1,388 research outputs found

    The translational potential of microRNAs as biofluid markers of urological tumours

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    MicroRNAs (miRNAs) are secreted by cells in vesicles, bound in a ribonucleoprotein complex or as free molecules. These miRNA secretion pathways are dysregulated in cancer, making miRNAs attractive candidate molecules for liquid biopsies. A number of studies have investigated the regulation of miRNA secretion into blood and urine and suggested that miRNAs are noninvasive diagnostic, prognostic and surveillance markers in urological carcinomas, and research in this area has increased over the past 5 years. However, methodological and analytical pitfalls exist and require addressing to enable future translation of the laboratory findings regarding miRNAs as biomarkers into clinical practice in bladder cancer, kidney cancer, prostate cancer and testicular cancer

    Modifying the product distribution of a reaction within the controlled microenvironment of a colloidosome

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    A water-soluble colloidosome composed of PGMA–PS latex was used as a microcapsule to host a catalyzed oxidation reaction within its dodecane core. When compared to a control reaction a significant colloidosome effect was observed. Specifically, a 233% increase in the relative yield of all products was observed for the colloidosome reaction. Furthermore, when the product distributions were calculated it was evident that a switch in selectivity had taken place. These studies showed there is a significant reduction in the relative yield of the epoxide product compared to the remaining oxidation products. Additional control experiments confirmed that rate enhancements were not simply a result of concentration and that reactions were not occurring in the outer latex phase. As a consequence of these control experiments, we suggest that the colloidosome enhancement and shift in product distribution, comes about from differences in electronic environment at or close to the interface between the internal oil phase and the outer colloidal particles. This environment is able to stabilize any specific intermediates and or transition states leading to enhanced reactions for these products and higher relative yields

    The miRNA-kallikrein axis of interaction: a new dimension in the pathogenesis of prostate cancer

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    Kallikrein-related peptidases (KLKs) are a family of serine proteases that were shown to be useful cancer biomarkers. KLKs have been shown to be dysregulated in prostate cancer (PCa). microRNAs (miRNAs) are short RNA nucleotides that negatively regulate gene expression and have been reportedly dysregulated in PCa. We compiled a comprehensive list of 55 miRNAs that are differentially expressed in PCa from previous microarray analysis and published literature. Target prediction analyses showed that 29 of these miRNAs are predicted to target 10 KLKs. Eight of these miRNAs were predicted to target more than one KLK. Quantitative real-time (qRT)-PCR demonstrated that there was an inverse correlation pattern in the expression (normal vs. cancer) between dysregulated miRNAs and their target KLKs. In addition, we experientially validated the miRNA-KLK interaction by transfecting miR-331-3p and miR-143 into a PCa cell line. Decreased expression of targets KLK4 and KLK10, respectively, and decreased cellular growth were observed. In addition to KLKs, dysregulated miRNAs were predicted to target other genes involved in the pathogenesis of PCa. These data show that miRNAs can contribute to KLK regulation in PCa. The miRNA-KLK axis of interaction projects a new element in the pathogenesis of PCa that may have therapeutic implications

    Establishment of kidney cancer organoid cultures

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    This protocol describes an efficient novel method for cultivating kidney cancer organoids, derived directly from human clear cell renal cell carcinomas (ccRCC) or sorted cancer stem cells. The organoids recapitulate tumor-specific characteristics and display inter-tumor heterogeneity. Here we explain how to establish the organoid cultures, maintain them in defined, serum-free medium and use them for patient-specific drug testing. Within 10-14 days, a patient-derived organoid culture is established and can be serially passaged. Compared to other protocols focusing on organoid cultures derived from pediatric kidney malignancies or healthy kidneys, the protocol described here is optimized for adult ccRCC organoid cultures. Organoids established using this protocol can be used to further investigate tumor biology in a complex 3D in vitro system, complement current preclinical model-based drug studies, and advance the development of personalized therapy design

    Universal Negative Poisson Ratio of Self Avoiding Fixed Connectivity Membranes

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    We determine the Poisson ratio of self-avoiding fixed-connectivity membranes, modeled as impenetrable plaquettes, to be sigma=-0.37(6), in statistical agreement with the Poisson ratio of phantom fixed-connectivity membranes sigma=-0.32(4). Together with the equality of critical exponents, this result implies a unique universality class for fixed-connectivity membranes. Our findings thus establish that physical fixed-connectivity membranes provide a wide class of auxetic (negative Poisson ratio) materials with significant potential applications in materials science.Comment: 4 pages, 3 figures, LaTeX (revtex) Published version - title changed, one figure improved and one reference change

