65 research outputs found

    The Usefulness Of Social Exclusion As A Theoretical Concept To Inform Social Policy In Transport

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    Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    MicroRNA signature refine response prediction in CML

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    microRNAs (miRs) dysregulation have emerged as a crucial step in tumorigenesis, being related with cancer development, progression and response to treatment. In chronic myeloid leukaemia (CML), the resistance to tyrosine kinase inhibitors (TKI) is responsible for treatment failure and could be linked to changes in miRs expression. This work aimed to correlate the expression levels of 3 miRs, miR-21, miR-26b and miR-451, with response to TKI treatment in CML patients. miR-451 levels at diagnosis were significantly higher in patients with optimal response after 6 and 12 months of therapy. Conversely, patients without optimal response had highest levels of miR-21. miR-21 and miR-451 appear to be good biomarkers of response, able to predict optimal TKI responders (p < 0.05). Using the combined profile of both miRs, we create a predictive model of optimal response after one year of treatment. This study highlights the role of miR-21 and miR-451 expression levels at diagnosis in predicting which patients achieve the optimal response.info:eu-repo/semantics/publishedVersio

    Genetic variants of ABC and SLC transporter genes and chronic myeloid leukaemia: impact on susceptibility and prognosis

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    Solute carrier (SLC) and ATP-binding cassette (ABC) transporters comprise a variety of proteins expressed on cell membranes responsible for intrusion or extrusion of substrates, respectively, including nutrients, xenobiotics, and chemotherapeutic agents. These transporters mediate the cellular disposition of tyrosine kinase inhibitors (TKIs), and their genetic variants could affect its function, potentially predisposing patients to chronic myeloid leukaemia (CML) and modulating treatment response. We explored the impact of genetic variability (single nucleotide variants—SNVs) of drug transporter genes (ABCB1, ABCG2, SLC22A1, and SLC22A5) on CML susceptibility, drug response, and BCR-ABL1 mutation status. We genotyped 10 SNVs by tetra-primers-AMRS-PCR in 198 CML patients and 404 controls, and assessed their role in CML susceptibility and prognosis. We identified five SNVs associated with CML predisposition, with some variants increasing disease risk, including TT genotype ABCB1 (rs1045642), and others showing a protective effect (GG genotype SLC22A5 rs274558). We also observed different haplotypes and genotypic profiles associated with CML predisposition. Relating to drug response impact, we found that CML patients with the CC genotype (rs2231142 ABCG2) had an increased risk of TKI resistance (six-fold). Additionally, CML patients carrying the CG genotype (rs683369 SLC22A1) presented a 4.54-fold higher risk of BCR-ABL1 mutations. Our results suggest that drug transporters’ SNVs might be involved in CML susceptibility and TKI response, and predict the risk of BCR-ABL1 mutations, highlighting the impact that SNVs could have in therapeutic selection.info:eu-repo/semantics/publishedVersio

    The Hydropathy Index of the HCDR3 Region of the B-Cell Receptor Identifies Two Subgroups of IGHV-Mutated Chronic Lymphocytic Leukemia Patients With Distinct Outcome

