77 research outputs found

    Characterization of two functional NKX3.1 binding sites upstream of the PCAN1 gene that are involved in the positive regulation of PCAN1 gene transcription

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    <p>Abstract</p> <p>Background</p> <p><it>NKX3.1 </it>and <it>PCAN1 </it>are both prostate-specific genes related to prostate development and prostate cancer. So far, little is known about the regulatory mechanisms of the expression of these two genes. In the present study, we found that NKX3.1 upregulated <it>PCAN1 </it>gene transcription in LNCaP prostate cancer cells. To understand the regulatory mechanisms, our work focused on identifying the functional NKX3.1 binding sites upstream of the <it>PCAN1 </it>gene, which might be involved in the positive regulation of <it>PCAN1 </it>expression by NKX3.1.</p> <p>Results</p> <p>We cloned and characterized a 2.6 kb fragment upstream of the <it>PCAN1 </it>gene. Analysis of the 2.6 kb sequence with MatInspector 2.2 revealed five potential binding sites of NKX3.1 transcription factor. Luciferase reporter assays, electrophoretic mobility shift assays, chromatin immunoprecipitation and RNA interference were performed to study the effects of NKX3.1 on <it>PCAN1 </it>gene expression in prostate cancer cells. Our results showed that <it>PCAN1 </it>promoter activity and mRNA expression were increased by transfection with the <it>NKX3.1 </it>containing plasmid (pcDNA3.1-<it>NKX3.1</it>) and that <it>PCAN1 </it>mRNA expression was decreased by RNA interference targeting human <it>NKX3.1 </it>in LNCaP prostate cancer cells. The results of electrophoretic mobility shift assays and chromatin immunoprecipitation showed that NKX3.1 bound to NBS1 (-1848 to -1836) and NBS3 (-803 to -791) upstream of the <it>PCAN1 </it>gene. The luciferase reporter assays showed that NBS1 and NBS3 enhanced the promoter activity in pGL<sub>3</sub>-promoter vector with cotransfection of the <it>NKX3.1 </it>containing plasmid. Furthermore, the deletion of NBS1 or both NBS1 and NBS3 reduced <it>PCAN1 </it>promoter activity and abolished the positive regulation of <it>PCAN1 </it>expression by NKX3.1.</p> <p>Conclusion</p> <p>Our results suggested that two functional NKX3.1 binding sites located at -1848 to -1836 and -803 to -791 upstream of the <it>PCAN1 </it>gene were involved in the positive regulation of <it>PCAN1 </it>gene transcription by NKX3.1.</p

    Tin Assisted Fully Exposed Platinum Clusters Stabilized on Defect-Rich Graphene for Dehydrogenation Reaction

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    Tin assisted fully exposed Pt clusters are fabricated on the core-shell nanodiamond@graphene (ND@G) hybrid support (a-PtSn/ND@G). The obtained atomically dispersed Pt clusters, with an average Pt atom number of 3, were anchored over the ND@Gsupport by the assistance of Sn atoms as a partition agent and through the Pt-C bond between Pt clusters and defect-rich graphene nanoshell. The atomically dispersed Pt clusters guaranteed a full metal availability to the reactants, a high thermal stability, and an optimized adsorption/desorption behavior. It inhibits the side reactions and enhances catalytic performance in direct dehydrogenation of n-butane at a low temperature of 450 °C, leading to \u3e98% selectivity toward olefin products, and the turnover frequency (TOF) of a-PtSn/ND@G is approximately 3.9 times higher than that of the traditional Pt3Sn alloy catalyst supported on Al2O3 (Pt3Sn/Al2O3)

    An Investigation into the Cytotoxic Effects of 13-Acetoxysarcocrassolide from the Soft Coral Sarcophyton crassocaule on Bladder Cancer Cells

