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Metastasis has been considered as the terminal step of tumor progression. However, recent genomic studies suggest that many metastases are initiated by further spread of other metastases. Nevertheless, the corresponding pre-clinical models are lacking, and underlying mechanisms are elusive. Using several approaches, including parabiosis and an evolving barcode system, we demonstrated that the bone microenvironment facilitates breast and prostate cancer cells to further metastasize and establish multi-organ secondary metastases. We uncovered that this metastasis-promoting effect is driven by epigenetic reprogramming that confers stem cell-like properties on cancer cells disseminated from bone lesions. Furthermore, we discovered that enhanced EZH2 activity mediates the increased stemness and metastasis capacity. The same findings also apply to single cell-derived populations, indicating mechanisms distinct from clonal selection. Taken together, our work revealed an unappreciated role of the bone microenvironment in metastasis evolution and elucidated an epigenomic reprogramming process driving terminal-stage, multi-organ metastases.
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Neoplasias Ósseas/secundário , Neoplasias da Mama/patologia , Metástase Neoplásica , Neoplasias da Próstata/patologia , Microambiente Tumoral , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proliferação de Células , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Prostate cancer (PC) is the most frequently diagnosed malignancy and a leading cause of cancer deaths in US men. Many PC cases metastasize and develop resistance to systemic hormonal therapy, a stage known as castration-resistant prostate cancer (CRPC). Therefore, there is an urgent need to develop effective therapeutic strategies for CRPC. Traditional drug discovery pipelines require significant time and capital input, which highlights a need for novel methods to evaluate the repositioning potential of existing drugs. Here, we present a computational framework to predict drug sensitivities of clinical CRPC tumors to various existing compounds and identify treatment options with high potential for clinical impact. We applied this method to a CRPC patient cohort and nominated drugs to combat resistance to hormonal therapies including abiraterone and enzalutamide. The utility of this method was demonstrated by nomination of multiple drugs that are currently undergoing clinical trials for CRPC. Additionally, this method identified the tetracycline derivative COL-3, for which we validated higher efficacy in an isogenic cell line model of enzalutamide-resistant vs. enzalutamide-sensitive CRPC. In enzalutamide-resistant CRPC cells, COL-3 displayed higher activity for inhibiting cell growth and migration, and for inducing G1-phase cell cycle arrest and apoptosis. Collectively, these findings demonstrate the utility of a computational framework for independent validation of drugs being tested in CRPC clinical trials, and for nominating drugs with enhanced biological activity in models of enzalutamide-resistant CRPC. The efficiency of this method relative to traditional drug development approaches indicates a high potential for accelerating drug development for CRPC.
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Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/patologia , Nitrilas/farmacologia , Descoberta de Drogas , Castração , Resistencia a Medicamentos Antineoplásicos , Receptores Androgênicos/metabolismoRESUMO
BACKGROUND: Observational studies suggest that voluntary medical male circumcision (VMMC) may lower HIV risk among men who have sex with men (MSM). A randomized controlled trial (RCT) is needed to confirm this. OBJECTIVE: To assess the efficacy of VMMC in preventing incident HIV infection among MSM. DESIGN: An RCT with up to 12 months of follow-up. (Chinese Clinical Trial Registry: ChiCTR2000039436). SETTING: 8 cities in China. PARTICIPANTS: Uncircumcised, HIV-seronegative men aged 18 to 49 years who self-reported predominantly practicing insertive anal intercourse and had 2 or more male sex partners in the past 6 months. INTERVENTION: VMMC. MEASUREMENTS: Rapid testing for HIV was done at baseline and at 3, 6, 9, and 12 months. Behavioral questionnaires and other tests for sexually transmitted infections were done at baseline, 6 months, and 12 months. The primary outcome was HIV seroconversion using an intention-to-treat analysis. RESULTS: The study enrolled 124 men in the intervention group and 123 in the control group, who contributed 120.7 and 123.1 person-years of observation, respectively. There were 0 seroconversions in the intervention group (0 infections [95% CI, 0.0 to 3.1 infections] per 100 person-years) and 5 seroconversions in the control group (4.1 infections [CI, 1.3 to 9.5 infections] per 100 person-years). The HIV hazard ratio was 0.09 (CI, 0.00 to 0.81; P = 0.029), and the HIV incidence was lower in the intervention group (log-rank P = 0.025). The incidence rates of syphilis, herpes simplex virus type 2, and penile human papillomavirus were not statistically significantly different between the 2 groups. There was no evidence of HIV risk compensation. LIMITATION: Few HIV seroconversions and limited follow-up period. CONCLUSION: Among MSM who predominantly practice insertive anal intercourse, VMMC is efficacious in preventing incident HIV infection; MSM should be included in VMMC guidelines. PRIMARY FUNDING SOURCE: The National Science and Technology Major Project of China.