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    © 2021 Rodríguez-Caballero, Fuentes Herrero, Oliva Ariza, Criado, Alcoceba, Prieto, Pérez Caro, García-Montero, González Díaz, Forconi, Sarmento-Ribeiro, Almeida and Orfao.The HCDR3 sequences of the B-cell receptor (BCR) undergo constraints in length, amino acid use, and charge during maturation of B-cell precursors and after antigen encounter, leading to BCR and antibodies with high affinity to specific antigens. Chronic lymphocytic leukemia consists of an expansion of B-cells with a mixed immature and “antigen-experienced” phenotype, with either a mutated (M-CLL) or unmutated (U-CLL) tumor BCR, associated with distinct patient outcomes. Here, we investigated the hydropathy index of the BCR of 138 CLL patients and its association with the IGHV mutational status and patient outcome. Overall, two clearly distinct subgroups of M-CLL patients emerged, based on a neutral (mean hydropathy index of -0.1) vs. negatively charged BCR (mean hydropathy index of -1.1) with molecular features closer to those of B-cell precursors and peripheral/mature B-cells, respectively. Despite that M-CLL with neutral HCDR3 did not show traits associated with a mature B-cell repertoire, important differences in IGHV gene usage of tumor cells and patient outcome were observed in this subgroup of patients once compared to both U-CLL and M-CLL with negatively charged HCDR3 sequences. Compared to M-CLL with negatively charged HCDR3 sequences, M-CLL with neutral HCDR3 sequences showed predominance of men, more advanced stages of the disease, and a greater frequency of genetic alterations—e.g., del(17p)—together with a higher rate of disease progression and shorter time to therapy (TTT), independently of other prognostic factors. Our data suggest that the hydropathy index of the HCDR3 sequences of CLL cells allows the identification of a subgroup of M-CLL with intermediate prognostic features between U-CLL and the more favorable subgroup of M-CLL with a negatively charged BCR.This work was supported by the following grants: FS/37-2017, from the Fundación Memoria D. Samuel Solórzano, Universidad de Salamanca; FIS PI17/00399-FEDER, from the Fondo de Investigación Sanitaria of Instituto de Salud Carlos III, Madrid, Spain; 0639_IDIAL_NET_3_E, from cooperative network EPINTERREG V A España Portugal (POCTEP); and ECRIN-M3, Accelerator Award Full, Cancer Research UK, Fundación Cientıfíca de la Asociación Española Contra el Cáncer (AECC), Fondazione AIRC per la Ricerca sul Cancro.

    Chemical characterization and cytotoxic potential of an ellagitannin-enriched fraction from Fragaria vesca leaves

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    The hepatocellular carcinoma, a primary malignancy of the liver, has a very poor prognosis and a lower survival rate. Moreover, the inefficacy of conventional therapies emphasizes the importance of discovering new bioactive compounds. Several studies clearly state that plant-derived polyphenols, namely ellagitannins, have several health benefits. Fragaria vesca leaves contain high amounts of polyphenols, being especially rich in ellagitannins. Therefore, this study aimed to characterize an ellagitannin-enriched fraction (EEF) from F. vesca leaves and to unveil the anticancer potential of this fraction on human hepatocellular carcinoma cells. The analysis of EEF by HPLC-PDA-ESI/MSn allowed the detection of 12 ellagitannins. The cell viability of both EEF and crude extract was determined after 24 h of cells treatment and the halfmaximal inhibitory concentration (IC50) was evaluated. The IC50 of the EEF (113 lg/mL) was about 6 times lower than the IC50 of the crude extract (690 lg/mL). Furthermore, EEF induced cell cycle arrest at G2/M checkpoint and decreased cell proliferation in a dose-dependent way. This fraction also induced an accumulation of LC3-II protein through blockage of autophagic flux, and inhibited chymotrypsin-like activity of 26S proteasome. These results showed, for the first time, that EEF from F. vesca leaves inhibits both, autophagic and ubiquitin-proteasome system pathways, two main intracellular protein degradation systems that are targets for anticancer therapies. Additionally, a proteomic analysis allowed the identification of 914 proteins, among which 133 were modulated after cells treatment with EEF, most of them related to metabolic pathways. Overall, this study shows that the EEF from F. vesca leaves decreased cell proliferation, inhibited the proteolytic mechanisms and modulated the metabolic pathways of the cell. Additionally this study points out F. vesca as a source of valuable molecules with anticancer potential, suggesting that ellagitannins, the polyphenols identified in this fraction, could be useful in the development of new fine-tuned therapeutic strategies against carcinogenesis

    Multiple Myeloma Treatment Guidelines by the Portuguese Group of Multiple Myeloma

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    The treatment of multiple myeloma has profoundly changed with the introduction of several innovative therapies. The optimization of therapeutic sequencing through the combined use of the various drugs developed in recent years and the attention given to the characteristics of patients have allowed the reduction of toxicities and increased survival and quality of life of patients with multiple myeloma. These treatment recommendations from the Portuguese Multiple Myeloma Group offer guidance for first-line treatment and progression/relapse situations. These recommendations are given highlighting the data that justify each choice and referring to the respective levels of evidence that support these options. Whenever possible, the respective national regulatory framework is presented. These recommendations constitute an advance towards the best treatment of multiple myeloma in Portugal.publishersversionpublishe

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Alterações fenotípicas da célula tumoral e a sua relação com a resistência à quimioterapia.

