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1.
J Colloid Interface Sci ; 679(Pt A): 75-89, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39357228

RESUMO

Transition metal alloys can exhibit synergistic intermetallic effects to obtain high activities for oxygen reduction/evolution reactions (ORR/OER). However, due to the insufficient stability of active sites in alkaline electrolytes, conventional alloy catalysts still do not meet practical needs. Herein, by using polypyrrole tubes and cobalt-iron (CoFe) Prussian blue analogs as precursors, CoFe sulfides is in-situ formed on CoFe alloys to construct (CoFe)(S2)2/CoFe heterostructure in sulfur (S) and nitrogen (N) co-doped carbon nanotubes (CoFe@NCNTs-nS) via a low-temperature sulfidation strategy. The as-marked CoFe@NCNTs-12.5S exhibits a comparable ORR activity (half-wave potential of 0.901 V) to Pt/C (0.903 V) and a superior OER activity (overpotential of 272 mV at 10 mA cm-2) to RuO2 (299 mV). CoFe@NCNTs-12.5S also exhibits ultralow charge transfer resistances (ORR-6.36 Ω and OER-0.21 Ω) and an excellent potential difference of 0.617 V. The sulfidation-induced (CoFe)(S2)2/CoFe heterojunctions can accelerate interfacial charge transfer process. Tubular structure not only disperses the (CoFe)(S2)2/CoFe heterostructure, but also reduces the corrosion of active-sites to enhance catalysis stability. Zinc-air battery with CoFe@NCNTs-12.5S achieves a high specific capacity (718.1 mAh g-1), maintaining a voltage gap of 0.957 V after 400 h. This work reveals the potential of interface engineering for boosting ORR/OER activities of alloys via in-situ heterogenization.

2.
Biochim Biophys Acta Gen Subj ; 1868(10): 130683, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39089637

RESUMO

BACKGROUND: Pancreatic cancer (PC) is characterized by a poor prognosis and limited treatment options. Ferroptosis plays an important role in cancer, SET and MYND domain-containing protein 2 (SMYD2) is widely expressed in various cancers. However, the role of SMYD2 in regulating ferroptosis in PC remains unexplored. This study aimed to investigate the role of SMYD2 in mediating ferroptosis and its mechanistic implications in PC progression. METHODS: The levels of SMYD2, c-Myc, and NCOA4 were assessed in PC tissues, and peritumoral tissues. SMYD2 expression was further analyzed in human PC cell lines. In BxPC3 cells, the expression of c-Myc, NCOA4, autophagy-related proteins, and mitochondrial morphology, was evaluated following transfection with si-SMYD2 and treatment with autophagy inhibitors and ferroptosis inhibitors. Ferroptosis levels were quantified using flow cytometry and ELISA assays. RNA immunoprecipitation was conducted to elucidate the interaction between c-Myc and NCOA4 mRNA. A xenograft mouse model was constructed to validate the impact of SMYD2 knockdown on PC growth. RESULTS: SMYD2 and c-Myc were found to be highly expressed in PC tissues, while NCOA4 showed reduced expression. Among the PC cell lines studied, BxPC3 cells exhibited the highest SMYD2 expression. SMYD2 knockdown led to decreased c-Myc levels, increased NCOA4 expression, reduced autophagy-related protein expression, mitochondrial shrinkage, and heightened ferroptosis levels. Additionally, an interaction between c-Myc and NCOA4 was identified. In vivo, SMYD2 knockdown inhibited tumor growth. CONCLUSIONS: Targeting SMYD2 inhibits PC progression by promoting ferritinophagy-dependent ferroptosis through the c-Myc/NCOA4 axis. These findings provide insights into potential diagnostic and therapeutic strategies for PC.


