61 research outputs found

    Zinc finger and SCAN domain containing 1, ZSCAN1, is a novel stemness-related tumor suppressor and transcriptional repressor in breast cancer targeting TAZ

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    IntroductionCancer stem cells (CSCs) targeted therapy holds the potential for improving cancer management; identification of stemness-related genes in CSCs is necessary for its development.MethodsThe Cancer Genome Atlas (TCGA) and the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) datasets were used for survival analysis. ZSCAN1 correlated genes was identified by Spearman correlation analysis. Breast cancer stem-like cells (BCSLCs) were isolated by sorting CD44+CD24- cells from suspension cultured breast cancer (BC) spheroids. The sphere-forming capacity and sphere- and tumor-initiating capacities were determined by sphere formation and limiting dilution assays. The relative gene expression was determined by qRT-PCR, western blot. Lentivirus system was used for gene manipulation. Nuclear run-on assay was employed to examine the levels of nascent mRNAs. DNA pull-down and Chromatin immunoprecipitation (ChIP) assays were used for determining the interaction between protein and target DNA fragments. Luciferase reporter assay was used for evaluating the activity of the promoter.Results and discussionZSCAN1 is aberrantly suppressed in BC, and this suppression indicates a bad prognosis. Ectopic expression of ZSCAN1 inhibited the proliferation, clonogenicity, and tumorigenicity of BC cells. ZSCAN1-overexpressing BCSLCs exhibited weakened stemness properties. Normal human mammary epithelial (HMLE) cells with ZSCAN1 depletion exhibited enhanced stemness properties. Mechanistic studies showed that ZSCAN1 directly binds to -951 ~ -925bp region of WWTR1 (encodes TAZ) promoter, inhibits WWTR1 transcription, thereby inhibiting the stemness of BCSCs. Our work thus revealed ZSCAN1 as a novel stemness-related tumor suppressor and transcriptional repressor in BC

    Effects of different altitudes on the structure and properties of potato starch

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    The main element influencing the quality of potato starch is the environment. To investigate the effects of different altitude cultivation locations on the molecular structure and physicochemical properties of starch, two potato varieties, Jiusen No.1 B1 and Qingshu No.9 B2, were planted in three different altitude zones: A1 at low altitude (Chongzhou 450 m), A2 at middle altitude (Xichang 2800 m), and A3 at high altitude (Litang 3650 m). The results showed that the average volume, number, surface area diameter, average branched polymerization degree, crystallinity, and gelatinization temperature of two potato granules in high altitude areas were significantly lower than those in middle and low altitude areas were, and the gelatinization performance of potato starch was affected according to the correlation of starch structure characteristics. Potato starch with more short-branched chains and less long branched chains resulted in a lower gelatinization temperature in high altitude areas. The results showed that Jiusen No. 1 and Qingshu No. 9 were mainly affected by accumulated radiation and accumulated rainfall in Litang, a high altitude area, and by effective accumulated temperature in Xichang, a middle altitude area. This study quantified the influence of meteorological factors on the main starch quality of potato tubers. The results can be used as a theoretical basis for the scientific planting of high-quality potatoes

    Particle Design of Membrane Emulsification for Protein Drug and Vaccine Delivery

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    Biodegradable particles have important applications in Drug Delivery Systems (DDS) of protein/peptide drugs. And recently, particle systems have also showed to be powerful for vaccine delivery (adjuvant) in order to solve the difficulties when conventional Alum adjuvant was used. However, in above applications, the problems of broad size distribution and poor reproducibility of particles, and deactivation of protein during the preparation, storage and release, are still big challenges. Furthermore, particle should be designed specially according to antigen type and purpose in vaccine delivery. In this article, the techniques to control the diameter of microparticle (MP) will be introduced at the first, and then the strategies about how to maintain the bioactivity of protein drugs during preparation and drug release will be reviewed. Furthermore, particle application specially designed for vaccine delivery to enhance both humoral response and cellular response, will be described

