1,439 research outputs found

    Pharmacogenomics, CYP2D6, and tamoxifen: A survey of the reasons sustaining european clinical practice paradigms

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    Tamoxifen is a drug that is often used in the clinical management of breast cancer. CYP2D6 is a key metabolizing enzyme that is involved in the conversion of tamoxifen to its active drug metabolites. CYP2D6 has several alleles that metabolize tamoxifen and other drugs at different rates that can alter therapeutic impact, a characteristic that renders it one of the most studied enzymes in the field of pharmacogenetics. Background and objectives: Portugal has no implemented measures based on pharmacogenomics analysis prior to therapy that might function as a cultural sample control when analyzing the individual and economic factors present in clinical practice paradigms. Therefore, we aim to investigate the impact of CYP2D6 genotyping of the tamoxifen metabolizing enzymes in the clinical management of breast cancer patients. Materials and Methods: Qualitative/quantitative studies regarding the impact of pharmacogenomics in breast cancer; personal interviews in different Portuguese laboratories within hospital setting using a survey. Analysis of data through interviews to management board and/or decision makers from major oncological centers. Results: Reasons for common adoption of pharmacogenomics practice are contradictory and based both in economic factors and cultural/clinical bias. Conclusions: This research study identifies specific cultural and/or clinical bias that act as obstacles to pharmacogenomic implementation and proposes viable courses of action that might bring about change in cultural/medical habits.This research was partially support by UID/BIM/04293/2013 and UID/EQU/0470/2019

    Glycosylation in cancer: Mechanisms and clinical implications

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    Despite recent progress in understanding the cancer genome, there is still a relative delay in understanding the full aspects of the glycome and glycoproteome of cancer. Glycobiology has been instrumental in relevant discoveries in various biological and medical fields, and has contributed to the deciphering of several human diseases. Glycans are involved in fundamental molecular and cell biology processes occurring in cancer, such as cell signalling and communication, tumour cell dissociation and invasion, cell-matrix interactions, tumour angiogenesis, immune modulation and metastasis formation. The roles of glycans in cancer have been highlighted by the fact that alterations in glycosylation regulate the development and progression of cancer, serving as important biomarkers and providing a set of specific targets for therapeutic intervention. This Review discusses the role of glycans in fundamental mechanisms controlling cancer development and progression, and their applications in oncology.The Institute of Molecular Pathology and Immunology of the University of Porto integrates the Institute for Research and Innovation in Health, which is partially supported by the Portuguese Foundation for Science and Technology (FCT). This work is funded by the European Regional Development Fund (FEDER) through the Operational Programme for Competitiveness Factors (COMPETE) and by national funds through the FCT, under the projects PEst‑C/SAU/ LA0003/2013, PTDC/BBB-EBI/0786/2012 and EXPL/BIM-MEC/0149/2012. S.S.P. acknowledges a grant from the FCT (number SFRH/BPD/63094/2009). C.A.R. acknowledges sup­port from the European Union Seventh Framework Programme GastricGlycoExplorer (grant number 316929). The authors apologize that they cannot include all the relevant studies on glycosylation in cancer in this article owing to limitation of space. The authors thank Tiago Fontes- Oliveira for support in figures preparations

    Cadherins Glycans in Cancer: Sweet Players in a Bitter Process

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    Cadherins are key components in tissue morphogenesis and architecture, contributing to the establishment of cohesive cell adhesion. Reduced cellular adhesiveness as a result of cadherin dysfunction is a defining feature of cancer. During tumor development and progression, major changes in the glycan repertoire of cancer cells take place, affecting the stability, trafficking, and cell-adhesion properties of cadherins. Importantly, the different glycoforms of cadherins are promising biomarkers, with potential clinical application to improve the management of patients, and constitute targets for the development of new therapies. This review discusses the most recent insights on the impact of glycan structure on the regulation of cadherin function in cancer, and provides a perspective on how cadherin glycans constitute tumor biomarkers and potential therapeutic targets.IPATIMUP integrates the I3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology (Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação). This work was financed by FEDER – Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 – Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through the FCT in the framework of the project ‘Institute for Research and Innovation in Health Sciences’ (POCI-01-0145-FEDER-007274), PTDC/DTP-PIC/0560/2014, and PTDC/BBB-EBI/0567/2014. S.C. also acknowledges funding from the FCT (SFRH/BD/77386/2011)

