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1.
J Virol ; 98(6): e0050724, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38775482

RESUMO

Viruses employ a series of diverse translational strategies to expand their coding capacity, which produces viral proteins with common domains and entangles virus-host interactions. P3N-PIPO, which is a transcriptional slippage product from the P3 cistron, is a potyviral protein dedicated to intercellular movement. Here, we show that P3N-PIPO from watermelon mosaic virus (WMV) triggers cell death when transiently expressed in Cucumis melo accession PI 414723 carrying the Wmr resistance gene. Surprisingly, expression of the P3N domain, shared by both P3N-PIPO and P3, can alone induce cell death, whereas expression of P3 fails to activate cell death in PI 414723. Confocal microscopy analysis revealed that P3N-PIPO targets plasmodesmata (PD) and P3N associates with PD, while P3 localizes in endoplasmic reticulum in melon cells. We also found that mutations in residues L35, L38, P41, and I43 of the P3N domain individually disrupt the cell death induced by P3N-PIPO, but do not affect the PD localization of P3N-PIPO. Furthermore, WMV mutants with L35A or I43A can systemically infect PI 414723 plants. These key residues guide us to discover some WMV isolates potentially breaking the Wmr resistance. Through searching the NCBI database, we discovered some WMV isolates with variations in these key sites, and one naturally occurring I43V variation enables WMV to systemically infect PI 414723 plants. Taken together, these results demonstrate that P3N-PIPO, but not P3, is the avirulence determinant recognized by Wmr, although the shared N terminal P3N domain can alone trigger cell death.IMPORTANCEThis work reveals a novel viral avirulence (Avr) gene recognized by a resistance (R) gene. This novel viral Avr gene is special because it is a transcriptional slippage product from another virus gene, which means that their encoding proteins share the common N-terminal domain but have distinct C-terminal domains. Amazingly, we found that it is the common N-terminal domain that determines the Avr-R recognition, but only one of the viral proteins can be recognized by the R protein to induce cell death. Next, we found that these two viral proteins target different subcellular compartments. In addition, we discovered some virus isolates with variations in the common N-terminal domain and one naturally occurring variation that enables the virus to overcome the resistance. These results show how viral proteins with common domains interact with a host resistance protein and provide new evidence for the arms race between plants and viruses.


Assuntos
Doenças das Plantas , Potyvirus , Proteínas Virais , Doenças das Plantas/virologia , Potyvirus/genética , Potyvirus/patogenicidade , Proteínas Virais/genética , Proteínas Virais/metabolismo , Cucumis melo/virologia , Resistência à Doença/genética , Morte Celular , Plasmodesmos/virologia , Plasmodesmos/metabolismo , Virulência , Cucurbitaceae/virologia , Interações Hospedeiro-Patógeno , Retículo Endoplasmático/virologia , Retículo Endoplasmático/metabolismo , Mutação , Citrullus/virologia
2.
Semin Cancer Biol ; 76: 279-286, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34428550

RESUMO

MicroRNAs (miRNAs) are small endogenous non-coding RNAs that regulate cancer initiation, development, angiogenesis, and therapeutic resistance. Metal exposure widely occurs through air, water, soil, food, and industrial contaminants. Hundreds of millions of people may have metal exposure associated with toxicity, serious health problems, and cancer occurrence. Metal exposure is found to induce oxidative stress, DNA damage and repair, and activation of multiple signaling pathways. However, molecular mechanisms of metal-induced carcinogenesis remain to be elucidated. Recent studies demonstrated that the exposure of metals such as arsenic, hexavalent chromium, cadmium, and nickel caused dysregulation of microRNAs that are implicated to play an important role in cell transformation, tumor growth and angiogenesis. This review focuses on the recent studies that show metal-induced miRNA dysregulation and underlined mechanisms in cell malignant transformation, angiogenesis and tumor growth.


Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Metais/efeitos adversos , MicroRNAs , Neovascularização Patológica/induzido quimicamente , Animais , Humanos
3.
Plant Physiol ; 186(2): 853-864, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33764466

RESUMO

Cucurbits are economically important crops worldwide. The genomic data of many cucurbits are now available. However, functional analyses of cucurbit genes and noncoding RNAs have been impeded because genetic transformation is difficult for many cucurbitaceous plants. Here, we developed a set of tobacco ringspot virus (TRSV)-based vectors for gene and microRNA (miRNA) function studies in cucurbits. A TRSV-based expression vector could simultaneously express GREEN FLUORESCENT PROTEIN (GFP) and heterologous viral suppressors of RNA silencing in TRSV-infected plants, while a TRSV-based gene silencing vector could knock down endogenous genes exemplified by PHYTOENE DESATURASE (PDS) in Cucumis melo, Citrullus lanatus, Cucumis sativus, and Nicotiana benthamiana plants. We also developed a TRSV-based miRNA silencing vector to dissect the functions of endogenous miRNAs. Four representative miRNAs, namely, miR159, miR166, miR172, and miR319, from different cucurbits were inserted into the TRSV vector using a short tandem target mimic strategy and induced characteristic phenotypes in TRSV-miRNA-infected plants. This TRSV-based vector system will facilitate functional genomic studies in cucurbits.


Assuntos
Citrullus/genética , Cucumis sativus/genética , Vetores Genéticos , MicroRNAs/genética , Nepovirus/genética , Nicotiana/genética , Citrullus/virologia , Cucumis sativus/virologia , Técnicas de Silenciamento de Genes , Engenharia Genética , Proteínas de Fluorescência Verde , Oxirredutases/genética , Proteínas de Plantas/genética , Interferência de RNA , RNA de Plantas/genética , Nicotiana/virologia
4.
Int J Mol Sci ; 23(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35743145

RESUMO

The diverse repertoires of cellular mechanisms that progress certain cancer types are being uncovered by recent research and leading to more effective treatment options. Ovarian cancer (OC) is among the most difficult cancers to treat. OC has limited treatment options, especially for patients diagnosed with late-stage OC. The dysregulation of miRNAs in OC plays a significant role in tumorigenesis through the alteration of a multitude of molecular processes. The development of OC can also be due to the utilization of endogenously derived reactive oxygen species (ROS) by activating signaling pathways such as PI3K/AKT and MAPK. Both miRNAs and ROS are involved in regulating OC angiogenesis through mediating multiple angiogenic factors such as hypoxia-induced factor (HIF-1) and vascular endothelial growth factor (VEGF). The NAPDH oxidase subunit NOX4 plays an important role in inducing endogenous ROS production in OC. This review will discuss several important miRNAs, NOX4, and ROS, which contribute to therapeutic resistance in OC, highlighting the effective therapeutic potential of OC through these mechanisms.


Assuntos
MicroRNAs , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , MicroRNAs/genética , NADPH Oxidases/metabolismo , Neovascularização Patológica/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Fosfatidilinositol 3-Quinases , Espécies Reativas de Oxigênio/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Cancer Cell Int ; 21(1): 542, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34663310

RESUMO

BACKGROUND: Chemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer. METHODS: As measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms. RESULTS: We found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. CONCLUSIONS: Our data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and decreasing PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.

6.
Phys Rev Lett ; 126(23): 235501, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34170161

RESUMO

Surface triple junctions (STJs), i.e., the termination lines of grain boundaries at solid surface, are the common line defects in polycrystalline materials. Compared with planar defects such as grain boundaries and surfaces, STJ lines are usually overlooked in a material's strengthening although abundant atoms may reside at STJs in many nanomaterials. In this study, by in situ compression of coarse-grained and nanocrystalline nanoporous gold samples in an electrochemical environment, the effect of STJs on the strength of nanoporous gold was successfully decoupled from grain-boundary and surface effects. We found that the strength of nanoporous gold became sensitive to STJ modification when ligament size was decreased to below ∼100 nm, indicating that STJs started to influence ligament strength at sub-100 nm scale. This STJ effect was associated with the emission of dislocations from STJs during plastic deformation. Our findings strongly suggest that the structure and chemistry at STJs should be considered in understanding the mechanical response of sub-100 nm scale materials.