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Circuncisão Masculina , Infecções por HIV , Homossexualidade Masculina , Humanos , Masculino , Adulto , Infecções por HIV/prevenção & controle , Infecções por HIV/epidemiologia , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , China/epidemiologia , Incidência , Comportamento Sexual , Análise de Intenção de TratamentoRESUMO
Protein succinylation modification is a common post-translational modification (PTM) that plays an important role in bacterial metabolic regulation. In this study, quantitative analysis was conducted on the succinylated proteome of wild-type and florfenicol-resistant Vibrio alginolyticus to investigate the mechanism of succinylation regulating antibiotic resistance. Bioinformatic analysis showed that the differentially succinylated proteins were mainly enriched in energy metabolism, and it was found that the succinylation level of phosphoenolpyruvate carboxyl kinase (PEPCK) was highly expressed in the florfenicol-resistant strain. Site-directed mutagenesis was used to mutate the lysine (K) at the succinylation site of PEPCK to glutamic acid (E) and arginine (R), respectively, to investigate the function of lysine succinylation of PEPCK in the florfenicol resistance of V. alginolyticus. The detection of site-directed mutagenesis strain viability under florfenicol revealed that the survival rate of the E mutant was significantly higher than that of the R mutant and wild type, indicating that succinylation modification of PEPCK protein may affect the resistance of V. alginolyticus to florfenicol. This study indicates the important role of PEPCK during V. alginolyticus antibiotic-resistance evolution and provides a theoretical basis for the prevention and control of vibriosis and the development of new antibiotics.
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Antibacterianos , Farmacorresistência Bacteriana , Lisina , Processamento de Proteína Pós-Traducional , Tianfenicol , Vibrio alginolyticus , Tianfenicol/farmacologia , Tianfenicol/análogos & derivados , Tianfenicol/metabolismo , Vibrio alginolyticus/genética , Vibrio alginolyticus/efeitos dos fármacos , Vibrio alginolyticus/metabolismo , Farmacorresistência Bacteriana/genética , Lisina/metabolismo , Antibacterianos/farmacologia , Mutagênese Sítio-Dirigida , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Ácido Succínico/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/genéticaRESUMO
BACKGROUND: Despite radiotherapy ability to significantly improve treatment outcomes and survival in triple-negative breast cancer (TNBC) patients, acquired resistance to radiotherapy poses a serious clinical challenge. Protein disulfide isomerase exists in endoplasmic reticulum and plays an important role in promoting protein folding and post-translational modification. However, little is known about the role of protein disulfide isomerase family member 4 (PDIA4) in TNBC, especially in the context of radiotherapy resistance. METHODS: We detected the presence of PDIA4 in TNBC tissues and paracancerous tissues, then examined the proliferation and apoptosis of TNBC cells with/without radiotherapy. As part of the validation process, xenograft tumor mouse model was used. Mass spectrometry and western blot analysis were used to identify PDIA4-mediated molecular signaling pathway. RESULTS: Based on paired clinical specimens of TNBC patients, we found that PDIA4 expression was significantly higher in tumor tissues compared to adjacent normal tissues. In vitro, PDIA4 knockdown not only increased apoptosis of tumor cells with/without radiotherapy, but also decreased the ability of proliferation. In contrast, overexpression of PDIA4 induced the opposite effects on apoptosis and proliferation. According to Co-IP/MS results, PDIA4 prevented Tax1 binding protein 1 (TAX1BP1) degradation by binding to TAX1BP1, which inhibited c-Jun N-terminal kinase (JNK) activation. Moreover, PDIA4 knockdown suppressed tumor growth xenograft model in vivo, which was accompanied by an increase in apoptosis and promoted tumor growth inhibition after radiotherapy. CONCLUSIONS: The results of this study indicate that PDIA4 is an oncoprotein that promotes TNBC progression, and targeted therapy may represent a new and effective anti-tumor strategy, especially for patients with radiotherapy resistance.
