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1.
Int J Biol Sci ; 20(5): 1744-1762, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481809

RESUMO

Glycolysis exerts a key role in the metabolic reprogramming of cancer. Specific long non-coding RNAs (lncRNAs) have been identified to exhibit oncogenic glycolysis regulation. Nevertheless, the precise mechanisms by which glycolysis-related lncRNAs control hepatocellular carcinoma (HCC) are still unknown. We profiled and analyzed glycolysis-associated lncRNA signatures using HCC specimens from The Cancer Genome Atlas (TCGA) dataset. Considerable upregulation of the glycolysis-related lncRNA SLC2A1-DT was noted in HCC tissues; this upregulation was strongly linked with advanced tumor stage and poor prognosis. Cell culture and animal-related studies indicated that knockdown or overexpression of SLC2A1-DT obviously restrained or promoted glycolysis, propagation, and metastasis in HCC cells. Mechanistically, SLC2A1-DT enhanced the interaction of protein between ß-catenin and YWHAZ, suppressing the binding between ß-catenin and ß-TrCP, an E3 ubiquitin ligase. Thereby, SLC2A1-DT impeded the ß-TrCP-dependent ubiquitination and ß-catenin degradation. The upregulated ß-catenin activated the transcription of c-Myc, which then increased the transcription of glycolytic genes including SLC2A1, LDHA, and HK2. Additionally, we revealed that c-Myc transcriptionally induced the expression of methyltransferase 3 (METTL3), which increased N6-methyladenosine (m6A) modification and stability of SLC2A1-DT in a YTHDF1 dependent manner. Collectively, we show that the lncRNA SLC2A1-DT promotes glycolysis and HCC tumorigenesis by a m6A modification-mediated positive feedback mechanism with glycolytic regulator c-Myc and suggested as an innovative treatment option and indicator for HCC.


Assuntos
Adenina/análogos & derivados , Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Animais , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , beta Catenina/genética , beta Catenina/metabolismo , Retroalimentação , Proteínas Contendo Repetições de beta-Transducina/metabolismo , Linhagem Celular Tumoral , Carcinogênese/genética , Transformação Celular Neoplásica/genética , Glicólise/genética , Regulação Neoplásica da Expressão Gênica/genética , Proliferação de Células/genética
2.
Bioinspir Biomim ; 18(4)2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37285858

RESUMO

Particle-jamming soft robots are characterised by high flexibility in motion and high stiffness when executing a task. Regarding particle jamming of soft robots, the discrete element method (DEM)-finite element method (FEM) coupling was used for modelling and control. At first, a real-time particle-jamming soft actuator was proposed by integrating advantages of the driving Pneu-Net and the driven particle-jamming mechanism. Then, DEM and FEM were separately employed to determine the force-chain structure of the particle-jamming mechanism and the bending deformation performance of the pneumatic actuator. Furthermore, the piecewise constant curvature method was adopted for forward and inverse kinematic modelling of the particle-jamming soft robot. Finally, a prototype of the coupled particle-jamming soft robot was prepared, and a visual tracking test platform was established. The adaptive control method was proposed to compensate for the accuracy of motion trajectories. The variable-stiffness performance of the soft robot was verified by conducting stiffness tests and bending tests. The results provide novel theoretical and technical support for the modelling and control of variable-stiffness soft robots.


Assuntos
Robótica , Fenômenos Biomecânicos , Desenho de Equipamento , Fenômenos Mecânicos , Movimento (Física)
3.
IEEE Trans Neural Netw Learn Syst ; 34(5): 2659-2669, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-34495847

RESUMO

Real neural networks are characterized by large-scale and complex topology. However, the current dynamical analysis is limited to low-dimensional models with simplified topology. Therefore, there is still a huge gap between neural network theory and its application. This article proposes a class of large-scale neural networks with a ring-hub structure, where a hub node is connected to n peripheral nodes and these peripheral nodes are linked by a ring. In particular, there exists a hybrid coupling mode in the network topology. The mathematical model of such systems is described by fractional-order delayed differential equations. The aim of this article is to investigate the local stability and Hopf bifurcation of this high-dimensional neural network. First, the Coates flow graph is employed to obtain the characteristic equation of the linearized high-dimensional neural network model, which is a transcendental equation including multiple exponential items. Then, the sufficient conditions ensuring the stability of equilibrium and the existence of Hopf bifurcation are achieved by taking time delay as a bifurcation parameter. Finally, some numerical examples are given to support the theoretical results. It is revealed that the increasing time delay can effectively induce the occurrence of periodic oscillation. Moreover, the fractional order, the self-feedback coefficient, and the number of neurons also have effects on the onset of Hopf bifurcation.

