estomatitis Vesicular Indiana/efectos de los fármacosRESUMEN
By conferring systemic protection and durable benefits, cancer immunotherapies are emerging as long-term solutions for cancer treatment. One such approach that is currently undergoing clinical testing is a therapeutic anti-cancer vaccine that uses two different viruses expressing the same tumor antigen to prime and boost anti-tumor immunity. By providing the additional advantage of directly killing cancer cells, oncolytic viruses (OVs) constitute ideal platforms for such treatment strategy. However, given that the targeted tumor antigen is encoded into the viral genomes, its production requires robust infection and therefore, the vaccination efficiency partially depends on the unpredictable and highly variable intrinsic sensitivity of each tumor to OV infection. In this study, we demonstrate that anti-cancer vaccination using OVs (Adenovirus (Ad), Maraba virus (MRB), Vesicular stomatitis virus (VSV) and Vaccinia virus (VV)) co-administered with antigenic peptides is as efficient as antigen-engineered OVs and does not depend on viral replication. Our strategy is particularly attractive for personalized anti-cancer vaccines targeting patient-specific mutations. We suggest that the use of OVs as adjuvant platforms for therapeutic anti-cancer vaccination warrants testing for cancer treatment.
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Antígenos de Neoplasias/administración & dosificación , Vacunas contra el Cáncer/administración & dosificación , Neoplasias/terapia , Viroterapia Oncolítica/métodos , Virus Oncolíticos/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Animales , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer/genética , Vacunas contra el Cáncer/inmunología , Línea Celular Tumoral , Ensayos Clínicos Fase I como Asunto , Ensayos Clínicos Fase II como Asunto , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Neoplasias/inmunología , Virus Oncolíticos/genética , Poli I-C/administración & dosificación , Poli I-C/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Virus Vaccinia , Virus de la Estomatitis Vesicular Indiana , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The 5th Canadian Cancer Research Conference (ccrc) took place 3-5 November 2019 in Ottawa, Ontario. Nearly 1000 participants-scientists, oncologists, community members, and patients-gathered to share knowledge, foster collaboration, and fuel the future of cancer research in Canada. The scientific program included 3 plenary sessions, 26 concurrent sessions, and 2 poster sessions presenting research described in more than 600 submitted abstracts, giving participants the opportunity to share health research that collectively encompassed the 4 pillars recognized by the Canadian Institutes of Health Research. In addition to the breadth of topics addressed by Canadian and international experts, the highlights of the meeting included the integration of patients and patient advocates, new rapid-fire sessions for abstract presentation, and events that enhanced learning opportunities for trainees.
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Neoplasias/epidemiología , Canadá , Historia del Siglo XXI , HumanosRESUMEN
Live cells offer unique advantages as vehicles for systemic oncolytic virus (OV) delivery. Recent studies from our laboratory and others have shown that virus-infected cells can serve as Trojan horse vehicles to evade antiviral mechanisms encountered in the bloodstream, prevent uptake by off-target tissues and act as microscale factories to produce OV upon arrival in tumor beds. However to be employed effectively, OV-infected cells are best viewed as dynamic biological systems rather than static therapeutic agents. The time-dependent processes of infection and in vivo cell trafficking will inevitably vary depending on which particular OV is being delivered, as well as the type of carrier cells (CC) employed. Understanding these parameters with respect to each unique CC/OV combination will therefore be required in order to effectively evaluate and harness their potential in preclinical study. In the following review, we discuss how early studies of OV delivery led us to investigate the use of cell carriers in our laboratory, and the approaches we are currently undertaking to compare the dynamics of different CC/OV systems. On the basis of these studies and others it is apparent that the success of any cell-based system for OV delivery rests upon the coordinated timing of three sequential phases--(1) ex vivo loading, (2) stealth delivery and (3) virus production at the tumor site. While at the current time, the timing of these processes are coupled to the natural cycle of infection and in vivo trafficking properties innate to each cell virus system, a quantitative delineation of their dynamics will lay the foundation for engineering CC/OV biotherapeutic systems that can be clinically deployed in a highly directed and controlled manner.