    Dynamics at a smeared phase transition

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    We investigate the effects of rare regions on the dynamics of Ising magnets with planar defects, i.e., disorder perfectly correlated in two dimensions. In these systems, the magnetic phase transition is smeared because static long-range order can develop on isolated rare regions. We first study an infinite-range model by numerically solving local dynamic mean-field equations. Then we use extremal statistics and scaling arguments to discuss the dynamics beyond mean-field theory. In the tail region of the smeared transition the dynamics is even slower than in a conventional Griffiths phase: the spin autocorrelation function decays like a stretched exponential at intermediate times before approaching the exponentially small equilibrium value following a power law at late times.Comment: 10 pages, 8eps figures included, final version as publishe

    Total oxidation of propene at low temperature over Co3O4-CeO2 mixed oxides: Role of surface oxygen vacancies and bulk oxygen mobility in the catalytic activity

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    Co3O4, CeO2 and Co3O4\u2013CeO2 mixed oxides with Co/Ce nominal atomic ratio 0.1:5, prepared by coprecipitation method with sodium carbonate, were tested in the oxidation of propene under lean condition and the catalyst stability was checked by performing three consecutive heating\u2013cooling cycles. Characterization of the textural properties were performed by surface area measurement BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. Among the Co3O4\u2013CeO2 mixed oxides, Co3O4 (30 wt%)\u2013CeO2 (70 wt%) gives the best activity attaining full propene conversion at 250 \ub0C. This sample is characterized by the presence of Co3O4 particles well dispersed and in good contact with ceria according to BET and XRD data and as evidenced by SEM micrographs. Oxygen temperature-programmed desorption (O2 -TPD) and C3H6 -temperature-programmed reduction (C3H6-TPR) experiments were carried out in order to study the surface and bulk oxygen mobility and to correlate it to the activity. At temperature around 200 \ub0C, O2-TPD experiments showed the desorption of mobile surface oxygen species for the most active samples, Co3O4 and Co3O4 (30 wt%)\u2013 CeO2 (70 wt%). C3H6-TPR experiments for both of the oxides also evidenced a high reactivity at low temperature, especially, for Co3O4 (30 wt%)\u2013 CeO2 (70 wt%) giving at 345 \ub0C an intense peak of CO2 formation. Conversely, the ceria sample showed by C3H6-TPR much less pronounced oxygen bulk mobility, starting to react with propene above 500 \ub0C and forming only CO. In this case, the catalytic activity of ceria was explained in terms of formation of surface oxygen vacancies which are relevant to the propene oxidation in presence of gaseous oxygen

    Inhibiting WNT and NOTCH in renal cancer stem cells and the implications for human patients

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    Current treatments for clear cell renal cell cancer (ccRCC) are insufficient because two-thirds of patients with metastases progress within two years. Here we report the identification and characterization of a cancer stem cell (CSC) population in ccRCC. CSCs are quantitatively correlated with tumor aggressiveness and metastasis. Transcriptional profiling and single cell sequencing reveal that these CSCs exhibit an activation of WNT and NOTCH signaling. A significant obstacle to the development of rational treatments has been the discrepancy between model systems and the in vivo situation of patients. To address this, we use CSCs to establish non-adherent sphere cultures, 3D tumor organoids, and xenografts. Treatment with WNT and NOTCH inhibitors blocks the proliferation and self-renewal of CSCs in sphere cultures and organoids, and impairs tumor growth in patient-derived xenografts in mice. These findings suggest that our approach is a promising route towards the development of personalized treatments for individual patients

    Salen-Based Amphiphiles:Directing Self-Assembly in Water by Metal Complexation

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    Tuning morphologies of self‐assembled structures in water is a major challenge. Herein we present a salen‐based amphiphile which, using complexation with distinct transition metal ions, allows to control effectively the self‐assembly morphology in water, as observed by Cryo‐TEM and confirmed by DLS measurements. Applying this strategy with various metal ions gives a broad spectrum of self‐assembled structures starting from the same amphiphilic ligand (from cubic structures to vesicles and micelles). Thermogravimetric analysis and electric conductivity measurements reveal a key role for water coordination apparently being responsible for the distinct assembly behavior.Supramolecular & Biomaterials Chemistr

    On twisted Fourier analysis and convergence of Fourier series on discrete groups

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    We study norm convergence and summability of Fourier series in the setting of reduced twisted group CC^*-algebras of discrete groups. For amenable groups, F{\o}lner nets give the key to Fej\'er summation. We show that Abel-Poisson summation holds for a large class of groups, including e.g. all Coxeter groups and all Gromov hyperbolic groups. As a tool in our presentation, we introduce notions of polynomial and subexponential H-growth for countable groups w.r.t. proper scale functions, usually chosen as length functions. These coincide with the classical notions of growth in the case of amenable groups.Comment: 35 pages; abridged, revised and update
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