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1.
Drug Resist Updat ; 76: 101114, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38924995

RESUMO

Therapy resistance poses a significant obstacle to effective cancer treatment. Recent insights into cell plasticity as a new paradigm for understanding resistance to treatment: as cancer progresses, cancer cells experience phenotypic and molecular alterations, corporately known as cell plasticity. These alterations are caused by microenvironment factors, stochastic genetic and epigenetic changes, and/or selective pressure engendered by treatment, resulting in tumor heterogeneity and therapy resistance. Increasing evidence suggests that cancer cells display remarkable intrinsic plasticity and reversibly adapt to dynamic microenvironment conditions. Dynamic interactions between cell states and with the surrounding microenvironment form a flexible tumor ecosystem, which is able to quickly adapt to external pressure, especially treatment. Here, this review delineates the formation of cancer cell plasticity (CCP) as well as its manipulation of cancer escape from treatment. Furthermore, the intrinsic and extrinsic mechanisms driving CCP that promote the development of therapy resistance is summarized. Novel treatment strategies, e.g., inhibiting or reversing CCP is also proposed. Moreover, the review discusses the multiple lines of ongoing clinical trials globally aimed at ameliorating therapy resistance. Such advances provide directions for the development of new treatment modalities and combination therapies against CCP in the context of therapy resistance.

2.
Neuroimage ; 290: 120565, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38453102

RESUMO

People tend to perceive the same information differently depending on whether it is expressed in an individual or a group frame. It has also been found that the individual (vs. group) frame of expression tends to lead to more charitable giving and greater tolerance of wealth inequality. However, little is known about whether the same resource allocation in social interactions elicits distinct responses depending on proposer type. Using the second-party punishment task, this study examined whether the same allocation from different proposers (individual vs. group) leads to differences in recipient behavior and the neural mechanisms. Behavioral results showed that reaction times were longer in the unfair (vs. fair) condition, and this difference was more pronounced when the proposer was the individual (vs. group). Neural results showed that proposer type (individual vs. group) influenced early automatic processing (indicated by AN1, P2, and central alpha band), middle processing (indicated by MFN and right frontal theta band), and late elaborative processing (indicated by P3 and parietal alpha band) of fairness in resource allocation. These results revealed more attentional resources were captured by the group proposer in the early stage of fairness processing, and more cognitive resources were consumed by processing group-proposed unfair allocations in the late stage, possibly because group proposers are less identifiable than individual proposers. The findings provide behavioral and neural evidence for the effects of "individual/group" framing leading to cognitive differences. They also deliver insights into social governance issues, such as punishing individual and/or group violations.


Assuntos
Eletroencefalografia , Jogos Experimentais , Humanos , Potenciais Evocados/fisiologia , Interação Social , Punição/psicologia
3.
Cereb Cortex ; 33(8): 4927-4938, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36190437

RESUMO

Fear of negative evaluation (FNE) is a susceptible and maintaining factor of social anxiety disorders. However, the question, how people process negative evaluation is influenced by individual differences in FNE, is poorly understood. To clarify the habitual processing characteristics of individuals with different levels of FNE, electroencephalography was recorded when two groups of participants with high FNE (hFNE) and low FNE (lFNE) performed a social evaluation perception task in which the feedback context/source (human vs. a computer) and valence (thumb-up/like vs. thumb-down/dislike) were manipulated. We found effects of feedback source and valence on N1, P2, and P3, which reflect early attention, integrated perception, and elaborative processing, respectively, as well as general reward effects on reward positivity (RewP) across contexts. Importantly, compared to the lFNE group, the hFNE group showed larger midfrontal N1 and theta oscillation in response to negative feedback indicating dislike (vs. like), and also showed larger P3. These findings suggest that individuals with hFNE are more attentional vigilance to negative (vs. positive) social feedback, implying that individuals with different levels of FNE assign different implicit threat values to social-evaluation threat stimuli.


