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1.
Nature ; 600(7889): 439-443, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34912084

RESUMEN

Fractional Chern insulators (FCIs) are lattice analogues of fractional quantum Hall states that may provide a new avenue towards manipulating non-Abelian excitations. Early theoretical studies1-7 have predicted their existence in systems with flat Chern bands and highlighted the critical role of a particular quantum geometry. However, FCI states have been observed only in Bernal-stacked bilayer graphene (BLG) aligned with hexagonal boron nitride (hBN)8, in which a very large magnetic field is responsible for the existence of the Chern bands, precluding the realization of FCIs at zero field. By contrast, magic-angle twisted BLG9-12 supports flat Chern bands at zero magnetic field13-17, and therefore offers a promising route towards stabilizing zero-field FCIs. Here we report the observation of eight FCI states at low magnetic field in magic-angle twisted BLG enabled by high-resolution local compressibility measurements. The first of these states emerge at 5 T, and their appearance is accompanied by the simultaneous disappearance of nearby topologically trivial charge density wave states. We demonstrate that, unlike the case of the BLG/hBN platform, the principal role of the weak magnetic field is merely to redistribute the Berry curvature of the native Chern bands and thereby realize a quantum geometry favourable for the emergence of FCIs. Our findings strongly suggest that FCIs may be realized at zero magnetic field and pave the way for the exploration and manipulation of anyonic excitations in flat moiré Chern bands.

2.
Nature ; 583(7817): 537-541, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32699401

RESUMEN

The electron-hole plasma in charge-neutral graphene is predicted to realize a quantum critical system in which electrical transport features a universal hydrodynamic description, even at room temperature1,2. This quantum critical 'Dirac fluid' is expected to have a shear viscosity close to a minimum bound3,4, with an interparticle scattering rate saturating1 at the Planckian time, the shortest possible timescale for particles to relax. Although electrical transport measurements at finite carrier density are consistent with hydrodynamic electron flow in graphene5-8, a clear demonstration of viscous flow at the charge-neutrality point remains elusive. Here we directly image viscous Dirac fluid flow in graphene at room temperature by measuring the associated stray magnetic field. Nanoscale magnetic imaging is performed using quantum spin magnetometers realized with nitrogen vacancy centres in diamond. Scanning single-spin and wide-field magnetometry reveal a parabolic Poiseuille profile for electron flow in a high-mobility graphene channel near the charge-neutrality point, establishing the viscous transport of the Dirac fluid. This measurement is in contrast to the conventional uniform flow profile imaged in a metallic conductor and also in a low-mobility graphene channel. Via combined imaging and transport measurements, we obtain viscosity and scattering rates, and observe that these quantities are comparable to the universal values expected at quantum criticality. This finding establishes a nearly ideal electron fluid in charge-neutral, high-mobility graphene at room temperature4. Our results will enable the study of hydrodynamic transport in quantum critical fluids relevant to strongly correlated electrons in high-temperature superconductors9. This work also highlights the capability of quantum spin magnetometers to probe correlated electronic phenomena at the nanoscale.

3.
Nature ; 569(7754): 93-98, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31019296

RESUMEN

Topological superconductors can support localized Majorana states at their boundaries1-5. These quasi-particle excitations obey non-Abelian statistics that can be used to encode and manipulate quantum information in a topologically protected manner6,7. Although signatures of Majorana bound states have been observed in one-dimensional systems, there is an ongoing effort to find alternative platforms that do not require fine-tuning of parameters and can be easily scaled to large numbers of states8-21. Here we present an experimental approach towards a two-dimensional architecture of Majorana bound states. Using a Josephson junction made of a HgTe quantum well coupled to thin-film aluminium, we are able to tune the transition between a trivial and a topological superconducting state by controlling the phase difference across the junction and applying an in-plane magnetic field22. We determine the topological state of the resulting superconductor by measuring the tunnelling conductance at the edge of the junction. At low magnetic fields, we observe a minimum in the tunnelling spectra near zero bias, consistent with a trivial superconductor. However, as the magnetic field increases, the tunnelling conductance develops a zero-bias peak, which persists over a range of phase differences that expands systematically with increasing magnetic field. Our observations are consistent with theoretical predictions for this system and with full quantum mechanical numerical simulations performed on model systems with similar dimensions and parameters. Our work establishes this system as a promising platform for realizing topological superconductivity and for creating and manipulating Majorana modes and probing topological superconducting phases in two-dimensional systems.