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    Active compounds from natural products have been widely studied. The anti-tumor effects of 13-acetoxysarcocrassolide isolated from Formosan soft coral Sarcophyton crassocaule on bladder cancer cells were examined in this study. An MTT assay showed that 13-acetoxysarcocrassolide was cytotoxic to bladder female transitional cancer (BFTC) cells. We determined that the BFTC cells underwent cell death through apoptosis by flow cytometry. Due to the highly-migratory nature of the BFTC cells, the ability of 13-acetoxysarcocrassolide to stop their migration was assessed by a wound healing assay. To determine which proteins were affected in the BFTC cells upon treatment, a comparative proteomic analysis was performed. By LC-MS/MS analysis, we identified that 19 proteins were up-regulated and eight were down-regulated. Seven of the proteins were confirmed by western blotting analysis. This study reveals clues to the potential mechanism of the cytotoxic effects of 13-acetoxysarcocrassolide on BFTC cells. Moreover, it suggests that PPT1 and hnRNP F could be new biomarkers for bladder cancer. The results of this study are also helpful for the diagnosis, progression monitoring and therapeutic strategies of transitional cell tumors

    Filamin and its interactions in cell migration

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    Human filamin is a large dimeric, modular protein made up of two calponin homology domains and twenty-four immunoglobulin-like (Ig_FLMN) domains. Filamin cross-links actin filaments and is deeply involved in cell migration processes, largely through interactions with plasma membrane proteins, especially integrins. In the work presented here, the structural properties of filamin fragments involved in integrin binding have been studied. NMR investigations of individual dissected Ig_FLMN modules from human . filamin A (called FLNa here) revealed that, although homologous at the sequence level, they have variable folding properties. A series of NMR titrations located the binding interface between the cytoplasmic tails of integrins and filamin modules, showing that binding of FLNa19 and FLNa21 to the tails was very similar. Further analysis of NMR experimental results quantitatively characterized a dimerization of the integrin-filamin complex in solution. Inter-module interactions in a triple module (FLNa19-21) were also observed and studied. NMRstudies on module pairs of filamin (FLNaI9-20 and FLNa20-21) disclosed that part ofFLNa20 'zips' along FLNa21 in a similar pattern as integrin tails. NMR studies show that this structure is, however, readily disrupted by addition of integrin tails. The observed affinities, dimerization behaviour and the structure of FLNa19-21 led to an 'integrin clip' hypothesis. This model was supported by evidence that suggested a module rearrangement of FLNa19-21 was induced by integrin binding. Several potential regulation mechanisms for filamin-integrin binding, including selective expression of isoforrns, splicing variation and phosphorylation, were also studied. Based on previous knowledge of Ig_FLMN complexes, a strategy to predict filamin binding affinity was developed and applied to the binding site detennination for two newly identified filamin binding proteins,' migfilin and FILIP; this was successfully confinned by NMR titration experiments.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A Novel Weighted-Graph-Based Grouping Algorithm for Metadata Prefetching

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    Although data prefetching algorithms have been extensively studied for years, there is no counterpart research done for metadata access performance. Existing data prefetching algorithms, either lack of emphasis on group prefetching, or bearing a high level of computational complexity, do not work well with metadata prefetching cases. Therefore, an efficient, accurate, and distributed metadata-oriented prefetching scheme is critical to leverage the overall performance in large distributed storage systems. In this paper, we present a novel weighted-graph-based prefetching technique, built on both direct and indirect successor relationship, to reap performance benefit from prefetching specifically for clustered metadata servers, an arrangement envisioned necessary for petabyte-scale distributed storage systems. Extensive trace-driven simulations show that by adopting our new metadata prefetching algorithm, the miss rate for metadata accesses on the client site can be effectively reduced, while the average response time of metadata operations can be dramatically cut by up to 67 percent, compared with legacy LRU caching algorithm and existing state-of-the-art prefetching algorithms

    Measurement of Rock Joint Surfaces by Using Smartphone Structure from Motion (SfM) Photogrammetry