Assuntos
Autofagia , Ferroptose , Histona-Lisina N-Metiltransferase , Coativadores de Receptor Nuclear , Neoplasias Pancreáticas , Proteínas Proto-Oncogênicas c-myc , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/genética , Humanos , Ferroptose/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Histona-Lisina N-Metiltransferase/metabolismo , Histona-Lisina N-Metiltransferase/genética , Camundongos , Coativadores de Receptor Nuclear/metabolismo , Coativadores de Receptor Nuclear/genética , Linhagem Celular Tumoral , Progressão da Doença , Ferritinas/metabolismo , Ferritinas/genética , Regulação Neoplásica da Expressão Gênica , Masculino
3.
Plant J ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39040005

RESUMO

The outcome of certain plant-virus interaction is symptom recovery, which is accompanied with the emergence of asymptomatic tissues in which the virus accumulation decreased dramatically. This phenomenon shows the potential to reveal critical molecular factors for controlling viral disease. MicroRNAs act as master regulators in plant growth, development, and immunity. However, the mechanism by which miRNA participates in regulating symptom recovery remains largely unknown. Here, we reported that miR172 was scavenged in the recovered tissue of tobacco mosaic virus (TMV)-infected Nicotiana tabacum plants. Overexpression of miR172 promoted TMV infection, whereas silencing of miR172 inhibited TMV infection. Then, TARGET OF EAT3 (TOE3), an APETALA2 transcription factor, was identified as a downstream target of miR172. Overexpression of NtTOE3 significantly improved plant resistance to TMV infection, while knockout of NtTOE3 facilitated virus infection. Furthermore, transcriptome analysis indicated that TOE3 promoted the expression of defense-related genes, such as KL1 and MLP43. Overexpression of these genes conferred resistance of plant against TMV infection. Importantly, results of dual-luciferase assay, chromatin immunoprecipitation-quantitative PCR, and electrophoretic mobility shift assay proved that TOE3 activated the transcription of KL1 and MLP43 by binding their promoters. Moreover, overexpression of rTOE3 (the miR172-resistant form of TOE3) significantly reduced TMV accumulation compared to the overexpression of TOE3 (the normal form of TOE3) in miR172 overexpressing Nicotiana benthamiana plants. Taken together, our study reveals the pivotal role of miR172/TOE3 module in regulating plant immunity and in the establishment of recovery in virus-infected tobacco plants, elucidating a regulatory mechanism integrating plant growth, development, and immune response.

4.
Physiol Plant ; 176(3): e14375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38837224

RESUMO

MicroRNA(miRNA) is a class of non-coding small RNA that plays an important role in plant growth, development, and response to environmental stresses. Unlike most miRNAs, which usually target homologous genes across a variety of species, miR827 targets different types of genes in different species. Research on miR827 mainly focuses on its role in regulating phosphate (Pi) homeostasis of plants, however, little is known about its function in plant response to virus infection. In the present study, miR827 was significantly upregulated in the recovery tissue of virus-infected Nicotiana tabacum. Overexpression of miR827 could improve plants resistance to the infection of chilli veinal mottle virus (ChiVMV) in Nicotiana benthamiana, whereas interference of miR827 increased the susceptibility of the virus-infected plants. Further experiments indicated that the antiviral defence regulated by miR827 was associated with the reactive oxygen species and salicylic acid signalling pathways. Then, fructose-1,6-bisphosphatase (FBPase) was identified to be a target of miR827, and virus infection could affect the expression of FBPase. Finally, transient expression of FBPase increased the susceptibility to ChiVMV-GFP infection in N. benthamiana. By contrast, silencing of FBPase increased plant resistance. Taken together, our results demonstrate that miR827 plays a positive role in tobacco response to virus infection, thus providing new insights into understanding the role of miR827 in plant-virus interaction.


Assuntos
Resistência à Doença , Regulação da Expressão Gênica de Plantas , MicroRNAs , Nicotiana , Doenças das Plantas , Nicotiana/virologia , Nicotiana/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Doenças das Plantas/virologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Resistência à Doença/genética , Frutose-Bifosfatase/genética , Frutose-Bifosfatase/metabolismo , Ácido Salicílico/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tobamovirus/fisiologia , Tobamovirus/genética , Plantas Geneticamente Modificadas
6.
Plant J ; 119(2): 720-734, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38713838