4.
J Exp Clin Cancer Res ; 41(1): 69, 2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35183226

RESUMO

BACKGROUND: Glycolysis is a pivotal process in metabolic reprogramming of tumorigenesis. Previous research has indicated that lncRNAs might play crucial roles in glycolysis of various tumors. However, the function of lncRNAs in glycolysis of pancreatic cancer has not been fully elucidated. METHODS: Bio-information analyses were applied to reveal the potential glycolysis-associated lncRNA. RT-PCR and fluorescence in situ hybridization (FISH) assays were applied to detect the expression of antisense RNA1 of DICER1 (DICER1-AS1) in pancreatic cancer tissues and cell lines. Gain- and loss-of-function experiments were performed to evaluate the roles of DICER1-AS1 in glycolysis and tumorigenesis of PC. Mechanistic experiments including luciferase reporter assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) were employed to uncover the downstream targets and regulatory mechanism of DICER1-AS1 in glycolysis of PC. RESULTS: Bio-information analysis indicated that DICER1-AS1 was downregulated in PC and negatively correlated with glycolytic genes expression. Meanwhile, overexpression of DICER1-AS1 inhibited glycolysis, proliferation, and metastasis of PC cells both in vitro and in vivo. Mechanistically, DICER1-AS1 promoted transcription of its sense gene DICER1 by recruiting transcriptional factor YY1 to the DICER1 promoter. Meanwhile, DICER1 promoted maturation of miR-5586-5p which consequently inhibited glycolytic gene expression including LDHA, HK2, PGK1, and SLC2A1. Notably, enhanced interaction between N6-methyladenosine (m6A) reader YTHDF3 and DICER1-AS1 led to degradation of DICER1-AS1 in response to glucose depletion. Moreover, our data revealed that YTHDF3 was a critical target for miR-5586-5p, by which forming a negative feedback with DICER1-AS1 to regulate glycolysis of PC. CONCLUSION: Our results implicate a negative feedback of m6A reader YTHDF3 and glycolytic lncRNA DICER1-AS1 is involved in glycolysis and tumorigenesis of PC.


Assuntos
Adenosina/análogos & derivados , RNA Helicases DEAD-box/metabolismo , Neoplasias Pancreáticas/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/metabolismo , Adenosina/metabolismo , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Glicólise , Humanos , Neoplasias Pancreáticas/patologia , Transfecção
5.
Cancer Cell Int ; 21(1): 692, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930270

RESUMO

BACKGROUND: Researches indicated the process of Endothelial-Mesenchymal-Transition (EndMT) of vascular endothelial cells (ECs) was critically involved in the progression of tumor. ECs demonstrated functional and phenotypic heterogeneity when located under different microenvironments. The extracellular pH of tumor tissues was acidic compared to that of normal tissues. However, there was still unclear whether the acidic microenvironment affected the EndMT of vascular ECs. METHODS: Human Umbilical Vein Endothelial Cell (HUVECs) was cultured under the normal or acidic medium to evaluate the alteration of morphology, migration, permeability, and EndMT markers. Microarray assay was adopted to analyze the differential expression of miRNAs in the acidity-treated HUVECs. Gain- and loss- of function experiments were performed to evaluate the functional role of miRNA-548ac on acidity-induced EndMT of HUVECs. Luciferase reporter and Chromatin-immunoprecipitation assays were conducted to assess the downstream pathway of miRNA-548ac in acidity-induced EndMT of HUVECs. RESULTS: Our results showed that HUVECs demonstrated mesenchymal transition under acidic conditions with the increase of migration, permeability, and expression of α-SMA and Vimentin, but the expression of vascular endothelial cadherin (VE-cadherin) and CD31 were reduced. In addition, the acidity-treated HUVECs remarkably facilitated the transmigration of pancreatic cancer cells. The expression of miRNA-548ac was significantly decreased in the acidity-treated HUVECs. Moreover, overexpression of miR-548ac inhibited the EndMT of HUVECs and consequently impeded the transmigration of pancreatic cancer cells. The miR-548ac inhibited the expression of YB-1 by binding to the 3'UTR of its mRNA, and YB-1 promoted the translation of Snail which was a critical regulator of EndMT. What's more, Snail transcriptionally inhibited the expression of miR-548ac through binding to the promoter of its host gene. CONCLUSIONS: Our data implicated that the acidic microenvironment promoted the EndMT of HUVECs by the miR-548ac/YB-1/Snail axis, which could contribute to the metastasis of pancreatic cancer.