    Facile fabrication of varisized calcium carbonate microspheres as vaccine adjuvants

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    Functional calcium carbonate (CaCO3) particles of micron and submicron sizes used in catalysis and biomedicine have attracted considerable attention for decades. In this paper, the process parameters for CaCO3 crystallization were systematically investigated. Our experimental results demonstrated the significance of temperature during fabrication. Under the optimized conditions, various uniform-sized and spherical CaCO3 microparticles (MPs) with average diameters from 0.8 mm to 5 mm were facilely and rapidly fabricated via different mixing strategies including mechanical stirring, homogenization, and ultrasonication. The physicochemical characteristics of the CaCO3 microspheres were evaluated. And, the hepatitis B surface antigen (HBsAg) used as a model antigen was encapsulated into the particles (1 mm and 4 mm) for investigating the immune responses elicited after vaccination. In vitro, dendritic cells (DCs) were significantly activated by the MP-based vaccine formulations with up-regulated co-stimulatory molecules expression of CD40 and CD83. After immunization, CaCO3 MPs loaded with HBsAg induced greater lymphocyte activation, more cytokine secretion, higher antigen-specific IgG titers and more memory T cell generation to protect against reinfection. Therefore, the CaCO3 MPs, especially the 1 mm particles, could induce strong cellular and humoral immune responses, probably because of easier uptake and more efficient antigen-presentation by DCs. With the advantages of good biocompatibility, high loading capacity and easy preparation, they could be potentially useful as vaccine adjuvants. These results might provide further design principles for potent inorganic particulate adjuvant and delivery systems.</p

    Acta Biomater.

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    Poly(DL-lactic-co-glycolic acid) (PLGA) microspheres have been widely prepared by many methods, including solvent evaporation, solvent extraction and the co-solvent method. However, very few studies have compared the properties of microspheres fabricated by these methods. This is partly because the broad size distribution of the resultant particles severely complicates the analysis and affects the reliability of the comparison. To this end, uniform-sized PLGA microspheres have been prepared by Shirasu porous glass premix membrane emulsification and used to encapsulate exenatide, a drug for treating Type 2 diabetes. Based on this technique, the influences on the properties of microspheres fabricated by the aforementioned three methods were intensively investigated, including in vitro release, degradation and pharmacology. We found that these microspheres presented totally different release behaviors in vitro and in vivo, but exhibited a similar trend of PLGA degradation. Moreover, the internal structural evolution visually demonstrated these release behaviors. We selected for further examination the microsphere prepared by solvent evaporation because of its constant release rate, and explored its pharmacodynamics, histology, etc., in more detail. This microsphere when injected once showed equivalent efficacy to that of twice-daily injections of exenatide with no inflammatory response. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.Poly(DL-lactic-co-glycolic acid) (PLGA) microspheres have been widely prepared by many methods, including solvent evaporation, solvent extraction and the co-solvent method. However, very few studies have compared the properties of microspheres fabricated by these methods. This is partly because the broad size distribution of the resultant particles severely complicates the analysis and affects the reliability of the comparison. To this end, uniform-sized PLGA microspheres have been prepared by Shirasu porous glass premix membrane emulsification and used to encapsulate exenatide, a drug for treating Type 2 diabetes. Based on this technique, the influences on the properties of microspheres fabricated by the aforementioned three methods were intensively investigated, including in vitro release, degradation and pharmacology. We found that these microspheres presented totally different release behaviors in vitro and in vivo, but exhibited a similar trend of PLGA degradation. Moreover, the internal structural evolution visually demonstrated these release behaviors. We selected for further examination the microsphere prepared by solvent evaporation because of its constant release rate, and explored its pharmacodynamics, histology, etc., in more detail. This microsphere when injected once showed equivalent efficacy to that of twice-daily injections of exenatide with no inflammatory response. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

    Int. J. Pharm.

