Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 269
Filtrar
1.
Sci Rep ; 14(1): 6856, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514760

RESUMO

The use of nature-based solutions (NBS) for coastal climate adaptation has broad and growing interest, but NBS are rarely assessed with the same rigor as traditional engineering solutions or with respect to future climate change scenarios. These gaps pose challenges for the use of NBS for climate adaptation. Here, we value the flood protection benefits of stakeholder-identified marsh restoration under current and future climate change within San Francisco Bay, a densely urbanized estuary, and specifically on the shores of San Mateo County, the county most vulnerable to future flooding in California. Marsh restoration provides a present value of $21 million which increases to over $100 million with 0.5 m of sea level rise (SLR), and to about $500 million with 1 m of SLR. There are hotspots within the county where marsh restoration delivers very high benefits for adaptation, which reach $9 million/hectare with likely future sea level and storm conditions. Today's investments in nature and community resilience can result in increasing payoffs as climate change progresses and risk increases.

2.
Cell Chem Biol ; 30(11): 1354-1365.e6, 2023 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-37643616

RESUMO

RAF dimer inhibitors offer therapeutic potential in RAF- and RAS-driven cancers. The utility of such drugs is predicated on their capacity to occupy both RAF protomers in the RAS-RAF signaling complex. Here we describe a method to conditionally quantify drug-target occupancy at selected RAF protomers within an active RAS-RAF complex in cells. RAF target engagement can be measured in the presence or absence of any mutant KRAS allele, enabling the high-affinity state of RAF dimer inhibitors to be quantified in the cellular milieu. The intracellular protomer selectivity of clinical-stage type II RAF inhibitors revealed that ARAF protomer engagement, but not engagement of BRAF or CRAF, is commensurate with inhibition of MAPK signaling in various mutant RAS cell lines. Our results support a fundamental role for ARAF in mutant RAS signaling and reveal poor ARAF protomer vulnerability for a cohort of RAF inhibitors undergoing clinical evaluation.


Assuntos
Proteínas Proto-Oncogênicas B-raf , Transdução de Sinais , Humanos , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Linhagem Celular Tumoral , Inibidores de Proteínas Quinases/farmacologia , Mutação , Sistema de Sinalização das MAP Quinases
3.
Urologie ; 62(9): 879-888, 2023 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-37526710

RESUMO

Spectacular advances have been made in personalized medicine , which has rapidly revolutionized our traditional understanding of disease diagnosis and treatment. Molecular testing of tissue and liquid samples using next generation sequencing has developed into a key technology in this scenario. It can be used for both the determination of biomarkers for diagnostic, prognostic and predictive purposes, as well as the possible improvement of treatment outcome through the use of targeted therapies and the avoidance of therapies in the event of special resistance situations. In addition to drugs that have already been approved, which among other things intervene in cellular DNA repair, many new drugs have been developed and are in clinical testing. Furthermore, new possibilities in molecular imaging have dramatically expanded our understanding of tumor spread and created new approaches for targeted therapies.


Assuntos
Neoplasias , Medicina de Precisão , Humanos , Medicina de Precisão/métodos , Biomarcadores Tumorais/genética , Neoplasias/diagnóstico , Prognóstico , Resultado do Tratamento
4.
ACS Omega ; 8(25): 22596-22602, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37396204

RESUMO

Being able to predict molecular properties and interactions is of utmost interest for academia as well as industry. But the vast complexity of strongly correlated molecular systems limits the performance of classical algorithms. In contrast, quantum computation has the potential to be a game changer in the field of molecular simulations. Despite the hope in quantum computation, the capabilities of current quantum computers are still insufficient for handling molecular systems of interest. In this paper, we propose a variational ansatz for today's noisy quantum computers to calculate the ground state with the help of imaginary time evolution. Although the imaginary time evolution operator is not unitary, it can be implemented on a quantum computer by a linear decomposition and subsequent Taylor series expansion. This has the advantage that only a set of shallow circuits needs to be computed on a quantum computer. The parallel nature of this algorithm can be exploited to speed-up simulations even further, if a privileged access to quantum computers is granted.