    Myosin II synergizes with F-actin to promote DNGR-1-dependent cross-presentation of dead cell-associated antigens

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    Conventional type 1 DCs (cDC1s) excel at cross-presentation of dead cell-associated antigens partly because they express DNGR-1, a receptor that recognizes exposed actin filaments on dead cells. In vitro polymerized F-actin can be used as a synthetic ligand for DNGR-1. However, cellular F-actin is decorated with actin-binding proteins, which could affect DNGR-1 recognition. Here, we demonstrate that myosin II, an F-actin-associated motor protein, greatly potentiates the binding of DNGR-1 to F-actin. Latex beads coated with F-actin and myosin II are taken up by DNGR-1+ cDC1s, and antigen associated with those beads is efficiently cross-presented to CD8+ T cells. Myosin II-deficient necrotic cells are impaired in their ability to stimulate DNGR-1 or to serve as substrates for cDC1 cross-presentation to CD8+ T cells. These results provide insights into the nature of the DNGR-1 ligand and have implications for understanding immune responses to cell-associated antigens and for vaccine design

    Studying T Cells N-Glycosylation by Imaging Flow Cytometry

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    Imaging flow cytometry is an emerging imaging technology that combines features of both conventional flow cytometry and fluorescence microscopy allowing quantification of the imaging parameters. The analysis of protein posttranslational modifications by glycosylation using imaging flow cytometry constitutes an important bioimaging tool in the glycobiology field. This technique allows quantification of the glycan fluorescence intensity, co-localization with proteins, and evaluation of the membrane/cytoplasmic expression. In this chapter we provide the guidelines to analyze glycan expression, particularly the ß1,6 GlcNAc branched N-glycans, on the membrane of intestinal T cells from inflammatory bowel disease patients.This work was supported by grants from the Portuguese Foundation for Science and Technology (FCT), project grants (PTDC/DTPPIC/0560/2014; PTDC/BBB-EBI/0786/2012; EXPL/BIMMEC/0149/2012), “financiados no âmbito do Programa Operacional Temático Factores de Competitividade (COMPETE) e comparticipado pelo fundo Comunitário Europeu FEDER,” e do Quadro de Referência Estratégia Nacional QREN. This work was further supported by a Portuguese grant from “Grupo de Estudo da Doença Infl amatória Intestinal” (GEDII). This work had also the fi nantial support of FCT/MEC through National Funds and, when applicable, co-fi nanced by the FEDER via the PT2020 Partnership Agreement under the 4293 Unit I&D. S.S.P. (SFRH/BPD/63094/2009) also acknowledges FCT. A.M.D. PD/BD/105982/2014 also acknowledges FCT and BiotechHealth Doctoral Programme. The Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP) integrates the Institute for Research and Innovation in Health (I3S), which is partially supported by the Portuguese Foundation for Science and Technology (FCT). Data was acquired at the Bioimaging Center for Biomaterials and Regenerative Therapies (b.IMAGE, INEB, Porto, Portugal)

    Chitosan/virgin-coconut-oil-based system enriched with cubosomes: a 3D drug-delivery approach

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    Emulsion-based systems that combine natural polymers with vegetable oils have been identified as a promising research avenue for developing structures with potential for biomedical applications. Herein, chitosan (CHT), a natural polymer, and virgin coconut oil (VCO), a resource obtained from coconut kernels, were combined to create an emulsion system. Phytantriol-based cubosomes encapsulating sodium diclofenac, an anti-inflammatory drug, were further dispersed into CHT/VCO- based emulsion. Then, the emulsions were frozen and freeze-dried to produce scaffolds. The scaffolds had a porous structure ranging from 20.4 to 73.4 µm, a high swelling ability (up to 900%) in PBS, and adequate stiffness, notably in the presence of cubosomes. Moreover, a well-sustained release of the entrapped diclofenac in the cubosomes into the CHT/VCO-based system, with an accumulated release of 45 ± 2%, was confirmed in PBS, compared to free diclofenac dispersed (80 ± 4%) into CHT/VCO-based structures. Overall, the present approach opens up new avenues for designing porous biomaterials for drug delivery through a sustainable pathway.The authors especially acknowledge the financial support from the Portuguese FCT (grants CEECIND/01306/2018, SFRH/BPD/93697/2013, and SFRH/BPD/85790/2012). This work was also financially supported by the FCT R&D&I project, with reference PTDC/BII-BIO/31570/2017, and the R&D&I Structured Projects, with reference NORTE-01-0145-FDER-000021. We also acknowledge the financial support from São Paulo Research Foundation (FAPESP) in Brasil through projects 2015/25406-5 and 2021/12071-6, and for the postdoctoral grant to D.G.V., 2019/12665-3. The project 2018/08045-7 is part of a bilateral agreement between FAPESP and the FCT (Portugal), involving the project Nature4Health