RESUMO

The RNA regulatory network is a complex and dynamic regulation in plant cells involved in mRNA modification, translation, and degradation. Ras-GAP SH3 domain-binding protein (G3BP) is a scaffold protein for the assembly of stress granules (SGs) and is considered an antiviral component in mammals. However, the function of G3BP during virus infection in plants is still largely unknown. In this study, four members of the G3BP-like proteins (NtG3BPLs) were identified in Nicotiana tabacum and the expression levels of NtG3BPL1 were upregulated during chilli veinal mottle virus (ChiVMV) infection. NtG3BPL1 was localized in the nucleus and cytoplasm, forming cytoplasmic granules under transient high-temperature treatment, whereas the abundance of cytoplasmic granules was decreased under ChiVMV infection. Overexpression of NtG3BPL1 inhibited ChiVMV infection and delayed the onset of symptoms, whereas knockout of NtG3BPL1 promoted ChiVMV infection. In addition, NtG3BPL1 directly interacted with ChiVMV 6K2 protein, whereas 6K2 protein had no effect on NtG3BPL1-derived cytoplasmic granules. Further studies revealed that the expression of NtG3BPL1 reduced the chloroplast localization of 6K2-GFP and the NtG3BPL1-6K2 interaction complex was localized in the cytoplasm. Furthermore, NtG3BPL1 promoted the degradation of 6K2 through autophagy pathway, and the accumulation of 6K2 and ChiVMV was affected by autophagy activation or inhibition in plants. Taken together, our results demonstrate that NtG3BPL1 plays a positive role in tobacco resistance against ChiVMV infection, revealing a novel mechanism of plant G3BP in antiviral strategy.


Assuntos
Nicotiana , Doenças das Plantas , Proteínas de Plantas , Nicotiana/virologia , Nicotiana/genética , Nicotiana/metabolismo , Doenças das Plantas/virologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas , Potyvirus/fisiologia
7.
Materials (Basel) ; 17(5)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38473690

RESUMO

Waterborne epoxy (WEP) coatings with enhanced corrosion resistance were prepared using graphene oxide (GO) that was obtained from kish graphite, and amino-functionalized graphene oxide (AGO) was modified by 2-aminomalonamide. The structural characteristics of the GO and AGO were analyzed using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). And the anti-corrosive performance of waterborne epoxy-cased composite coatings with different addition amounts of AGO was investigated using electrochemical measurements, pull-off adhesion tests, and salt spray tests. The results indicate that AGO15/WEP with 0.15 wt.% of AGO has the best anti-corrosive performance, and the lowest frequency impedance modulus increased from 1.03 × 108 to 1.63 × 1010 ohm·cm-2 compared to that of WEP. Furthermore, AGO15/WEP also demonstrates the minimal corrosion products or bubbles in the salt spray test for 200 h, affirming its exceptional long-term corrosion protection capability.

8.
Viruses ; 15(12)2023 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-38140565

RESUMO

Autophagy, as a conserved protein degradation pathway in plants, has also been reported to be intricately associated with antiviral defense mechanisms. However, the relationship between chilli veinal mottle virus (ChiVMV) and autophagy has not been investigated in the existing research. Here, we reveal that ChiVMV infection caused the accumulation of autophagosomes in infected Nicotiana benthamiana leaves and the upregulation of autophagy-related genes (ATGs). Moreover, the changes in gene expression were correlated with the development of symptoms. Treatment with autophagy inhibitors (3-MA or E-64D) could increase the infection sites and facilitate virus infection, whereas treatment with the autophagy activator (Rapamycin) limited virus infection. Then, ATG8f was identified to interact with ChiVMV 6K2 protein directly in vitro and in vivo. The silencing of ATG8f promoted virus infection, whereas the overexpression of ATG8f inhibited virus infection. Furthermore, the expression of 6K2-GFP in ATG8f- or ATG7-silenced plants was significantly higher than that in control plants. Rapamycin treatment reduced the accumulation of 6K2-GFP in plant cells, whereas treatment with the inhibitor of the ubiquitin pathway (MG132), 3-MA, or E-64D displayed little impact on the accumulation of 6K2-GFP. Thus, our results demonstrated that ATG8f interacts with the ChiVMV 6K2 protein, promoting the degradation of 6K2 through the autophagy pathway.