5.
Front Artif Intell ; 6: 1200977, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37483870

RESUMO

Introduction: Machine learning tasks often require a significant amount of training data for the resultant network to perform suitably for a given problem in any domain. In agriculture, dataset sizes are further limited by phenotypical differences between two plants of the same genotype, often as a result of different growing conditions. Synthetically-augmented datasets have shown promise in improving existing models when real data is not available. Methods: In this paper, we employ a contrastive unpaired translation (CUT) generative adversarial network (GAN) and simple image processing techniques to translate indoor plant images to appear as field images. While we train our network to translate an image containing only a single plant, we show that our method is easily extendable to produce multiple-plant field images. Results: Furthermore, we use our synthetic multi-plant images to train several YoloV5 nano object detection models to perform the task of plant detection and measure the accuracy of the model on real field data images. Discussion: The inclusion of training data generated by the CUT-GAN leads to better plant detection performance compared to a network trained solely on real data.

6.
Cell Chem Biol ; 30(8): 987-998.e24, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37490918

RESUMO

DNA-encoded libraries (DELs) provide unmatched chemical diversity and starting points for novel drug modalities. Here, we describe a workflow that exploits the bifunctional attributes of DEL ligands as a platform to generate BRET probes for live cell target engagement studies. To establish proof of concept, we performed a DEL screen using aurora kinase A and successfully converted aurora DEL ligands as cell-active BRET probes. Aurora BRET probes enabled the validation and stratification of the chemical series identified from primary selection data. Furthermore, we have evaluated the effective repurposing of pre-existing DEL screen data to find suitable leads for BRET probe development. Our findings support the use of DEL workflows as an engine to create cell-active BRET probes independent of structure or compound SAR. The combination of DEL and BRET technology accelerates hit-to-lead studies in a live cell setting.


Assuntos
Pesquisa , Ligantes
7.
ACS Med Chem Lett ; 14(5): 591-598, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37197473

RESUMO

Drug resistance mutations emerging during the treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) inhibitors represent a major challenge in personalized cancer treatment and require constant development of new inhibitors. For the covalent irreversible EGFR inhibitor osimertinib, the predominant resistance mechanism is the acquired C797S mutation, which abolishes the covalent anchor point and thus results in a dramatic loss in potency. In this study, we present next-generation reversible EGFR inhibitors with the potential to overcome this EGFR-C797S resistance mutation. For this, we combined the reversible methylindole-aminopyrimidine scaffold known from osimertinib with the affinity driving isopropyl ester of mobocertinib. By occupying the hydrophobic back pocket, we were able to generate reversible inhibitors with subnanomolar activity against EGFR-L858R/C797S and EGFR-L858R/T790M/C797S with cellular activity on EGFR-L858R/C797S dependent Ba/F3 cells. Additionally, we were able to resolve cocrystal structures of these reversible aminopyrimidines, which will guide further inhibitor design toward C797S-mutated EGFR.

8.
Sci Adv ; 9(15): eadg0885, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37043574

RESUMO

Many plants produce chemical defense compounds as protection against antagonistic herbivores. However, how beneficial insects such as pollinators deal with the presence of these potentially toxic chemicals in nectar and pollen is poorly understood. Here, we characterize a conserved mechanism of plant secondary metabolite detoxification in the Hymenoptera, an order that contains numerous highly beneficial insects. Using phylogenetic and functional approaches, we show that the CYP336 family of cytochrome P450 enzymes detoxifies alkaloids, a group of potent natural insecticides, in honeybees and other hymenopteran species that diverged over 281 million years. We linked this function to an aspartic acid residue within the main access channel of CYP336 enzymes that is highly conserved within this P450 family. Together, these results provide detailed insights into the evolution of P450s as a key component of detoxification systems in hymenopteran species and reveal the molecular basis of adaptations arising from interactions between plants and beneficial insects.