Assuntos
Medo , Fobia Social , Humanos , Retroalimentação , Eletroencefalografia , Percepção Social , Potenciais Evocados/fisiologia , Recompensa
4.
Cereb Cortex ; 33(12): 7659-7669, 2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-36916945

RESUMO

Previous research indicates that social distance can influence people's social evaluations of others. Individuals tend to evaluate intimate others more positively than distant others. The present study investigates the modulating effect of social distance on the time course underlying individuals' evaluation processes of others using adequate electroencephalography methods. The results reveal that in the initial processing stage, the P2 component is larger when friends are negatively evaluated, whereas this pattern is the opposite for strangers. In the second stage, medial frontal negativity and early mid-frontal theta band activity is enhanced for negative evaluations of friends, whereas this effect is absent in social evaluations of strangers. At the late stage, the P3 is larger for positive evaluations of friends but insensitive to social evaluations of strangers, and the late mid-frontal theta is also modulated by social distance. These findings provide direct and powerful evidence that social distance modulates individuals' evaluations of others with different levels of intimacy throughout all processing stages.


Assuntos
Encéfalo , Eletroencefalografia , Humanos , Amigos , Retroalimentação Psicológica , Tomada de Decisões , Potenciais Evocados
5.
Molecules ; 29(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38930986

RESUMO

In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating Pseudomonas fluorescens lipase (PFL) through the co-precipitation method, resulting in the preparation of immobilized lipase (PFL@ZIF-8@ZIF-67). Subsequently, it was further treated with glutaraldehyde to improve protein immobilization yield. Under optimal immobilization conditions, the specific hydrolytic activity of PFL@ZIF-8@ZIF-67 was 20.4 times higher than that of the free PFL. The prepared biocatalyst was characterized and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). Additionally, the thermal stability of PFL@ZIF-8@ZIF-67 at 50 °C was significantly improved compared to the free PFL. After 7 weeks at room temperature, PFL@ZIF-8@ZIF-67 retained 78% of the transesterification activity, while the free enzyme was only 29%. Finally, PFL@ZIF-8@ZIF-67 was applied to the neryl acetate preparation in a solvent-free system, and the yield of neryl acetate reached 99% after 3 h of reaction. After 10 repetitions, the yields of neryl acetate catalyzed by PFL@ZIF-8@ZIF-67 and the free PFL were 80% and 43%, respectively.


Assuntos
Enzimas Imobilizadas , Lipase , Pseudomonas fluorescens , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Pseudomonas fluorescens/enzimologia , Lipase/química , Lipase/metabolismo , Esterificação , Estabilidade Enzimática , Zeolitas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Acetatos/química , Difração de Raios X , Biocatálise , Imidazóis
6.
J Cogn Neurosci ; 35(6): 1021-1031, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36976905

RESUMO

The effect of transcranial random noise stimulation (tRNS) on visual perceptual learning has only been investigated during early training sessions, and the influence of tRNS on later performance is unclear. We engaged participants first in 8 days of training to reach a plateau (Stage 1) and then in continued training for 3 days (Stage 2). In the first group, tRNS was applied to visual areas of the brain while participants were trained on a coherent motion direction identification task over a period of 11 days (Stage 1 + Stage 2). In the second group, participants completed an 8-day training period without any stimulation to reach a plateau (Stage 1); after that, they continued training for 3 days, during which tRNS was administered (Stage 2). In the third group, participants completed the same training as the second group, but during Stage 2, tRNS was replaced by sham stimulation. Coherence thresholds were measured three times: before training, after Stage 1, and after Stage 2. Compared with sham simulation, tRNS did not improve coherence thresholds during the plateau period. The comparison of learning curves between the first and third groups showed that tRNS decreased thresholds in the early training stage, but it failed to improve plateau thresholds. For the second and third groups, tRNS did not further enhance plateau thresholds after the continued 3-day training period. In conclusion, tRNS facilitated visual perceptual learning in the early stage, but its effect disappeared as the training continued.