4.
EMBO J ; 39(6): e103777, 2020 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-32090359

RESUMEN

Research on non-coding RNA (ncRNA) is a rapidly expanding field. Providing an official gene symbol and name to ncRNA genes brings order to otherwise potential chaos as it allows unambiguous communication about each gene. The HUGO Gene Nomenclature Committee (HGNC, www.genenames.org) is the only group with the authority to approve symbols for human genes. The HGNC works with specialist advisors for different classes of ncRNA to ensure that ncRNA nomenclature is accurate and informative, where possible. Here, we review each major class of ncRNA that is currently annotated in the human genome and describe how each class is assigned a standardised nomenclature.


Asunto(s)
Genoma Humano/genética , ARN no Traducido/clasificación , Terminología como Asunto , Humanos , ARN no Traducido/genética
5.
Nature ; 554(7693): 544-548, 2018 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-29443960

RESUMEN

Therapeutic antibodies that block the programmed death-1 (PD-1)-programmed death-ligand 1 (PD-L1) pathway can induce robust and durable responses in patients with various cancers, including metastatic urothelial cancer. However, these responses only occur in a subset of patients. Elucidating the determinants of response and resistance is key to improving outcomes and developing new treatment strategies. Here we examined tumours from a large cohort of patients with metastatic urothelial cancer who were treated with an anti-PD-L1 agent (atezolizumab) and identified major determinants of clinical outcome. Response to treatment was associated with CD8+ T-effector cell phenotype and, to an even greater extent, high neoantigen or tumour mutation burden. Lack of response was associated with a signature of transforming growth factor ß (TGFß) signalling in fibroblasts. This occurred particularly in patients with tumours, which showed exclusion of CD8+ T cells from the tumour parenchyma that were instead found in the fibroblast- and collagen-rich peritumoural stroma; a common phenotype among patients with metastatic urothelial cancer. Using a mouse model that recapitulates this immune-excluded phenotype, we found that therapeutic co-administration of TGFß-blocking and anti-PD-L1 antibodies reduced TGFß signalling in stromal cells, facilitated T-cell penetration into the centre of tumours, and provoked vigorous anti-tumour immunity and tumour regression. Integration of these three independent biological features provides the best basis for understanding patient outcome in this setting and suggests that TGFß shapes the tumour microenvironment to restrain anti-tumour immunity by restricting T-cell infiltration.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Antígeno B7-H1/antagonistas & inhibidores , Linfocitos T CD8-positivos/efectos de los fármacos , Factor de Crecimiento Transformador beta/metabolismo , Neoplasias Urológicas/tratamiento farmacológico , Neoplasias Urológicas/inmunología , Urotelio/patología , Animales , Anticuerpos/inmunología , Anticuerpos/farmacología , Anticuerpos/uso terapéutico , Anticuerpos Monoclonales Humanizados , Antígenos de Neoplasias/análisis , Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/metabolismo , Antígeno B7-H1/inmunología , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Estudios de Cohortes , Colágeno/metabolismo , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Inmunoterapia , Ratones , Mutación , Metástasis de la Neoplasia , Fenotipo , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Resultado del Tratamiento , Microambiente Tumoral/inmunología , Neoplasias Urológicas/genética , Neoplasias Urológicas/patología , Urotelio/efectos de los fármacos , Urotelio/inmunología
6.
J Shoulder Elbow Surg ; 33(4): 900-907, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37625693