Assuntos
Nicotiana , Viroses , Sirolimo , Autofagia , Doenças das Plantas
9.
Sci Total Environ ; 903: 166424, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37634715

RESUMO

Nanopesticides have been selected as one of the top 10 chemical innovations for enhancing the efficacy and safety of agrochemicals. Herein, smart, degradable, and eco-friendly metal-organic framework MIL-101(FeIII) nanoherbicides coated with carboxymethyl cellulose-CaII (CMC-CaII) cross-linking hydrogel-like networks are synthesized via a simple strategy. The coating of the CMC-CaII hydrogel-like gatekeepers is oriented by the coordination unsaturated FeIII clusters on the surfaces of the MIL-101(FeIII) nanocarriers to form a dense film network to prevent paraquat (PQ) leakage. Based on the stimuli factors (acid/basic pH, GSH, phosphates, and EDTA) of physiological and natural environments of target plants, the nanoherbicides are combined with five stimuli-responsive properties to attain the various controlled release of packaged PQ by the disassembly of the gatekeepers and/or the degradation of the MOF skeleton structure. More importantly, based on the stimuli-responsive controlled release mechanisms, the eco-friendly nanocarriers are ultimately degraded against bioaccumulation in plants or soil. The coating of natural CMC could promote the spreading of PQ owing to improvement of wettability for aqueous droplets of nanoherbicides on hydrophobic foliage. The PQ trapped in nanocarriers can effectively prevent PQ degradation, which showed that cumulative degradation rate is ca. 2.6 times lower than that of technical PQ under UV irradiation. The prepared nanoherbicides loaded with PQ show good control efficacy against weeds by controlling the release of PQ; good safety on seed germination (germination rate 97.32-99.67 %), seedling emergence (emergence rate 95.53-99.67 %), and are beneficial for the growth of wheat seedling (increase rate of plant height 1.89-6.97 % and 0.54-5.67 % after 7 and 15 days of seedling emergence, respectively) in the greenhouse; good biosafety for honeybees (Apis mellifera L.), which shows that lethal rates were 2.04 and 2.55 times lower than technical PQ for incubation 24 and 48 h, respectively. The nanoherbicides have potential applications in the field for PQ green agriculture.

10.
Brain Pathol ; 33(4): e13160, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37186490

RESUMO

The pathological diagnosis of intracranial germinoma (IG), oligodendroglioma, and low-grade astrocytoma on intraoperative frozen section (IFS) and hematoxylin-eosin (HE)-staining section directly determines patients' treatment options, but it is a difficult task for pathologists. We aimed to investigate whether whole-slide imaging (WSI)-based deep learning can contribute new precision to the diagnosis of IG, oligodendroglioma, and low-grade astrocytoma. Two types of WSIs (500 IFSs and 832 HE-staining sections) were collected from 379 patients at multiple medical centers. Patients at Center 1 were split into the training, testing, and internal validation sets (3:1:1), while the other centers were the external validation sets. First, we subdivided WSIs into small tiles and selected tissue tiles using a tissue tile selection model. Then a tile-level classification model was established, and the majority voting method was used to determine the final diagnoses. Color jitter was applied to the tiles so that the deep learning (DL) models could adapt to the variations in the staining. Last, we investigated the effectiveness of model assistance. The internal validation accuracies of the IFS and HE models were 93.9% and 95.3%, respectively. The external validation accuracies of the IFS and HE models were 82.0% and 76.9%, respectively. Furthermore, the IFS and HE models can predict Ki-67 positive cell areas with R2 of 0.81 and 0.86, respectively. With model assistance, the IFS and HE diagnosis accuracy of pathologists improved from 54.6%-69.7% and 53.5%-83.7% to 87.9%-93.9% and 86.0%-90.7%, respectively. Both the IFS model and the HE model can differentiate the three tumors, predict the expression of Ki-67, and improve the diagnostic accuracy of pathologists. The use of our model can assist clinicians in providing patients with optimal and timely treatment options.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Aprendizado Profundo , Oligodendroglioma , Humanos , Oligodendroglioma/diagnóstico por imagem , Oligodendroglioma/cirurgia , Antígeno Ki-67 , Neuropatologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia
11.
Angew Chem Int Ed Engl ; 62(29): e202302096, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37026583

RESUMO

The direct electrochemical conversion of CO2 to multi-carbon products offers a promising pathway for producing value-added chemicals using renewable electricity. However, producing ethanol remains a challenge because of the competitive ethylene formation and hydrogen evolution reactions. Herein, we propose an active hydrogen (*H)-intermediate-mediating strategy for ethanol electroproduction on a layered precursor-derived CuAl2 O4 /CuO catalyst. The catalyst delivered a Faradaic efficiency of 70 % for multi-carbon products and 41 % for ethanol at current density of 200 mA cm-2 and exhibited a continuous 150 h durability in a flow cell. The intensive spectroscopic studies combined with theoretical calculations revealed that the in situ generated CuAl2 O4 could tailor *H intermediate coverage and the elevated *H coverage favors the hydrogenation of the *HCCOH intermediate, accounting for the increased yield of ethanol. This work directs a pathway for enhancing ethanol electroproduction from CO2 reduction by tailoring *H intermediate coverage.