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Sistema de Sinalização das MAP Quinases , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Isomerases de Dissulfetos de Proteínas/genética , Isomerases de Dissulfetos de Proteínas/metabolismo , Isomerases de Dissulfetos de Proteínas/farmacologia , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/radioterapia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Carcinogênese , Transformação Celular Neoplásica , Família , Linhagem Celular Tumoral , Proliferação de CélulasRESUMO
Marine microbes drive pivotal transformations in planetary-scale elemental cycles and have crucial impacts on global biogeochemical processes. Metaproteomics is a powerful tool for assessing the metabolic diversity and function of marine microbes. However, hundreds of liters of seawater are required for normal metaproteomic analysis due to the sparsity of microbial populations in seawater, which poses a substantial challenge to the widespread application of marine metaproteomics, particularly for deep seawater. Herein, a sensitive marine metaproteomics workflow, named sensitive marine metaproteome analysis (SMMP), was developed by integrating polycarbonate filter-assisted microbial enrichment, solid-phase alkylation-based anti-interference sample preparation, and narrow-bore nanoLC column for trace peptide separation and characterization. The method provided more than 8500 proteins from 1 L of bathypelagic seawater samples, which covered diverse microorganisms and crucial functions, e.g., the detection of key enzymes associated with the Wood-Ljungdahl pathway. Then, we applied SMMP to investigate vertical variations in the metabolic expression patterns of marine microorganisms from the euphotic zone to the bathypelagic zone. Methane oxidation and carbon monoxide (CO) oxidation were active processes, especially in the bathypelagic zone, which provided a remarkable energy supply for the growth and proliferation of heterotrophic microorganisms. In addition, marker protein profiles detected related to ammonia transport, ammonia oxidation, and carbon fixation highlighted that Thaumarchaeota played a critical role in primary production based on the coupled carbon-nitrogen process, contributing to the storage of carbon and nitrogen in the bathypelagic regions. SMMP has low microbial input requirements and yields in-depth metaproteome analysis, making it a prospective approach for comprehensive marine metaproteomic investigations.
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Proteômica , Água do Mar , Água do Mar/microbiologia , Água do Mar/química , Proteômica/métodos , Microbiota , Proteoma/análise , Proteoma/metabolismo , Metano/metabolismo , Metano/análise , Bactérias/metabolismo , Bactérias/isolamento & purificação , Oxirredução , Monóxido de Carbono/análise , Monóxido de Carbono/metabolismoRESUMO
Nonspecific cross-linker can provide distance restraints between surface residues of any type, which could be used to investigate protein structure construction and protein-protein interaction (PPI). However, the vast number of potential combinations of cross-linked residues or sites obtained with such a cross-linker makes the data challenging to analyze, especially for the proteome-wide applications. Here, we developed SpotLink software for identifying site nonspecific cross-links at the proteome scale. Contributed by the dual pointer dynamic pruning algorithm and the quality control of cross-linking sites, SpotLink identified > 3000 cross-links from human cell samples within a short period of days. We demonstrated that SpotLink outperformed other approaches in terms of sensitivity and precision on the datasets of the simulated succinimidyl 4,4'-azipentanoate dataset and the condensin complexes with known structures. In addition, some valuable PPI were discovered in the datasets of the condensin complexes and the HeLa dataset, indicating the unique identification advantages of site nonspecific cross-linking. These findings reinforce the importance of SpotLink as a fundamental characteristic of site nonspecific cross-linking technologies.