Assuntos
Alcaloides , Néctar de Plantas , Abelhas , Animais , Néctar de Plantas/química , Filogenia , Insetos , Sistema Enzimático do Citocromo P-450/genética
9.
Molecules ; 28(7)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37049713

RESUMO

PLK1 is a protein kinase that regulates mitosis and is both an important oncology drug target and a potential antitarget of drugs for the DNA damage response pathway or anti-infective host kinases. To expand the range of live cell NanoBRET target engagement assays to include PLK1, we developed an energy transfer probe based on the anilino-tetrahydropteridine chemotype found in several selective PLK inhibitors. Probe 11 was used to configure NanoBRET target engagement assays for PLK1, PLK2, and PLK3 and measure the potency of several known PLK inhibitors. In-cell target engagement for PLK1 was in good agreement with the reported cellular potency for the inhibition of cell proliferation. Probe 11 enabled the investigation of the promiscuity of adavosertib, which had been described as a dual PLK1/WEE1 inhibitor in biochemical assays. Live cell target engagement analysis of adavosertib via NanoBRET demonstrated PLK activity at micromolar concentrations but only selective engagement of WEE1 at clinically relevant doses.


Assuntos
Proteínas de Ciclo Celular , Proteínas Serina-Treonina Quinases , Proteínas de Ciclo Celular/metabolismo , Proteínas Quinases , Proliferação de Células , Mitose , Inibidores de Proteínas Quinases/farmacologia
10.
bioRxiv ; 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36865333

RESUMO

PLK1 is a protein kinase that regulates mitosis and is both an important oncology drug target and a potential anti target of drugs for the DNA damage response pathway or anti-infective host kinases. To expand the range of live cell NanoBRET target engagement assays to include PLK1 we developed an energy transfer probe based on the anilino-tetrahydropteridine chemotype found in several selective PLK inhibitors. Probe 11 was used to configure NanoBRET target engagement assays for PLK1, PLK2, and PLK3 and measure the potency of several known PLK inhibitors. In cell target engagement for PLK1 was in good agreement with the reported cellular potency for inhibition of cell proliferation. Probe 11 enabled investigation of the promiscuity of adavosertib, which had been described as a dual PLK1/WEE1 inhibitor in biochemical assays. Live cell target engagement analysis of adavosertib by NanoBRET demonstrated PLK activity at micromolar concentrations but only selective engagement of WEE1 at clinically relevant doses.

11.
Clin Pediatr (Phila) ; 62(8): 926-934, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36726290

RESUMO

Children's hospitals are discharging patients to home with increasingly complex outpatient needs, making safe transitions of care (ToCs) of vital importance. Our study involved a survey of both outpatient providers and pediatric hospitalists associated with our medical center to better describe providers' views on the ToC process. The survey included questions assessing views on patient care responsibilities, resource availability, our hospitalist-run postdischarge clinic (PDC), and comfort with telemedicine. Our hospitalists generally believed that primary care providers (PCPs) did not have adequate access to important ToC elements, whereas PCPs felt their access was adequate. Both provider types felt it was the inpatient team's responsibility to manage patient events between discharge and PCP follow-up and that a hospitalist-run PDC may reduce interim emergency room visits. This study challenges perceptions about the ToC process in children and describes a generalizable approach to assessing provider perceptions surrounding the ToC within individual health systems.


Assuntos
Médicos Hospitalares , Alta do Paciente , Humanos , Criança , Assistência ao Convalescente , Atenção Terciária à Saúde , Hospitais
12.
Pediatr Pulmonol ; 58(5): 1569-1573, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36807558

RESUMO

BACKGROUND: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have shown beneficial effects on both forced expiratory volume in 1 s (FEV1 ) and frequency of pulmonary exacerbations in people with cystic fibrosis (CF). These positive outcomes may be related to changes in bacterial colonization within the lungs. Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is the first triple therapy CFTR modulator approved for use in people with CF 6 years and older. This study aimed to determine the impact of ELX/TEZ/IVA on the isolation of Pseudomonas aeruginosa (Pa), methicillin-resistant and methicillin-susceptible Staphylococcus aureus (MRSA and MSSA, respectively) in respiratory cultures. METHODS: A retrospective chart review of the electronic medical record at the University of Iowa was completed for individuals 12 years and older taking ELX/TEZ/IVA for at least 12 months. The primary outcome was determined by assessing bacterial cultures pre- and postinitiation of ELX/TEZ/IVA. Baseline demographic and clinical characteristics were summarized using mean and standard deviation for continuous outcomes and count and percentage for categorical outcomes. Culture positivity for Pa, MSSA, and MRSA was compared among enrolled subjects between pre- and posttriple combination therapy periods using an exact McNemar's test. RESULTS: One hundred and twenty-four subjects prescribed ELX/TEZ/IVA for at least 12 months met the requirements for inclusion within our analysis. Culture positivity for Pa, MSSA, and MRSA was approximately 54%, 33%, and 31%, respectively, for the pre-ELX/TEZ/IVA period. Prevalence decreased to approximately 30%, 32%, and 24% (-24.2% [p < 0.0001], -0.7% [p = 1.00], and -6.5% [p = 0.0963], respectively) post-ELX/TEZ/IVA. The source of bacterial culture was predominantly sputum (70.2%) in the pre-ELX/TEZ/IVA group, whereas a throat source (66.1%) was more common post-ELX/TEZ/IVA. CONCLUSIONS: ELX/TEZ/IVA treatment has an appreciable impact on the detection of common bacterial pathogens in CF respiratory cultures. While previous studies have found a similar effect with single and double CFTR modulator therapies, this is the first single-center study to show the impact of triple therapy, ELX/TEZ/IVA, on bacterial isolation from airway secretions.