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    Oral delivery of antigens is patient-friendly and efficient way of treating intestinal infections. However, the efficacy of oral vaccines is limited by degradation in the gastrointestinal (GI) tract and poor absorption by enterocytes and antigen-presenting cells (APC). Here we report ulex europaeus agglutinin-1 (UEA-1) conjugated poly (D,L-lactide-co-glycolide) (PLGA)-lipid nanoparticles (NP) containing a Toll-like receptor (TLR)-agonist monophosphoryl lipid A (MPL) as an oral vaccine delivery system. The uniform-sized PLGA-lipid NPs (simplified as lipid NPs) were produced by the premix membrane emulsification method. They can protect the entrapped model antigen ovalbumin (OVA) from exposure to the GI tract and release the OVA in a controlled manner. With UEA-1 and MPL modification, the UEA-MPL/lipid NPs can be effectively transported by M-cells and captured by mucosal dendritic cells (DCs). After in vivo vaccination, the OVA-UEA-MPL/lipid NPs stimulated the most effective mucosal IgA and serum IgG antibodies during the oral formulations. These results suggest that this MPL containing M-cell targeted lipid NP can potentially be used as a universally robust oral vaccine delivery system. (C) 2014 Elsevier B.V. All rights reserved.Oral delivery of antigens is patient-friendly and efficient way of treating intestinal infections. However, the efficacy of oral vaccines is limited by degradation in the gastrointestinal (GI) tract and poor absorption by enterocytes and antigen-presenting cells (APC). Here we report ulex europaeus agglutinin-1 (UEA-1) conjugated poly (D,L-lactide-co-glycolide) (PLGA)-lipid nanoparticles (NP) containing a Toll-like receptor (TLR)-agonist monophosphoryl lipid A (MPL) as an oral vaccine delivery system. The uniform-sized PLGA-lipid NPs (simplified as lipid NPs) were produced by the premix membrane emulsification method. They can protect the entrapped model antigen ovalbumin (OVA) from exposure to the GI tract and release the OVA in a controlled manner. With UEA-1 and MPL modification, the UEA-MPL/lipid NPs can be effectively transported by M-cells and captured by mucosal dendritic cells (DCs). After in vivo vaccination, the OVA-UEA-MPL/lipid NPs stimulated the most effective mucosal IgA and serum IgG antibodies during the oral formulations. These results suggest that this MPL containing M-cell targeted lipid NP can potentially be used as a universally robust oral vaccine delivery system. (C) 2014 Elsevier B.V. All rights reserved

    In situ magnetization technique for synthesis of magnetic polymer microspheres

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    A new process was developed for synthesis of magnetic polymer microspheres which can be used as hyperthermia carrier for cancer therapy. Polymer microspheres containing magnetic nanoparticles were successfully prepared by in situ formation technique of magnetite combination with double emulsion method. Poly (styrene-co-2-hydroxyethyl methacrylate) (PS-HEMA) dissolved into ethyl acetate (EA) was employed as oil phase (O). Ferrous chloride (Fe2+) and ferric chloride (Fe3+) aqueous solution was used as an internal water phase (W-1), which was dispersed into polymer solution to form primary emulsion of W-1/O. Then, this emulsion was further dispersed into external water phase (W-2) to obtain double emulsion of W-1/O/W-2. Finally, the alkaline solution of ammonia was added into this system, and the ammonia continuously diffused into the internal water phase (W-1) to react with Fe2+ and Fe3+. As a result, Fe3O4 magnetic nanopartides were formed in situ in the internal water phase. Various process parameters including Fe2+/Fe3+ concentrations in internal water phase, PS-HEMA concentrations, Span85 amounts in oil phase and volume fractions of pre-solidification solution affected stability of primary emulsion, loading efficiency of magnetic nanoparticles, morphology and magnetization of microspheres, which were systematically investigated in this study. Compared with the traditional method, the magnetic polymer microspheres prepared by in situ magnetization technique demonstrated excellent encapsulation efficiency (26.1%) and high magnetization (12.2 emu/g). Therefore, the as-prepared magnetic polymer microspheres show good potential for cancer therapy. (C) 2012 Elsevier B.V. All rights reserved
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