Assuntos
Percepção de Movimento , Estimulação Transcraniana por Corrente Contínua , Humanos , Percepção de Movimento/fisiologia , Estimulação Luminosa , Encéfalo , Aprendizagem Espacial
7.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37834012

RESUMO

Triple-negative breast cancer (TNBC) is the most fatal subtype of breast cancer; however, effective treatment strategies for TNBC are lacking. Therefore, it is important to explore the mechanism of TNBC metastasis and identify its therapeutic targets. Dysregulation of ETHE1 leads to ethylmalonic encephalopathy in humans; however, the role of ETHE1 in TNBC remains elusive. Stable cell lines with ETHE1 overexpression or knockdown were constructed to explore the biological functions of ETHE1 during TNBC progression in vitro and in vivo. Mass spectrometry was used to analyze the molecular mechanism through which ETHE1 functions in TNBC progression. ETHE1 had no impact on TNBC cell proliferation and xenograft tumor growth but promoted TNBC cell migration and invasion in vitro and lung metastasis in vivo. The effect of ETHE1 on TNBC cell migratory potential was independent of its enzymatic activity. Mechanistic investigations revealed that ETHE1 interacted with eIF2α and enhanced its phosphorylation by promoting the interaction between eIF2α and GCN2. Phosphorylated eIF2α in turn upregulated the expression of ATF4, a transcriptional activator of genes involved in cell migration and tumor metastasis. Notably, inhibition of eIF2α phosphorylation through ISRIB or ATF4 knockdown partially abolished the tumor-promoting effect of ETHE1 overexpression. ETHE1 has a functional and mechanistic role in TNBC metastasis and offers a new therapeutic strategy for targeting ETHE1-propelled TNBC using ISRIB.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/patologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Linhagem Celular Tumoral , Transdução de Sinais , Proliferação de Células/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Mitocondriais/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo
8.
Cell Commun Signal ; 20(1): 127, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35986334

RESUMO

BACKGROUND: N-acetyltransferase 10 (NAT10), an abundant nucleolar protein with both lysine and RNA cytidine acetyltransferase activities, has been implicated in Hutchinson-Gilford progeria syndrome and human cancer. We and others recently demonstrated that NAT10 is translocated from the nucleolus to the nucleoplasm after DNA damage, but the underlying mechanism remains unexplored. METHODS: The NAT10 and PARP1 knockout (KO) cell lines were generated using CRISPR-Cas9 technology. Knockdown of PARP1 was performed using specific small interfering RNAs targeting PARP1. Cells were irradiated with γ-rays using a 137Cs Gammacell-40 irradiator and subjected to clonogenic survival assays. Co-localization and interaction between NAT10 and MORC2 were examined by immunofluorescent staining and immunoprecipitation assays, respectively. PARylation of NAT10 and translocation of NAT10 were determined by in vitro PARylation assays and immunofluorescent staining, respectively. RESULTS: Here, we provide the first evidence that NAT10 underwent covalent PARylation modification following DNA damage, and poly (ADP-ribose) polymerase 1 (PARP1) catalyzed PARylation of NAT10 on three conserved lysine (K) residues (K1016, K1017, and K1020) within its C-terminal nucleolar localization signal motif (residues 983-1025). Notably, mutation of those three PARylation residues on NAT10, pharmacological inhibition of PARP1 activity, or depletion of PARP1 impaired NAT10 nucleoplasmic translocation after DNA damage. Knockdown or inhibition of PARP1 or expression of a PARylation-deficient mutant NAT10 (K3A) attenuated the co-localization and interaction of NAT10 with MORC family CW-type zinc finger 2 (MORC2), a newly identified chromatin-remodeling enzyme involved in DNA damage response, resulting in a decrease in DNA damage-induced MORC2 acetylation at lysine 767. Consequently, expression of a PARylation-defective mutant NAT10 resulted in enhanced cellular sensitivity to DNA damage agents. CONCLUSION: Collectively, these findings indicate that PARP1-mediated PARylation of NAT10 is key for controlling its nucleoplasmic translocation and function in response to DNA damage. Moreover, our findings provide novel mechanistic insights into the sophisticated paradigm of the posttranslational modification-driven cellular response to DNA damage. Video Abstract.


