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PP2A B55α, encoded by PPP2R2A, acts as a regulatory subunit of the serine/threonine phosphatase PP2A. Despite a frequent loss of heterozygosity of PPP2R2A in cases of non-small cell lung cancer (NSCLC), research on PP2A B55α's functions remains limited and controversial. To investigate the biological roles of PP2A B55α, we conducted bulk RNA-sequencing to assess the impact of PPP2R2A knockdown using two shRNAs in a NSCLC cell line. Gene set enrichment analysis (GSEA) of the RNA-sequencing data revealed significant enrichment of the epithelial-mesenchymal transition (EMT) pathway, with SNAI2 (the gene encoding Slug) emerging as one of the top candidates. Our findings demonstrate that PP2A B55α suppresses EMT, as PPP2R2A deficiency through knockdown or homozygous or hemizygous depletion promotes EMT and metastatic behavior in NSCLC cells, as evidenced by changes in EMT biomarkers, invasion and migration abilities, as well as metastasis in a tail vein assay. Mechanistically, PP2A B55α inhibits EMT by downregulating SNAI2 expression via the GSK3ß-ß-catenin pathway. Importantly, PPP2R2A deficiency also slows cell proliferation by disrupting DNA replication, particularly in PPP2R2A-/- cells. Furthermore, PPP2R2A deficiency, especially PPP2R2A-/- cells, leads to an increase in the cancer stem cell population, which correlates with enhanced resistance to chemotherapy. Overall, the decrease in PP2A B55α levels due to hemizygous/homozygous depletion heightens EMT and the metastatic or stemness/drug resistance potential of NSCLC cells despite their proliferation disadvantage. Our study highlights the significance of PP2A B55α in EMT and metastasis and suggests that targeting EMT/stemness could be a potential therapeutic strategy for treating PPP2R2A-deficient NSCLC.
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Carcinoma Pulmonar de Células não Pequenas , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , Proteína Fosfatase 2 , Fatores de Transcrição da Família Snail , Transição Epitelial-Mesenquimal/genética , Humanos , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Animais , Movimento Celular , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/genética , Células A549 , Camundongos , Invasividade NeoplásicaRESUMO
Checkpoint kinase 1 (CHK1) is critical for cell survival under replication stress (RS). CHK1 inhibitors (CHK1i's) in combination with chemotherapy have shown promising results in preclinical studies but have displayed minimal efficacy with substantial toxicity in clinical trials. To explore combinatorial strategies that can overcome these limitations, we perform an unbiased high-throughput screen in a non-small cell lung cancer (NSCLC) cell line and identify thioredoxin1 (Trx1), a major component of the mammalian antioxidant-system, as a determinant of CHK1i sensitivity. We establish a role for redox recycling of RRM1, the larger subunit of ribonucleotide reductase (RNR), and a depletion of the deoxynucleotide pool in this Trx1-mediated CHK1i sensitivity. Further, the TrxR inhibitor auranofin, an approved anti-rheumatoid arthritis drug, shows a synergistic interaction with CHK1i via interruption of the deoxynucleotide pool. Together, we show a pharmacological combination to treat NSCLC that relies on a redox regulatory link between the Trx system and mammalian RNR activity.
