117 research outputs found

    FLYWCH1, a novel suppressor of nuclear b-catenin, regulates migration and morphology in colorectal cancer

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    © 2018 American Association for Cancer Research. Wnt/b-catenin signaling plays a critical role during development of both normal and malignant colorectal cancer tissues. Phosphorylation of b-catenin protein alters its trafficking and function. Such conventional allosteric regulation usually involves a highly specialized set of molecular interactions, which may specifically turn on a particular cell phenotype. This study identifies a novel transcription modulator with an FLYWCH/Zn-finger DNA-binding domain, called "FLYWCH1." Using a modified yeast-2-hybrid based Ras-Recruitment system, it is demonstrated that FLYWCH1 directly binds to unphosphorylated (nuclear) b-catenin efficiently suppressing the transcriptional activity of Wnt/ b-catenin signaling that cannot be rescued by TCF4. FLYWCH1 rearranges the transcriptional activity of b-catenin/TCF4 to selectively block the expression of specific downstream genes associated with colorectal cancer cell migration and morphology, including ZEB1, EPHA4, and E-cadherin. Accordingly, overexpression of FLYWCH1 reduces cell motility and increases cell attachment. The expression of FLYWCH1 negatively correlates with the expression level of ZEB1 and EPHA4 in normal versus primary and metastatic colorectal cancer tissues in patients. Thus, FLYWCH1 antagonizes b-catenin/TCF4 signaling during cell polarity/migration in colorectal cancer. Implications: This study uncovers a new molecular mechanism by which FLYWCH1 with a possible tumor suppressive role represses b-catenin-induced ZEB1 and increases cadherin-mediated cell attachment preventing colorectal cancer metastasis

    Characteristic of double-stator PM machine for modular type power train in electric vehicles

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    This paper presents a double-stator permanent magnet brushless DC machine (DS-PMBLDC) which is proposed to be used in light electric vehicles and to replace a typical motor for electric vehicles in future. However, to fulfill the limitation of motor performance at different conditions, electric vehicles require their own specific motor design. Thus, a modular type of motor which can easily replace the electrical motor based on requirements for the electric driving system in power train of an electric vehicle was proposed and discussed in this paper. The operating principle of the proposed machine is reported. Concentrated winding is adopted for the stators of a 9-slot 8-pole DS-PMBLDC machine. The cogging torque, back-EMF, air-gap flux density, torque and power characteristic have been analyzed using 2-dimensional Finite-Element Analysis (2D-FEA). Experimental and simulation results are compared and discussed. Theoretical analysis of the proposed machine show an efficiency of 80% and 75% efficiency in motoring and generating mode respectively. The 2D-FEA simulation results are in good agreement with the measurement results

    Direct non-cyclooxygenase-2 targets of celecoxib and their potential relevance for cancer therapy

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    Celecoxib (Celebrex®) was developed as a selective cyclooxygenase-2 (COX-2) inhibitor for the treatment of chronic pain. However, it now appears that this compound harbours additional pharmacologic activities that are entirely independent of its COX-2-inhibitory activity. This review presents the recently emerged direct non-COX-2 targets of celecoxib and their proposed role in mediating this drug's antitumour effects

    Hydrogen sulphide-induced hypometabolism in human-sized porcine kidneys

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    Background Since the start of organ transplantation, hypothermia-forced hypometabolism has been the cornerstone in organ preservation. Cold preservation showed to protect against ischemia, although post-transplant injury still occurs and further improvement in preservation techniques is needed. We hypothesize that hydrogen sulphide can be used as such a new preservation method, by inducing a reversible hypometabolic state in human sized kidneys during normothermic machine perfusion. Methods Porcine kidneys were connected to an ex-vivo isolated, oxygen supplemented, normothermic blood perfusion set-up. Experimental kidneys (n = 5) received a 85mg NaHS infusion of 100 ppm and were compared to controls (n = 5). As a reflection of the cellular metabolism, oxygen consumption, mitochondrial activity and tissue ATP levels were measured. Kidney function was assessed by creatinine clearance and fractional excretion of sodium. To rule out potential structural and functional deterioration, kidneys were studied for biochemical markers and histology. Results Hydrogen sulphide strongly decreased oxygen consumption by 61%, which was associated with a marked decrease in mitochondrial activity/function, without directly affecting ATP levels. Renal biological markers, renal function and histology did not change after hydrogen sulphide treatment. Conclusion In conclusion, we showed that hydrogen sulphide can induce a controllable hypometabolic state in a human sized organ, without damaging the organ itself and could thereby be a promising therapeutic alternative for cold preservation under normothermic conditions in renal transplantation

