178 research outputs found

    YM155 Induces EGFR Suppression in Pancreatic Cancer Cells

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    YM155, which inhibits the anti-apoptotic protein survivin, is known to exert anti-tumor effects in various cancers, including prostate and lung cancer. However, there are few reports describing the inhibitory effect of YM155 on human pancreatic cancers that highly express survivin. Here, we tested the effects of YM155 on a variety of cancer cell lines, including pancreatic cancer cells. We found that YM155 exerts an anti-proliferative effect in pancreatic cancer cells, inducing cell death through suppression of XIAP (X-linked inhibitor of apoptosis) as well as survivin without affecting the anti-apoptotic proteins Bcl-xL or Mcl-1. YM155 also inhibited tumor growth in vivo, reducing the size of pancreatic cancer cell line MIAPaCa-2 xenografts by 77.1% on day 31. Western blot analyses further showed that YM155 downregulated phosphoinoside 3-kinase (PI3K) expression and reduced the levels of phosphorylated (activated) extracellular signal-regulated kinase (ERK) and STAT3 (signal transducer and activator of transcription 3) in PANC-1 cells. Interestingly, we also found that YM155 downregulated the epidermal growth factor receptor (EGFR) in various cancer cell lines and induced the EGFR phosphorylation and ubiquitination of EGFR in PANC-1 cells. YM155 also modestly promoted the ubiquitination of survivin and XIAP. Therefore, YM155 acts through modulation of EGFR and survivin expression to subsequently reduce survival. We suggest that YM155 has potential as a therapeutic agent in the treatment of pancreatic cancer

    The role of prostaglandin E2 (PGE 2) in toll-like receptor 4 (TLR4)-mediated colitis-associated neoplasia

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    <p>Abstract</p> <p>Background</p> <p>We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE <sub>2 </sub>and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE <sub>2 </sub>is the central factor downstream of TLR4 signaling that promotes intestinal tumorigenesis. To further elucidate critical downstream pathways involving TLR4-mediated intestinal tumorigenesis, we examined the effects of exogenously administered PGE <sub>2 </sub>in TLR4-/- mice to see if PGE <sub>2 </sub>bypasses the protection from colitis-associated tumorigenesis.</p> <p>Method</p> <p>Mouse colitis-associated neoplasia was induced by azoxymethane (AOM) injection followed by two cycles of dextran sodium sulfate (DSS) treatment. Two different doses of PGE <sub>2 </sub>(high dose group, 200 Îźg, n = 8; and low dose group, 100 Îźg, n = 6) were administered daily during recovery period of colitis by gavage feeding. Another group was given PGE <sub>2 </sub>during DSS treatment (200 Îźg, n = 5). Inflammation and dysplasia were assessed histologically. Mucosal Cox-2 and amphiregulin (AR) expression, prostanoid synthesis, and EGFR activation were analyzed.</p> <p>Results</p> <p>In control mice treated with PBS, the average number of tumors was greater in WT mice (n = 13) than in TLR4-/- mice (n = 7). High dose but not low dose PGE <sub>2 </sub>treatment caused an increase in epithelial proliferation. 28.6% of PBS-treated TLR4-/- mice developed dysplasia (tumors/animal: 0.4 Âą 0.2). By contrast, 75.0% (tumors/animal: 1.5 Âą 1.2, P < 0.05) of the high dose group and 33.3% (tumors/animal: 0.3 Âą 0.5) of the low dose group developed dysplasia in TLR4-/- mice. Tumor size was also increased by high dose PGE <sub>2 </sub>treatment. Endogenous prostanoid synthesis was differentially affected by PGE <sub>2 </sub>treatment during acute and recovery phases of colitis. Exogenous administration of PGE <sub>2 </sub>increased colitis-associated tumorigenesis but this only occurred during the recovery phase. Lastly, PGE <sub>2 </sub>treatment increased mucosal expression of AR and Cox-2, thus inducing EGFR activation and forming a positive feedback mechanism to amplify mucosal Cox-2.</p> <p>Conclusions</p> <p>These results highlight the importance of PGE <sub>2 </sub>as a central downstream molecule involving TLR4-mediated intestinal tumorigenesis.</p

    The effects of direct current stimulation on exercise performance, pacing and perception in temperate and hot environments

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    Background. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique and has previously been shown to enhance submaximal exercise by reducing rating of perceived exertion (RPE). The present study examined the effects of tDCS on high-intensity self-paced exercise in temperate conditions and fixed followed by maximal exercise in the heat; it was hypothesised performance and RPE would be altered. Methods. Two separate studies were undertaken in which exercise was preceded by 20-minutes of sham tDCS (SHAM), or anodal tDCS (TDCS). Study 1: six males completed a 20-km cycling time trial, on two occasions. Power output (PO), RPE, O2 pulse, and heart rate (HR) were measured throughout. Study 2: eight males completed fixed intensity cycling exercise at 55% of a pre-determined maximal power output (PMax) for 25-minutes before undertaking a time to exhaustion test (TTE; 75% PMax) in hot conditions (33°C), on two occasions. Test duration, heart rate, thermal and perceptual responses were measured. Study specific and combined statistical analyses was undertaken and effect sizes established.. Results. Study 1: mean PO was not improved with the tDCS (197 ¹ 20 W) compared to SHAM (197 ¹ 12 W) and there were no differences in pacing profile HR, O2 pulse or RPE (p > .05). Study 2: TTE duration (SHAM 314 ¹ 334 s cf 237 ¹ 362 s tDCS), thermal, heart rate and perceptual responses were unchanged by tDCS compared to SHAM (p > .05). When combined, performance in the SHAM trial tended to better than the tDCS. Conclusion. tDCS did not influence cycling performance (study 1) exercise tolerance (study 2) or perception (studies 1&2). tDCS does not appear to facilitate high intensity exercise performance or exercise performance in the heat