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Proteoma , Software , Algoritmos , Reagentes de Ligações Cruzadas/química , HumanosRESUMO
MOTIVATION: Chemical cross-linking combined with mass spectrometry (CXMS) is now a well-established method for profiling existing protein-protein interactions (PPIs) with partially known structures. It is expected to map the results of CXMS with existing structure databases to study the protein dynamic profile in the structure analysis. However, currently available structure-based analysis software suffers from the difficulty of achieving large-scale analysis. Besides, it is infeasible for structure analysis and data mining on a large scale, since of lacking global measurement of dynamic structure mapping results. RESULTS: ComMap (protein complex structure mapping) is a software designed to perform large-scale structure-based mapping by integrating CXMS data with existing structures. It allows complete the distance calculation of PPIs with existing structures in batch within minutes and provides scores for different PPI-structure pairs of testable hypothetical structural dynamism via a global view. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Proteínas , Software , Reagentes de Ligações Cruzadas/química , Proteínas/química , Espectrometria de Massas/métodos , Mapeamento de Interação de Proteínas/métodosRESUMO
Monkeypox (mpox), a viral zoonotic disease, is spreading worldwide. However, evidence that informs prevention and control strategies in the Asia Pacific Region is very limited. Our study aims to investigate the experiences of mpox patients from infection to treatment to provide scientific basis for the prevention and control. A multicenter qualitative design was used. A total of 15 mpox patients were recruited between July 6 and July 25, 2023, from six cities in China. Semistructured interviews were conducted by telephone and analyzed using the thematic analysis. The interview was divided into two sections: patients' experiences (prediagnosis experience, treatment-seeking experience, and quarantine experience) and advice. Prediagnosis experience was summarized into three themes: symptoms, possible routes of infection, and knowledge of mpox. Treatment-seeking experience was summarized into three themes: time of visit to hospital, diagnostic difficulties, and attitude toward diagnosis. Quarantine experience was summarized into three themes: body and mind reactions, reluctance to self-disclose infection status, and factors facilitating recovery. Themes identified from patients' advice were as follows: (1) Increase in testing channels and methods, (2) Development and introduction of vaccines, (3) Adjustment of quarantine program, (4) Improvement of treatment measures, and (5) Improvement of publicity and education. To effectively curb the mpox epidemic, structured measures are urgently needed to address the mpox-related stigma and discrimination. Targeted health education should be provided to MSM, focusing on the prevention, detection, and treatment services. Hospitals should enhance the training of clinicians in key departments including infectious disease and dermatology, to improve diagnostic capability and sensitivity. Furthermore, given the absence of specific antiviral medications, supervised home quarantine may be a good option.
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Mpox , Humanos , China/epidemiologia , Ásia , Antivirais , CidadesRESUMO
Wood density is a fundamental property related to tree biomechanics and hydraulic function while playing a crucial role in assessing vegetation carbon stocks by linking volumetric retrieval and a mass estimate. This study provides a high-resolution map of the global distribution of tree wood density at the 0.01° (~1 km) spatial resolution, derived from four decision trees machine learning models using a global database of 28,822 tree-level wood density measurements. An ensemble of four top-performing models combined with eight cross-validation strategies shows great consistency, providing wood density patterns with pronounced spatial heterogeneity. The global pattern shows lower wood density values in northern and northwestern Europe, Canadian forest regions and slightly higher values in Siberia forests, western United States, and southern China. In contrast, tropical regions, especially wet tropical areas, exhibit high wood density. Climatic predictors explain 49%-63% of spatial variations, followed by vegetation characteristics (25%-31%) and edaphic properties (11%-16%). Notably, leaf type (evergreen vs. deciduous) and leaf habit type (broadleaved vs. needleleaved) are the most dominant individual features among all selected predictive covariates. Wood density tends to be higher for angiosperm broadleaf trees compared to gymnosperm needleleaf trees, particularly for evergreen species. The distributions of wood density categorized by leaf types and leaf habit types have good agreement with the features observed in wood density measurements. This global map quantifying wood density distribution can help improve accurate predictions of forest carbon stocks, providing deeper insights into ecosystem functioning and carbon cycling such as forest vulnerability to hydraulic and thermal stresses in the context of future climate change.
