152 research outputs found

    The current status and future prospects for therapeutic targeting of KEAP1-NRF2 and β-TrCP-NRF2 interactions in cancer chemoresistance

    Get PDF
    Drug resistance is one of the biggest challenges in cancer treatment and limits the potential to cure patients. In many tumors, sustained activation of the protein NRF2 makes tumor cells resistant to chemo- and radiotherapy. Thus, blocking inappropriate NRF2 activity in cancers has been shown to reduce resistance in models of the disease. There is a growing scientific interest in NRF2 inhibitors. However, the compounds developed so far are not target-specific and are associated with a high degree of toxicity, hampering clinical applications. Compounds that can enhance the binding of NRF2 to its ubiquitination-facilitating regulator proteins, either KEAP1 or β-TrCP, have the potential to increase NRF2 degradation and may be of value as potential chemosensitising agents in cancer treatment. Approaches based on molecular glue-type mechanisms, in which ligands stabilise a ternary complex between a protein and its binding partner have shown to enhance β-catenin degradation by stabilising its interaction with β-TrCP. This strategy could be applied to rationally discover degradative β-TrCP-NRF2 and KEAP1-NRF2 protein-protein interaction enhancers. We are proposing a novel approach to selectively suppress NRF2 activity in tumors. It is based on recent methodology and has the potential to be a promising new addition to the arsenal of anticancer agents

    Inhibition of glycogen synthase kinase-3 enhances NRF2 protein stability, nuclear localisation and target gene transcription in pancreatic beta cells

    Get PDF
    Accumulation of reactive oxygen species (i.e., oxidative stress) is a leading cause of beta cell dysfunction and apoptosis in diabetes. NRF2 (NF-E2 p45-related factor-2) regulates the adaptation to oxidative stress, and its activity is negatively regulated by the redox-sensitive CUL3 (cullin-3) ubiquitin ligase substrate adaptor KEAP1 (Kelch-like ECH-associated protein-1). Additionally, NRF2 is repressed by the insulin-regulated Glycogen Synthase Kinase-3 (GSK3). We have demonstrated that phosphorylation of NRF2 by GSK3 enhances β-TrCP (beta-transducin repeat-containing protein) binding and ubiquitylation by CUL1 (cullin-1), resulting in increased proteasomal degradation of NRF2. Thus, we hypothesise that inhibition of GSK3 activity or β-TrCP binding upregulates NRF2 and so protects beta cells against oxidative stress. We have found that treating the pancreatic beta cell line INS-1832/13 with the KEAP1 inhibitor TBE31 significantly enhanced NRF2 protein levels. The presence of the GSK3 inhibitor CT99021 or the β-TrCP-NRF2 protein-protein interaction inhibitor PHAR, along with TBE31, resulted in prolonged NRF2 stability and enhanced nuclear localisation (p

    Transcription factor NRF2 uses the Hippo pathway effector TAZ to induce tumorigenesis in glioblastomas

    Full text link
    Transcription factor NRF2 orchestrates a cellular defense against oxidative stress and, so far, has been involved in tumor progression by providing a metabolic adaptation to tumorigenic demands and resistance to chemotherapeutics. In this study, we discover that NRF2 also propels tumorigenesis in gliomas and glioblastomas by inducing the expression of the transcriptional co-activator TAZ, a protein of the Hippo signaling pathway that promotes tumor growth. The expression of the genes encoding NRF2 (NFE2L2) and TAZ (WWTR1) showed a positive correlation in 721 gliomas from The Cancer Genome Atlas database. Moreover, NRF2 and TAZ protein levels also correlated in immunohistochemical tissue arrays of glioblastomas. Genetic knock-down of NRF2 decreased, while NRF2 overexpression or chemical activation with sulforaphane, increased TAZ transcript and protein levels. Mechanistically, we identified several NRF2-regulated functional enhancers in the regulatory region of WWTR1. The relevance of the new NRF2/TAZ axis in tumorigenesis was demonstrated in subcutaneous and intracranial grafts. Thus, intracranial inoculation of NRF2-depleted glioma stem cells did not develop tumors as determined by magnetic resonance imaging. Forced TAZ overexpression partly rescued both stem cell growth in neurospheres and tumorigenicity. Hence, NRF2 not only enables tumor cells to be competent to proliferate but it also propels tumorigenesis by activating the TAZ-mediated Hippo transcriptional program.This study was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grant SAF2016-76520-R. ME is recipient of a postdoctoral contract Juan de la Cierva; DL and NRA of a FPU contract of MINECO; MP and RFG of a FPI contracts of Autonomous University of Madrid. RG has been funded by the AECC Scientific Foundation