RESUMEN

BACKGROUND: Outpatient total shoulder arthroplasty (TSA) presents a safe alternative to inpatient arthroplasty, while helping meet the rapidly rising volume of shoulder arthroplasty needs and minimizing health care costs. Identifying the correct patient for outpatient surgery is critical to maintaining the safety standards with TSA. This study sought to update an ambulatory surgery center (ASC) TSA patient-selection algorithm previously published by our institution. METHODS: A retrospective chart review of TSAs was performed in an ASC at a single institution to collect patient demographics, perioperative risk factors, and postoperative outcomes with regard to reoperations, hospital admissions, and complications. The existing ASC algorithm for outpatient TSA was altered based on collected perioperative information, review of pertinent literature, and anesthesiology recommendations. RESULTS: A total of 319 TSAs were performed in an ASC in 298 patients over 7 years. Medically related complications occurred in 3 patients (0.9%) within 90 days of surgery, 2 of whom required hospital admission (0.6%) for acute kidney injury and pulmonary embolus. There were no instances of major cardiac events. Orthopedic-related complications occurred in 11 patients (3.4%), with hematoma development requiring evacuation and instability requiring revision being the most common causes. CONCLUSIONS: There was a low rate of perioperative complications and hospital admissions, confirming the safety of TSAs in an ASC setting. Based on prior literature and the population included, a pre-existing patient-selection algorithm was updated to better reflect increased comfort, knowledge, and data regarding safe patient selection for TSA in an ASC.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Humanos , Estudios Retrospectivos , Procedimientos Quirúrgicos Ambulatorios/efectos adversos , Pacientes Ambulatorios , Selección de Paciente , Algoritmos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología
7.
J Arthroplasty ; 39(8S1): S130-S136.e2, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38604282

RESUMEN

BACKGROUND: Wearable sensors and associated supporting technologies (ie, patient applications) can provide both objective (joint position, step counts, etc.) and subjective data (ie, pain scores and patient-reported outcome measures) to track a patient's episode of care. Establishing a subjective and objective baseline of a patient's experience may arguably be beneficial for multiple reasons, including setting recovery expectations for the patient and demonstrating the effectiveness or success of the intervention. METHODS: In this pilot study, we characterized a subset of patients (n = 82 from 7 surgeons) using a wearable sensor system at least 6 days before total knee arthroplasty and provided postsurgical data up to 50 days postintervention. The 5-day average before surgery for total step counts (activity), achieved flexion and extension on a progress test (functional limit) and visual analog scale daily pain score were calculated. The difference from baseline was then calculated for each patient for each day postsurgery and reported as averages. RESULTS: On average, a patient will experience a relative deficit of 4,000 steps immediately following surgery that will return to near-baseline levels 50 days postintervention. A 30° deficit in flexion and a 10° deficit in extension will return at a similar rate as steps. Relative pain scores will worsen with an increase of approximately 3 points immediately following surgery. However, pain will decrease by 2 points relative to baseline between 40 and 50 days. CONCLUSIONS: The results of this pilot study demonstrate a method to baseline a patient's presurgical subjective and objective data and to provide a reference for postsurgical recovery expectations. Applications for these data include benchmarking for evaluating intervention success as well as setting patient expectations.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Medición de Resultados Informados por el Paciente , Dispositivos Electrónicos Vestibles , Humanos , Artroplastia de Reemplazo de Rodilla/instrumentación , Proyectos Piloto , Masculino , Femenino , Anciano , Persona de Mediana Edad , Rango del Movimiento Articular , Articulación de la Rodilla/cirugía , Articulación de la Rodilla/fisiopatología , Dimensión del Dolor , Recuperación de la Función
8.
J Arthroplasty ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38823517

RESUMEN

BACKGROUND: Wearable devices provide the ability for clinical teams to continuously monitor patients' rehabilitation progress with objective data. Understanding expected recovery patterns following total knee arthroplasty (TKA) enables prompt identification of patients failing to meet these milestones. The aim of this study was to establish normative values for daily functional recovery in the first 6 weeks after TKA using a wearable device. METHODS: This prospective study included patients who underwent TKA between 2020 and 2023, treated by 11 surgeons from 8 institutions. Eligible participants were aged 18 or older, had a primary unilateral TKA, and owned a smartphone. Knee range of motion, total daily steps, cadence, and device usage were measured continuously over 6 weeks. Statistical analysis included analysis of variance using post hoc Tukey honest significant difference tests. RESULTS: The cohort of 566 participants had a mean age of 65 and 69 for men and women, respectively (range, 50 to 80). Women comprised 61% (n = 345) of study participants. There were 82% of women and 90% of men who had a body mass index > 30. The average daily wear time of the device was 12 hours (±4) for a total of 45 days (±27). Recovery was nonlinear, with the greatest gains in the first 3 weeks postsurgery for all metrics. Men demonstrated greater total daily step counts and cadence when compared to women. Obese patients demonstrated poorer performance when compared to lower body mass index patients. CONCLUSIONS: To our knowledge, this study presents the first normative data for tracking daily functional recovery in TKA patients using wearable sensors. Standardizing the TKA recovery timeline allows surgeons to isolate factors affecting patients' healing processes, accurately counsel them preoperatively, and intervene more promptly postoperatively when rehabilitation is not within standard recovery parameters.

