923 resultados para Transcription Factor 7-Like 2 Protein
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Lance Burghardt bracketed his exposures and provided 3 different shots of these items (2 tifs, 1 jpg). Each shares same housescan number, differentiated by suffix 1of3, 2of3, or 3of3....
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Thesis (doctoral)--Friedrich-Wilhelms-Universitat zu Berlin.
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Reasons for performing study: The dysadhesion and destruction of lamellar basement membrane of laminitis may be due to increased lamellar metalloproteinase activity. Characterising lamellar metalloproteinase-2 (MMP-2) and locating it in lamellar tissues may help determine if laminitis pathology is associated with increased MMP-2 transcription. Objectives: To clone and sequence the cDNA encoding lamellar MMP-2, develop antibody and in situ hybridisation probes to locate lamellar MMP-2 and quantitate MMP-2 transcription in normal and laminitis tissue. Methods: Total RNA was isolated, fragmented by RT-PCR, cloned into vector and sequenced. Rabbit anti-equine MMP-2 and labelled MMP-2 riboprobe were developed to analyse and quantitate MMP-2 expression. Results: Western immunoblotting with anti-MMP-2 detected 72 kDa MMP-2 in hoof tissue homogenates and cross-reacted with human MMP-2. Immunohistochemistry and in situ hybridisation detected MMP-2 in the cytoplasm of basal and parabasal cells in close proximity to the lamellar basement membrane. Northern analysis and quantitative real-time PCR showed MMP-2 expression significantly (P
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The SOX family of transcription factors are found throughout the animal kingdom and are important in a variety of developmental contexts. Genome analysis has identified 20 Sox genes in human and mouse, which can be subdivided into 8 groups, based on sequence comparison and intron-exon structure. Most of the SOX groups identified in mammals are represented by a single SOX sequence in invertebrate model organisms, suggesting a duplication and divergence mechanism has operated during vertebrate evolution. We have now analysed the Sox gene complement in the pufferfish, Fugu rubripes, in order to shed further light on the diversity and origins of the Sox gene family. Major differences were found between the Sox family in Fugu and those in humans and mice. In particular, Fugu does not have orthologues of Sry, Sox,15 and Sox30, which appear to be specific to mammals, while Sox19, found in Fugu and zebrafish but absent in mammals, seems to be specific to fishes. Six mammalian Sox genes are represented by two copies each in Fugu, indicating a large-scale gene duplication in the fish lineage. These findings point to recent Sox gene loss, duplication and divergence occurring during the evolution of tetrapod and teleost lineages, and provide further evidence for large-scale segmental or a whole-genome duplication occurring early in the radiation of teleosts. (C) 2004 Elsevier B.V. All rights reserved.
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The prediction of regulatory elements is a problem where computational methods offer great hope. Over the past few years, numerous tools have become available for this task. The purpose of the current assessment is twofold: to provide some guidance to users regarding the accuracy of currently available tools in various settings, and to provide a benchmark of data sets for assessing future tools.
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Sox8 is a member of the Sox family of developmental transcription factor genes and is closely related to Sox9, a critical gene involved in mammalian sex determination and differentiation. Both genes encode proteins with the ability to bind similar DNA target sequences, and to activate transcription in in vitro assays. Expression studies indicate that the two genes have largely overlapping patterns of activity during mammalian embryonic development. A knockout of Sox8 in mice has no obvious developmental phenotype, suggesting that the two genes are able to act redundantly in a variety of developmental contexts. In particular, both genes are expressed in the developing Sertoli cell lineage of the developing testes in mice, and both proteins are able to activate transcription of the gene encoding anti-Mullerian hormone (AMH), through synergistic action with steroidogenic factor I (SF1). We have hypothesized that Sox8 may substitute for Sox9 in species where Sox9 is expressed too late to be involved in sex determination or regulation of Amh expression. However, our studies involving the red-eared slider turtle indicate that Sox8 is expressed at similar levels in males and females throughout the sex-determining period, suggesting that Sox8 is neither a transcriptional regulator for Amh, nor responsible for sex determination or gonad differentiation in that species. Similarly, Sox8 is not expressed in a sexually dimorphic pattern during gonadogenesis in the chicken. Since a functional role(s) for Sox8 is implied by its conservation during evolution, the significance of Sox8 for sexual and other aspects of development will need to be uncovered through more directed lines of experimentation. Copyright (C) 2003 S. Karger AG, Basel.
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Report for Deliverable 7: Activity 2 of MEDOLICO Project - Mediterranean Cooperation in the Treatment and Valorisation of Olive Mill Wastewater, EU Programme ENPI-CBCMED I-B/2.1/090
Does BFR1, a component of the transcription factor (TFIIIB), have a role in prostate carcinogenesis?
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No abstract available.