6.
Cancer Res ; 81(22): 5678-5691, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34593522

RESUMO

Gemcitabine (GEM) resistance is a major challenge for chemotherapy of pancreatic cancer. Previous studies have reported on the role of long noncoding RNA (lncRNA) in tumorigenesis of pancreatic cancer, however, the involvement of lncRNA in the development of GEM resistance of pancreatic cancer remains unclear. In the present study, we demonstrated that the antisense RNA1 of HIF1α (HIF1A-AS1) was significantly elevated in the GEM-resistant pancreatic cancer cells. Gain- and lost-of-function experiments validated that HIF1A-AS1 promoted GEM resistance of pancreatic cancer cells both in vitro and vivo. We further revealed that HIF1A-AS1 upregulated HIF1α expression and thus promoted glycolysis to enhance GEM resistance of pancreatic cancer cells. Mechanistically, HIF1A-AS1 facilitated the interaction between serine/threonine kinase AKT and Y-box-binding protein 1 (YB1), which promoted phosphorylation of YB1 (pYB1). Meanwhile, HIF1A-AS1 recruited pYB1 to HIF1α mRNA that consequently promoted translation of HIF1α. Furthermore, HIF1α promoted HIF1A-AS1 transcription by directly binding to the HIF1α response element in the promoter area of HIF1A-AS1 to form a positive feedback. Consistently, both HIF1A-AS1 and HIF1α were upregulated in pancreatic cancer tissues and associated with poor overall survival. Together, our results underline a reciprocal loop of HIF1A-AS1 and HIF1α that contributes to GEM resistance of pancreatic cancer and indicate that HIF1A-AS1 might serve as a novel therapeutic target for GEM resistance of pancreatic cancer. SIGNIFICANCE: These findings show that a reciprocal feedback of HIF1A-AS1 and HIF1α promotes gemcitabine resistance of pancreatic cancer, which provides an applicable therapeutic target.


Assuntos
Biomarcadores Tumorais/metabolismo , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Glicólise , Neoplasias Pancreáticas/tratamento farmacológico , RNA Longo não Codificante/genética , Animais , Antimetabólitos Antineoplásicos/farmacologia , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Desoxicitidina/farmacologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína 1 de Ligação a Y-Box/genética , Proteína 1 de Ligação a Y-Box/metabolismo , Gencitabina
7.
Cell Death Dis ; 12(9): 830, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480024

RESUMO

The majority of long non-coding RNAs (lncRNAs) have been discovered to be overexpressed in pancreatic cancer (PC) and served as promoters in the tumorigenesis of PC, while the inhibitory functions of lncRNAs in the development of PC have not been fully elucidated yet. LncRNA microarray was adopted to analyze the differential expression of lncRNAs in PC tissues and that in normal peritumoral (NP) tissues. Functional role of lncRNA BM466146.1 on PC was evaluated by gain- and loss-of-function experiments in vivo and in vitro. RNA pull-down, RNA immunoprecipitation, luciferase reporter, and Chromatin-immunoprecipitation assays were performed to assess the mechanism of ZNFTR, respectively. The correlation between the expression of ZNFTR and various clinicopathological characteristics was accessed in PC specimens. This study displayed lncRNA BM466146.1 was downregulated in PC tissues and functioned as a suppressor through regulating the expression of adjacent gene Zinc finger protein 24 (ZNF24), which was assigned as ZNFTR. Mechanistically, ZNFTR interacted with activating transcription factor 3 (ATF3) and sequestered ATF3 away from the ZNF24 promoter, which consequently increased the expression of ZNF24. Further, ZNF24 inhibited the proliferative, metastatic, and pro-angiogenic abilities of PC cells by suppressing transcription of vascular endothelial growth factor A (VEGFA). Therefore, the downregulation of ZNFTR in PC led to the decreased expression of ZNF24, which further resulted in the upregulation of VEGFA to facilitate the development of PC. Meanwhile, ZNFTR was transcriptionally inhibited by the HIF-1α/HDAC1 complex-mediated deacetylation. Clinical results further demonstrated that the low expression of ZNFTR was associated with poor overall survival time. Taken together, our results implicated that ZNFTR was a hypoxia-responsive lncRNA, and functioned as an inhibitor by modulating ATF3/ZNF24/VEGFA pathway in PC.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias Pancreáticas/genética , RNA Longo não Codificante/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Acetilação , Animais , Sequência de Bases , Hipóxia Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Histona Desacetilase 1/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias Pancreáticas/patologia , Regiões Promotoras Genéticas/genética , RNA Longo não Codificante/genética
8.
Rev Sci Instrum ; 92(4): 044709, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243432