Assuntos
Acetiltransferases , Poli ADP Ribosilação , Núcleo Celular , Dano ao DNA , Humanos , Lisina , Acetiltransferases N-Terminal , Poli(ADP-Ribose) Polimerase-1/genética , Fatores de Transcrição
9.
Appl Opt ; 61(17): 5090-5097, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256187

RESUMO

We propose an instantaneous frequency measurement (IFM) scheme featured with unambiguous measurement utilizing a Sagnac loop with an embedded bi-directional phase modulator and an optical filter with a linear frequency response. The frequency of the microwave signal to be measured is instantaneously estimated by calculating an amplitude comparison function (ACF) of photocurrents from the upper and lower branches of the proposed structure. Compared to previous IFM schemes, the ACF in the proposed scheme is monotonic, by which the frequency of the unknown microwave signal can be uniquely confirmed without ambiguity. Only one laser source and a phase modulator are needed, which simplifies the measurement system. In addition, the monotonous ACF can guarantee measurement accuracy in a wide range, from low frequency to high frequency. The IFM system has robustness in optical and RF power shifts. Simulation results show that frequency measurement over the range of 30 GHz with a measurement error of 0.4 GHz is achieved.

10.
Angew Chem Int Ed Engl ; 61(32): e202204899, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35639417

RESUMO

The structural diversity of three-dimensional (3D) covalent organic frameworks (COFs) are limited as there are only a few choices of building units with multiple symmetrically distributed connection sites. To date, 4 and 6-connected stereoscopic nodes with Td , D3h , D3d and C3 symmetries have been mostly reported, delivering limited 3D topologies. We propose an efficient approach to expand the 3D COF repertoire by introducing a high-valency quadrangular prism (D4h ) stereoscopic node with a connectivity of eight, based on which two isoreticular 3D imine-linked COFs can be created. Low-dose electron microscopy allows the direct visualization of their 2-fold interpenetrated bcu networks. These 3D COFs are endowed with unique pore architectures and strong molecular binding sites, and exhibit excellent performance in separating C2 H2 /CO2 and C2 H2 /CH4 gas pairs. The introduction of high-valency stereoscopic nodes would lead to an outburst of new topologies for 3D COFs.

11.
J Nanobiotechnology ; 19(1): 137, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33985525

RESUMO

Photothermal therapy has attracted extensive attentions in cancer treatment due to its precise spatial-temporal controllability, minimal invasiveness, and negligible side effects. However, two major deficiencies, unsatisfactory heat conversion efficiency and limited tissue penetration depth, hugely impeded its clinical application. In this work, hollow carbon nanosphere modified with polyethylene glycol-graft-polyethylenimine (HPP) was elaborately synthesized. The synthesized HPP owns outstanding physical properties as a photothermal agent, such as uniform core-shell structure, good biocompatibility and excellent heat conversion efficiency. Upon NIR-II laser irradiation, the intracellular HPP shows excellent photothermal activity towards cancer cell killing. In addition, depending on the large internal cavity of HPP, the extended biomedical application as drug carrier was also demonstrated. In general, the synthesized HPP holds a great potential in NIR-II laser-activated cancer photothermal therapy.


Assuntos
Materiais Biocompatíveis , Carbono/química , Nanosferas/química , Fototerapia/métodos , Terapia Fototérmica , Animais , Portadores de Fármacos/química , Humanos , Neoplasias/terapia , Polietilenoglicóis
12.
Med Sci Monit ; 25: 3887-3893, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-31127792