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Terapia Genética/métodos , Neoplasias/terapia , Viroterapia Oncolítica/métodos , Virus Oncolíticos/fisiología , Animales , Trasplante de Células/métodos , Técnicas de Transferencia de Gen , Humanos , Neoplasias/inmunologíaRESUMEN
AIM: To determine population-based rates and outcomes of pre-gestational diabetes mellitus (pre-GDM) and gestational diabetes mellitus (GDM) in pregnancy. METHODS: This was a cross-sectional study, using linked population databases, of all women, and their infants, discharged from hospital following birth in New South Wales (NSW) between 1 July 1998 and 31 December 2002. Women with, and infants exposed to pre-GDM or GDM were compared with those without diabetes mellitus for pregnancy characteristics and outcomes. RESULTS: Women with a singleton pregnancy (n = 370,703) and their infants were included: 1248 women (0.3%) had pre-GDM and 17,128 (4.5%) had GDM. Of those women with pre-GDM, 57% had Type 1 diabetes, 20% had Type 2 diabetes and for 23% the type of diabetes was unknown. Major maternal morbidity or mortality was more common in women with pre-GDM (7.9%) [odds ratio (OR) 3.2, 95% confidence interval (CI) 2.6, 3.9] and in women with GDM (3.1%) (OR 1.2, 95% CI 1.1, 1.4) when compared with women without diabetes (2.6%). Major infant morbidity or mortality occurred more frequently in infants exposed to pre-GDM compared with no diabetes (13.6% vs. 3.1%) (OR 5.0, 95% CI 4.2, 5.8) and in infants exposed to GDM compared with no diabetes (3.2% vs. 2.3%) (OR 1.4, 95% CI 1.3, 1.5). CONCLUSIONS: Pre-GDM and GDM continue to be associated with an increased risk of adverse maternal and neonatal outcomes; however, women with GDM have adverse outcomes less frequently. Rates of GDM and pre-GDM appear to be increasing over time. Clinicians should consider the potential for adverse outcomes, and arrange referral to appropriate services.
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Diabetes Gestacional/epidemiología , Estado Prediabético/epidemiología , Adulto , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Humanos , Edad Materna , Nueva Gales del Sur/epidemiología , Embarazo , Resultado del Embarazo/epidemiologíaRESUMEN
Patients with high-risk bladder cancer who do not respond to bacillus Calmette-Guerin (BCG) immunotherapy represent a significant therapeutic challenge. The addition of interferon to BCG has recently evolved as a second-line treatment option; however, many high-grade tumors are nonresponsive to interferon. Thus, replication-competent oncolytic vesicular stomatitis viruses (VSV) that selectively target interferon-refractory tumors are promising intravesical agents. In vitro, wild-type VSV as well as a mutant variant (AV3) that has an impaired ability to shut down innate immunity preferentially killed undifferentiated, interferon-nonresponsive bladder cancer cells. Testing of these viruses in an orthotopic murine model of high-grade bladder cancer, which we have recently validated, revealed that both AV3 and wild-type VSV significantly inhibited orthotopic tumor growth. Despite the use of immunocompromised nude mice, there was no evidence of toxicity. In conclusion, VSV instillation therapy demonstrated strong antitumor activity and safety in an orthotopic model of high-risk disease. These findings provide preclinical proof-of-principle for the intravesical use of VSV, especially in interferon-refractory patients.
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Carcinoma de Células Transicionales/terapia , Viroterapia Oncolítica/métodos , Virus de la Estomatitis Vesicular Indiana/genética , Administración Intravesical , Animales , Carcinoma de Células Transicionales/inmunología , Carcinoma de Células Transicionales/patología , Línea Celular Tumoral , Luciferina de Luciérnaga , Humanos , Interferones/metabolismo , Ratones , Ratones Desnudos , Mutación/genética , Invasividad Neoplásica , Trasplante de Neoplasias , Carga Tumoral , Vejiga Urinaria/inmunología , Vejiga Urinaria/patología , Virus de la Estomatitis Vesicular Indiana/inmunología , Replicación ViralRESUMEN
Treatments for hematological malignancies have improved considerably over the past decade, but the growing therapeutic arsenal has not benefited adult T-cell leukemia (ATL) patients. Oncolytic viruses such as vesicular stomatitis virus (VSV) have recently emerged as a potential treatment of solid tumors and leukemias in vitro and in vivo. In the current study, we investigated the ability of VSV to lyse primary human T-lymphotropic virus type 1 (HTLV-1)-infected T-lymphocytes from patients with ATL. Ex vivo primary ATL cells were permissive for VSV and underwent rapid oncolysis in a time-dependent manner. Importantly, VSV infection showed neither viral replication nor oncolysis in HTLV-1-infected, nonleukemic cells from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and in naive CD4(+) T-lymphocytes from normal individuals or in ex vivo cell samples from patients with chronic lymphocytic leukemia (CLL). Interestingly, activation of primary CD4(+) T-lymphocytes with anti-CD3/CD28 monoclonal antibody, and specifically with anti-CD3, was sufficient to induce limited viral replication and oncolysis. However, at a similar level of T-cell activation, VSV replication was increased fourfold in ATL cells compared to activated CD4(+) T-lymphocytes, emphasizing the concept that VSV targets genetic defects unique to tumor cells to facilitate its replication. In conclusion, our findings provide the first essential information for the development of a VSV-based treatment for ATL.