Assuntos
Fibrose Cística , Humanos , Fibrose Cística/tratamento farmacológico , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/uso terapêutico , Estudos Retrospectivos , Aminofenóis/uso terapêutico , Benzodioxóis/uso terapêutico , Pseudomonas aeruginosa , Mutação
13.
Cancers (Basel) ; 14(19)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36230733

RESUMO

Background: In head and neck cancer patients, parameters of metabolic and morphologic response of the tumor to single-cycle induction chemotherapy (IC) with docetaxel, cis- or carboplatin are used to decide the further course of treatment. This study investigated the effect of adding a double immune checkpoint blockade (DICB) of tremelimumab and durvalumab to IC on imaging parameters and their significance with regard to tumor cell remission. Methods: Response variables of 53 patients treated with IC+DICB (ICIT) were compared with those of 104 who received IC alone. Three weeks after one cycle, pathologic and, in some cases, clinical and endoscopic primary tumor responses were evaluated and correlated with a change in 18F-FDG PET and CT/MRI-based maximum-standardized uptake values (SUVmax) before (SUVmaxpre), after treatment (SUVmaxpost) and residually (resSUVmax in % of SUVmaxpre), and in maximum tumor diameter (Dmax) before (Dmaxpre) and after treatment (Dmaxpost) and residually (resD). Results: Reduction of SUVmax and Dmax occurred in both groups; values were SUVmaxpre: 14.4, SUVmaxpost: 6.6, Dmaxpre: 30 mm and Dmaxpost: 23 mm for ICIT versus SUVmaxpre: 16.5, SUVmaxpost: 6.4, Dmaxpre: 21 mm, and Dmaxpost: 16 mm for IC alone (all p < 0.05). ResSUVmax was the best predictor of complete response (IC: AUC: 0.77; ICIT: AUC: 0.76). Metabolic responders with resSUVmax ≤ 40% tended to have a higher rate of CR to ICIT (88%; n = 15/17) than to IC (65%; n = 30/46; p = 0.11). Of the metabolic nonresponders (resSUVmax > 80%), 33% (n = 5/15) achieved a clinical CR to ICIT versus 6% (n = 1/15) to IC (p = 0.01). Conclusions: ICIT and IC quickly induce a response and 18F-FDG PET is the more accurate modality for identifying complete remission. The rate of discrepant response, i.e., pCR with metabolic nonresponse after ICIT was >30%.