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Auranofina , Carcinoma Pulmonar de Células não Pequenas , Quinase 1 do Ponto de Checagem , Neoplasias Pulmonares , Oxirredução , Tiorredoxinas , Quinase 1 do Ponto de Checagem/metabolismo , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Humanos , Oxirredução/efeitos dos fármacos , Tiorredoxinas/metabolismo , Linhagem Celular Tumoral , Auranofina/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/farmacologia , Ribonucleosídeo Difosfato Redutase/metabolismo , Ribonucleosídeo Difosfato Redutase/genética , Ribonucleotídeo Redutases/metabolismo , Ribonucleotídeo Redutases/antagonistas & inibidores , Sinergismo Farmacológico , AnimaisRESUMO
Conventional liquid-phase methods lack precise control in synthesizing and processing materials with macroscopic sizes and atomic thicknesses. Water interfaces are ubiquitous and unique in catalyzing many chemical reactions. However, investigations on two-dimensional (2D) materials related to water interfaces remain limited. Here we report the growth of millimeter-sized 2D PbI2 single crystals at the water-air interface. The growth mechanism is based on an inherent ion-specific preference, i.e. iodine and lead ions tend to remain at the water-air interface and in bulk water, respectively. The spontaneous accumulation and in-plane arrangement within the 2D crystal of iodide ions at the water-air interface leads to the unique crystallization of PbI2 as well as other metal iodides. In particular, PbI2 crystals can be customized to specific thicknesses and further transformed into millimeter-sized mono- to few-layer perovskites. Additionally, we have developed water-based techniques, including water-soaking, spin-coating, water-etching, and water-flow-assisted transfer to recycle, thin, pattern, and position PbI2, and subsequently, perovskites. Our water-interface mediated synthesis and processing methods represents a significant advancement in achieving simple, cost-effective, and energy-efficient production of functional materials and their integrated devices.
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In sustaining arch locked-segment-type slopes, natural soil arches play a key anti-sliding role in the slope's evolution. In this study, a self-developed model test device was used to simulate the whole process of deformation evolution of sustaining arch locked-segment-type slopes, and the formation of natural sustaining arch and its locking control effect on slope stability were studied. The test results show that the continuous formation and progressive destruction of the sustaining arch were observed. The sustaining arch formed in the second time has the best locking effect, and the anti-sliding force reaches its stress peak point. However, the slope is not in a critically unstable state, instead, the stress is continuously adjusted to form a larger range of soil arch to resist the slope thrust. Consequently, the slope destabilizes until the ultimate shear strength of arch foots is exceeded, at which point the critical arch height of the arch is reached. The critical arch height mechanical model for slope stability analysis was developed based on the soil arching effect and limit equilibrium theory. The applicability of the model was demonstrated by the physical test and Xintan slope data, which can provide some guidance for early warning of landslides.
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Individuals with methamphetamine use disorder (MUD) often experience anxiety and depressive symptoms during abstinence, which can worsen the likelihood of relapse. Thus, it is essential to understand the neuro-mechanism behind methamphetamine use and its associated emotional withdrawal symptoms in order to develop effective clinical strategies. This study aimed to evaluate associations between emotional withdrawal symptoms and structural covariance networks (SCNs) based on cortical thickness (CTh) across the brain. The CTh measures were obtained from Tl-weighted MRI data from a sample of 48 males with MUD during abstinence and 48 male healthy controls. The severity of anxiety and depressive symptoms was assessed by the Hamilton Anxiety Scale (HAMA) and depression (HAMD) scales. Two important nodes belonging to the brain reward system, the right rostral anterior cingulate cortex (rACC) and medial prefrontal cortex (medPFC), were selected as seeds to conduct SCNs and modulation analysis by emotional symptoms. MUDs showed higher structural covariance between the right rACC and regions in the dorsal attention, right frontoparietal, auditory, visual and limbic networks. They also displayed higher structural covariance between the right medPFC and regions in the limbic network. Moreover, the modulation analysis showed that higher scores on HAMA were associated with increased covariance between the right rACC and the left parahippocampal and isthmus cingulate cortex in the default mode network. These outcomes shed light on the complex neurobiological mechanisms underlying methamphetamine use and its associated emotional withdrawal symptoms and may provide new insights into the development of effective treatments for MUD.