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Leucemia de Células T/terapia , Leucemia de Células T/virología , Virus de la Estomatitis Vesicular Indiana/fisiología , Animales , Linfocitos T CD4-Positivos/virología , Muerte Celular , Línea Celular , Línea Celular Tumoral , Cricetinae , Humanos , Activación de Linfocitos , Replicación ViralRESUMEN
We transfected the human EJ bladder carcinoma oncogene (Ha-rasEJ-1) into multipotential embryonal carcinoma cell line P19. The transgenic P19(ras+) cells expressed high levels of both the mRNA and the p21EJ protein derived from the oncogene. When cultured in the presence of retinoic acid, P19(ras+) cells differentiated and developed into the same spectrum of differentiated cell types as the parental P19 cells (namely, neurons, astrocytes, and fibroblast-like cells). Thus, it seems unlikely that the Ha-ras-1 proto-oncogene product plays a role in initiation of differentiation or in the choice of differentiated cell lineage. Most of the P19(ras+)-derived differentiated cells contained relatively low levels of p21EJ and were nontransformed, whereas certain cells with fibroblast-like morphology continued to express the Ha-rasEJ-1 gene at high levels and were transformed (i.e., immortal and anchorage independent). Fibroblasts derived from P19 cells did not become transformed following transfection of the Ha-rasEJ-1 oncogene, suggesting that transformation of the fibroblast cells only occurred if the oncogene was present and expressed during the early stages of the developmental lineage.
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Transformación Celular Neoplásica , Oncogenes , Animales , Diferenciación Celular , Línea Celular , Humanos , Cinética , Ratones , Proto-Oncogenes Mas , Teratoma , Neoplasias de la Vejiga Urinaria/genética , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Double-stranded RNA (dsRNA) of viral origin triggers two programs of the innate immunity in virus-infected cells. One is intended to decrease the rate of host cell protein synthesis and thus to prevent viral replication. This program is mediated by protein kinase R (PKR) and by RNase L and contributes, eventually, to the self-elimination of the infected cell via apoptosis. The second program is responsible for the production of antiviral (type I) interferons and other alarmone cytokines and serves the purpose of preparing naive cells for the viral invasion. This second program requires the survival of the infected cell and depends on the expression of antiapoptotic genes through the activation of the NF-kappaB transcription factor. The second program therefore relies on ongoing transcription and translation. It has been proposed that PKR plays an essential role in the activation of NF-kappaB by dsRNA. Here we present evidence that the dsRNA-induced NF-kappaB activity and the expression of beta interferon and inflammatory cytokines do not require either PKR or RNase L. Our results indicate, therefore, that the two dsRNA-activated programs are separate and can function independently of each other.
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Virus de la Encefalomiocarditis/genética , Endorribonucleasas/metabolismo , Proteínas I-kappa B , FN-kappa B/metabolismo , ARN Bicatenario/metabolismo , ARN Viral/metabolismo , eIF-2 Quinasa/metabolismo , Transporte Activo de Núcleo Celular , Animales , Apoptosis , Línea Celular , Cisteína Endopeptidasas/metabolismo , ADN/genética , ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Endorribonucleasas/deficiencia , Endorribonucleasas/genética , Eliminación de Gen , Regulación de la Expresión Génica , Interferón beta/genética , Interleucina-6/genética , Ratones , Complejos Multienzimáticos/metabolismo , Fosforilación , Complejo de la Endopetidasa Proteasomal , Procesamiento Proteico-Postraduccional , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/genética , Ubiquitinas/metabolismo , eIF-2 Quinasa/deficiencia , eIF-2 Quinasa/genéticaRESUMEN
Controlled expression of cellular and viral genes through alternative precursor messenger RNA (pre-mRNA) splicing requires serine/arginine-rich (SR) proteins. The Clk1 kinase, which phosphorylates SR proteins, is regulated through alternative splicing of the Clk1 pre-mRNA, yielding mRNAs encoding catalytically active and truncated inactive polypeptides (Clk1 and Clk1T, respectively). We present evidence that Clk1 and Clk1T proteins regulate the splicing of Clk1 and adenovirus pre-mRNAs in vivo. The peptide domain encoded by the alternatively spliced exon of Clk1 is essential for the regulatory activity of the Clk1 kinase. This is the first direct demonstration of an in vivo link between alternative splicing and protein kinase activity.
