298 research outputs found

    Vitamin D and the RNA transcriptome: more than mRNA regulation

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    The GRCh37.p13 primary assembly of the human genome contains 20805 protein coding mRNA, and 37147 non-protein coding genes and pseudogenes that as a result of RNA processing and editing generate 196501 gene transcripts. Given the size and diversity of the human transcriptome, it is timely to revisit what is known of VDR function in the regulation and targeting of transcription.Early transcriptomic studies using microarray approaches focused on the protein coding mRNA that were regulated by the VDR, usually following treatment with ligand. These studies quickly established the approxamte size, and surprising diversity of the VDR transcriptome, revealing it to be highly heterogenous and cell type and time dependent. With the discovery of microRNA, investigators also considered VDR regulation of these non-protein coding RNA. Again, cell and time dependency has emerged. Attempts to integrate mRNA and miRNA regulation patterns are beginning to reveal patterns of co-regulation and interaction that allow for greater control of mRNA expression, and the capacity to govern more complex cellular events. As the awareness of the diversity of non-coding RNA increases, it is evident that VDR actions are mediated through these molecules also. Key knowledge gaps remain over the VDR transcriptome. The causes for the cell and type dependent transcriptional heterogenetiy remain enigmatic. ChIP-Seq approaches have confirmed that VDR binding choices differ very significantly by cell type, but as yet the underlying causes distilling VDR binding choices are unclear. Similarly, it is clear that many of the VDR binding sites are non-canonical in nature but again the mechanisms underlying these interactions are unclear. Finally, although alternative splicing is clearly a very significant process in cellular transcriptional control, the lack of RNA-Seq data centered on VDR function are currently limiting the global assessment of the VDR transcriptome. VDR focused research that complement

    Novel membrane separations in biotechnology.

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    Membrane processes have great potential in biotechnology. This study was an attempt to investigate ways in which greater novelty could be achieved. One of the advantages of ultrafiltration for the separation of proteins is the comparatively mild conditions used. Various parameters were considered when operating a crossflow filtration system containing polysulphide membranes. A key operational parameter in such a system is the temperature utilised for the process. There are conflicting demands when selecting an operating temperature between the fluid dynamics and the biochemical properties of the system. An analysis of this conflict, in order to establish the optimal temperature, involved a model crossflow filtration system, where shear rate, volume of protein containing solution and protein concentration can be kept constant and only the temperature varied. In such studies denaturation of the permeate was observed and an optimal operating temperature was observed between 30 and 40 °C. A supported liquid membrane system was investigated for the carrier mediated transport of phenylalanine to more fully understand the contradictory effects, described in the literature, of chloride ion concentration in the aqueous phases on the stability of the system. Various parameters were considered to optimise transport and stability. The role of the organic phase and its interaction with carrier and support material was also considered. The carrier mediated transport was comparable to an enzyme mediated process. Kinetic studies were undertaken and the data interpreted in a manner appropriate to biological transport processes to consider the transport process at a molecular level. The system was shown to deviate from a direct 1 : 1 exchange process between phenylalanine and chloride and had a high degree of selectivity with respect to phenylalanine

    A Role for the PPARγ in Cancer Therapy

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    In 1997, the first published reports highlighted PPARγ as a novel cancer therapeutic target regulating differentiation of cancer cells. A subsequent flurry of papers described these activities more widely and fuelled further enthusiasm for differentiation therapy, as the ligands for the PPARγ were seen as well tolerated and in several cases well-established in other therapeutic contexts. This initial enthusiasm and promise was somewhat tempered by contradictory findings in several murine cancer models and equivocal trial findings. As more understanding has emerged in recent years, a renaissance has occurred in targeting PPARγ within the context of either chemoprevention or chemotherapy. This clarity has arisen in part through a clearer understanding of PPARγ biology, how the receptor interacts with other proteins and signaling events, and the mechanisms that modulate its transcriptional actions. Equally greater translational understanding of this target has arisen from a clearer understanding of in vivo murine cancer models. Clinical exploitation will most likely require precise and quantifiable description of PPARγ actions, and resolution of which targets are the most beneficial to target combined with an understanding of the mechanisms that limits its anticancer effectiveness

    The vitamin D receptor in cancer

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    PseudoFuN: Deriving functional potentials of pseudogenes from integrative relationships with genes and microRNAs across 32 cancers