RESUMO

A magnet system is used in the SPERF to create the magnetic field configuration for simulating the space plasma environment. In this paper, the parameters of the system are designed to achieve the target fields needed by the scaling laws, and the electromagnetic analysis has been performed to validate the results. A procedure to obtain the parameters is proposed based on the investigation into the physical and technological constraints. The vacuum magnetic fields for studying the 3D magnetic reconnection at the magnetopause, Earth's magnetosphere, and 3D magnetic reconnection driven by a plasma gun are computed. In addition, the engineering complexity is reviewed in brief. This research is crucial to the construction of the SPERF, and it is valuable to designing the magnets applied in other fields.

9.
Oncogene ; 40(36): 5505-5517, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34294845

RESUMO

Research has indicated that hypoxia profoundly contributes to chemoresistance of pancreatic cancer (PC), while the precise mechanism has not been fully elucidated. In this study, we report a hypoxic exosomal circular RNA (circRNA)-mediated mechanism of conferred chemoresistance in PC cells. Gemcitabine (GEM) resistance was enhanced in normoxic PC cells incubated with exosomes derived from hypoxic PC cells. CircRNA microarray displayed that circZNF91 was remarkably increased in hypoxic exosomes of PC cells compared with normoxic exosomes. Overexpression of circZNF91 obviously stimulated chemoresistance in PC cells, while knockdown of circZNF91 retarded the hypoxic exosome-transmitted chemoresistance. Mechanistically, the hypoxic-induced exosomal circZNF91 transmitted into normoxic PC cells could competitively bind to miR-23b-3p, which deprives the inhibition of miR-23b-3p on expression of deacetylase Sirtuin1 (SIRT1). Consequently, the upregulated SIRT1 enhanced deacetylation-dependent stability of HIF-1α protein, leading to glycolysis and GEM chemoresistance of recipient PC cells. In addition, we revealed that the increased circZNF91 in hypoxic exosome was attributed to the transcriptional regulation by HIF-1α. Coincidently, transmission of hypoxic exosomes into subcutaneous xenografts in nude mice obviously facilitated the chemoresistance of transplanted PC tumor, which could be reversed by depletion of circZNF91 or upregulation of miR-23b-3p. Furthermore, clinical data showed that circZNF91 was significantly upregulated in PC tissues and correlated with overexpression of glycolytic enzymes and short overall survival time. Collectively, exosomal circZNF91 can function as a cargo mediating the signal transmission between hypoxic and normoxic tumor cells to promote GEM chemoresistance of PC and may potentially serve as a therapeutic target.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Pancreáticas , Animais , Exossomos , Glicólise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Camundongos
10.
Theranostics ; 10(22): 10120-10140, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32929338