9.
Br J Cancer ; 128(9): 1723-1732, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36807337

RESUMEN

BACKGROUND: A non-invasive endometrial cancer detection tool that can accurately triage symptomatic women for definitive testing would improve patient care. Urine is an attractive biofluid for cancer detection due to its simplicity and ease of collection. The aim of this study was to identify urine-based proteomic signatures that can discriminate endometrial cancer patients from symptomatic controls. METHODS: This was a prospective case-control study of symptomatic post-menopausal women (50 cancers, 54 controls). Voided self-collected urine samples were processed for mass spectrometry and run using sequential window acquisition of all theoretical mass spectra (SWATH-MS). Machine learning techniques were used to identify important discriminatory proteins, which were subsequently combined in multi-marker panels using logistic regression. RESULTS: The top discriminatory proteins individually showed moderate accuracy (AUC > 0.70) for endometrial cancer detection. However, algorithms combining the most discriminatory proteins performed well with AUCs > 0.90. The best performing diagnostic model was a 10-marker panel combining SPRR1B, CRNN, CALML3, TXN, FABP5, C1RL, MMP9, ECM1, S100A7 and CFI and predicted endometrial cancer with an AUC of 0.92 (0.96-0.97). Urine-based protein signatures showed good accuracy for the detection of early-stage cancers (AUC 0.92 (0.86-0.9)). CONCLUSION: A patient-friendly, urine-based test could offer a non-invasive endometrial cancer detection tool in symptomatic women. Validation in a larger independent cohort is warranted.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Endometriales , Humanos , Femenino , Estudios de Casos y Controles , Proteómica/métodos , Biomarcadores , Espectrometría de Masas/métodos , Neoplasias Endometriales/diagnóstico , Proteínas de Unión a Ácidos Grasos , Proteínas de la Matriz Extracelular
10.
J Pharmacol Exp Ther ; 387(2): 204-213, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37562970

RESUMEN

Pegozafermin (also known as BIO89-100) is a glycoPEGylated analog of fibroblast growth factor 21 (FGF21) under development to treat nonalcoholic steatohepatitis (NASH) and severe hypertriglyceridemia (SHTG). In cell-based assays, pegozafermin had a similar receptor engagement profile as recombinant FGF21, with approximately eightfold higher potency at fibroblast growth factor receptor 1c (FGFR1c). In diabetic monkeys, once-weekly and once-every-2-weeks regimens of subcutaneous pegozafermin provided rapid and robust benefits for an array of metabolic biomarkers, including triglycerides, cholesterol, fasting glucose, glycated hemoglobin, adiponectin, alanine aminotransferase, food intake, and body weight. In a single ascending dose study in healthy volunteers, subcutaneously administered pegozafermin was associated with statistically significant improvements in triglycerides, low- and high-density lipoprotein-cholesterol, and adiponectin, an insulin-sensitizing and anti-inflammatory adipokine. Pharmacokinetic half-lives ranged from 55 to 100 hours over the clinically relevant dose range, consistent with the expected half-life extension by glycoPEGylation. These findings provide evidence that pegozafermin is a promising candidate molecule for the treatment of patients with NASH or SHTG. SIGNIFICANCE STATEMENT: Fibroblast growth factor 21 (FGF21) is a stress-inducible hormone that has important roles in regulating energy balance and glucose and lipid homeostasis. Studies presented here demonstrate that a novel long-acting FGF21 analog, pegozafermin, has similar pharmacologic properties as FGF21 and that repeated, subcutaneous dosing of pegozafermin in diabetic monkeys and healthy humans improves lipid metabolism, glucose metabolism, weight, and liver transaminases. These results support future development of pegozafermin for the treatment of metabolic diseases, including nonalcoholic steatohepatitis and severe hypertriglyceridemia.