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    The measurement of rock joint surfaces is essential for the estimation of the shear strength of the rock discontinuities in rock engineering. Commonly used techniques for the acquisition of the morphology of the surfaces, such as profilometers and laser scanners, either have low accuracy or high cost. Therefore, a high-speed, low-cost, and high-accuracy method for obtaining the topography of the joint surfaces is necessary. In this paper, a smartphone structure from motion (SfM) photogrammetric solution for measuring rock joint surfaces is presented and evaluated. Image datasets of two rock joint specimens were taken under two different modes by using an iPhone 6s, a Pixel 2, and a T329t and subsequently processed through SfM-based software to obtain 3D models. The technique for measuring rock joint surfaces was evaluated using the root mean square error (RMSE) of the cloud-to-cloud distance and the mean error of the joint roughness coefficient (JRC). The results show that the RMSEs by using the iPhone 6s and Pixel 2 are both less than 0.08 mm. The mean errors of the JRC are −7.54 and −5.27% with point intervals of 0.25 and 1.0 mm, respectively. The smartphone SfM photogrammetric method has comparable accuracy to a 3D laser scanner approach for reconstructing laboratory-sized rock joint surfaces, and it has the potential to become a popular method for measuring rock joint surfaces

    Epidemics on interconnected lattices

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    Epidemic remains one of the major threats to human society, which has attracted much attention for decades. Since real-world systems usually depend on each other, epidemics on interconnected networks have been studied recently. However, in most studies spatial constraints in these interconnected networks are neglected. Here we study the epidemics in a system composed of two interconnected lattices, which is compared with the epidemics in interconnected Erdös-Rényi (ER) networks. Our results show that the epidemic threshold in interconnected lattices decreases with increasing spatial length of interconnected links between networks. When the infection rate is small, the spatial constraints limit the transmission of the disease, where the infection density is lower in interconnected lattices than in interconnected ER networks. For large infection rate, however, the infection density is higher in interconnected lattices than in interconnected ER networks

    A Novel Weighted-Graph-Based Grouping Algorithm For Metadata Prefetching

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    Although data prefetching algorithms have been extensively studied for years, there is no counterpart research done for metadata access performance. Existing data prefetching algorithms, either lack of emphasis on group prefetching, or bearing a high level of computational complexity, do not work well with metadata prefetching cases. Therefore, an efficient, accurate, and distributed metadata-oriented prefetching scheme is critical to leverage the overall performance in large distributed storage systems. In this paper, we present a novel weighted-graph-based prefetching technique, built on both direct and indirect successor relationship, to reap performance benefit from prefetching specifically for clustered metadata servers, an arrangement envisioned necessary for petabyte-scale distributed storage systems. Extensive trace-driven simulations show that by adopting our new metadata prefetching algorithm, the miss rate for metadata accesses on the client site can be effectively reduced, while the average response time of metadata operations can be dramatically cut by up to 67 percent, compared with legacy LRU caching algorithm and existing state-of-the-art prefetching algorithms. © 2006 IEEE

    PEG Gels Significantly Improve the Storage Stability of Nucleic Acid Preparations

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    Currently, nucleic acid preparations have gained much attention due to their unique working principle and application value. However, as macromolecular drugs, nucleic acid preparations have complex construction and poor stability. The current methods to promote stability face problems such as high cost and inconvenient operatios. In this study, the hydrophilic pharmaceutical excipient PEG was used to gelate nucleic acid preparations to avoid the random movements of liquid particles. The results showed that PEG gelation significantly improved the stability of PEI25K&minus;based and liposome&minus;based nucleic acid preparations, compared with nucleic acid preparations without PEG gelation. After being stored at 4 &deg;C for 3 days, non&minus;PEG gelled nucleic acid preparations almost lost transfection activity, while PEGylated preparations still maintained high transfection efficiency. Fluorescence experiments showed that this effect was caused by inhibiting particle aggregation. The method described in this study was simple and effective, and the materials used had good biocompatibility. It is believed that this study will contribute to the better development of gene therapy drugs
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