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Emoções , Síndrome de Abstinência a Substâncias , Humanos , Masculino , Encéfalo/diagnóstico por imagem , Ansiedade/diagnóstico por imagem , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Síndrome de Abstinência a Substâncias/diagnóstico por imagemRESUMO
Transient receptor potential vanilloid 4 (TRPV4) is a widely expressed cation channel that plays an important role in many physiological and pathological processes. However, most TRPV4 drugs carry a risk of side effects. Moreover, existing screening methods are not suitable for the high-throughput screening (HTS) of drugs. In this study, a cell model and HTS method for targeting TRPV4 channel drugs were established based on a calcium-activated chloride channel protein 1 Anoctamin 1 (ANO1) and a double mutant (YFP-H148Q/I152L) of the yellow fluorescent protein (YFP). Patch-clamp experiments and fluorescence quenching kinetic experiments were used to verify that the model could sensitively detect changes in intracellular Ca2+ concentration. The functionality of the TRPV4 cell model was examined through temperature variations and different concentrations of TRPV4 modulators, and the performance of the model in HTS was also evaluated. The model was able to sensitively detect changes in the intracellular Ca2+ concentration and also excelled at screening TRPV4 drugs, and the model was more suitable for HTS. We successfully constructed a drug cell screening model targeting the TRPV4 channel, which provides a tool to study the pathophysiological functions of TRPV4 in vitro.
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Ensaios de Triagem em Larga Escala , Canais de Cátion TRPV , Canais de Cátion TRPV/metabolismo , Anoctamina-1 , Cálcio/metabolismoRESUMO
OBJECTIVE: The aim of this study is to assess the impact of Liver X receptors (LXRs) on airway inflammation, airway remodeling, and lipid deposition induced by cigarette smoke and lipopolysaccharide (LPS) exposure in the lung. METHODS: Wild mice and LXR-deficient mice were exposed to cigarette smoke and LPS to induce airway inflammation and remodeling. In addition, some wild mice received intraperitoneal treatment with the LXR agonist GW3965 before exposure to cigarette smoke and LPS. Lung tissue and bronchoalveolar lavage fluid were collected to evaluate airway inflammation, airway remodeling and lipid deposition. RESULTS: Exposure to cigarette smoke and LPS resulted in airway inflammation, emphysema and lipid accumulation in wild mice. These mice also exhibited downregulated LXRα and ABCA1 in the lung. Treatment with GW3965 mitigated inflammation, remodeling and lipid deposition, while the deletion of LXRs exacerbated these effects. Furthermore, GW3965 treatment following exposure to cigarette smoke and LPS increased LXRα and ABCA1 expression and attenuated MyD88 expression in wild mice. CONCLUSION: LXRs demonstrate the potential to mitigate cigarette smoke and LPS- induced airway inflammation, emphysema and lipid disposition in mice.
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Benzoatos , Benzilaminas , Fumar Cigarros , Enfisema , Enfisema Pulmonar , Animais , Camundongos , Remodelação das Vias Aéreas , Líquido da Lavagem Broncoalveolar , Fumar Cigarros/efeitos adversos , Enfisema/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Receptores X do Fígado/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Pressure engineering has attracted growing interest in the understanding of structural changes and structure-property relations of layered materials. In this study, we investigated the effect of pressure on the crystal structure of Mn3Sn.In-situhigh-pressure x-ray diffraction experiments revealed that Mn3Sn maintained hexagonal lattice symmetry within the pressure range of ambient to 50.4 GPa. The ratio of lattice constantsc/ais almost independent of the pressure and remains constant at 0.80, indicating a stable cell shape. Density functional theory calculations revealed the strong correlation between the crystal structure and the localization ofdelectrons. The Mn3Sn has been found in flat energy bands near the Fermi level, exhibiting a large density of states (DOS) primarily contributed by thedelectrons. This large DOS near the Fermi level increases the energy barrier for a phase transition, making the transition from the hexagonal phase to the tetragonal phase challenging. Our results confirm the structural stability of Mn3Sn under high pressure, which is beneficial to the robustness of spintronic devices.