RESUMO

Rationale: Previous studies have reported on the role of extracellular acidity in the metastasis of numerous cancers. However, the involvement of long noncoding RNA (lncRNA) in the extracellular acidity-induced cancer metastasis of pancreatic cancer (PC) remains unclear. Methods: Different expression levels of lncRNAs in PC cells under normal and acidic conditions were compared by RNA sequencing (RNA-seq). The effects of antisense lncRNA of metastasis suppressor 1 (MTSS1-AS) on acidic PC cells were assessed by gain- and loss-of-function experiments. Fluorescence in situ hybridization, RNA immunoprecipitation, RNA pull-down, Western blot, luciferase reporter, and Chromatin immunoprecipitation assays were employed to determine the regulatory mechanisms of MTSS1-AS in the acidity-induced metastasis of PC cells. The expression of MTSS1-AS and associated pathways were compared in PC samples and peritumoral normal tissues. Results: RNA-seq demonstrated that MTSS1-AS was significantly downregulated in pancreatic cells cultured with the acidic medium. The overexpression of MTSS1-AS remarkably inhibited the acidity-promoted metastasis of PC cells by upregulating the expression of its sense gene metastasis suppressor 1 (MTSS1). Mechanistically, MTSS1-AS scaffolded the interaction between E3 ubiquitin-protein ligase STIP1 homology and U-box containing protein 1 (STUB1) and transcription regulator myeloid zinc finger 1 (MZF1), leading to ubiquitination-mediated degradation of MZF1. Further, MZF1 inhibited the expression of MTSS1 by binding to the MTSS1 promoter. Thus, the acidity-reduced MTSS1-AS facilitated the stability of MZF1 and its inhibitory effect on MTSS1 transcription, thereby promoting the metastasis of PC cells under acidic conditions. Moreover, MTSS1-AS was transcriptionally repressed by the binding of MYC proto-oncogene (Myc) with initiator (Inr) elements of the MTSS1-AS promoter. Meanwhile, MTSS1-AS mutually repressed the expression of Myc by impairing the MZF1-mediated transcription activation of Myc, thereby forming a negative feedback loop between MTSS1-AS and Myc in acidic PC cells. In accordance with the experimental results, MTSS1-AS and MTSS1 were downregulated in PC and correlated with poor overall survival. Conclusions: The results implicated that a reciprocal feedback loop between Myc and MTSS1-AS contributed to the extracellular acidity-promoted metastasis of PC, and indicated that MTSS1-AS was a valuable biomarker and therapeutic target for PC.


Assuntos
Proteínas dos Microfilamentos/genética , Metástase Neoplásica/genética , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , RNA Longo não Codificante/genética , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Retroalimentação , Humanos , Metástase Neoplásica/patologia , Regiões Promotoras Genéticas/genética , Proto-Oncogene Mas , Ativação Transcricional/genética , Regulação para Cima/genética
11.
Rev Sci Instrum ; 91(3): 034707, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32260001

RESUMO

In order to generate a current pulse with tens of milliseconds flattop time on an inductive load for pulse magnetic window technology research, a prototype of pulsed power supply is fabricated and tested. It is composed of several pulse forming units with capacitor banks and a thyristor switch and can generate a flattop current pulse by triggering sequentially the thyristor valve of pulse forming units at certain time or adjust a current waveform by altering triggering time of units. The results show that the prototype with four pulse forming units can generate a current pulse with 5 ms flattop time and 35 kA peak current, and its energy transfer efficiency is significantly higher than that of conventional circuits such as parallel capacitor banks or pulse forming networks.

12.
Theranostics ; 9(16): 4795-4810, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31367258

RESUMO

Rationale: Emerging evidences have highlighted the critical roles of lncRNAs in human cancer development. The work sought to assess the biological role and potential underlying mechanisms of lncRNA-CF129 (CF129) which is significantly reduced in pancreatic cancer (PC). Methods: CF129 expression and its association with multiple clinicopathologic characteristics in PC specimens were analyzed. The role of CF129 both in vitro and in vivo was assessed, with RNA pull-down and immunoprecipitation assays being performed to detect the interaction between CF129 and p53 and E3 ligase MKRN1. Chromatin immunoprecipitation and luciferase assays were utilized to identify the interaction between p53 and FOXC2 promoter, HIF-1α/HDAC1 complex and CF129 promoter, FOXC2 and HIF-1α promoter, respectively. Results: CF129 levels were markedly lower in PC compared with paired non-tumor adjacent tissues. Low CF129 expression predicted short overall survival in PC patients. CF129 inhibited invasion and metastasis of PC cells in a FOXC2-dependent manner. In addition, CF129 regulates FOXC2 transcription through association with mutant p53. CF129 directly binds to p53 and E3 ligase MKRN1, and such an interaction leading to p53 protein ubiquitination and degradation. Furthermore, CF129 is a hypoxia-responsive lncRNA, which is transcriptionally downregulated by binding between HIF-1α/HDAC1 complex and CF129 promoter. Finally, it is revealed that HIF-1α is reciprocally regulated by FOXC2 in transcriptional level. Clinically, CF129 downregulation coordinates overexpression of FOXC2. Conclusions: Our study suggests that CF129 inhibits pancreatic cell proliferation and invasion by suppression of FOXC2 transcription, which depends on MKRN1-mediated ubiquitin-dependent p53 degradation. The HIF-1α/CF129/ p53/FOXC2 axis may function as a potential biomarker and therapeutic target.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pancreáticas/metabolismo , RNA Longo não Codificante/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , RNA Longo não Codificante/genética , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Proteína Supressora de Tumor p53/genética
13.
Theranostics ; 9(18): 5298-5314, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31410216

