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1.
Breast Cancer Res ; 23(1): 89, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488828

RESUMO

BACKGROUND: Telomere maintenance is crucial for the unlimited proliferation of cancer cells and essential for the "stemness" of multiple cancer cells. TAZ is more extensively expressed in triple negative breast cancers (TNBC) than in other types of breast cancers, and promotes proliferation, transformation and EMT of cancer cells. It was reported that TAZ renders breast cancer cells with cancer stem cell features. However, whether TAZ regulates telomeres is still unclear. In this study, we explored the roles of TAZ in the regulation of telomere maintenance in TNBC cells. METHODS: siRNA and shRNA was used to generate TAZ-depleted TNBC cell lines. qPCR and Southern analysis of terminal restriction fragments techniques were used to test telomere length. Co-immunoprecipitation, Western blotting, immunofluorescence, Luciferase reporter assay and Chromatin-IP were conducted to investigate the underlying mechanism. RESULTS: By knocking down the expression of TAZ in TNBC cells, we found, for the first time, that TAZ is essential for the maintenance of telomeres in TNBC cells. Moreover, loss of TAZ causes senescence phenotype of TNBC cells. The observed extremely shortened telomeres in late passages of TAZ knocked down cells correlate with an elevated hTERT expression, reductions of shelterin proteins, and an activated DNA damage response pathway. Our data also showed that depletion of TAZ results in overexpression of TERRAs, which are a group of telomeric repeat-containing RNAs and regulate telomere length and integrity. Furthermore, we discovered that TAZ maintains telomere length of TNBC cells likely by facilitating the expression of Rad51C, a crucial element of homologous recombination pathway that promotes telomere replication. CONCLUSIONS: This study supports the notion that TAZ is an oncogenic factor in TNBC, and further reveals a novel telomere-related pathway that is employed by TAZ to regulate TNBC.

2.
BMC Cancer ; 21(1): 760, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193109

RESUMO

BACKGROUND: Breast cancer is the leading cause of cancer-related deaths in females worldwide. Formin-like protein 2 (FMNL2) is a member of formin family that governs cytokinesis, cell polarity, morphogenesis and cell division. To our knowledge, the function of FMNL2 in breast cancer proliferation still remains uncovered. METHODS: Tumor immune estimation resource (TIMER) analysis was used to detect the correlation between FMNL2 and Ki67 in breast cancer tissues. Quantitative real-time transcription polymerase chain reaction (qRT-PCR) and western blotting were performed to analyze the expression in human breast cancer cells. Moreover, RNA interference (RNAi) and plasmids were performed to silence and overexpress FMNL2 and p27. The CCK8, MTT, cell counting, colony formation, and 5-ethynyl-2-deoxyuridine (EdU) incorporation assays were used to detect cell proliferation, respectively. Flow cytometry analysis was used to detect cell cycle distribution. Further, the distribution of p27 was examined using immunofluorescence. RESULTS: We found that FMNL2 expression was positively associated with Ki67 among collected breast cancer tissues and in TCGA database. Compared to lower proliferative cells MCF7 and T47D, FMNL2 was overexpressed in highly proliferative breast cancer cells MDA-MB-231, BT549 and SUM159, accompanied by reduced levels of p27 and p21, and elevated CyclinD1 and Ki67 expression. FMNL2 silencing significantly inhibited the cell proliferation of MDA-MB-231 and BT549 cells. Meanwhile, FMNL2 overexpression distinctly promoted the cell proliferation of MCF7 cells. Furthermore, FMNL2 suppressed the nuclear levels of p27 and promoted p27 proteasomal degradation in human breast cancer cells. The ubiquitination of p27 was inhibited by FMNL2 silencing in BT549 cells. Besides, p27 silencing markedly elevated Ki67 expression and cell viability, which could be blocked by additionally FMNL2 silencing in MDA-MB-231 and BT549 cells. Furthermore, overexpression of p27WT significantly reversed the increased levels of FMNL2 and Ki67, cell viability and cell cycle progression induced by FMNL2 overexpression in MCF7 cells. More importantly, compared to p27WT group, those effects could be significantly reversed by p27△NLS overexpression. CONCLUSIONS: These results demonstrated that FMNL2 promoted cell proliferation partially by reducing p27 nuclear localization and p27 protein stability in human breast cancer cells, suggesting the pivotal role of FMNL2 in breast cancer progression.