11.
Nat Mater ; 21(2): 160-164, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34811494

RESUMEN

Since the discovery of high-temperature superconductivity in copper oxide materials1, there have been sustained efforts to both understand the origins of this phase and discover new cuprate-like superconducting materials2. One prime materials platform has been the rare-earth nickelates and, indeed, superconductivity was recently discovered in the doped compound Nd0.8Sr0.2NiO2 (ref. 3). Undoped NdNiO2 belongs to a series of layered square-planar nickelates with chemical formula Ndn+1NinO2n+2 and is known as the 'infinite-layer' (n = ∞) nickelate. Here we report the synthesis of the quintuple-layer (n = 5) member of this series, Nd6Ni5O12, in which optimal cuprate-like electron filling (d8.8) is achieved without chemical doping. We observe a superconducting transition beginning at ~13 K. Electronic structure calculations, in tandem with magnetoresistive and spectroscopic measurements, suggest that Nd6Ni5O12 interpolates between cuprate-like and infinite-layer nickelate-like behaviour. In engineering a distinct superconducting nickelate, we identify the square-planar nickelates as a new family of superconductors that can be tuned via both doping and dimensionality.


Asunto(s)
Electrones , Superconductividad , Calor
12.
Gen Comp Endocrinol ; 332: 114181, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36455641

RESUMEN

Consecutive and skip repeat spawning (1- or ≥2-year spawning interval) life histories commonly occur in seasonally breeding iteroparous fishes. Spawning interval variation is driven by energetic status and impacts fisheries management. In salmonids, energetic status (either absolute level of energy reserves or the rate of change of energy reserves, i.e., energy balance) is thought to determine reproductive trajectory during a critical period ∼1 year prior to initial spawning. However, information on repeat spawners is lacking. To examine the timing and the aspects of energetic status that regulate repeat spawning interval, female steelhead trout (Oncorhynchus mykiss) were fasted for 10 weeks after spawning and then fed ad libitum and compared to ad libitum fed controls. Plasma growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels were measured to assess long-term energy balance. Plasma estradiol levels showed that some fish in both groups initiated a consecutive spawning cycle. In fasted fish, GH was lower at spawning in consecutive versus skip spawners. In consecutive spawners, GH was higher at spawning in fed versus fasted fish. These results suggest that fish with a less negative energy balance at spawning initiated reproductive development in the absence of feeding, but that feeding during the post-spawning period enabled initiation of reproduction in some fish with a more negative energy balance at spawning. Thus, both energy balance at spawning and feeding after spawning regulated reproductive schedules. These results show that the critical period model of salmonid maturation applies to regulation of repeat spawning, and that the reproductive decision window extends into the first 10 weeks after spawning.


Asunto(s)
Oncorhynchus mykiss , Animales , Femenino , Hormona del Crecimiento
13.
Artículo en Inglés | MEDLINE | ID: mdl-37652290

RESUMEN

In iteroparous female salmonids, the growth and reproductive endocrine axes interact during the period after spawning. Energy depletion due to pre-spawn fasting, migration, and ovarian development must be restored, and the next reproductive cycle is initiated in consecutively maturing fish. In the natural environment, food availability is often limited during the post-spawn period. To investigate the growth and reproductive endocrinology of the post-spawn period, we sampled female rainbow trout over the 30 weeks following their first spawning. Fish were fasted for 2 months prior to spawning, then fed a standard or a restricted ration. Analysis was confined to reproductive fish. Plasma estradiol-17ß decreased during the 8 weeks following spawning and then began increasing in both ration groups and was lower in feed-restricted versus standard ration fish from 8 weeks onward. Plasma insulin-like growth factor-1 increased over the same period and then remained constant in both ration groups and was lower in feed-restricted versus standard ration fish from week 8 to week 30. Plasma growth hormone decreased following spawning in standard ration fish and became elevated in feed-restricted versus standard ration fish at 20- and 30-weeks post-spawn. Growth rates, condition factor, and muscle lipid levels were higher in standard ration versus feed-restricted fish within 2-4 weeks after spawning. These results suggest that two phases occurred during the post-spawn period: recovery from spawning and restoration of energy reserves over weeks 0 to 8, followed by adjustment of the growth and reproductive endocrine axes to ration level over weeks 8 to 30.