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Empalme Alternativo/fisiología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Proteínas E1A de Adenovirus/genética , Animales , Arginina , Células COS , Citomegalovirus/enzimología , Exones/genética , Proteínas/química , Precursores del ARN/genética , ARN Viral/genética , SerinaRESUMEN
Myelin-associated glycoprotein (MAG) has been implicated in the mediation of interactions between oligodendrocytes and neurons during the development of the myelin sheath. Here we show that MAG is phosphorylated in intact myelinating mouse brain primarily at serine residues and to a lesser extent at threonine and tyrosine residues. In vivo, only the larger of the two developmentally regulated MAG isoforms is phosphorylated. MAG can be phosphorylated at tyrosine by the v-fps and v-src protein-tyrosine kinases in vitro and by a kinase endogenous to myelin membrane preparations. MAG phosphorylated in myelin membranes in vitro also contains phosphoserine and phosphothreonine. These observations suggest that phosphorylation of MAG is physiologically significant in regulating oligodendrocyte-neuron interactions.
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Química Encefálica , Proteínas de la Mielina/análisis , Animales , Complejo Antígeno-Anticuerpo/análisis , Adhesión Celular , Electroforesis en Gel de Poliacrilamida , Peso Molecular , Proteínas de la Mielina/inmunología , Proteínas de la Mielina/metabolismo , Glicoproteína Asociada a Mielina , Fosforilación , Proteínas Tirosina Quinasas/metabolismoRESUMEN
We have cloned a novel kinase (STY) from an embryonal carcinoma cell line. Sequence analysis of the STY cDNA reveals that it shares sequence homology with serine/threonine-type kinases and yet the bacterial expression product of the STY cDNA appears to have serine-, threonine-, and tyrosine-phosphorylating activities. The predicted STY protein is highly basic and contains a putative nuclear localization signal. During differentiation, two new mRNAs were detected in addition to the embryonic transcript.
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Proteínas Serina-Treonina Quinasas , Proteínas Tirosina Quinasas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Diferenciación Celular , Clonación Molecular , ADN/genética , Expresión Génica , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/genética , Proteínas Tirosina Quinasas/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Especificidad por Sustrato , Células Tumorales CultivadasRESUMEN
A novel protein kinase, the Esk kinase, has been isolated from an embryonal carcinoma (EC) cell line by using an expression cloning strategy. Sequence analysis of two independent cDNA clones (2.97 and 2.85 kb) suggested the presence of two Esk isoforms in EC cells. The esk-1 cDNA sequence predicted an 857-amino-acid protein kinase with a putative membrane-spanning domain, while the esk-2 cDNA predicted an 831-amino-acid kinase which lacked this domain. In adult mouse cells, esk mRNA levels were highest in tissues possessing a high proliferation rate or a sizeable stem cell compartment, suggesting that the Esk kinase may play some role in the control of cell proliferation or differentiation. As anticipated from the screening procedure, bacterial expression of the Esk kinase reacted with antiphosphotyrosine antibodies on immunoblots. Furthermore, in in vitro kinase assays, the Esk kinase was shown to phosphorylate both itself and the exogenous substrate myelin basic protein on serine, threonine, and tyrosine residues, confirming that the Esk kinase is a novel member of the serine/threonine/tyrosine family of protein kinases.