14.
Genet Med ; 24(12): 2434-2443, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36194207

RESUMO

PURPOSE: Gangliosidoses are a group of inherited neurogenetic autosomal recessive lysosomal storage disorders usually presenting with progressive macrocephaly, developmental delay, and regression, leading to significant morbidity and premature death. A quantitative definition of the natural history would support and enable clinical development of specific therapies. METHODS: Single disease registry of 8 gangliosidoses (NCT04624789). Cross-sectional analysis of baseline data in N = 26 patients. Primary end point: disease severity assessed by the 8-in-1 score. Secondary end points: first neurologic sign or symptom observed (1) by parents and (2) by physicians, diagnostic delay, as well as phenotypical characterization. Tertiary end points: neurologic outcomes (development, ataxia, dexterity) and disability. RESULTS: The 8-in-1 score quantitatively captured severity of disease. Parents recognized initial manifestations (startle reactions) earlier than physicians (motor developmental delay and hypotonia). Median diagnostic delay was 3.16 (interquartile range 0.69-6.25) years. In total, 8 patients presented with late-infantile phenotypes. CONCLUSION: Data in this registry raise awareness of these rare and fatal conditions to accelerate diagnosis, inform counseling of afflicted families, define quantitative end points for clinical trials, and can serve as historical controls for future therapeutic studies. We provide further insight into the rare late-infantile phenotype for GM2-gangliosidosis. Longitudinal follow up is planned.


Assuntos
Gangliosidoses GM2 , Gangliosidoses , Doença de Tay-Sachs , Humanos , Estudos Transversais , Gangliosidoses GM2/diagnóstico , Gangliosidoses GM2/terapia , Diagnóstico Tardio , Gangliosidoses/diagnóstico , Sistema de Registros , Doença de Tay-Sachs/genética
15.
Front Artif Intell ; 5: 871162, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35647528

RESUMO

The development of state-of-the-art convolutional neural networks (CNN) has allowed researchers to perform plant classification tasks previously thought impossible and rely on human judgment. Researchers often develop complex CNN models to achieve better performances, introducing over-parameterization and forcing the model to overfit on a training dataset. The most popular process for evaluating overfitting in a deep learning model is using accuracy and loss curves. Train and loss curves may help understand the performance of a model but do not provide guidance on how the model could be modified to attain better performance. In this article, we analyzed the relation between the features learned by a model and its capacity and showed that a model with higher representational capacity might learn many subtle features that may negatively affect its performance. Next, we showed that the shallow layers of a deep learning model learn more diverse features than the ones learned by the deeper layers. Finally, we propose SSIM cut curve, a new way to select the depth of a CNN model by using the pairwise similarity matrix between the visualization of the features learned at different depths by using Guided Backpropagation. We showed that our proposed method could potentially pave a new way to select a better CNN model.

16.
Orphanet J Rare Dis ; 17(1): 238, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725623

RESUMO

BACKGROUND: Patient registries provide long-term, real-world evidence that aids the understanding of the natural history and progression of disease, and the effects of treatment on large patient populations with rare diseases. The year 2021 marks the 20th anniversary of the Fabry Outcome Survey (FOS), an international, multicenter, observational registry (NCT03289065). The primary aims of FOS are to broaden the understanding of Fabry disease (FD), an X-linked lysosomal storage disorder, and to improve the clinical management of affected patients. Here, we review the history of FOS and the analyses and publications disseminated from the registry, and we discuss the contributions FOS studies have made in understanding FD. RESULTS: FOS was initiated in April 2001 and, as of January 2021, 4484 patients with a confirmed diagnosis and patient informed consent have been enrolled from 144 centers across 26 countries. Data from FOS have been published in nearly 60 manuscripts on a wide variety of topics relevant to FD. Analyses of FOS data have investigated the long-term effectiveness and safety of enzyme replacement therapy (ERT) with agalsidase alfa and its effects on morbidity and mortality, as well as the benefits of prompt and early treatment with agalsidase alfa on the progression of cardiomyopathy and the decline in renal function associated with FD. Based on analyses of FOS data, ERT with agalsidase alfa has also been shown to improve additional signs and symptoms of FD experienced by patients. FOS data analyses have provided a better understanding of the natural history of FD and the specific populations of women, children, and the elderly, and have provided practical tools for the study of FD. FOS has also provided methodology and criteria for assessing disease severity which contributed to the continuous development of medical practice in FD and has largely improved our understanding of the challenges and needs of long-term data collection in rare diseases, aiding in future rare disease real-world evidence studies. CONCLUSION: FOS over the last 20 years has substantially increased the scientific knowledge around improved patient management of FD and continues to expand our understanding of this rare disease.