RESUMO

Rationale: Hypoxia has been proved to contribute to aggressive phenotype of cancers, while functional and regulatory mechanism of long noncoding RNA (lncRNA) in the contribution of hypoxia on pancreatic cancer (PC) tumorigenesis is incompletely understood. The aim of this study was to uncover the regulatory and functional roles for hypoxia-induced lncRNA-MTA2TR (MTA2 transcriptional regulator RNA, AF083120.1) in the regulation of PC tumorigenesis. Methods: A lncRNA microarray confirmed MTA2TR expression in tissues of PC patients. The effects of MTA2TR on proliferation and metastasis of PC cells and xenograft models were determined, and the key mechanisms by which MTA2TR promotes PC were further dissected. Furthermore, the expression and regulation of MTA2TR under hypoxic conditions in PC cells were assessed. We also assessed the correlation between MTA2TR expression and PC patient clinical outcomes. Results: We found that metastasis associated protein 2 (MTA2) transcriptional regulator lncRNA (MTA2TR) was overexpressed in PC patient tissues relative to paired noncancerous tissues. Furthermore, we found that depletion of MTA2TR significantly inhibited PC cell proliferation and invasion both in vitro and in vivo. We further demonstrated that MTA2TR transcriptionally upregulates MTA2 expression by recruiting activating transcription factor 3 (ATF3) to the promoter area of MTA2. Consequentially, MTA2 can stabilize the HIF-1α protein via deacetylation, which further activates HIF-1α transcriptional activity. Interestingly, our results revealed that MTA2TR is transcriptionally regulated by HIF-1α under hypoxic conditions. Our clinical samples further indicated that the overexpression of MTA2TR was correlated with MTA2 upregulation, as well as with reduced overall survival (OS) in PC patients. Conclusions: These results suggest that feedback between MTA2TR and HIF-1α may play a key role in regulating PC tumorigenesis, thus potentially highlighting novel avenues PC treatment.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pancreáticas/genética , RNA Longo não Codificante/metabolismo , Acetilação , Fator 3 Ativador da Transcrição/metabolismo , Animais , Hipóxia Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Neoplasias Pancreáticas/patologia , Prognóstico , Regiões Promotoras Genéticas , Estabilidade Proteica , RNA Longo não Codificante/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transcrição Gênica
14.
Cancer Res ; 79(7): 1398-1412, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30563888

RESUMO

Cancer cells are known to undergo metabolic reprogramming, such as glycolysis and glutamine addiction, to sustain rapid proliferation and metastasis. It remains undefined whether long noncoding RNAs (lncRNA) coordinate the metabolic switch in pancreatic cancer. Here we identify a nuclear-enriched antisense lncRNA of glutaminase (GLS-AS) as a critical regulator involved in pancreatic cancer metabolism. GLS-AS was downregulated in pancreatic cancer tissues compared with noncancerous peritumor tissues. Depletion of GLS-AS promoted proliferation and invasion of pancreatic cancer cells both in vitro and in xenograft tumors of nude mice. GLS-AS inhibited GLS expression at the posttranscriptional level via formation of double stranded RNA with GLS pre-mRNA through ADAR/Dicer-dependent RNA interference. GLS-AS expression was transcriptionally downregulated by nutrient stress-induced Myc. Conversely, GLS-AS decreased Myc expression by impairing the GLS-mediated stability of Myc protein. These results imply a reciprocal feedback loop wherein Myc and GLS-AS regulate GLS overexpression during nutrient stress. Ectopic overexpression of GLS-AS inhibited proliferation and invasion of pancreatic cancer cells by repressing the Myc/GLS pathway. Moreover, expression of GLS-AS and GLS was inversely correlated in clinical samples of pancreatic cancer, while low expression of GLS-AS was associated with poor clinical outcomes. Collectively, our study implicates a novel lncRNA-mediated Myc/GLS pathway, which may serve as a metabolic target for pancreatic cancer therapy, and advances our understanding of the coupling role of lncRNA in nutrition stress and tumorigenesis.Significance: These findings show that lncRNA GLS-AS mediates a feedback loop of Myc and GLS, providing a potential therapeutic target for metabolic reprogramming in pancreatic cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/7/1398/F1.large.jpg.See related commentary by Mafra and Dias, p. 1302.