    Structural Conformers of (1,3-Dithiol-2-ylidene)ethanethioamides: The Balance Between Thioamide Rotation and Preservation of Classical Sulfur-Sulfur Hypervalent Bonds

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    The reaction of N-(2-phthalimidoethyl)-N-alkylisopropylamines and S2Cl2 gave 4-N-(2-phthalimidoethyl)-N-alkylamino-5-chloro-1,2-dithiol-3-thiones that quantitatively cycloadded to dimethyl or diethyl acetylenedicarboxylate to give stable thioacid chlorides, which in turn reacted with one equivalent of aniline or a thiole to give thioanilides or a dithioester. Several compounds of this series showed atropisomers that were studied by a combination of dynamic NMR, simulation of the signals, conformational analysis by DFT methods, and single crystal X-ray diffraction, showing a good correlation between the theoretical calculations, the experimental values of energies, and the preferred conformations in the solid state. The steric hindering of the crowded substitution at the central amine group was found to be the reason for the presence of permanent atropisomers in this series of compounds and the cause of a unique disposition of the thioxo group at close-to-right angles with respect to the plane defined by the 1,3-dithiole ring in the dithiafulvene derivatives, thus breaking the sulfur–sulfur hypervalent bond that is always found in this kind of compounds.Ministerio de Economıá y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411

    Induction of cell cycle changes and modulation of apoptogenic/anti-apoptotic and extracellular signaling regulatory protein expression by water extracts of I'm-Yunity™ (PSP)

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    BACKGROUND: I'm-Yunity™ (PSP) is a mushroom extract derived from deep-layer cultivated mycelia of the patented Cov-1 strain of Coriolus versicolor (CV), which contains as its main bioactive ingredient a family of polysaccharo-peptide with heterogeneous charge properties and molecular sizes. I'm-Yunity™ (PSP) is used as a dietary supplement by cancer patients and by individuals diagnosed with various chronic diseases. Laboratory studies have shown that I'm-Yunity™ (PSP) enhances immune functions and also modulates cellular responses to external challenges. Recently, I'm-Yunity™ (PSP) was also reported to exert potent anti-tumorigenic effects, evident by suppression of cell proliferation and induction of apoptosis in malignant cells. We investigate the mechanisms by which I'm-Yunity™ (PSP) elicits these effects. METHODS: Human leukemia HL-60 and U-937 cells were incubated with increasing doses of aqueous extracts of I'm-Yunity™ (PSP). Control and treated cells were harvested at various times and analyzed for changes in: (1) cell proliferation and viability, (2) cell cycle phase transition, (3) induction of apoptosis, (4) expression of cell cycle, apoptogenic/anti-apoptotic, and extracellular regulatory proteins. RESULTS: Aqueous extracts of I'm-Yunity™ (PSP) inhibited cell proliferation and induced apoptosis in HL-60 and U-937 cells, accompanied by a cell type-dependent disruption of the G(1)/S and G(2)/M phases of cell cycle progression. A more pronounced growth suppression was observed in treated HL-60 cells, which was correlated with time- and dose-dependent down regulation of the retinoblastoma protein Rb, diminution in the expression of anti-apoptotic proteins bcl-2 and survivin, increase in apoptogenic proteins bax and cytochrome c, and cleavage of poly(ADP-ribose) polymerase (PARP) from its native 112-kDa form to the 89-kDa truncated product. Moreover, I'm-Yunity™ (PSP)-treated HL-60 cells also showed a substantial decrease in p65 and to a lesser degree p50 forms of transcription factor NF-κB, which was accompanied by a reduction in the expression of cyclooxygenase 2 (COX2). I'm-Yunity™ (PSP) also elicited an increase in STAT1 (signal transducer and activator of transcription) and correspondingly, decrease in the expression of activated form of ERK (extracellular signal-regulated kinase). CONCLUSION: Aqueous extracts of I'm-Yunity™ (PSP) induces cell cycle arrest and alterations in the expression of apoptogenic/anti-apoptotic and extracellular signaling regulatory proteins in human leukemia cells, the net result being suppression of proliferation and increase in apoptosis. These findings may contribute to the reported clinical and overall health effects of I'm-Yunity™ (PSP)
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