    The diagnosis and management of pre-invasive breast disease: editor's reply

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    Introduction: The letter from Badve [1] relating to the series on pre-invasive breast disease, published in the September and November issues of Breast Cancer Research [2-10], is timely and very welcome. It rightly points out that one should be careful in changing classification systems based on limited knowledge and that perhaps discarding the term atypical ductal hyperplasia at the present time may be premature. I completely agree with him; however, there are a few issues I feel obliged to clarify

    Dysregulation of T cell receptor N-glycosylation: A molecular mechanism involved in ulcerative colitis

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    The incidence of inflammatory bowel disease is increasing worldwide and the underlying molecular mechanisms are far from being fully elucidated. Herein, we evaluated the role of N-glycosylation dysregulation in T cells as a key mechanism in the ulcerative colitis (UC) pathogenesis. The evaluation of the branched N-glycosylation levelsandprofile of intestinalTcell receptor (TCR)wereassessedin colonic biopsies fromUCpatientsand healthy controls. Expression alterations of the glycosyltransferase gene MGAT5 were also evaluated. We demonstrated thatUCpatients exhibit a dysregulation ofTCRbranchedN-glycosylationonlamina propriaTlymphocytes. Patients with severe UC showed the most pronounced defect on N-glycan branching in T cells. Moreover, UC patients showed a significant reduction of MGAT5 gene transcription in T lymphocytes. In this study, we disclose for the first time that a deficiency in branched N-glycosylation on TCR due to a reduced MGAT5 gene expression is a new molecular mechanism underlying UC pathogenesis, being a potential novel biomarker with promising clinical and therapeutic applications.This work was supported by grants from the Portuguese Foundation for Science and Technology (FCT), project grants (PTDC/ CVT/111358/2009; PTDC/BBB-EBI/0786/2012; EXPL/ BIM-MEC/0149/2012), ‘financiados no âmbito do Programa Operacional Temático Factores de Competitividade (COMPETE) e comparticipado pelo fundo Comunitário Europeu FEDER’, e do Quadro de Referência Estratégia Nacio-nal QREN. This work was further supported by a portuguese grant from ‘Grupo de Estudo da Doenc¸a Inflamatória Intestinal’ (GEDII). S.S.P. (SFRH/BPD/63094/2009); S.C. (SFRH/BD/ 77386/2011) also acknowledge FCT. IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education, and is partially supported by FCT

    Cytogenetic analysis of five Hypostomus species (Siluriformes, Loricariidae)

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    In this work, we analyzed the karyotypes of five Hypostomus species. Hypostomus cf. heraldoi, from the Mogi-Guaçu River, had 2n = 72 chromosomes, with a nucleolar organizer region (NOR) in one chromosomal pair. Hypostomus regani, from the Mogi-Guaçu River had 2n = 72 chromosomes with NORs in two chromosomal pairs. Hypostomus sp., from the Mogi-Guaçu River basin, had 2n = 68 chromosomes, with NORs in two chromosomal pairs. Hypostomus aff. agna, from Cavalo Stream, had 2n = 74 chromosomes with NORs in two chromosomal pairs. Hypostomus cf. topavae, from Carrapato Stream, had 2n = 80 chromosomes, with NORs in two chromosomal pairs. Hypostomus species showed marked diversity in the karyotypic formula, which suggested the occurrence of several Robertsonian rearrangements and pericentric inversions during the evolutionary history of this genus. This hypothesis was supported by the occurrence of a large number of uniarmed chromosomes and multiple NORs in a terminal position in most species and may be a derived condition in the Loricariidae
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