150 research outputs found
The current status and future prospects for therapeutic targeting of KEAP1-NRF2 and β-TrCP-NRF2 interactions in cancer chemoresistance
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
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
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
Comparative Study between the Combination of Dexamethasone and Bupivacaine for Third Molar Surgery Postoperative Pain: A Triple-Blind, Randomized Clinical Trial
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
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
[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
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.
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
Desarrollo de nuevos moduladores de actividad del factor de transcripción NRF2
Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de Lectura: 24-11-2022Esta Tesis tiene embargado el acceso al texto completo hasta el 24-05-2024La inflamación juega un papel crucial en la patología de la mayoría de las enfermedades crónicas, incluida la enfermedad del hígado graso no alcohólico (siglas en inglés, NAFLD), para la que actualmente no existe un fármaco aprobado que detenga la progresión de la enfermedad. El factor de transcripción NRF2 promueve mecanismos anti-inflamatorios dentro del rango fisiológico. Sin embargo, la mayoría de los compuestos identificados como activadores de NRF2 son electrófilos que actúan inhibiendo a su principal represor, KEAP1, pero presentan muchos efectos inespecíficos.
Como alternativa, en esta Tesis Doctoral hemos planteado la prueba de concepto basada en que NRF2 se puede activar farmacológicamente mediante la interrupción de su interacción con otro represor más débil, β-TrCP, cuya asociación estructural y funcional fue descrita por nuestro grupo de investigación hace 10 años. Mediante el cribado in silico de una quimioteca de ~ 1 M de moléculas pequeñas y validación en células nulas para la expresión de KEAP1, ensayos de ubiquitinación in vitro, células silenciadas para la expresión de las dos isoformas de β-TrCP y ensayos de ligadura por proximidad (siglas en inglés, PLA), hemos identificado al compuesto PHAR, como un posible inhibidor de la interacción entre β-TrCP y NRF2. Los estudios de farmacodinámica demostraron exposición y activación de NRF2 en el hígado en respuesta a PHAR. Ratones sometidos a inflamación hepática aguda inducida por lipopolisacárido (LPS) junto con el compuesto inyectado por vía intraperitoneal, atenuó en gran medida la activación de la vía de NF-κB, así como la activación de las células de Kupffer. Analizamos el posible efecto protector de PHAR en el modelo murino STAM de daño hepático progresivo mediante MRI (relación grasa/agua), histoquímica con Oil Red O (medición de grasa), rojo Sirio (medición de fibrosis) y mediante la determinación de parámetros inflamatorios y metabólicos. Nuestros resultados indican que PHAR previene la progresión de la degeneración hepática y su evolución hacia fibrosis.
PHAR es el primer activador de NRF2 basado en la interferencia con -TrCP y NRF2 y sirve de punto de partida para una detallada optimización (hit-to-lead) con la finalidad de llegar a su aplicación clínica. Como punto de partida en el proceso de optimización, hemos buscado computacionalmente nuevos compuestos que comparten el 70% del espacio químico con PHAR. Aunque es necesario profundizar en el mecanismo, el compuesto P10 produjo activación de NRF2 y de su firma transcripcional con un efecto similar al de PHAR, abriendo el camino para estudios más profundos de Relación Estructura Actividad. Finalmente, la búsqueda de compuestos homólogos al compuesto GS143 (único inhibidor descrito para β-TrCP), como estrategia alternativa para la búsqueda de inhibidores de β-TrCP, reveló que el compuesto UBJ009 estabiliza NRF2. Sin embargo, esta estabilización parece estar mediada indirectamente por la inhibición de GSK-3.
En resumen, esta Tesis Doctoral abre campo aún no explorado en la búsqueda de activadores de NRF2 mediante la interrupción de su degradación por β-TrCP, que promete ser una nueva estrategia terapéutica en las enfermedades crónicas que, como NASH, cursan con inflamación crónica de bajo grad
- …