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Ecossistema , Madeira , Canadá , Florestas , Folhas de Planta , CarbonoRESUMO
A yet-outstanding supramolecular chemistry challenge is isolation of novel varieties of stacked complexes with finely-tuned donor-acceptor bonding and optoelectronic properties, as herein reported for binary adducts comprising two different cyclic trinuclear complexes (CTC@CTC'). Most previous attempts focused only on 1-2 factors among metal/ligand/substituent combinations, resulting in heterobimetallic complexes. Instead, here we show that, when all 3 factors are carefully considered, a broadened variety of CTC@CTC' stacked pairs with intuitively-enhanced intertrimer coordinate-covalent bonding strength and ligand-ligand/metal-ligand dispersion are attained (dM-M' 2.868(2) Å; ΔE>50â kcal/mol, an order of magnitude higher than aurophilic/metallophilic interactions). Significantly, CTC@CTC' pairs remain intact/strongly-bound even in solution (Keq 4.67×105â L/mol via NMR/UV-vis titrations), and the gas phase (mass spectrometry revealing molecular peaks for the entire CTC@CTC' units in sublimed samples), rather than simple co-crystal formation. Photo-/electro-luminescence studies unravel metal-centered phosphorescence useful for novel all metal-organic light-emitting diodes (MOLEDs) optoelectronic device concepts. This work manifests systematic design of supramolecular bonding and multi-faceted spectral properties of pure metal-organic macrometallacyclic donor/acceptor (inorganic/inorganic) stacks with remarkably-rich optoelectronic properties akin to well-established organic/organic and organic/inorganic analogues.
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Refractory or relapsed acute myeloid leukemia (R/R AML) remains the major challenge of AML treatment. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only valid option to achieve cure, but the prognosis is still dismal. We conducted a retrospective analysis for the feasibility of CLAG regimens (cladribine, cytarabine, and granulocyte colony-stimulating factor) combined with total body irradiation (TBI) as new intensive conditioning chemotherapy prior to HSCT in R/R AML. A total of 70 patients, including 21 primary refractory and 49 relapsed AML, were analyzed. Forty-nine (70%) patients had extramedullary diseases, and 54 (77%) patients received haploidentical transplantation. Except for one who died before white blood cell engraftment, all of the 69 evaluable patients achieved measurable residual disease (MRD) negative complete remission. The 3-year overall survival (OS) and relapse-free survival (RFS) rates were 46.0% (95% confidence interval [CI], 33.5-57.7%) and 38.5% (95%CI, 26.8-50.0%). The 1-year cumulative incidences of relapse and non-relapse mortality (NRM) were 38.6% (95%CI, 27.3-49.3%) and 11.6% (95%CI: 5.4-20.3%), respectively. The presence of chronic graft-versus-host disease (cGVHD) showed a trend to be associated with a lower risk of relapse (P = 0.054) and extramedullary diseases with a higher risk of NRM (P = 0.074). Multivariate analyses identified low leukemia burden pre-HSCT (defined as bone marrow blasts ≤ 50%) and cGVHD as independent factors associated with favorable OS and RFS. In conclusion, intensive conditioning with CLAG regimens plus TBI may be an effective and well-tolerated choice for R/R AML patients undergoing allo-HSCT.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Humanos , Estudos Retrospectivos , Irradiação Corporal Total/efeitos adversos , Leucemia Mieloide Aguda/tratamento farmacológico , Recidiva , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Condicionamento Pré-Transplante/efeitos adversos , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controleRESUMO
Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.