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The O-GlcNAc transferase (OGT) is an essential enzyme that mediates protein O-GlcNAcylation, a unique form of posttranslational modification of many nuclear and cytosolic proteins. Recent studies observed increased OGT and O-GlcNAcylation levels in a broad range of human cancer tissues compared to adjacent normal tissues, indicating a universal effect of OGT in promoting tumorigenesis. Here, we show that OGT is essential for tumor growth in immunocompetent hosts by repressing the cyclic GMP-AMP synthase (cGAS)-dependent DNA sensing pathway. We found that deletion of OGT (Ogt -/- ) caused a marked reduction in tumor growth in both syngeneic tumor models and a genetic colorectal cancer (CRC) model induced by mutation of the Apc gene (Apc min ). Pharmacological inhibition or genetic deletion of OGT induced a robust genomic instability (GIN), leading to cGAS-dependent production of the type I interferon (IFN-I) and IFN-stimulated genes (ISGs). As a result, deletion of Cgas or Sting from Ogt -/- cancer cells restored tumor growth, and this correlated with impaired CD8+ T cell-mediated antitumor immunity. Mechanistically, we found that OGT-dependent cleavage of host cell factor C1 (HCF-1) is required for the avoidance of GIN and IFN-I production in tumors. In summary, our results identify OGT-mediated genomic stability and activate cGAS-STING pathway as an important tumor cell-intrinsic mechanism to repress antitumor immunity.
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Adding different materials to soil can improve its engineering properties, but traditional materials such as cement, lime, fly ash, etc., have caused pollution to the environment. Recently, biopolymers have shown many advantages, such as economy and environmental protection, which make them applicable to geotechnical engineering. This study summarizes the effects of biopolymers on soil's engineering properties and the main directions of current research. Firstly, the advantages and disadvantages of a variety of widely used biopolymer materials and their effects on the specific engineering characteristics of soil (i.e., water retention characteristics, strength characteristics, permeability characteristics, microstructure) are introduced, as well as the source, viscosity, pH, and cost of these biopolymers. Then, based on the theory of unsaturated soil, the current research progress on the water retention characteristics of improved soil is summarized. The key factors affecting the strength of biopolymer-treated soil are introduced. Due to the actual environmental conditions, such as rainfall, the permeability and durability of biopolymer-treated soil are also worthy of attention. In summary, it is necessary to study the variation laws of the engineering properties of biopolymer-treated soil in the full suction range, and to predict such laws reasonably. The relevant results are conducive to the safer and more scientific application of biopolymers in geotechnical engineering practice.
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The chiral helimagnet CrNb3S6 hosts various temperature- and magnetic-field-stabilized chiral soliton lattices (CSLs) and corresponding exotic collective spin resonance modes, which make it an ideal candidate for future magnetic storage/memory and magnon-based information processing. While most studies have focused on characterizing various static spin textures in this chiral helimagnet, its corresponding collective dynamics have rarely been explored. This study systematically investigates the temperature- and magnetic-field-dependent magnetic dynamics of a single crystal of CrNb3S6 using broadband microwave spectroscopy. We observe an optical mode with a temperature-independent mode number in addition to Kittel-like ferromagnetic resonance (FMR) modes in the CSL phase, consistent with the temperature-independent normalized CSL period L(H)/L(0) based on the 1D chiral sine-Gordon model. Furthermore, combining theoretical model fitting and micromagnetic simulation, we provide a detailed phase diagram and temporal-spatial resolution of dynamic modes, which may help to develop high-frequency exchange-coupling-based spintronic devices.