RESUMO

BACKGROUND Myocardial infarction (MI) is the main cause of heart failure (HF), and sympathetic nerve activity is associated with prognosis chronic heart failure. Renal sympathetic denervation (RDN) is noted for its powerful effect on the inhibition of sympathetic nerve activity. This study investigated the effect of RDN on heart failure in dogs after myocardial infarction. MATERIAL AND METHODS The experimental animals were randomized into 2 groups: the MI group (n=12) and the sham operation group (n=6). In the MI group we established an MI model by permanently ligating the left anterior descending branch. After 4 weeks, the MI dogs were randomly divided into 2 groups: the MI+RDN group (MI+renal sympathetic denervation, n=6) and the simple MI group (n=6). Animals in the MI+RDN group underwent both surgical and chemical renal denervation. RESULTS Compared with sham operation group, left ventricular fraction shortening (LVFS) and left ventricular ejection fraction (LVEF) were significantly reduced in the simple MI group, while the reduction was partly reversed in the MI+RDN group. RDN reduced sympathetic nerve activity and release of B-type natriuretic peptide (BNP) and Angiotensin II (AngII) in the MI+ RDN group but not in the simple MI group. CONCLUSIONS Canine renal sympathetic denervation prevents myocardial malignant remodeling by lowering the activity of the systemic sympathetic nerve and inhibiting renin-angiotensin-aldosterone system (RASS) activation, providing a new target and method for the treatment of heart failure.


Assuntos
Rim/inervação , Infarto do Miocárdio/patologia , Simpatectomia/métodos , Angiotensina II , Animais , Pressão Sanguínea , Denervação , Modelos Animais de Doenças , Cães , Ecocardiografia , Feminino , Coração/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Rim/patologia , Masculino , Miocárdio/patologia , Artéria Renal/patologia , Sistema Renina-Angiotensina/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Função Ventricular Esquerda/fisiologia
13.
Appl Opt ; 58(3): 579-587, 2019 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-30694243

RESUMO

In this work, an all-optical scheme to improve the gain and linearity of the downconverted analog photonic link is proposed and verified. We utilize the different electro-optic coefficients of the z-cut LiNbO3 phase modulator to realize the suppression of the third-order intermodulation distortion. On this basis, the link gain is improved by reusing optical carrier and lower sidebands. The simulation results show that the spurious-free dynamic range is improved by ∼7.4 dB. And the link gain is increased by ∼13.42 dB compared to the linearized downconversion link without full spectrum utilization. This photonic downconversion has good feasibility and robustness in inaccurate polarized angle and phase mismatch situations. It can be realized in a wide frequency range and has a stable conversion gain on the condition of RF power changing.

14.
Anal Chem ; 90(22): 13687-13694, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30346134

RESUMO

Point-of-care testing (POCT) devices represent a growing field that aims to develop low-cost, rapid, sensitive diagnostic testing platforms that are portable and self-contained. Surface-enhanced Raman spectroscopy (SERS) is an approach has shown high potential in POCT technology. However, the specificity or ability to uniquely detect a desired biomarker in complex biological samples is a key factor for translating SERS technologies to POCT. Herein, we fabricated cellulose SERS strips (CS) decorated with novel plasmonic nanoparticles, termed graphene-isolated-Au-nanocrystals (GIANs), for the portable detection of complex biological samples. This CS@GIANs SERS strip was used to detect free bilirubin (BR) in the blood of newborns, a biomarker of jaundice, without sample labeling or prepreparation. CS@GIANs showed superior affinity to hydrophobic BR molecules compared to typical SERS substrate, which reduced the steric hindrance effect from the nonspecific binding of BR with serum albumin in blood and improved sensitivity. Meanwhile, with the separation property of cellulose chromatography papers, CS@GIANs showed superior anti-interference to other biomolecules that had been previously adsorbed on the SERS strip. Moreover, the SERS signal from the graphitic shell of GIANs could be used as a stable internal calibration standard, which improved the reproducibility and accuracy of Raman analysis. Such a cellulose SERS strip holds high potential for enhancing current efforts in the development of rapid and low-cost point-of-care diagnostic testing.