12.
J Colloid Interface Sci ; 635: 208-220, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36587574

RESUMO

Transition metal alloys have emerged as promising catalysts for oxygen reduction/evolution reactions (ORR/OER) because of their intermetallic synergy and tunable redox properties. However, for alloy nanoparticles, it is quite challenging to suppress the self-aggregation and promote the bifunctional activity. Anchoring alloys in heteroatoms-doped carbon matrix with excellent electro-conductibility is a powerful strategy to form strongly-coupled alloy-carbon nanohybrids. Here, highly-dispersed NiFe alloys are evenly in-situ anchored on the surface of Co, N co-doped carbon nanotubes (NiFe/Co-N@CNTs) via a gravity-guided chemical vapor deposition and self-assembly strategy. Stably-structured NiFe/Co-N@CNTs possesses a tubular skeleton with diameters of 80-100 nm and a hydrophilic surface. For ORR, half-wave potential of NiFe/Co-N@CNTs (0.87 V vs RHE) is higher than that of Pt/C (0.85 V). Strong synergies between NiFe alloys and Co-Nx species facilitate the charge transfer on one-dimensional conductive structure to boost the 4e- ORR kinetics. For OER, NiFe/Co-N@CNTs has a lower overpotential (300 mV) than RuO2 (400 mV) at 10 mA cm-2 due to in-situ formation of highly-active NiOOH/FeOOH species (as indicated by in-situ X-ray diffraction) at the catalytic sites on NiFe alloy. Rechargeable Zn-air battery (ZAB) with NiFe/Co-N@CNTs-based air-cathode exhibits promising open-circuit potential (1.52 V) and charge-discharge cycling stability (350 h). This alloy-carbon integrating strategy is meaningful for promoting dispersion, activity and stability of non-noble metal alloys for oxygen electrocatalysis.

14.
Cancer Lett ; 520: 172-183, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34265399

RESUMO

The UHRF1 and CDC6, oncogenes play critical roles in therapeutic resistance. In the present study, we found that UHRF1 mediates androgen receptor (AR)-regulated CDC6 transcription in prostate cancer cells. In prostate cancer tissues and cell lines, levels of UHRF1 and CDC6 were simultaneously upregulated, and this was associated with worse survival. UHRF1 silencing significantly promoted the cytotoxicity and anti-prostate cancer efficacy of bicalutamide in mouse xenografts by inhibiting CDC6 gene expression. UHRF1 promoted AR-regulated CDC6 transcription by binding to the CCAAT motif near the androgen response element (ARE) in the CDC6 promoter. We further found that UHRF1 promoted androgen-dependent chromatin occupancy of AR protein by recruiting the H3K9me2/3-specific demethyltransferase KDM4C and modifying the intense heterochromatin status. Altogether, we found for the first time that UHRF1 promotes AR-regulated CDC6 transcription through a novel chromatin modification mechanism and contributes to anti-AR drug resistance in prostate cancer. Targeting AR and UHRF1 simultaneously may be a novel and promising therapeutic modality for prostate cancer.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas de Ciclo Celular/genética , Histona Desmetilases com o Domínio Jumonji/genética , Proteínas Nucleares/genética , Hiperplasia Prostática/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/genética , Ubiquitina-Proteína Ligases/genética , Antagonistas de Androgênios/farmacologia , Antagonistas de Receptores de Andrógenos/farmacologia , Animais , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Hiperplasia Prostática/genética , Hiperplasia Prostática/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Receptores Androgênicos/efeitos dos fármacos
15.
Front Microbiol ; 12: 672559, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34084157