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Preclinical in vitro models play an important role in studying cancer cell biology and facilitating translational research, especially in the identification of drug targets and drug discovery studies. This is particularly relevant in breast cancer, where the global burden of disease is quite high based on prevalence and a relatively high rate of lethality. Predictive tools to select patients who will be responsive to invasive or morbid therapies (radiotherapy, chemotherapy, immunotherapy, and/or surgery) are relatively lacking. To be clinically relevant, a model must accurately replicate the biology and cellular heterogeneity of the primary tumor. Addressing these requirements and overcoming the limitations of most existing cancer cell lines, which are typically derived from a single clone, we have recently developed conditional reprogramming (CR) technology. The CR technology refers to a co-culture system of primary human normal or tumor cells with irradiated murine fibroblasts in the presence of a Rho-associated kinase inhibitor to allow the primary cells to acquire stem cell properties and the ability to proliferate indefinitely in vitro without any exogenous gene or viral transfection. This innovative approach fulfills many of these needs and offers an alternative that surpasses the deficiencies associated with traditional cancer cell lines. These CR cells (CRCs) can be reprogrammed to maintain a highly proliferative state and reproduce the genomic and histological characteristics of the parental tissue. Therefore, CR technology may be a clinically relevant model to test and predict drug sensitivity, conduct gene profile analysis and xenograft research, and undertake personalized medicine. This review discusses studies that have applied CR technology to conduct breast cancer research.
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Neoplasias da Mama , Humanos , Camundongos , Animais , Feminino , Neoplasias da Mama/genética , Técnicas de Cocultura , Linhagem CelularRESUMO
Poly (ADP-ribose) Polymerase (PARP) inhibitors (PARPi) have been approved for both frontline and recurrent setting in ovarian cancer with homologous recombination (HR) repair deficiency. However, more than 40% of BRCA1/2-mutated ovarian cancer lack the initial response to PARPi treatment, and the majority of those that initially respond eventually develop resistance. Our previous study has demonstrated that increased expression of aldehyde dehydrogenase 1A1 (ALDH1A1) contributes to PARPi resistance in BRCA2-mutated ovarian cancer cells by enhancing microhomology-mediated end joining (MMEJ) but the mechanism remains unknown. Here, we find that ALDH1A1 enhances the expression of DNA polymerase θ (Polθ, encoded by the POLQ gene) in ovarian cancer cells. Furthermore, we demonstrate that the retinoic acid (RA) pathway is involved in the transcription activation of the POLQ gene. The RA receptor (RAR) can bind to the retinoic acid response element (RARE) located in the promoter of the POLQ gene, promoting transcription activation-related histone modification in the presence of RA. Given that ALDH1A1 catalyzes the biosynthesis of RA, we conclude that ALDH1A1 promotes POLQ expression via the activation of the RA signaling pathway. Finally, using a clinically-relevant patient-derived organoid (PDO) model, we find that ALDH1A1 inhibition by the pharmacological inhibitor NCT-505 in combination with the PARP inhibitor olaparib synergistically reduce the cell viability of PDOs carrying BRCA1/2 mutation and positive ALDH1A1 expression. In summary, our study elucidates a new mechanism contributing to PARPi resistance in HR-deficient ovarian cancer and shows the therapeutic potential of combining PARPi and ALDH1A1 inhibition in treating these patients.
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Checkpoint kinase 1 (CHK1) is critical for cell survival under replication stress (RS). CHK1 inhibitors (CHK1i's) in combination with chemotherapy have shown promising results in preclinical studies but minimal efficacy with substantial toxicity in clinical trials. To explore novel combinational strategies that can overcome these limitations, we performed an unbiased high-throughput screen in a non-small cell lung cancer (NSCLC) cell line and identified thioredoxin1 (Trx1), a major component of the mammalian antioxidant-system, as a novel determinant of CHK1i sensitivity. We established a role for redox recycling of RRM1, the larger subunit of ribonucleotide reductase (RNR), and a depletion of the deoxynucleotide pool in this Trx1-mediated CHK1i sensitivity. Further, the TrxR1 inhibitor auronafin, an anti-rheumatoid arthritis drug, shows a synergistic interaction with CHK1i via interruption of the deoxynucleotide pool. Together, these findings identify a new pharmacological combination to treat NSCLC that relies on a redox regulatory link between the Trx system and mammalian RNR activity.