Assuntos
Bilirrubina/sangue , Ouro/química , Grafite/química , Nanopartículas/química , Papel , Humanos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Análise Espectral/métodos
15.
Plant Mol Biol ; 89(3): 253-61, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26362289

RESUMO

Traits related to grain and reproductive organs in grass crops have been under continuous directional selection during domestication. Barley is one of the oldest domesticated crops in human history. Thus genes associated with the grain and reproductive organs in barley may show evidence of dramatic evolutionary change. To understand how artificial selection contributes to protein evolution of biased genes in different barley organs, we used Digital Gene Expression analysis of six barley organs (grain, pistil, anther, leaf, stem and root) to identify genes with biased expression in specific organs. Pairwise comparisons of orthologs between barley and Brachypodium distachyon, as well as between highland and lowland barley cultivars mutually indicated that grain and pistil biased genes show relatively higher protein evolutionary rates compared with the median of all orthologs and other organ biased genes. Lineage-specific protein evolutionary rates estimation showed similar patterns with elevated protein evolution in barley grain and pistil biased genes, yet protein sequences generally evolve much faster in the lowland barley cultivar. Further functional annotations revealed that some of these grain and pistil biased genes with rapid protein evolution are related to nutrient biosynthesis and cell cycle/division. Our analyses provide insights into how domestication differentially shaped the evolution of genes specific to different organs of a crop species, and implications for future functional studies of domestication genes.


Assuntos
Evolução Biológica , Regulação da Expressão Gênica de Plantas/fisiologia , Hordeum/metabolismo , Sementes/fisiologia , Flores/metabolismo , Folhas de Planta/metabolismo , Caules de Planta/metabolismo , RNA/genética , RNA/metabolismo , Seleção Genética , Transcriptoma
16.
Cancer Lett ; 586: 216672, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38280476

RESUMO

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer with no targeted therapy. Spermatid perinuclear RNA binding protein (STRBP), a poorly characterized RNA-binding protein (RBP), has an essential role in normal spermatogenesis and sperm function, but whether and how its dysregulation contributing to cancer progression has not yet been explored. Here, we report that STRBP functions as a novel oncogene to drive TNBC progression. STRBP expression was upregulated in TNBC tissues and correlated with poor disease prognosis. Functionally, STRBP promoted TNBC cell proliferation, migration, and invasion in vitro, and enhanced xenograft tumor growth and lung colonization in mice. Mechanistically, STRBP interacted with Dicer, a core component of the microRNA biogenesis machinery, and promoted its proteasomal degradation through enhancing its interaction with E3 ubiquitin ligase UBR5. MicroRNA-sequencing analysis identified miR-200a-3p as a downstream effector of STRBP, which was regulated by Dicer and affected epithelial-mesenchymal transition. Importantly, the impaired malignant phenotypes of TNBC cells caused by STRBP depletion were largely rescued by knockdown of Dicer, and these effects were compromised by transfection of miR-200a-3p mimics. Collectively, these findings revealed a previously unrecognized oncogenic role of STRBP in TNBC progression and identified STRBP as a promising target against TNBC.


Assuntos
MicroRNAs , Neoplasias de Mama Triplo Negativas , Animais , Humanos , Masculino , Camundongos , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Proteólise , Sêmen/metabolismo , Espermátides/metabolismo , Espermátides/patologia , Neoplasias de Mama Triplo Negativas/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
17.
Cancer Lett ; 597: 217008, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38849012

RESUMO

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and it lacks specific therapeutic targets and effective treatment protocols. By analyzing a proteomic TNBC dataset, we found significant upregulation of sideroflexin 1 (SFXN1) in tumor tissues. However, the precise function of SFXN1 in TNBC remains unclear. Immunoblotting was performed to determine SFXN1 expression levels. Label-free quantitative proteomics and liquid chromatography-tandem mass spectrometry were used to identify the downstream targets of SFXN1. Mechanistic studies of SFXN1 and cellular inhibitor of PP2A (CIP2A) were performed using immunoblotting, immunofluorescence staining, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Functional experiments were used to investigate the role of SFXN1 in TNBC cells. SFXN1 was significantly overexpressed in TNBC tumor tissues and was associated with unfavorable outcomes in patients with TNBC. Functional experiments demonstrated that SFXN1 promoted TNBC growth and metastasis in vitro and in vivo. Mechanistic studies revealed that SFXN1 promoted TNBC progression by inhibiting the autophagy receptor TOLLIP (toll interacting protein)-mediated autophagic degradation of CIP2A. The pro-tumorigenic effect of SFXN1 overexpression was partially prevented by lapatinib-mediated inhibition of the CIP2A/PP2A/p-AKT pathway. These findings may provide a new targeted therapy for patients with TNBC.