    Specific targeting of the NRF2/β-TrCP axis promotes beneficial effects in NASH

    Get PDF
    Non-alcoholic steatohepatitis (NASH) is a common chronic liver disease that compromises liver function, for which there is not a specifically approved medicine. Recent research has identified transcription factor NRF2 as a potential therapeutic target. However, current NRF2 activators, designed to inhibit its repressor KEAP1, exhibit unwanted side effects. Alternatively, we previously introduced PHAR, a protein-protein interaction inhibitor of NRF2/β-TrCP, which induces a mild NRF2 activation and selectively activates NRF2 in the liver, close to normal physiological levels. Herein, we assessed the effect of PHAR in protection against NASH and its progression to fibrosis. We conducted experiments to demonstrate that PHAR effectively activated NRF2 in hepatocytes, Kupffer cells, and stellate cells. Then, we used the STAM mouse model of NASH, based on partial damage of endocrine pancreas and insulin secretion impairment, followed by a high fat diet. Non-invasive analysis using MRI revealed that PHAR protects against liver fat accumulation. Moreover, PHAR attenuated key markers of NASH progression, including liver steatosis, hepatocellular ballooning, inflammation, and fibrosis. Notably, transcriptomic data indicate that PHAR led to upregulation of 3 anti-fibrotic genes (Plg, Serpina1a, and Bmp7) and downregulation of 6 pro-fibrotic (including Acta2 and Col3a1), 11 extracellular matrix remodeling, and 8 inflammatory genes. Overall, our study suggests that the mild activation of NRF2 via the protein-protein interaction inhibitor PHAR holds promise as a strategy for addressing NASH and its progression to liver fibrosisThis research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) (grants PID2019-110061RB-I00, PID-2021-122766OB-100 and PDC2021-121421-I00, PDC2022-133765-I00, MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe” by the European Union.), CIBERdem and CIBERned (ISCIII), and The Autonomous Community of Madrid (grant P2022/BMD-7230). RFG enjoyed a FPI contract of MINECO (FPI-2017). DCS is a holder of a FPI contract of MICINN (Ministry of Science and Innovation, FPI-2020, PRE2020-091886). JJV is holder of a FPU contract of MIU (Ministry of Universities, FPU2020, FPU20/03326

    Comparative Study between the Combination of Dexamethasone and Bupivacaine for Third Molar Surgery Postoperative Pain: A Triple-Blind, Randomized Clinical Trial

    Get PDF
    Objectives: To compare the possible benefits of the combination of dexamethasone–bupivacaine with articaine–epinephrine as an anaesthetic block after third molar surgery. Materials and Methods: Triple-blind, randomized, controlled, parallel, phase 3 clinical trial. Two groups: experimental (93 patients) with standard anaesthetic block: 40/0.005 mg/mL articaine–epinephrine and submucosal reinforcement with 0.8 mg dexamethasone–5% bupivacaine; and control group (91 patients) with standard block: 40/0.005 mg/mL articaine–epinephrine. The surgery consisted of the extraction of the impacted mandibular third molar by performing a procedure following the same repeatable scheme. The visual analogue scale (VAS) was used to analyse postoperative pain. Results: Groups were homogeneous, without significant differences related to epidemiological variables. Postoperative pain among the first, second, and seventh postoperative days was statistically significantly lower in the experimental group compared to the control group (p < 0.001). Drug consumption was lower in the experimental group throughout the study period (p < 0.04). Conclusion: Bupivacaine is an alternative to articaine in oral surgery, being more effective in reducing postoperative pain by reducing patients’ scores on the VAS as well as their consumption of analgesic drugs after surgery

    Tuning melatonin receptor subtype selectivity in oxadiazolone-based analogues: Discovery of QR2 ligands and NRF2 activators with neurogenic properties