Assuntos
Neoplasias Pancreáticas/genética , RNA Longo não Codificante/genética , Animais , Glutaminase , Camundongos , Camundongos Nus , Nutrientes
15.
Oncogene ; 37(44): 5811-5828, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29970904

RESUMO

The contribution of long noncoding RNAs (lncRNAs) to pancreatic cancer progression and the regulatory mechanisms of their expression are attractive areas. In the present study, the overexpression of lncRNA-BX111887 (BX111) in pancreatic cancer tissues was detected by microarray and further validated in a cohort of pancreatic cancer tissues. We further demonstrated that knockdown or overexpression of BX111 dramatically repressed or enhanced proliferation and invasion of pancreatic cancer cells. Mechanically, BX111 activated transcription of ZEB1, a key regulator for epithelia-mesenchymal transition (EMT), via recruiting transcriptional factor Y-box protein (YB1) to its promoter region. Moreover, we revealed that BX111 transcription was induced by hypoxia-inducible factor (HIF-1α) in response to hypoxia. In addition, BX111 contributed to the hypoxia-induced EMT of pancreatic cells by regulating expression of ZEB1 and its downstream proteins E-cadherin and MMP2. Coincidence with in vitro results, BX111 depletion effectively inhibited growth and metastasis of xenograft tumor in vivo. The clinical samples of pancreatic cancer further confirmed a positive association between BX111 and ZEB1. Moreover, high BX111 expression was correlated with late TNM stage, lymphatic invasion and distant metastasis, as well as short overall survival time in patients. Taken together, our findings implicate a hypoxia-induced lncRNA contributes to metastasis and progression of pancreatic cancer, and suggest BX111 might be applied as a potential biomarker and therapeutic target for pancreatic cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pancreáticas/genética , RNA Longo não Codificante/fisiologia , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Animais , Hipóxia Celular , Linhagem Celular Tumoral , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Transição Epitelial-Mesenquimal/fisiologia , Humanos , Fator 1 Induzível por Hipóxia/genética , Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metástase Linfática , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/fisiopatologia , Neoplasias Pancreáticas/secundário , RNA Longo não Codificante/metabolismo , Transcrição Gênica , Proteína 1 de Ligação a Y-Box/genética , Proteína 1 de Ligação a Y-Box/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
16.
Sensors (Basel) ; 18(2)2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29364856

RESUMO

Feature recognition and fault diagnosis plays an important role in equipment safety and stable operation of rotating machinery. In order to cope with the complexity problem of the vibration signal of rotating machinery, a feature fusion model based on information entropy and probabilistic neural network is proposed in this paper. The new method first uses information entropy theory to extract three kinds of characteristics entropy in vibration signals, namely, singular spectrum entropy, power spectrum entropy, and approximate entropy. Then the feature fusion model is constructed to classify and diagnose the fault signals. The proposed approach can combine comprehensive information from different aspects and is more sensitive to the fault features. The experimental results on simulated fault signals verified better performances of our proposed approach. In real two-span rotor data, the fault detection accuracy of the new method is more than 10% higher compared with the methods using three kinds of information entropy separately. The new approach is proved to be an effective fault recognition method for rotating machinery.

17.
IEEE Access ; 6: 45617-45624, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31011504

RESUMO

The robust distributed finite time consensus of second-order multi-agent systems via pinning control has been investigated in this paper. A new nonsingular finite time TSM control method is proposed for second-order single system with disturbances. Based on the pinning error function vector, robust distributed finite time consensus of second-order multi-agent systems via pinning control method is given. Simulations results are performed to validate the effectiveness of the theoretical results.