18.
Sci Adv ; 10(14): eadj4009, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38569025

RESUMO

Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer owing to the lack of effective therapeutic targets. Splicing factor 3a subunit 2 (SF3A2), a poorly defined splicing factor, was notably elevated in TNBC tissues and promoted TNBC progression, as confirmed by cell proliferation, colony formation, transwell migration, and invasion assays. Mechanistic investigations revealed that E3 ubiquitin-protein ligase UBR5 promoted the ubiquitination-dependent degradation of SF3A2, which in turn regulated UBR5, thus forming a feedback loop to balance these two oncoproteins. Moreover, SF3A2 accelerated TNBC progression by, at least in part, specifically regulating the alternative splicing of makorin ring finger protein 1 (MKRN1) and promoting the expression of the dominant and oncogenic isoform, MKRN1-T1. Furthermore, SF3A2 participated in the regulation of both extrinsic and intrinsic apoptosis, leading to cisplatin resistance in TNBC cells. Collectively, these findings reveal a previously unknown role of SF3A2 in TNBC progression and cisplatin resistance, highlighting SF3A2 as a potential therapeutic target for patients with TNBC.


Assuntos
Cisplatino , Neoplasias de Mama Triplo Negativas , Humanos , Cisplatino/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Processamento Alternativo , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo
19.
Cancer Res ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748783

RESUMO

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Transcriptional dysregulation is a hallmark of cancer, and several transcriptional regulators have been demonstrated to contribute to cancer progression. Here, we identified upregulation of the transcriptional corepressor DRAP1 in TNBC, which was closely associated with poor recurrence-free survival in TNBC patients. DRAP1 promoted TNBC proliferation, migration, and invasion in vitro and tumor growth and metastasis in vivo. Mechanistically, the DR1/DRAP1 heterodimer complex inhibited expression of the arginine sensor CASTOR1 and thereby increased activation of mTOR, which sensitized TNBC to treatment with the mTOR inhibitor everolimus. DRAP1 and DR1 also formed a positive feedback loop. DRAP1 enhanced the stability of DR1, recruiting the deubiquitinase USP7 to inhibit its proteasomal degradation; in turn, DR1 directly promoted DRAP1 transcription. Collectively, this study uncovered a DRAP1-DR1 bidirectional regulatory pathway that promotes TNBC progression, suggesting that targeting the DRAP1/DR1 complex might be a potential therapeutic strategy to treat TNBC.

20.
Materials (Basel) ; 16(16)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37629960

RESUMO

Recently, Mg-Zn/hydroxyapatite (HA) composites have attracted much attention as potential candidates for use in bone implants. In this paper, the MgZn/HA composites were prepared using powder metallurgy (PM) and the merging mechanism of MgZn and HA particles was investigated by adjusting the weight ratio of the HA powder. The evolution of the HA distribution in the matrix was examined using SEM and micro-CT images. Afterward, the mechanical properties and biocompatibility of the composites were discussed in detail. The results revealed that the mechanical properties and biocompatibility of the Mg-Zn/HA composites were significantly affected by the HA content. Composites with a low HA content showed increased porosity, improved mechanical strength, and enhanced corrosion resistance after ball milling and cold pressing. These results underscore the importance of optimizing the HA content in Mg-Zn/HA composites for bone implants. Based on our findings, PM Mg-Zn/HA composites with a moderate HA content demonstrate the most promising characteristics as bone implants. The insights gained from this work contribute to the advancement of bone implant materials and hold great potential for enhancing orthopedic surgery outcomes.

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