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Electro-responsive dynamic hydrogels, which possess robust mechanical properties and precise spatiotemporal resolution, have a wide range of applications in biomedicine and energy science. However, it is still challenging to design and prepare electro-responsive hydrogels (ERHs) which have all of these properties. Here, we report one such class of ERHs with these features, based on the direct current voltage (DCV)-induced rearrangement of sodium dodecyl sulfate (SDS) micelles, where the rearrangement can tune the hydrogel networks that are originally maintained by the SDS micelle-assisted hydrophobic interactions. An enlarged mesh size is demonstrated for these ERHs after DCV treatment. Given the unique structure and properties of these ERHs, hydrophobic cargo (thiostrepton) has been incorporated into the hydrogels and is released upon DCV loading. Additionally, these hydrogels are highly stretchable (>6000%) and tough (507 J/m2), showing robust mechanical properties. Moreover, these hydrogels have a high spatiotemporal resolution. As the cross-links within our ERHs are enabled by the non-covalent (i.e., hydrophobic) interactions, these hydrogels are self-healing and malleable. Considering the robust mechanical properties, precise spatiotemporal resolution, dynamic nature (e.g., injectable and self-healing), and on-demand drug delivery ability, this class of ERHs will be of great interest in the fields of wearable bioelectronics and smart drug delivery systems.
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Hidrogéis , Dispositivos Eletrônicos Vestíveis , Hidrogéis/química , Liberação Controlada de Fármacos , Sistemas de Liberação de Medicamentos , MicelasRESUMO
Brain network analysis is an effective method to seek abnormalities in functional interactions for brain disorders such as autism spectrum disorder (ASD). Traditional studies of brain networks focus on the node-centric functional connectivity (nFC), ignoring interactions of edges to miss much information that facilitates diagnostic decisions. In this study, we present a protocol based on an edge-centric functional connectivity (eFC) approach, which significantly improves classification performance by utilizing the co-fluctuations information between the edges of brain regions compared with nFC to build the classification mode for ASD using the multi-site dataset Autism Brain Imaging Data Exchange I (ABIDE I). Our model results show that even using the traditional machine-learning classifier support vector machine (SVM) on the challenging ABIDE I dataset, relatively high performance is achieved: 96.41% of accuracy, 98.30% of sensitivity, and 94.25% of specificity. These promising results suggest that the eFC can be used to build a reliable machine-learning framework to diagnose mental disorders such as ASD and promote identifications of stable and effective biomarkers. This study provides an essential complementary perspective for understanding the neural mechanisms of ASD and may facilitate future investigations on early diagnosis of neuropsychiatric disorders.
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Transtorno do Espectro Autista , Humanos , Transtorno do Espectro Autista/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , BiomarcadoresRESUMO
High-grade serous carcinoma (HGSC) is the most common and lethal ovarian cancer subtype. PARP inhibitors (PARPi) have become the mainstay of HGSC-targeted therapy, given that these tumors are driven by a high degree of genomic instability (GI) and homologous recombination (HR) defects. Nonetheless, approximately 30% of patients initially respond to treatment, ultimately relapsing with resistant disease. Thus, despite recent advances in drug development and an increased understanding of genetic alterations driving HGSC progression, mortality has not declined, highlighting the need for novel therapies. Using a small-molecule activator of protein phosphatase 2A (PP2A; SMAP-061), we investigated the mechanism by which PP2A stabilization induces apoptosis in patient-derived HGSC cells and xenograft (PDX) models alone or in combination with PARPi. We uncovered that PP2A genes essential for cellular transformation (B56α, B56γ, and PR72) and basal phosphatase activity (PP2A-A and -C) are heterozygously lost in the majority of HGSC. Moreover, loss of these PP2A genes correlates with worse overall patient survival. We show that SMAP-061-induced stabilization of PP2A inhibits the HR output by targeting RAD51, leading to chronic accumulation of DNA damage and ultimately apoptosis. Furthermore, combination of SMAP-061 and PARPi leads to enhanced apoptosis in both HR-proficient and HR-deficient HGSC cells and PDX models. Our studies identify PP2A as a novel regulator of HR and indicate PP2A modulators as a therapeutic therapy for HGSC. In summary, our findings further emphasize the potential of PP2A modulators to overcome PARPi insensitivity, given that targeting RAD51 presents benefits in overcoming PARPi resistance driven by BRCA1/2 mutation reversions.