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Proteínas Quinasas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Compartimento Celular , Membrana Celular/enzimología , Clonación Molecular , Citoplasma/enzimología , ADN/genética , Expresión Génica , Técnicas In Vitro , Ratones , Datos de Secuencia Molecular , Fosfoproteínas/genética , Fosfoserina/metabolismo , Fosfotreonina/metabolismo , Fosfotirosina , Proteínas Quinasas/metabolismo , ARN Mensajero/genética , Alineación de Secuencia , Especificidad por Sustrato , Células Tumorales Cultivadas , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMEN
The tumor suppressor p53 plays a key role in inducing G1 arrest and apoptosis following DNA damage. The double-stranded-RNA-activated protein PKR is a serine/threonine interferon (IFN)-inducible kinase which plays an important role in regulation of gene expression at both transcriptional and translational levels. Since a cross talk between IFN-inducible proteins and p53 had already been established, we investigated whether and how p53 function was modulated by PKR. We analyzed p53 function in several cell lines derived from PKR+/+ and PKR-/- mouse embryonic fibroblasts (MEFs) after transfection with the temperature-sensitive (ts) mutant of mouse p53 [p53(Val135)]. Here we report that transactivation of transcription by p53 and G0/G1 arrest were impaired in PKR-/- cells upon conditions that ts p53 acquired a wild-type conformation. Phosphorylation of mouse p53 on Ser18 was defective in PKR-/- cells, consistent with an impaired transcriptional induction of the p53-inducible genes encoding p21(WAF/Cip1) and Mdm2. In addition, Ser18 phosphorylation and transcriptional activation by mouse p53 were diminished in PKR-/- cells after DNA damage induced by the anticancer drug adriamycin or gamma radiation but not by UV radiation. Furthermore, the specific phosphatidylinositol-3 (PI-3) kinase inhibitor LY294002 inhibited the induction of phosphorylation of Ser18 of p53 by adriamycin to a higher degree in PKR+/+ cells than in PKR-/- cells. These novel findings suggest that PKR enhances p53 transcriptional function and implicate PKR in cell signaling elicited by a specific type of DNA damage that leads to p53 phosphorylation, possibly through a PI-3 kinase pathway.
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Activación Transcripcional , Proteína p53 Supresora de Tumor/metabolismo , eIF-2 Quinasa/metabolismo , Animales , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas , Daño del ADN , Fase G1 , Ratones , Venenos de Moluscos , Mutación , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Receptor Cross-Talk , Fase de Descanso del Ciclo Celular , Transducción de Señal , Transcripción Genética , eIF-2 Quinasa/genéticaRESUMEN
The purpose of this study was to compare the holding powers of 2.7 mm pre-tapped and self-tapped screws placed closely together and tightened in small bones. Pairs of metatarsals were collected from healthy, skeletally mature Greyhounds and part of a 2.7 mm dynamic compression plate was fixed to the dorsal surface of each bone using three 2.7 mm screws. Identical screws were used throughout but only one of each pair of bones had threads pre-cut using a tap prior to insertion. All of the screws were tightened before the constructs were mounted in a materials testing machine and the centrally placed screw was loaded incrementally until failure. Load-deformation curves were plotted and yield point, ultimate load to failure, stiffness and energy prior to yield point were measured. Mean values were recorded for each parameter and Student's T-test was used to test the null hypothesis that there is no difference in holding power between pre-tapped and self-tapped screws. Significant mechanical differences were not found between pre-tapped and self-tapped screws placed closely together and tightened into small bones. Self-tapped screws can be considered for use in small animal surgery even when multiple screws are to be placed closely together in relatively small pieces of bone.
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Tornillos Óseos/veterinaria , Perros/lesiones , Fijación Intramedular de Fracturas/veterinaria , Fracturas Óseas/veterinaria , Huesos Metatarsianos/lesiones , Animales , Fenómenos Biomecánicos , Perros/cirugía , Diseño de Equipo , Fijación Intramedular de Fracturas/instrumentación , Fijación Intramedular de Fracturas/métodos , Fracturas Óseas/cirugía , Ensayo de Materiales , Huesos Metatarsianos/cirugíaRESUMEN
Structural features of the multidrug resistance protein encoded by the mouse mdr1 gene were studied in multidrug-resistant cell clones stably transfected with a biologically active cDNA clone. Independently derived transfectant cell clones, initially selected in Adriamycin, were shown to be cross-resistant to several drugs, including actinomycin D, amsacrine, mitoxantrone, VP-16, and vinblastine but remained sensitive to cis-platinum, 5-fluorouracil, arabinocytosine, and bleomycin. In drug-resistant transfectants the mdr1 gene product was greatly overexpressed as a polypeptide of apparent molecular weight 160,000-170,000. This protein was present in membrane enriched fractions and could be metabolically labeled with [3H )glucosamine, confirming that the transfected mdr1 gene encodes a membrane glycoprotein. The protein was found phosphorylated on serine residues and was shown to be photolabeled by both the calcium antagonist azidopine and the ATP analogue 8-azido ATP. Tryptic mapping of the ATP-photoaffinity labeled protein indicated that ATP crosslinking was site-specific and limited to two discrete peptide fragments of the protein, suggesting that the overexpressed mdr protein is capable of direct and specific ATP binding.