RESUMO

Protein lysine acetylation (Kac) is an important post-translational modification mechanism in eukaryotes that is involved in cellular regulation. To investigate the role of Kac in virus-infected plants, we characterized the lysine acetylome of Nicotiana benthamiana plants with or without a Chinese wheat mosaic virus (CWMV) infection. We identified 4,803 acetylated lysine sites on 1,964 proteins. A comparison of the acetylation levels of the CWMV-infected group with those of the uninfected group revealed that 747 sites were upregulated on 422 proteins, including chloroplast localization proteins and histone H3, and 150 sites were downregulated on 102 proteins. Nineteen conserved motifs were extracted and 51 percent of the acetylated proteins located on chloroplast. Nineteen Kac sites were located on histone proteins, including 10 Kac sites on histone 3. Bioinformatics analysis results indicated that lysine acetylation occurs on a large number of proteins involved in biological processes, especially photosynthesis. Furthermore, we found that the acetylation level of chloroplast proteins, histone 3 and some metabolic pathway-related proteins were significantly higher in CWMV-infected plants than in uninfected plants. In summary, our results reveal the regulatory roles of Kac in response to CWMV infection.

16.
J Exp Clin Cancer Res ; 38(1): 468, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730000

RESUMO

BACKGROUND: The deubiquitinase USP7 has been identified as an oncogene with key roles in tumorigenesis and therapeutic resistance for a series of cancer types. Recently small molecular inhibitors have been developed to target USP7. However, the anticancer mechanism of USP7 inhibitors is still elusive. METHODS: Cell viability or clonogenicity was tested by violet crystal assay. Cell apoptosis or cell cycle was analyzed by flow cytometry, and chromosome misalignment was observed by a fluorescent microscopy. The protein interaction of PLK1 and USP7 was detected by tandem affinity purification and high throughput proteomics, and further confirmed by co-immunoprecipitation, GST pull-down and protein co-localization. The correlation between USP7 level of tumor tissues and taxane-resistance was evaluated. RESULTS: Pharmacological USP7 inhibition by P5091 retarded cell proliferation and induced cell apoptosis. Further studies showed that P5091 induced cell cycle arrest at G2/M phase, and particularly induced chromosome misalignment, indicating the key roles of USP7 in mitosis. USP7 protein was detected in the PLK1-interacted protein complex. USP7 interacts with PLK1 protein through its PBD domain by catalytic activity. USP7 as a deubiquitinase sustained PLK1 protein stability via the C223 site, and inversely, USP7 inhibition by P5091 promoted the protein degradation of PLK1 through the ubiquitination-proteasome pathway. By overexpressing PLK1, USP7 that had been depleted by RNAi ceased to induce chromosome misalignment in mitosis and again supported cell proliferation and cell survival. Both USP7 and PLK1 were overexpressed in taxane-resistant cancer cells, and negatively correlated with the MP scores in tumor tissues. Either USP7 or PLK1 knockdown by RNAi significantly sensitized taxane-resistant cells to taxane cell killing. CONCLUSION: This is the first report that PLK1 is a novel substrate of USP7 deubiquitinase, and that USP7 sustained the protein stability of PLK1. USP7 inhibition induces cell apoptosis and cell cycle G2/M arrest, and overcomes taxane resistance by inducing the protein degradation of PLK1, resulting in chromosome misalignment in mitosis.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Peptidase 7 Específica de Ubiquitina/genética , Peptidase 7 Específica de Ubiquitina/metabolismo , Apoptose/efeitos dos fármacos , Cromossomos , Cromossomos Humanos , Docetaxel/farmacologia , Resistencia a Medicamentos Antineoplásicos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HEK293 , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Masculino , Mitose/fisiologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Inibidores de Proteases/farmacologia , Estabilidade Proteica , Transdução de Sinais , Tiofenos/farmacologia , Transfecção , Peptidase 7 Específica de Ubiquitina/antagonistas & inibidores , Quinase 1 Polo-Like
17.
Oncogene ; 38(4): 549-563, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30158672