3.
Cancer Sci ; 111(11): 4075-4087, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32860308

RESUMO

Suppressor of Ty 16 (Spt16) is a component of the facilitates chromatin transcription (FACT) complex, which is a histone chaperone and involved in gene transcription, DNA replication, and DNA repair. Previous studies showed that FACT is highly expressed in cancer, and cancer cells are more reliant on FACT than normal cells. However, the relationship between Spt16 and lung cancer remains unclear. In this study, we explored the functions of Spt16 in lung cancer cells. The effects of Spt16 on lung cancer cell proliferation, cell cycle progression, apoptosis, migration, and invasion were examined. We found that knockdown of Spt16 led to obvious decreases of both Rb and MCM7, and further activated the DNA damage response (DDR) pathway. In addition, a novel micro-RNA, miR-1227-5p, directly targeted the 3'-UTR of Spt16 and regulated the mRNA levels of Spt16. Furthermore, we found that CBL0137, the functional inhibitor of FACT, showed similar effects as loss of Spt16. Together, our data indicated that Spt16 is likely to be an essential regulator for lung cancer malignancy and is negatively regulated by miR-1227-5p.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , MicroRNAs/genética , Fatores de Transcrição/metabolismo , Regiões 3' não Traduzidas , Apoptose/genética , Carbazóis/farmacologia , Ciclo Celular/genética , Cromatina/genética , Cromatina/metabolismo , Dano ao DNA , Progressão da Doença , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/patologia , Gradação de Tumores , Interferência de RNA , Transcrição Genética/efeitos dos fármacos
4.
Chem Commun (Camb) ; 55(18): 2692-2695, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30747934

RESUMO

Nb2O5@carbon/reduced graphene oxide (M-Nb2O5@C/rGO) composites are fabricated by annealing the precursor of graphene oxide supported Nb-based metal organic frameworks for the first time. The lithium ion capacitor using M-Nb2O5@C/rGO as the anode and activated carbon as the cathode delivers a high energy density of 71.5 W h kg-1 and excellent cycling stability.

5.
ChemSusChem ; 11(5): 907-915, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29388379

RESUMO

The incorporation of spacers between graphene sheets has been investigated as an effective method to improve the electrochemical performance of graphene papers (GPs) for supercapacitors. Here, we report the design of free-standing GP@NiO and GP@Ni hybrid GPs in which NiO nanoclusters and Ni nanoparticles are encapsulated into graphene sheets through electrostatic assembly and subsequent vacuum filtration. The encapsulated NiO nanoclusters and Ni nanoparticles can mitigate the restacking of graphene sheets, providing sufficient spaces for high-speed ion diffusion and electron transport. In addition, the spacers strongly bind to graphene sheets, which can efficiently improve the electrochemical stability. Therefore, at a current density of 0.5 A g-1 , the GP@NiO and GP@Ni electrodes exhibit higher specific capacitances of 306.9 and 246.1 F g-1 than the GP electrode (185.7 F g-1 ). The GP@NiO and GP@Ni electrodes exhibit capacitance retention of 98.7 % and 95.6 % after 10000 cycles, demonstrating an outstanding cycling stability. Additionally, the GP@NiO∥GP@Ni delivers excellent cycling stability (93.7 % after 10 000 cycles) and high energy density. These free-standing encapsulated hybrid GPs have great potential as electrode for high-performance supercapacitors.


Assuntos
Capacitância Elétrica , Grafite/química , Nanoestruturas/química , Eletrodos , Transporte de Elétrons , Níquel/química , Eletricidade Estática
6.
ACS Appl Mater Interfaces ; 10(4): 3549-3561, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29297668