7.
Phys Rev Lett ; 127(9): 095501, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34506204

RESUMO

We report a transition from homogeneous deformation to localized densification for nanoporous gold (NPG) under compression, with its solid fraction (φ) increasing to above ∼1/3. Results obtained herein suggest that this transition is inverted compared to that of conventional porous materials. Consequently, under compression, the low-density NPGs with φ<1/3 showed evident strain hardening, whereas a stress plateau was observed for high-density NPGs with φ>1/3, which is contrary to the established notions for conventional porous materials. The ligament pinch-offs and bending-dominated structures are responsible for the homogeneous deformation of low-density NPGs. For high-density NPGs, the compression- or tension-dominated structure enables the collective strain bursts in nanoligaments, resulting in localized densification and stress plateau in their compression curves. In addition to the nanosize effect, the surface-diffusion-mediated topology evolution and the large-scale crystal-lattice coherency arising from the large grain size are also decisive to the mechanical response of dealloyed NPGs, which might be universal for self-organized nanonetwork materials.

8.
Toxicol Appl Pharmacol ; 378: 114606, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31170415

RESUMO

Inorganic arsenic is an environmental carcinogen that poses a major global public health risk. A high percentage of drinking water from wells in the U.S. contains higher-than-normal levels of arsenic, suggesting an increased risk of arsenic-induced deleterious effects. In addition to primary preventive measures, therapeutic strategies need to effectively address and integrate multiple molecular mechanisms underlying arsenic-induced carcinogenesis. We previously showed that the loss of miR-199a-5p in arsenic-transformed cells is pivotal to promote arsenic-induced angiogenesis and tumor growth in lung epithelial cells. In this study, we further showed that subacute or chronic exposure to arsenic diminished miR-199a-5p levels largely due to DNA methylation, which was achieved by increased DNA methyltransferase-1 (DNMT1) activity, mediated by the formation of specific protein 1 (Sp1)/DNMT1 complex. In addition to the DNA hypermethylation, arsenic exposure also repressed miR-199a transcription through a transcriptional repressor Sp1. We further identified an association between miR-199a-5p repression and the arsenic-mediated energy metabolic shift, as reflected by mitochondria defects and a switch to glycolysis, in which a glycolytic enzyme pyruvate kinase 2 (PKM2) was a functional target of miR-199a-5p. Taken together, the repression of miR-199a-5p through both Sp1-dependent DNA methylation and Sp1 transcriptional repression promotes an arsenic-mediated metabolic shift from mitochondria respiration to aerobic glycolysis via PKM2.


Assuntos
Arsênio/efeitos adversos , Metilação de DNA/efeitos dos fármacos , MicroRNAs/genética , Fator de Transcrição Sp1/genética , Ativação Metabólica/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Linhagem Celular , Glicólise/efeitos dos fármacos , Humanos
9.
Toxicol Appl Pharmacol ; 378: 114603, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152816

RESUMO

Hexavalent chromium [Cr(VI)] is a known occupational and environmental contaminant and carcinogen, but new mechanisms of Cr(VI)-induced carcinogenesis remain to be elucidated. In this study, we found that expression of miR-143 is decreased, whereas that of Interleukin 6 (IL-6) is increased in blood samples of Cr(VI)-exposing workers compared with corresponding unexposed workers. In addition, IL-6 was increased in human bronchial epithelial cells (BEAS-Cr) exposed to Cr(VI) compared with unexposed BEAS-2B cells. To further investigate the mechanisms by which Cr(VI) promotes these changes, we assessed the effects of miR-143 on gene expression and found that miR-143 suppressed expression of IL-6, HIF-1α and NF-κB p65, and that inhibiting miR-143 promoted expression of IL-6, HIF-1α and NF-κB p65. Interestingly, IL-6 regulated expression of HIF-1α, and HIF-1α transcriptionally regulated expression of IL-6. Experiments in animals showed that miR-143 inhibited tumor growth and angiogenesis by regulating IL-6/HIF-1α and downstream signaling pathways in vivo. These outcomes support the hypothesis that the miR-143/IL-6/HIF-1α pathway functions to regulate Cr(VI)-induced carcinogenesis.