Asunto(s)
Hormona del Crecimiento , Oncorhynchus mykiss , Femenino , Animales , Factor I del Crecimiento Similar a la Insulina , Ambiente , Ayuno
14.
Br J Cancer ; 126(8): 1168-1177, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34969998

RESUMEN

BACKGROUND: Improving cancer immunotherapy long-term clinical benefit is a major priority. It has become apparent that multiple axes of immune suppression restrain the capacity of T cells to provide anti-tumour activity including signalling through PD1/PD-L1 and LAG3/MHC-II. METHODS: CB213 has been developed as a fully human PD1/LAG3 co-targeting multi-specific Humabody composed of linked VH domains that avidly bind and block PD1 and LAG3 on dual-positive T cells. We present the preclinical primary pharmacology of CB213: biochemistry, cell-based function vs. immune-suppressive targets, induction of T cell proliferation ex vivo using blood obtained from NSCLC patients, and syngeneic mouse model anti-tumour activity. CB213 pharmacokinetics was assessed in cynomolgus macaques. RESULTS: CB213 shows picomolar avidity when simultaneously engaging PD1 and LAG3. Assessing LAG3/MHC-II or PD1/PD-L1 suppression individually, CB213 preferentially counters the LAG3 axis. CB213 showed superior activity vs. αPD1 antibody to induce ex vivo NSCLC patient T cell proliferation and to suppress tumour growth in a syngeneic mouse tumour model, for which both experimental systems possess PD1 and LAG3 suppressive components. Non-human primate PK of CB213 suggests weekly clinical administration. CONCLUSIONS: CB213 is poised to enter clinical development and, through intercepting both PD1 and LAG3 resistance mechanisms, may benefit patients with tumours escaping front-line immunological control.


Asunto(s)
Antígenos CD/inmunología , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Animales , Antígenos CD/metabolismo , Antígeno B7-H1 , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones , Receptor de Muerte Celular Programada 1 , Linfocitos T , Proteína del Gen 3 de Activación de Linfocitos
15.
Nature ; 534(7607): 341-6, 2016 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-27281222

RESUMEN

Chronic myeloid leukaemia (CML) arises after transformation of a haemopoietic stem cell (HSC) by the protein-tyrosine kinase BCR-ABL. Direct inhibition of BCR-ABL kinase has revolutionized disease management, but fails to eradicate leukaemic stem cells (LSCs), which maintain CML. LSCs are independent of BCR-ABL for survival, providing a rationale for identifying and targeting kinase-independent pathways. Here we show--using proteomics, transcriptomics and network analyses--that in human LSCs, aberrantly expressed proteins, in both imatinib-responder and non-responder patients, are modulated in concert with p53 (also known as TP53) and c-MYC regulation. Perturbation of both p53 and c-MYC, and not BCR-ABL itself, leads to synergistic cell kill, differentiation, and near elimination of transplantable human LSCs in mice, while sparing normal HSCs. This unbiased systems approach targeting connected nodes exemplifies a novel precision medicine strategy providing evidence that LSCs can be eradicated.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Acetamidas/farmacología , Acetamidas/uso terapéutico , Animales , Antígenos CD34/metabolismo , Azepinas/farmacología , Azepinas/uso terapéutico , Muerte Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Femenino , Proteínas de Fusión bcr-abl/metabolismo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Humanos , Mesilato de Imatinib/farmacología , Mesilato de Imatinib/uso terapéutico , Imidazolinas/farmacología , Imidazolinas/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Masculino , Ratones , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/trasplante , Proteómica , Proteínas Proto-Oncogénicas c-myc/deficiencia , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Reproducibilidad de los Resultados , Transducción de Señal/efectos de los fármacos , Transcriptoma , Proteína p53 Supresora de Tumor/deficiencia , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo
16.
J Environ Manage ; 304: 114255, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34942550