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Cajanus , Staphylococcus aureus Resistente à Meticilina , Estilbenos , Antibacterianos/farmacologia , Estilbenos/farmacologia , Testes de Sensibilidade Microbiana , Anticorpos/farmacologia , BiofilmesRESUMO
BACKGROUND: The RNA N6-methyladenosine (m6A) modification has become an essential hotspot in epigenetic modulation. Serine-arginine protein kinase 1 (SRPK1) is associated with the pathogenesis of various cancers. However, the m6A modification of SRPK1 and its association with the mechanism of in lung adenocarcinoma (LUAD) remains unclear. METHODS: Western blotting and polymerase chain reaction (PCR) analyses were carried out to identify gene and protein expression. m6A epitranscriptomic microarray was utilized to the assess m6A profile. Loss and gain-of-function assays were carried out elucidate the impact of METTL3 and SRPK1 on LUAD glycolysis and tumorigenesis. RNA immunoprecipitation (RIP), m6A RNA immunoprecipitation (MeRIP), and RNA stability tests were employed to elucidate the SRPK1's METTL3-mediated m6A modification mechanism in LUAD. Metabolic quantification and co-immunoprecipitation assays were applied to investigate the molecular mechanism by which SRPK1 mediates LUAD metabolism. RESULTS: The epitranscriptomic microarray assay revealed that SRPK1 could be hypermethylated and upregulated in LUAD. The main transmethylase METTL3 was upregulated and induced the aberrant high m6A levels of SRPK1. Mechanistically, SRPK1's m6A sites were directly methylated by METTL3, which also stabilized SRPK1 in an IGF2BP2-dependent manner. Methylated SRPK1 subsequently promoted LUAD progression through enhancing glycolysis. Further metabolic quantification, co-immunoprecipitation and western blot assays revealed that SRPK1 interacts with hnRNPA1, an important modulator of PKM splicing, and thus facilitates glycolysis by upregulating PKM2 in LUAD. Nevertheless, METTL3 inhibitor STM2457 can reverse the above effects in vitro and in vivo by suppressing SRPK1 and glycolysis in LUAD. CONCLUSION: It was revealed that in LUAD, aberrantly expressed METTL3 upregulated SRPK1 levels via an m6A-IGF2BP2-dependent mechanism. METTL3-induced SRPK1 fostered LUAD cell proliferation by enhancing glycolysis, and the small-molecule inhibitor STM2457 of METTL3 could be an alternative novel therapeutic strategy for individuals with LUAD.
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Adenocarcinoma de Pulmão , Adenosina , Glicólise , Neoplasias Pulmonares , Metiltransferases , Proteínas Serina-Treonina Quinases , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Glicólise/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Animais , Regulação Neoplásica da Expressão Gênica , Camundongos , Linhagem Celular Tumoral , Camundongos Nus , Splicing de RNA/genética , Proteínas de Ligação a Hormônio da Tireoide , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proliferação de Células/genéticaRESUMO
In this paper, a broadband photoelectric fusion transceiver-multiplexed system is proposed to realize a frequency converter. The system achieves a high spurious suppression ratio through two frequency conversions that utilize the advantages of microwave and photonics technology simultaneously to reduce the complexity of the system and improve the effective spectrum utilization. In addition, the core components, such as the Mach-Zehnder modulator (MZM), are multiplexed in the up and down frequency conversion link. High-frequency local oscillator (LO) signals are used to keep image frequency signals and various kinds of spurious signals obtained by beating frequency outside the system bandwidth. Experimental results demonstrate that the operating frequency ranges from 2 to 18 GHz with high performance for both transmitter and receiver. The image rejection is 57.35 dB for up-conversion and 46.56 dB for down-conversion, and the in-band spurious suppression achieves at least 55.02 dB. At the same time, the spurious-free dynamic range (SFDR) can reach at least 89.11d Bâ H z 2/3.
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Three polysaccharides, PTC, PTH, and PTB, were extracted from Pinellia ternata using three different extraction conditions: room temperature water, hot water, and 2 % Na2CO3 solution. PTC and PTH were composed of rhamnose, glucose, galactose, mannose, glucuronic acid, galacturonic acid, and arabinose, which combine to form complex structures. PTB was composed solely of glucose and rhamnose. Further analysis indicated that PTC and PTB exhibited triple-helix structures. PTC showed the highest scavenging capacity against DPPH, superoxide anion, and hydroxyl radicals, with half maximal inhibitory concentrations (IC50) of 1004.1, 1584.1, and 1584.1â µg/mL, respectively. Additionally, PTC, PTH, and PTB were subjected to sulfation, phosphorylation, and selenization, resulting in the production of nine derivates. The distinctive absorptive bands of these derivates were determined through infrared spectroscopy. Selenized and sulfated derivates have shown significant antitumor and immunoenhancing properties. Our findings revealed that at 400â µg/mL, the inhibition rate of selenated PTB on HeLa cells was 54.2 % and that on HepG2 cells was 43.1 %. Additionally, selenized PTC displayed significant immunoenhancing activity, with a proliferation rate of 63.7 % at 400â µg/mL in RAW264.7 cells. These results provide valuable evidence supporting the consideration of polysaccharides from Pinellia ternata as a potential candidate for the development of antineoplastic drugs.