RESUMO

Ionizing radiation (IR) is a conventional cancer therapeutic, to which cancer cells develop radioresistance with exposure. The residual cancer cells after radiation treatment also have increased metastatic potential. The mechanisms by which cancer cells develop radioresistance and gain metastatic potential are still unknown. In this study acute IR exposure induced cancer cell senescence and apoptosis, but after long-term IR exposure, cancer cells exhibited radioresistance. The proliferation of radioresistant cells was retarded, and most cells were arrested in G0/G1 phase. The radioresistant cells simultaneously showed resistance to further IR-induced apoptosis, premature senescence, and epithelial to mesenchymal transformation (EMT). Acute IR exposure steadily elevated CDC6 protein levels due to the attenuation of ubiquitination, while CDC6 overexpression was observed in the radioresistant cells because the insufficiency of CDC6 phosphorylation blocked protein translocation from nucleus to cytoplasm, resulting in subcellular protein accumulation when the cells were arrested in G0/G1 phase. CDC6 ectopic overexpression in CNE2 cells resulted in apoptosis resistance, G0/G1 cell cycle arrest, premature senescence, and EMT, similar to the characteristics of radioresistant CNE2-R cells. Targeting CDC6 with siRNA promoted IR-induced senescence, sensitized cancer cells to IR-induced apoptosis, and reversed EMT. Furthermore, CDC6 depletion synergistically repressed the growth of CNE2-R xenografts when combined with IR. The study describes for the first time cell models for IR-induced senescence, apoptosis resistance, and EMT, three major mechanisms by which radioresistance develops. CDC6 is a novel radioresistance switch regulating senescence, apoptosis, and EMT. These studies suggest that CDC6highKI67low represents a new diagnostic marker of radiosensitivity, and CDC6 represents a new therapeutic target for cancer radiosensitization.


Assuntos
Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos T/fisiologia , Apoptose/efeitos da radiação , Carcinoma/patologia , Senescência Celular/fisiologia , Transição Epitelial-Mesenquimal/efeitos da radiação , Neoplasias Nasofaríngeas/patologia , Proteínas de Neoplasias/fisiologia , Processamento de Proteína Pós-Traducional/efeitos da radiação , Tolerância a Radiação/fisiologia , Animais , Antígenos CD/biossíntese , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/biossíntese , Antígenos de Diferenciação de Linfócitos T/genética , Carcinoma/radioterapia , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Antígeno Ki-67/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Nasofaríngeas/radioterapia , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Fosforilação/efeitos da radiação , Estabilidade Proteica , Transporte Proteico/efeitos da radiação , Interferência de RNA , RNA Interferente Pequeno/genética , Ubiquitinação/efeitos da radiação , Raios X
18.
Artigo em Inglês | MEDLINE | ID: mdl-30393630

RESUMO

Many brain-based disorders are traditionally diagnosed based on clinical interviews and behavioral assessments, which are recognized to be largely imperfect. Therefore, it is necessary to establish neuroimaging-based biomarkers to improve diagnostic precision. Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising technique for the characterization and classification of varying disorders. However, most of these classification methods are supervised, i.e., they require a priori clinical labels to guide classification. In this study, we adopted various unsupervised clustering methods using static and dynamic rs-fMRI connectivity measures to investigate whether the clinical diagnostic grouping of different disorders is grounded in underlying neurobiological and phenotypic clusters. In order to do so, we derived a general analysis pipeline for identifying different brain-based disorders using genetic algorithm-based feature selection, and unsupervised clustering methods on four different datasets; three of them-ADNI, ADHD-200, and ABIDE-which are publicly available, and a fourth one-PTSD and PCS-which was acquired in-house. Using these datasets, the effectiveness of the proposed pipeline was verified on different disorders: Attention Deficit Hyperactivity Disorder (ADHD), Alzheimer's Disease (AD), Autism Spectrum Disorder (ASD), Post-Traumatic Stress Disorder (PTSD), and Post-Concussion Syndrome (PCS). For ADHD and AD, highest similarity was achieved between connectivity and phenotypic clusters, whereas for ASD and PTSD/PCS, highest similarity was achieved between connectivity and clinical diagnostic clusters. For multi-site data (ABIDE and ADHD-200), we report site-specific results. We also reported the effect of elimination of outlier subjects for all four datasets. Overall, our results suggest that neurobiological and phenotypic biomarkers could potentially be used as an aid by the clinician, in additional to currently available clinical diagnostic standards, to improve diagnostic precision. Data and source code used in this work is publicly available at https://github.com/xinyuzhao/identification-of-brain-based-disorders.git.