    Get PDF
    New multi-target indole and naphthalene derivatives containing the oxadiazolone scaffold as a bioisostere of the melatonin acetamido group have been developed. The novel compounds were characterized at melatonin receptors MT1R and MT2R, quinone reductase 2 (QR2), lipoxygenase-5 (LOX-5), and monoamine oxidases (MAO-A and MAO-B), and also as radical scavengers. We found that selectivity within the oxadiazolone series can be modulated by modifying the side chain functionality and coplanarity with the indole or naphthalene ring. In phenotypic assays, several oxadiazolone-based derivatives induced signalling mediated by the transcription factor NRF2 and promoted the maturation of neural stem-cells into a neuronal phenotype. Activation of NRF2 could be due to the binding of indole derivatives to KEAP1, as deduced from surface plasmon resonance (SPR) experiments. Molecular modelling studies using the crystal structures of QR2 and the KEAP1 Kelch-domain, as well as the recently described X-ray free-electron laser (XFEL) structures of chimeric MT1R and MT2R, provided a rationale for the experimental data and afforded valuable insights for future drug design endeavoursThe authors gratefully acknowledge the following financial supports: Spanish Ministry of Science, Innovation and Universities; Spanish Research Agency; and European Regional Development Funds (grants RTI2018-093955-B-C21 and SAF2015-64948-C2-1-R to M.I.R.-F.; RTI2018-095793-B-I00 to M.G.L., SAF2015-64629-C2- 2-R to F.G.), General Council for Research and Innovation of the Community of Madrid and European Structural Funds (grant B2017/BMD-3827 e NRF24ADCM), Health Institute Carlos III (Miguel Servet II ProgramCP16/00014 and grant PI17/01700 to R.L.). CH-A and P.M. thank their PhD fellowships from Spanish Ministry of Education (MEC, PhD grant FPU16/01704 and mobility grant FPUEST17/00233 to CH-A and FPU13/03737 to P.M.)

    A Phase I-II multicenter trial with Avelumab plus autologous dendritic cell vaccine in pre-treated mismatch repair-proficient (MSS) metastatic colorectal cancer patients; GEMCAD 1602 study

    Get PDF
    [Background]: Immune check-point blockade (ICB) has shown clinical beneft in mismatch repair-defcient/microsatellite instability high metastatic colorectal cancer (mCRC) but not in mismatch repair-profcient/microsatellite stable patients. Cancer vaccines with autologous dendritic cells (ADC) could be a complementary therapeutic approach to ICB as this combination has the potential to achieve synergistic efects. [Methods]: This was a Phase I/II multicentric study with translational sub-studies, to evaluate the safety, pharmacodynamics and anti-tumor efects of Avelumab plus ADC vaccine in heavily pre-treated MSS mCRC patients. Primary objective was to determine the maximum tolerated dose and the efcacy of the combination. The primary end-point was 40% progressionfree survival at 6 months with a 2 Simon Stage. [Results]: A total of 28 patients were screened and 19 pts were included. Combined therapy was safe and well tolerated. An interim analysis (Simon design frst-stage) recommended early termination because only 2/19 (11%) patients were disease free at 6 months. Median PFS was 3.1 months [2.1–5.3 months] and overall survival was 12.2 months [3.2–23.2 months]. Stimulation of immune system was observed in vitro but not clinically. The evaluation of basal RNA-seq noted signifcant changes between pre and post-therapy liver biopsies related to lipid metabolism and transport, infammation and oxidative stress pathways. [Conclusions]: The combination of Avelumab plus ADC vaccine is safe and well tolerated but exhibited modest clinical activity. Our study describes, for the frst-time, a de novo post-therapy metabolic rewiring, that could represent novel immunotherapyinduced tumor vulnerabilities.The study was funded by grants from the FIS PI17/00732 from Instituto de Salud Carlos III, Premi Fi de Residència Emili Letang from Hospital Clínic Barcelona, Plan Nacional de I + D (PID-107139RB-C21 to DB-R and PID2020-115051RB-I00 to MC) and Grupo Español Multidisciplinar en Cáncer Digestivo (GEMCAD). The study was funded with Grants from Catalan Agency for Management of University and Research Grants (AGAUR) (2014-SGR-474, 2017-SGR-1174 and 2017-SGR-1033), Fundació la Marató de TV3 (201330.10), Instituto de Salud Carlos III (PI13/01728 and PI19/00740) and Fundacion Olga Torres (Modalitat A. 2019/2020) to JM. IMMETCOLS signature is under patent protection (EP21382772.8.) This research was financially supported by GEMCAD and (OR Avelumab was provided) by Merck, S.L.U., Madrid, Spain, an affiliate of Merck KGaA, Darmstadt, Germany, as part of an alliance between the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: https://doi.org/10.13039/100009945) and Pfizer

    Educafarma 10.0

    Get PDF
    Memoria ID-030. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2021-2022

    Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

    Get PDF
    BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden
    corecore