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Tuning the metal-ligand interfaces of heterogeneous catalysts has emerged as an effective strategy to optimize their catalytic performance. However, improving the selectivity via organic modification remains a challenge so far. In this work, we demonstrate a simple ligand modification by preparing cysteamine-coated ultrathin palladium nanosheets. The as-prepared catalyst exhibits excellent selectivity with durability during catalytic hydrogenation of terminal alkynes, superior to most previously reported ligand-protected palladium catalysts. Further study reveals that a zwitterionic transformation occurs on the palladium interface under the H2 conditions, generating a rigid hydrogen bond network. Such an unexpected effect beyond the traditional steric effect derived from van der Waals interactions makes the catalytic surface favor the hydrogenation of alkynes over alkenes without significantly sacrificing the catalytic activity. These results not only provide a unique steric effect concept for surface coordination chemistry but also provide a practical application to improve the selectivity and activity comprehensively.
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The search for highly active and selective catalysts with high precious metal atom utilization efficiency has attracted increasing interest in both the fundamental synthesis of materials and important industrial reactions. Here, we report the synthesis of Pd-Cu nanocubes with a Cu core and an ordered B2 intermetallic CuPd shell with controllable atomic layers on the surface (denoted as Cu/B2 CuPd), which can efficiently and robustly catalyze the selective hydrogenation of acetylene (C2H2) to ethylene (C2H4) under mild conditions. The optimized Cu/B2 CuPd with a Pd loading of 9.5 at. % exhibited outstanding performance in the C2H2 semi-hydrogenation with 100% C2H2 conversion and 95.2% C2H4 selectivity at 90 °C. We attributed this outstanding performance to the core/shell structure with a high surface density of active Pd sites isolated by Cu in the B2 intermetallic matrix, representing a structural motif of single-atom alloys (SAAs) on the surface. The combined experimental and computational studies further revealed that the electronic states of Pd and Cu are modulated by SAAs from the synergistic effect between Pd and Cu, leading to enhanced performance compared with pristine Pd and Cu catalysts. This study provides a new synthetic methodology for making single-atom catalysts with high precious metal atom utilization efficiency, enabling simultaneous tuning of both geometric and electronic structures of Pd active sites for enhanced catalysis.
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Colloidal chemistry holds promise to prepare uniform and size-controllable pre-catalysts; however, it remains a challenge to unveil the atomic-level transition from pre-catalysts to active catalytic surfaces under the reaction conditions to enable the mechanistic design of catalysts. Here, we report an ambient-pressure X-ray photoelectron spectroscopy study, coupled with in situ environmental transmission electron microscopy, infrared spectroscopy, and theoretical calculations, to elucidate the surface catalytic sites of colloidal Ni nanoparticles for CO2 hydrogenation. We show that Ni nanoparticles with phosphine ligands exhibit a distinct surface evolution compared with amine-capped ones, owing to the diffusion of P under oxidative (air) or reductive (CO2 + H2) gaseous environments at elevated temperatures. The resulting NiPx surface leads to a substantially improved selectivity for CO production, in contrast to the metallic Ni, which favors CH4. The further elimination of surface metallic Ni sites by designing multi-step P incorporation achieves unit selectivity of CO in high-rate CO2 hydrogenation.
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Intravenous immunoglobulin (IVIG) has been developed for over 40 years. The mechanisms of action of IVIG are complex and diverse, and there may be multiple mechanisms that combine to influence it. IVIG has been used in kidney transplantation for desensitization, treatment of antibody-mediated rejection, and ABO-incompatible transplantation. and treatment or prevention of some infectious diseases. Hyperimmune globulins such as cytomegalovirus hyperimmune globulin (CMV-IG) and hepatitis B hyperimmune globulin (HBIG) have also been used to protect against cytomegalovirus and hepatitis B virus, respectively. However, IVIG is also associated with some rare but serious adverse effects and some application risks, and clinicians need to weigh the pros and cons and develop individualized treatment programs to benefit more patients. This review will provide an overview of the multiple mechanisms of action, clinical applications, adverse effects, and prophylactic measures of IVIG, and hyperimmune globulin will also be introduced in it.