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    Um dos problemas da oncologia médica é o desenvolvimento de resistência natural ou adquirida, das células neoplásicas aos fármacos anticancerígenos. Os mecanismos envolvidos na sindrome de resistência a múltiplos fármacos (MDR) estão ainda mal esclarecidos. O objectivo deste trabalho é avaliar a contribuição da persistência do stresse oxidativo, da mitocôndria, das alterações membranares e da expressão das proteinas envolvidas na regulação da morte celular por apoptose, na patogenia, e no desenvolvimento de recidiva e de resistência à quimioterapia na leucemia. Observámos uma diminuição das defesas antioxidantes, particularmente das defesas de natureza enzimática, superóxido dismutase e peroxidase do glutatião, nos doentes com leucemia aguda, e das defesas de natureza não enzimática, glutatião reduzido e vitamina E, nos doentes com leucemia crónica. Encontrámos também um aumento da produção de peróxidos intracelulares, diminuição da actividade da cadeia respiratória mitocondrial, nomeadamente do complexo IV, diminuição da desidrogenase do lactato e ainda um aumento da expressão de Bcl-2 e diminuição da expressão de Bax e de Fas. Estes dados poderão relacionar-se com a elevada capacidade proliferativa das células, na leucemia linfoblástica aguda, e/ou com a resistência à morte celular, na leucemia linfocítica crónica. Por outro lado, os doentes com leucemia linfoblástica aguda em recidiva apresentam aumento da expressão de glicoproteína P de superfície, da razão fosfolípido/proteína e fosfolípido/colesterol, e do conteúdo em triacilglicerídeos. Os doentes com leucemia linfoblástica aguda, de sobrevida mais curta e recidiva mais precoce, são os que apresentam níveis de expressão de Bcl-2 mais elevados e/ou de Bax mais baixos, ou níveis mais elevados de GSH, o que poderá contribuir para essa recidiva e, provavelmente, para a resistência à quimioterapia. Verificou-se também que a citotoxicidade induzida por fármacos anticancerígenos em células de leucemia humana em cultura é mediada por morte celular apoptótica, para a qual pode contribuir o aumento da expressão de Bax e de Fas, bem como o aumento da produção de peróxidos, e a alteração da actividade da cadeia respiratória mitocondrial. Nas células resistentes aos fármacos anticancerígenos, observámos, além do aumento da expressão de glicoproteina P, de Bcl-2 e da razão Bcl-2/Bax, uma diminuição da expressão de Bax e de Fas e um aumento dos níveis de glutatião reduzido, o que pode contribuir para a resistência à quimioterapia, podendo a disfunção mitocondrial ter um papel determinante nos mecanismos de resistência. Um conhecimento mais aprofundado sobre a participação do stresse oxidativo, do envolvimento da mitocôndria e das proteínas reguladoras da apoptose nos mecanismos de resistência à morte celular, pode permitir uma avaliação prognóstica e melhor abordagem terapêutica do doente com leucemia

    Zinc: From Biological Functions to Therapeutic Potential

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    The trace element zinc (Zn) displays a wide range of biological functions. Zn ions control intercellular communication and intracellular events that maintain normal physiological processes. These effects are achieved through the modulation of several Zn-dependent proteins, including transcription factors and enzymes of key cell signaling pathways, namely those involved in proliferation, apoptosis, and antioxidant defenses. Efficient homeostatic systems carefully regulate intracellular Zn concentrations. However, perturbed Zn homeostasis has been implicated in the pathogenesis of several chronic human diseases, such as cancer, diabetes, depression, Wilson's disease, Alzheimer's disease, and other age-related diseases. This review focuses on Zn's roles in cell proliferation, survival/death, and DNA repair mechanisms, outlines some biological Zn targets, and addresses the therapeutic potential of Zn supplementation in some human diseases
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