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    BACKGROUND: Long thought "relics" of evolution, not until recently have pseudogenes been of medical interest regarding regulation in cancer. Often, these regulatory roles are a direct by-product of their close sequence homology to protein-coding genes. Novel pseudogene-gene (PGG) functional associations can be identified through the integration of biomedical data, such as sequence homology, functional pathways, gene expression, pseudogene expression, and microRNA expression. However, not all of the information has been integrated, and almost all previous pseudogene studies relied on 1:1 pseudogene-parent gene relationships without leveraging other homologous genes/pseudogenes. RESULTS: We produce PGG families that expand beyond the current 1:1 paradigm. First, we construct expansive PGG databases by (i) CUDAlign graphics processing unit (GPU) accelerated local alignment of all pseudogenes to gene families (totaling 1.6 billion individual local alignments and >40,000 GPU hours) and (ii) BLAST-based assignment of pseudogenes to gene families. Second, we create an open-source web application (PseudoFuN [Pseudogene Functional Networks]) to search for integrative functional relationships of sequence homology, microRNA expression, gene expression, pseudogene expression, and gene ontology. We produce four "flavors" of CUDAlign-based databases (>462,000,000 PGG pairwise alignments and 133,770 PGG families) that can be queried and downloaded using PseudoFuN. These databases are consistent with previous 1:1 PGG annotation and also are much more powerful including millions of de novo PGG associations. For example, we find multiple known (e.g., miR-20a-PTEN-PTENP1) and novel (e.g., miR-375-SOX15-PPP4R1L) microRNA-gene-pseudogene associations in prostate cancer. PseudoFuN provides a "one stop shop" for identifying and visualizing thousands of potential regulatory relationships related to pseudogenes in The Cancer Genome Atlas cancers. CONCLUSIONS: Thousands of new PGG associations can be explored in the context of microRNA-gene-pseudogene co-expression and differential expression with a simple-to-use online tool by bioinformaticians and oncologists alike

    Regulation of the human p21((waf1/cip1)) gene promoter via multiple binding sites for p53 and the vitamin D(3) receptor

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    The main regulator of the human tumor suppresser gene p21((waf1/cip1)) is the transcription factor p53, but more recently it has been suggested to be a primary anti-proliferative target for the nuclear receptor VDR in the presence of its ligand 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)). To identify VDR responding regions, we analyzed 20 overlapping regions covering the first 7.1 kb of the p21((waf1/cip1)) promoter in MCF-7 human breast cancer cells using chromatin immuno-precipitation assays (ChIP) with antibodies against p53 and VDR. We confirmed two known p53 binding regions at approximate positions −1400 and −2300 and identified a novel site at position −4500. In addition, we found three VDR-associated promoter regions at positions −2300, −4500 and −6900, i.e. two regions showed binding for both p53 and VDR. In silico screening and in vitro binding assays using recombinant and in vitro translated proteins identified five p53 binding sites within the three p53-positive promoter regions and also five 1α,25(OH)(2)D(3) response elements within the three VDR-positive regions. Reporter gene assays confirmed the expected responsiveness of the respective promoter regions to the p53 inducer 5-fluorouracil and 1α,25(OH)(2)D(3). Moreover, re-ChIP assays confirmed the functionality of the three 1α,25(OH)(2)D(3)-reponsive promoter regions by monitoring simultaneous occupancy of VDR with the co-activator proteins CBP, SRC-1 and TRAP220. Taken together, we demonstrated that the human p21((waf1/cip1)) gene is a primary 1α,25(OH)(2)D(3)-responding gene with at least three VDR binding promoter regions, in two of which also p53 co-localizes

    К вопросу подготовки медицинских кадров в условиях реформирования системы здравоохранения

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    Реформирование системы здравоохранения в Украине вносит серьезные кор­рективы в работу лечебно-профилактических учреждений, и определяет необходимость подготовки, переподготовки, повышения квалификации, как врачей так и среднего медицинского персонала. Система дополнительного профессионального образования должна быть одной из основополагающих систем, обеспечивающих практическое здравоохранение высокопрофессиональными кадрами. Реализация этого возможна при использовании современных, актуальных и апробированных методик обучения, переобучения и повышения квалификации

    Актуальные вопросы совершенствования медико-психологической помощи детям с пороками грудной клетки

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    Врожденные деформации грудной клетки в виде воронкообразной и килевидной встречаются более чем у 0,3% населения. Воронкообразная деформация грудной клетки (ВДГК) встречается в 5-7 раз чаще, чем килевидная деформация грудной клетки (КДГК). Общепризнанным методом лечения деформации грудной клетки является исключительно хирургическая коррекция
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