RESUMEN

Wildfire sizes and proportions burned with high severity effects are increasing in seasonally dry forests, especially in the western USA. A critical need in efforts to restore or maintain these forest ecosystems is to determine where fuel build-up caused by fire exclusion reaches thresholds that compromise resilience to fire. Empirical studies identifying drivers of fire severity patterns in actual wildfires can be confounded by co-variation of vegetation and topography and the stochastic effects of weather and rarely consider long-term changes in fuel caused by fire exclusion. To overcome these limitations, we used a spatially explicit fire model (FlamMap) to compare potential fire behavior by topographic position in Lassen Volcanic National Park (LAVO), California, a large (43,000 ha), mountainous, unlogged landscape with extensive historical and contemporary fuels data. Fuel loads were uniformly distributed and incrementally increased across the landscape, meaning variation in fire behavior within each simulation was due to topography and among simulations, to fuels. We analyzed changes in fire line intensity (FLI) and crown fire potential as surface and canopy fuels increased from historical to contemporary levels and with percentile and actual wildfire weather conditions. Sensitivity to the influence of fuel build-up on fire behavior varied by topographic position. Steep slopes and ridges were most sensitive. At lower surface fuel loads, under pre-exclusion and contemporary canopy conditions, fire behavior was comparable and remained surface-type. As fuels increased, FLI and passive crown fire increased on steep slopes and ridgetops but remained largely unchanged on gentle slopes. Topographic variability in fire behavior was greatest with intermediate fuels. At higher surface fuel loads, under contemporary canopy fuels, passive crown fire dominated all topographic positions. With LAVO's current surface fuels, the area with potential for passive crown fire during actual fire weather increased from 6% pre-exclusion to 34% due to canopy fuel build-up. For topographically diverse landscapes, the results highlight where contemporary fire characteristics are most likely to deviate from historical patterns and may help managers prioritize locations for prescribed burning and managed wildfire to increase fire resilience in fuel rich landscapes.


Asunto(s)
Ecosistema , Incendios Forestales , California , Bosques , Tiempo (Meteorología)
17.
Neurobiol Dis ; 159: 105494, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34464706

RESUMEN

The gene GPNMB is known to play roles in phagocytosis and tissue repair, and is upregulated in microglia in many mouse models of neurodegenerative disease as well as in human patients. Nearby genomic variants are associated with both elevated Parkinson's disease (PD) risk and higher expression of this gene, suggesting that inhibiting GPNMB activity might be protective in Parkinson's disease. We tested this hypothesis in three different mouse models of neurological diseases: a remyelination model and two models of alpha-synuclein pathology. We found that Gpnmb deletion had no effect on histological, cellular, behavioral, neurochemical or gene expression phenotypes in any of these models. These data suggest that Gpnmb does not play a major role in the development of pathology or functional defects in these models and that further work is necessary to study its role in the development or progression of Parkinson's disease.


Asunto(s)
Proteínas del Ojo/genética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Enfermedad de Parkinson/metabolismo , Remielinización/genética , Sustancia Negra/metabolismo , Sinucleinopatías/genética , Anciano , Anciano de 80 o más Años , Animales , Encéfalo/metabolismo , Encéfalo/patología , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Enfermedad de Parkinson/patología , Sustancia Negra/patología , Sinucleinopatías/metabolismo , Sinucleinopatías/patología
18.
Br J Cancer ; 124(5): 951-962, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33339894

RESUMEN

BACKGROUND: Schlafen 11 (SLFN11) has been linked with response to DNA-damaging agents (DDA) and PARP inhibitors. An in-depth understanding of several aspects of its role as a biomarker in cancer is missing, as is a comprehensive analysis of the clinical significance of SLFN11 as a predictive biomarker to DDA and/or DNA damage-response inhibitor (DDRi) therapies. METHODS: We used a multidisciplinary effort combining specific immunohistochemistry, pharmacology tests, anticancer combination therapies and mechanistic studies to assess SLFN11 as a potential biomarker for stratification of patients treated with several DDA and/or DDRi in the preclinical and clinical setting. RESULTS: SLFN11 protein associated with both preclinical and patient treatment response to DDA, but not to non-DDA or DDRi therapies, such as WEE1 inhibitor or olaparib in breast cancer. SLFN11-low/absent cancers were identified across different tumour types tested. Combinations of DDA with DDRi targeting the replication-stress response (ATR, CHK1 and WEE1) could re-sensitise SLFN11-absent/low cancer models to the DDA treatment and were effective in upper gastrointestinal and genitourinary malignancies. CONCLUSION: SLFN11 informs on the standard of care chemotherapy based on DDA and the effect of selected combinations with ATR, WEE1 or CHK1 inhibitor in a wide range of cancer types and models.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Daño del ADN , Resistencia a Antineoplásicos , Proteínas Nucleares/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Nivel de Atención , Animales , Neoplasias de la Mama/patología , Femenino , Estudios de Seguimiento , Humanos , Ratones , Proteínas Nucleares/genética , Isoformas de Proteínas , Estudios Retrospectivos , Análisis de Matrices Tisulares , Ensayos Antitumor por Modelo de Xenoinjerto
19.
Br J Cancer ; 125(12): 1666-1676, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34663950