    Specificity factors in cytoplasmic polyadenylation

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    Poly(A) tail elongation after export of an messenger RNA (mRNA) to the cytoplasm is called cytoplasmic polyadenylation. It was first discovered in oocytes and embryos, where it has roles in meiosis and development. In recent years, however, has been implicated in many other processes, including synaptic plasticity and mitosis. This review aims to introduce cytoplasmic polyadenylation with an emphasis on the factors and elements mediating this process for different mRNAs and in different animal species. We will discuss the RNA sequence elements mediating cytoplasmic polyadenylation in the 3′ untranslated regions of mRNAs, including the CPE, MBE, TCS, eCPE, and C-CPE. In addition to describing the role of general polyadenylation factors, we discuss the specific RNA binding protein families associated with cytoplasmic polyadenylation elements, including CPEB (CPEB1, CPEB2, CPEB3, and CPEB4), Pumilio (PUM2), Musashi (MSI1, MSI2), zygote arrest (ZAR2), ELAV like proteins (ELAVL1, HuR), poly(C) binding proteins (PCBP2, αCP2, hnRNP-E2), and Bicaudal C (BICC1). Some emerging themes in cytoplasmic polyadenylation will be highlighted. To facilitate understanding for those working in different organisms and fields, particularly those who are analyzing high throughput data, HUGO gene nomenclature for the human orthologs is used throughout. Where human orthologs have not been clearly identified, reference is made to protein families identified in man

    European Position Paper on Rhinosinusitis and Nasal Polyps 2020

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    The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise. The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included.Peer reviewe

    Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

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    Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ(15)N). Animal excrement is known to impact plant δ(15)N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint.This paper presents isotopic (δ(13)C and δ(15)N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of (15)N enrichment in fertilized plants is very large, with δ(15)N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ(15)N values ranged between -0.3 and 5.7‰. Intraplant and temporal variability in δ(15)N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ(13)C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk.The results presented in this study demonstrate the very large impact of seabird guano on maize δ(15)N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must be considered when interpreting isotopic data from archaeological material

    Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo

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    Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201

    Epigenetic modulators as therapeutic targets in prostate cancer

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    Prostate cancer is one of the most common non-cutaneous malignancies among men worldwide. Epigenetic aberrations, including changes in DNA methylation patterns and/or histone modifications, are key drivers of prostate carcinogenesis. These epigenetic defects might be due to deregulated function and/or expression of the epigenetic machinery, affecting the expression of several important genes. Remarkably, epigenetic modifications are reversible and numerous compounds that target the epigenetic enzymes and regulatory proteins were reported to be effective in cancer growth control. In fact, some of these drugs are already being tested in clinical trials. This review discusses the most important epigenetic alterations in prostate cancer, highlighting the role of epigenetic modulating compounds in pre-clinical and clinical trials as potential therapeutic agents for prostate cancer management.info:eu-repo/semantics/publishedVersio

    Driver mutations of cancer epigenomes

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    Potential influences of submarine groundwater discharge, nutrients, and herbivory on Hawaiian reef algae

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    Ph.D. University of Hawaii at Manoa 2011.Includes bibliographical references.Phase shifts have occurred on tropical reefs throughout the world. In Hawaii, phase shifts have been attributed to eutrophication, herbivore reduction, and alien algae. The first study from this dissertation examines the environmental relationships of Submarine Groundwater Discharge (SGD), a likely source of anthropogenic nutrients to Hawaii‟s reefs. The second study analyzes the relative and simultaneous effects of nutrient enrichment and reduced herbivory on algal succession in contrast to control conditions. The third study assesses the potential of indigenous herbivorous fish to control alien algae. The fine scale salinity profiles in the first study established differences between the average salinity values of three sample events, and correlations between SGD and low tide and, SGD and depth. Water quality samples displayed correlations with SGD and concentrations of numerous chemical constituents. Nitrate from water quality samples at Waiopae were up to 3.8 times greater than samples from upland wells suggesting that anthropogenic sources of nitrate are intruding the aquifer. This study exemplifies the dynamics of SGD and nutrient intrusion. Results from the second study in Kealakekua Bay show that the effects of nutrient enrichment were minor, herbivore reduction were considerable, and nutrient enrichment combined with herbivore reduction were major in governing algal biomass and cover. Coralline crustose algae dominated surfaces under control and nutrient enrichment. In herbivore reduction treatments turf algae dominated. Nutrient enrichment had a greater effect at one site, and herbivore reduction had a greater effect at another site, demonstrating that a single solution may not be equally effective for all Hawaiian reefs. Feeding assays from the third study documented that two herbivorous fish species were potential biological control agents for managing alien algae. These fish can achieve different objectives in an effort to manage alien algae. Acanthurus triostegus is suited to control attached populations, Kyphosus vaigiensis is crucial in reducing dispersal by fragments. Results from this dissertation show that nutrient concentrations enter the near shore environment quite rapidly on Hawaii. With sustainable land use practices and increasing herbivore pressure by enhancing select herbivore species, we can improve the resilience of Hawaiian reefs and minimize the possibility of phase shifts
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