RESUMO

In this work, we synthesized the hierarchical ZnO@C@NiO core-shell nanorods arrays (CSNAs) grown on a carbon cloth (CC) conductive substrate by a three-step method involving hydrothermal and chemical bath methods. The morphology and chemical structure of the hybrid nanoarrays were characterized in detail. The combination and formation mechanism was proposed. The conducting carbon layer between ZnO and NiO layers can efficiently enhance the electric conductivity of the integrated electrodes, and also protect the corrosion of ZnO in an alkaline solution. Compared with ZnO@NiO nanorods arrays (NAs), the NiO in CC/ZnO@C@NiO electrodes, which possess a unique multilevel core-shell nanostructure exhibits a higher specific capacity (677 C/g at 1.43 A/g) and an enhanced cycling stability (capacity remain 71% after 5000 cycles), on account of the protection of carbon layer derived from glucose. Additionally, a flexible all-solid-state supercapacitor is readily constructed by coating the PVA/KOH gel electrolyte between the ZnO@C@NiO CSNAs and commercial graphene. The energy density of this all-solid-state device decreases from 35.7 to 16.0 Wh/kg as the power density increases from 380.9 to 2704.2 W/kg with an excellent cycling stability (87.5% of the initial capacitance after 10000 cycles). Thereby, the CC/ ZnO@C@NiO CSNAs of three-dimensional hierarchical structure is promising electrode materials for flexible all-solid-state supercapacitors.

7.
Nanotechnology ; 28(31): 315403, 2017 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-28635618

RESUMO

Strongly coupled boron and nitrogen co-doped graphene (BN-G) hybrids with nickel cobaltite (NiCo2O4) nanosheets (NCO/BN-G) were fabricated by a facile soft-chemical method for asymmetric supercapacitors with high-performance. The strong interaction between BN-G and NiCo2O4 nanosheets are explored by various techniques. The effect of heteroatom doping on electrochemical properties of the hybrids is systematically investigated. The strong synergistic effect between NiCo2O4 and BN-G leads to a specific capacitance of 106.5 mA h g-1 at the current density of 0.5 A g-1 and capacitance retention of 96.8% after 10 000 cycles at 5 A g-1, much better than those of the pure NiCo2O4 and its hybrid with N-doped graphene. Moreover, an asymmetric supercapacitor device, assembled with NCO/BN-G and activated carbon (NCO/BN-G//AC), exhibits a maximum energy density of 45.6 Wh kg-1 and an excellent cycling stability. The improved electrochemical performance of the NCO/BN-G hybrid is attributed to the good conductivity of BN-G and the synergistic effect between NiCo2O4 nanosheets and BN-G combined together through a plane-to-plane contact mode.

8.
J Immunol ; 194(6): 2596-606, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25694612

RESUMO

Ag recognition and Ab production in B cells are major components of the humoral immune response. In the current study, we found that the core fucosylation catalyzed by α1,6-fucosyltransferase (Fut8) was required for the Ag recognition of BCR and the subsequent signal transduction. Moreover, compared with the 3-83 B cells, the coalescing of lipid rafts and Ag-BCR endocytosis were substantially reduced in Fut8-knockdown (3-83-KD) cells with p31 stimulation and then completely restored by reintroduction of the Fut8 gene to the 3-83-KD cells. Indeed, Fut8-null (Fut8(-/-)) mice evoked a low immune response following OVA immunization. Also, the frequency of IgG-producing cells was significantly reduced in the Fut8(-/-) spleen following OVA immunization. Our results clearly suggest an unexpected mode of BCR function, in which the core fucosylation of IgG-BCR mediates Ag recognition and, concomitantly, cell signal transduction via BCR and Ab production.


Assuntos
Formação de Anticorpos/imunologia , Antígenos/imunologia , Linfócitos B/imunologia , Imunoglobulina G/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Sequência de Aminoácidos , Animais , Linfócitos B/metabolismo , Sequência de Bases , Sítios de Ligação/genética , Western Blotting , Células Cultivadas , Endocitose/imunologia , Citometria de Fluxo , Fucose/imunologia , Fucose/metabolismo , Fucosiltransferases/deficiência , Fucosiltransferases/genética , Fucosiltransferases/imunologia , Glicosilação , Imunoglobulina G/genética , Imunoglobulina G/metabolismo , Microdomínios da Membrana/imunologia , Microdomínios da Membrana/metabolismo , Camundongos Endogâmicos ICR , Camundongos Knockout , Dados de Sequência Molecular , Ovalbumina/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/imunologia , Baço/imunologia , Baço/metabolismo
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