Assuntos
Doença de Fabry , Doenças Raras , Idoso , Criança , Terapia de Reposição de Enzimas/métodos , Doença de Fabry/tratamento farmacológico , Feminino , Humanos , Estudos Multicêntricos como Assunto , Doenças Raras/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Sistema de Registros , Resultado do Tratamento , alfa-Galactosidase/uso terapêutico
17.
Mol Cell Biochem ; 477(8): 2059-2071, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35449483

RESUMO

Non-alcoholic steatohepatitis (NASH) is a rapidly growing liver disease. The chemoattractant chemerin is abundant in hepatocytes, and hepatocyte expressed prochemerin protected from NASH. Prochemerin is inactive and different active isoforms have been described. Here, the effect of hepatocyte expressed muChem-156, a highly active murine chemerin isoform, was studied in the methionine-choline deficient dietary model of NASH. Mice overexpressing muChem-156 had higher hepatic chemerin protein. Serum chemerin levels and the capability of serum to activate the chemerin receptors was unchanged showing that the liver did not release active chemerin. Notably, activation of the chemerin receptors by hepatic vein blood did not increase in parallel to total chemerin protein in patients with liver cirrhosis. In experimental NASH, muChem-156 had no effect on liver lipids. Accordingly, overexpression of active chemerin in hepatocytes or treatment of hepatocytes with recombinant chemerin did not affect cellular triglyceride and cholesterol levels. Importantly, overexpression of muChem-156 in the murine liver did not change the hepatic expression of inflammatory and profibrotic genes. The downstream targets of chemerin such as p38 kinase were neither activated in the liver of muChem-156 producing mice nor in HepG2, Huh7 and Hepa1-6 cells overexpressing this isoform. Recombinant chemerin had no effect on global gene expression of primary human hepatocytes and hepatic stellate cells within 24 h of incubation. Phosphorylation of p38 kinase was, however, increased upon short-time incubation of HepG2 cells with chemerin. These findings show that muChem-156 overexpression in hepatocytes does not protect from liver steatosis and inflammation.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Quimiocinas , Modelos Animais de Doenças , Células Estreladas do Fígado/metabolismo , Hepatócitos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fígado/metabolismo , Camundongos , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Isoformas de Proteínas/metabolismo
18.
Nat Chem Biol ; 18(6): 596-604, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35314814

RESUMO

Current small-molecule inhibitors of KRAS(G12C) bind irreversibly in the switch-II pocket (SII-P), exploiting the strong nucleophilicity of the acquired cysteine as well as the preponderance of the GDP-bound form of this mutant. Nevertheless, many oncogenic KRAS mutants lack these two features, and it remains unknown whether targeting the SII-P is a practical therapeutic approach for KRAS mutants beyond G12C. Here we use NMR spectroscopy and a cellular KRAS engagement assay to address this question by examining a collection of SII-P ligands from the literature and from our own laboratory. We show that the SII-Ps of many KRAS hotspot (G12, G13, Q61) mutants are accessible using noncovalent ligands, and that this accessibility is not necessarily coupled to the GDP state of KRAS. The results we describe here emphasize the SII-P as a privileged drug-binding site on KRAS and unveil new therapeutic opportunities in RAS-driven cancer.


Assuntos
Mieloma Múltiplo , Proteínas Proto-Oncogênicas p21(ras) , Humanos , Ligantes , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética
19.
Chembiochem ; 23(12): e202200069, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35255177

RESUMO

Carboxylesterase 1 (CES1) plays a key role in the metabolism of endogenous biomolecules and xenobiotics including a variety of pharmaceuticals. Despite the established importance of CES1 in drug metabolism, methods to study factors that can vary CES1 activity are limited with only a few suitable for use in live cells. Herein, we report the development of FCP1, a new CES1 specific fluorescent probe with a unique carbonate substrate constructed from commercially available reagents. We show that FCP-1 can specifically report on endogenous CES1 activity with a robust fluorescence response in live HepG2 cells through studies with inhibitors and genetic knockdowns. Subsequently, we deployed FCP-1 to develop a live cell fluorescence microscopy-based approach to identify activity differences between CES1 isoforms. To the best of our knowledge, this is the first application of a fluorescent probe to measure the activity of CES1 sequence variants in live cells.


Assuntos
Carboxilesterase , Hidrolases de Éster Carboxílico , Carbonatos , Carboxilesterase/metabolismo , Hidrolases de Éster Carboxílico/química , Corantes Fluorescentes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...