19.
J Exp Clin Cancer Res ; 37(1): 153, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-30012171

RESUMO

BACKGROUND: The poly ADP ribose polymerase (PARP) inhibitor olaparib has been approved for treating prostate cancer (PCa) with BRCA mutations, and veliparib, another PARP inhibitor, is being tested in clinical trials. However, veliparib only showed a moderate anticancer effect, and combination therapy is required for PCa patients. Histone deacetylase (HDAC) inhibitors have been tested to improve the anticancer efficacy of PARP inhibitors for PCa cells, but the exact mechanisms are still elusive. METHODS: Several types of PCa cells and prostate epithelial cell line RWPE-1 were treated with veliparib or SAHA alone or in combination. Cell viability or clonogenicity was tested with violet crystal assay; cell apoptosis was detected with Annexin V-FITC/PI staining and flow cytometry, and the cleaved PARP was tested with western blot; DNA damage was evaluated by staining the cells with γH2AX antibody, and the DNA damage foci were observed with a fluorescent microscopy, and the level of γH2AX was tested with western blot; the protein levels of UHRF1 and BRCA1 were measured with western blot or cell immunofluorescent staining, and the interaction of UHRF1 and BRCA1 proteins was detected with co-immunoprecipitation when cells were treated with drugs. The antitumor effect of combinational therapy was validated in DU145 xenograft models. RESULTS: PCa cells showed different sensitivity to veliparib or SAHA. Co-administration of both drugs synergistically decreased cell viability and clonogenicity, and synergistically induced cell apoptosis and DNA damage, while had no detectable toxicity to normal prostate epithelial cells. Mechanistically, veliparib or SAHA alone reduced BRCA1 or UHRF1 protein levels, co-treatment with veliparib and SAHA synergistically reduced BRCA1 protein levels by targeting the UHRF1/BRCA1 protein complex, the depletion of UHRF1 resulted in the degradation of BRCA1 protein, while the elevation of UHRF1 impaired co-treatment-reduced BRCA1 protein levels. Co-administration of both drugs synergistically decreased the growth of xenografts. CONCLUSIONS: Our studies revealed that the synergistic lethality of HDAC and PARP inhibitors resulted from promoting DNA damage and inhibiting HR DNA damage repair pathways, in particular targeting the UHRF1/BRCA1 protein complex. The synergistic lethality of veliparib and SAHA shows great potential for future PCa clinical trials.


Assuntos
Benzimidazóis/uso terapêutico , Dano ao DNA/genética , Inibidores de Histona Desacetilases/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Animais , Benzimidazóis/farmacologia , Sinergismo Farmacológico , Inibidores de Histona Desacetilases/farmacologia , Humanos , Masculino , Camundongos , Camundongos Nus , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Neoplasias da Próstata/patologia
20.
Cell Death Dis ; 9(5): 562, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29752436

RESUMO

Therapy-induced expansion of cancer stem cells (CSCs) has been identified as one of the most critical factors contributing to therapeutic resistance, but the mechanisms of this adaptation are not fully understood. UHRF1 is a key epigenetic regulator responsible for therapeutic resistance, and controls the self-renewal of stem cells. In the present study, taxane-resistant cancer cells were established and stem-like cancer cells were expanded. UHRF1 was overexpressed in the taxane-resistant cancer cells, which maintained CSC characteristics. UHRF1 depletion overcame taxane resistance in vitro and in vivo. Additionally, FOXM1 has been reported to play a role in therapeutic resistance and the self-renewal of CSCs. FOXM1 and UHRF1 are highly correlated in prostate cancer tissues and cells, FOXM1 regulates CSCs by regulating uhrf1 gene transcription in an E2F-independent manner, and FOXM1 protein directly binds to the FKH motifs at the uhrf1 gene promoter. This present study clarified a novel mechanism by which FOXM1 controls CSCs and taxane resistance through a UHRF1-mediated signaling pathway, and validated FOXM1 and UHRF1 as two potential therapeutic targets to overcome taxane resistance.


Assuntos
Hidrocarbonetos Aromáticos com Pontes/farmacologia , Proteínas Estimuladoras de Ligação a CCAAT/genética , Resistencia a Medicamentos Antineoplásicos/genética , Proteína Forkhead Box M1/fisiologia , Regulação Neoplásica da Expressão Gênica , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias da Próstata/genética , Taxoides/farmacologia , Animais , Linhagem Celular Tumoral , Docetaxel/farmacologia , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Fenótipo , Regiões Promotoras Genéticas , Neoplasias da Próstata/dietoterapia , Neoplasias da Próstata/metabolismo , Ligação Proteica , Transdução de Sinais , Ubiquitina-Proteína Ligases
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