18.
Environ Technol ; 38(3): 377-384, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27241800

RESUMO

Paramagnetic materials, such as ferric hydroxides, which are cost-effective and highly-efficient, have been little studied in relation to the magnetic separation process. In this study, freshly formed hydrous ferric oxide (HFO) sols were used to remove aqueous phosphate, followed by superconducting magnetic separation. The magnetization of HFO was determined to be 5.7 emu/g in 5.0 T. The particle size distributions ranged from 1 to 80 µm. Ferrihydrite was the primary mineral phase according to XRD analysis. Dissolved P (DP) was first adsorbed on HFO, and second, the P-containing HFO were separated by high gradient superconducting magnetic separation (HGSMS) to remove the Total P (TP). To obtain a P concentration of <0.05 mg/l in the effluent, 0.3, 1.0 and 1.3 g/l HFO were added to 2.5, 5 and 10 mg/l P solutions. The capacity of the HGSMS canister for capturing P-adsorbed HFO depends on the magnetic intensity and flow rate. In the 5.0 T HGSMS at a 1.0 cm/s flow rate, there were 75 column volumes in a single HGSMS cycle. The P concentration increased by 37.5 times after regeneration. Approximately 170 mg/l TP was measured in the backwash water.


Assuntos
Compostos Férricos/química , Fosfatos/química , Poluentes Químicos da Água/química , Adsorção , Fenômenos Magnéticos , Purificação da Água/métodos
19.
Environ Technol ; 36(19): 2495-501, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25828094

RESUMO

Several studies have focused on pollutant removal by magnetic seeding and high-gradient superconducting magnetic separation (HGSMS). However, few works reported the application of HGSMS for treating non-magnetic pollutants by an industrial large-scale system. The feasibility of turbidity removal by a 600 mm bore superconducting magnetic separation system was evaluated in this study. The processing parameters were evaluated by using a 102 mm bore superconducting magnetic separation system that was equipped with the same magnetic separation chamber that was used in the 600 mm bore system. The double-canister system was used to process water pollutants. Analytical grade magnetite was used as a magnetic seed and the turbidity of the simulated raw water was approximately 110 NTU, and the effects of polyaluminum chloride (PAC) and magnetic seeds on turbidity removal were evaluated. The use of more PAC and magnetic seeds had few advantages for the HGSMS at doses greater than 8 and 50 mg/l, respectively. A magnetic intensity of 5.0 T was beneficial for HGSMS, and increasing the flow rate through the steel wool matrix decreased the turbidity removal efficiency. In the breakthrough experiments, 90% of the turbidity was removed when 100 column volumes were not reached. The processing capacity of the 600 mm bore industry-scale superconducting magnetic separator for turbidity treatment was approximately 78.0 m(3)/h or 65.5 × 10(4) m(3)/a. The processing cost per ton of water for the 600 mm bore system was 0.1 $/t. Thus, the HGSMS separator could be used in the following special circumstances: (1) when adequate space is not available for traditional water treatment equipment, especially the sedimentation tank, and (2) when decentralized sewage treatment HGSMS systems are easier to transport and install.


Assuntos
Hidróxido de Alumínio/química , Magnetismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Floculação , Qualidade da Água
20.
Environ Technol ; 35(9-12): 1243-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24701921

RESUMO

Red mud (RM) accumulated over the years and caused a serious environmental problem. Iron-rich fraction separation is a cost-effective way to reduce the amount of disposal RM. A circulating high-gradient superconducting magnetic separator was produced in this work. Steel wool was filled in the circulating boxes. The boxes were connected by two chains, which moved in and out the magnetic field by a drive motor. The efficiency of iron-rich RM separation by the superconducting magnetic separator was investigated. An amount of 25% (w/w) iron-rich RM fractions with a grade of 65% were separated from the 56% iron content raw RM. The parameters of the steel wool matrix were important in controlling the iron-rich RM magnetic separation. Finer steel wool increased the iron recovery ratio, but decreased the grade of the iron-rich RM concentrates. Microscopic photographs of the RM particles showed that opaque mineral particles were enriched in the collected RM. The particle size distributions of raw, concentrate and residue RM were measured. The increased particle size of concentrate RM implied that large particles were entrapped in the steel wool matrix.


Assuntos
Resíduos Industriais , Fenômenos Magnéticos , Tamanho da Partícula
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