RESUMEN

BACKGROUND: The absence of the putative DNA/RNA helicase Schlafen11 (SLFN11) is thought to cause resistance to DNA-damaging agents (DDAs) and PARP inhibitors. METHODS: We developed and validated a clinically applicable SLFN11 immunohistochemistry assay and retrospectively correlated SLFN11 tumour levels to patient outcome to the standard of care therapies and olaparib maintenance. RESULTS: High SLFN11 associated with improved prognosis to the first-line treatment with DDAs platinum-plus-etoposide in SCLC patients, but was not strongly linked to paclitaxel-platinum response in ovarian cancer patients. Multivariate analysis of patients with relapsed platinum-sensitive ovarian cancer from the randomised, placebo-controlled Phase II olaparib maintenance Study19 showed SLFN11 tumour levels associated with sensitivity to olaparib. Study19 patients with high SLFN11 had a lower progression-free survival (PFS) hazard ratio compared to patients with low SLFN11, although both groups had the benefit of olaparib over placebo. Whilst caveated by small sample size, this trend was maintained for PFS, but not overall survival, when adjusting for BRCA status across the olaparib and placebo treatment groups, a key driver of PARP inhibitor sensitivity. CONCLUSION: We provide clinical evidence supporting the role of SLFN11 as a DDA therapy selection biomarker in SCLC and highlight the need for further clinical investigation into SLFN11 as a PARP inhibitor predictive biomarker.


Asunto(s)
Daño del ADN/genética , Proteínas Nucleares/metabolismo , Animales , Femenino , Humanos , Masculino , Ratones , Ratones Desnudos , Estudios Retrospectivos , Resultado del Tratamiento
20.
Anal Chem ; 93(5): 2767-2775, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33474935

RESUMEN

Clinical tissue specimens are often unscreened, and preparation of tissue sections for analysis by mass spectrometry imaging (MSI) can cause aerosolization of particles potentially carrying an infectious load. We here present a decontamination approach based on ultraviolet-C (UV-C) light to inactivate clinically relevant pathogens such as herpesviridae, papovaviridae human immunodeficiency virus, or SARS-CoV-2, which may be present in human tissue samples while preserving the biodistributions of analytes within the tissue. High doses of UV-C required for high-level disinfection were found to cause oxidation and photodegradation of endogenous species. Lower UV-C doses maintaining inactivation of clinically relevant pathogens to a level of increased operator safety were found to be less destructive to the tissue metabolome and xenobiotics. These doses caused less alterations of the tissue metabolome and allowed elucidation of the biodistribution of the endogenous metabolites. Additionally, we were able to determine the spatially integrated abundances of the ATR inhibitor ceralasertib from decontaminated human biopsies using desorption electrospray ionization-MSI (DESI-MSI).


Asunto(s)
Descontaminación/métodos , Rayos Ultravioleta , Animales , Azetidinas/análisis , Azetidinas/uso terapéutico , COVID-19/patología , COVID-19/virología , Neoplasias de Cabeza y Cuello/química , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Metaboloma , Naftalenos/análisis , Naftalenos/uso terapéutico , Fotólisis/efectos de la radiación , Ratas , Ratas Wistar , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/efectos de la radiación , Espectrometría de Masa por Ionización de Electrospray/métodos , Terfenadina/química , Inactivación de Virus/efectos de la radiación
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