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Acute myeloid leukemia (AML) involves the proliferation, abnormal survival and arrest of cells at a very early stage of myeloid cell differentiation. The biological and clinical heterogeneity of this disease complicates treatment and highlights the significance of understanding the underlying causes of AML, which may constitute potential therapeutic targets, as well as offer prognostic information. Tribbles homolog 2 (Trib2) is a potent murine oncogene capable of inducing transplantable AML with complete penetrance. The pathogenicity of Trib2 is attributed to its ability to induce proteasomal degradation of the full length isoform of the transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα p42). The role of TRIB2 in human AML cells, however, has not been systematically investigated or targeted. Across human cancers, TRIB2 oncogenic activity was found to be associated with its elevated expression. In the context of AML, TRIB2 overexpression was suggested to be associated with the large and heterogeneous subset of cytogenetically normal AML patients. Based upon the observation that overexpression of TRIB2 has a role in cellular transformation, the effect of modulating its expression in human AML was examined in a human AML cell line that expresses high levels of TRIB2, U937 cells. Specific suppression of TRIB2 led to impaired cell growth, as a consequence of both an increase in apoptosis and a decrease in cell proliferation. Consistent with these in vitro results, TRIB2 silencing strongly reduced progression of the U937 in vivo xenografts, accompanied by detection of a lower spleen weight when compared with mice transplanted with TRIB2- expressing control cells. Gene expression analysis suggested that TRIB2 modulates apoptosis and cell-cycle sensitivity by influencing the expression of a subset of genes known to have implications on these phenotypes. Furthermore, TRIB2 was found to be expressed in a significant subset of AML patient samples analysed. To investigate whether increased expression of this gene could be afforded prognostic significance, primary AML cells with dichotomized levels of TRIB2 transcripts were evaluated in terms of their xenoengraftment potential, an assay reported to correlate with disease aggressiveness observed in humans. A small cohort of analysed samples with higher TRIB2 expression did not associate with preferential leukaemic cell engraftment in highly immune-deficient mice, hence, not predicting for an adverse prognosis. However, further experiments including a larger cohort of well characterized AML patients would be needed to clarify TRIB2 significance in the diagnostic setting. Collectively, these data support a functional role for TRIB2 in the maintenance of the oncogenic properties of human AML cells and suggest TRIB2 can be considered a rational therapeutic target. Proteasome inhibition has emerged as an attractive target for the development of novel anti-cancer therapies and results from translational research and clinical trials support the idea that proteasome inhibitors should be considered in the treatment of AML. The present study argued that proteasome inhibition would effectively inhibit the function of TRIB2 by abrogating C/EBPα p42 protein degradation and that it would be an effective pharmacological targeting strategy in TRIB2-positive AMLs. Here, a number of cell models expressing high levels of TRIB2 were successfully targeted by treatment with proteasome inhibitors, as demonstrated by multiple measurements that included increased cytotoxicity, inhibition of clonogenic growth and anti-AML activity in vivo. Mechanistically, it was shown that block of the TRIB2 degradative function led to an increase of C/EBPα p42 and that response was specific to the TRIB2-C/EBPα axis. Specificity was addressed by a panel of experiments showing that U937 cells (express detectable levels of endogenous TRIB2 and C/EBPα) treated with the proteasome inhibitor bortezomib (Brtz) displayed a higher cytotoxic response upon TRIB2 overexpression and that ectopic expression of C/EBPα rescued cell death. Additionally, in C/EBPα-negative leukaemia cells, K562 and Kasumi 1, Brtz-induced toxicity was not increased following TRIB2 overexpression supporting the specificity of the compound on the TRIB2-C/EBPα axis. Together these findings provide pre-clinical evidence that TRIB2- expressing AML cells can be pharmacologically targeted with proteasome inhibition due, in part, to blockage of the TRIB2 proteolytic function on C/EBPα p42. A large body of evidence indicates that AML arises through the stepwise acquisition of genetic and epigenetic changes. Mass spectrometry data has identified an interaction between TRIB2 and the epigenetic regulator Protein Arginine Methyltransferase 5 (PRMT5). Following assessment of TRIB2‟s role in AML cell survival and effective targeting of the TRIB2-C/EBPα degradation pathway, a putative TRIB2/PRMT5 cooperation was investigated in order to gain a deeper understanding of the molecular network in which TRIB2 acts as a potent myeloid oncogene. First, a microarray data set was interrogated for PRMT5 expression levels and the primary enzyme responsible for symmetric dimethylation was found to be transcribed at significantly higher levels in AML patients when compared to healthy controls. Next, depletion of PRMT5 in the U937 cell line was shown to reduce the transformative phenotype in the high expressing TRIB2 AML cells, which suggests that PRMT5 and TRIB2 may cooperate to maintain the leukaemogenic potential. Importantly, PRMT5 was identified as a TRIB2-interacting protein by means of a protein tagging approach to purify TRIB2 complexes from 293T cells. These findings trigger further research aimed at understanding the underlying mechanism and the functional significance of this interplay. In summary, the present study provides experimental evidence that TRIB2 has an important oncogenic role in human AML maintenance and, importantly in such a molecularly heterogeneous disease, provides the rational basis to consider proteasome inhibition as an effective targeting strategy for AML patients with high TRIB2 expression. Finally, the identification of PRMT5 as a TRIB2-interacting protein opens a new level of regulation to consider in AML. This work may contribute to our further understanding and therapeutic strategies in acute leukaemias.