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Proteína BRCA1 , Neoplasias Ovarianas , Feminino , Humanos , Proteína BRCA1/genética , Proteína Fosfatase 2/genética , Proteína BRCA2/genética , Dano ao DNA , Neoplasias Ovarianas/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Recombinação Homóloga , Morte CelularRESUMO
The extraction of neuroimaging features of migraine patients and the design of identification models are of great significance for the auxiliary diagnosis of related diseases. Compared with the commonly used image features, this study directly uses time-series signals to characterize the functional state of the brain in migraine patients and healthy controls, which can effectively utilize the temporal information and reduce the computational effort of classification model training. Firstly, Group Independent Component Analysis and Dictionary Learning were used to segment different brain areas for small-sample groups and then the regional average time-series signals were extracted. Next, the extracted time series were divided equally into multiple subseries to expand the model input sample. Finally, the time series were modeled using a bi-directional long-short term memory network to learn the pre-and-post temporal information within each time series to characterize the periodic brain state changes to improve the diagnostic accuracy of migraine. The results showed that the classification accuracy of migraine patients and healthy controls was 96.94%, the area under the curve was 0.98, and the computation time was relatively shorter. The experiments indicate that the method in this paper has strong applicability, and the combination of time-series feature extraction and bi-directional long-short term memory network model can be better used for the classification and diagnosis of migraine. This work provides a new idea for the lightweight diagnostic model based on small-sample neuroimaging data, and contributes to the exploration of the neural discrimination mechanism of related diseases.
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Transtornos de Enxaqueca , Humanos , Fatores de Tempo , Transtornos de Enxaqueca/diagnóstico por imagem , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , NeuroimagemRESUMO
The liquid-air interface offers a platform for the in-plane growth of free-standing materials. However, it is rarely used for inorganic perovskites and ultrathin non-layered perovskites. Herein the liquid-air interfacial synthesis of inorganic perovskite nanosheets (Cs3 Bi2 I9 , Cs3 Sb2 I9 ) is achieved simply by drop-casting the precursor solution with only the addition of iodine. The products are inaccessible without iodine addition. The thickness and lateral size of these nanosheets can be adjusted through the iodine concentration. The high volatility of the iodine spontaneously drives precursors that normally stay in the liquid to the liquid-air interface. The iodine also repairs in situ iodine vacancies during perovskite growth, giving enhanced optical and optoelectronic properties. The liquid-air interfacial growth of ultrathin perovskites provides multi-degree-of-freedom for constructing perovskite-based heterostructures and devices at atomic scale.
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2D metal oxides (2DMOs) have stimulated tremendous attention due to their distinct electronic structures and abundant surface chemistry. However, it remains a standing challenge for the synthesis of 2DMOs because of their intrinsic 3D lattice structure and ultrahigh synthesis temperature. Here, a reliable WSe2 -assisted chemical vapor deposition (CVD) strategy to grow nonlayered WO2 nanoplates with tunable thickness and lateral dimension is reported. Optical microscopy and scanning electron microscopy studies demonstrate that the WO2 nanoplates exhibit a well-faceted rhombic geometry with a lateral dimension up to the sub-millimeter level (≈135 µm), which is the largest size of 2DMO single crystals obtained by CVD to date. Scanning transmission electron microscopy studies reveal that the nanoplates are high-quality single crystals. Electrical measurements show the nanoplates exhibit metallic behavior with strong anisotropic resistance, outstanding conductivity of 1.1 × 106 S m-1 , and breakdown current density of 7.1 × 107 A cm-2 . More interestingly, low-temperature magnetotransport studies demonstrate that the nanoplates show a quantum-interference-induced weak-localization effect. The developed WSe2 -assisted strategy for the growth of WO2 nanoplates can enrich the library of 2DMO materials and provide a material platform for other property explorations based on 2D WO2 .