Assuntos
Proliferação de Células/efeitos dos fármacos , Cromo/efeitos adversos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Interleucina-6/genética , MicroRNAs/genética , Fator de Transcrição RelA/genética , Animais , Brônquios/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Linhagem Celular , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , NF-kappa B/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
Mol Cancer ; 17(1): 83, 2018 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-29685157

RESUMO

BACKGROUND: Estrogen plays a critical role in breast cancer (BC) progression through estrogen receptor (ER)-mediated gene regulation. Emerging studies suggest that the malignant progress of BC cells is influenced by the cross talk between microRNAs (miRNAs) and ER-α signaling. However, the mechanism and functional linkage between estrogen and miRNAs remain unclear. METHODS: The expression levels of miR-196a and SPRED1 in BC were tested by qRT-PCR in 46 paired BC and adjacent tissues and by the GEO datasets. The role of miR-196a in estrogen-induced BC development was examined by CCK-8 assay, wound healing assay, Matrigel invasion assay and tumorigenicity assay in nude mice. The binding site of ER-α in miR-196a promoter region was analyzed by ChIP-seq, ChIP assay and luciferase reporter assay. The potential targets of miR-196a in BC cells were explored using the luciferase reporter assay and western blot analysis, and the correlation between miR-196a and SPRED1 was analyzed by Spearman's correlation analysis in BC specimens and GEO dataset. TCGA BRCA data was used to characterize the ESR1 signatures according to MSigDB gene set. RESULTS: The expression levels of miR-196a were higher in ER-positive (ER+) breast tumors compared to ER-negative (ER-) tumor tissue samples. Besides, miR-196a was involved in estrogen-induced BC cell proliferation, migration and invasion. Notably, the up-regulation of miR-196a was mediated by a direct interaction with estrogen receptor α (ER-α) but not estrogen receptor ß (ER-ß) in its promoter region, and miR-196a expression levels were positively correlated to ER-α signature scores. Furthermore, SPRED1 was a new direct target of miR-196a which participated in miR-196a-promoted BC development and was suppressed by ligand-activated ER-α signal pathway. Finally, forced expression of miR-196a induced tumor growth of MCF7 cells, while inhibition of miR-196a significantly suppressed the tumor progress in vivo. CONCLUSIONS: Overall, the identification of estrogen/miR-196a/SPRED1 cascade will shed light on new molecular mechanism of estrogen signaling in BC development and therapy.


Assuntos
Neoplasias da Mama/patologia , Estrogênios/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal , Animais , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , MicroRNAs/química , Metástase Neoplásica , Transplante de Neoplasias , Transdução de Sinais
11.
Molecules ; 23(5)2018 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-29748523

RESUMO

Two unprecedented homometallic CoII and ZnII coordination compounds, [M2(L)(OCH3)][M2(L)(OAc)] (MII = CoII (1) and ZnII (2)), with a novel symmetric bis(salamo)-like tetraoxime ligand H3L were synthesized and characterized by elemental analyses, infrafred (IR), ultraviolet⁻visible spectroscopy (UV-Vis), fluorescent spectra and single-crystal X-ray diffraction analyses. The unit cell of the two coordination compounds contains two crystallographically and chemically independent dinuclear coordination compounds. In the two coordination compounds, three metal ions are five-coordinated, formed two square pyramidal and a trigonal bipyramidal geometries, and the other metal ion is a hexacoordinate octahedral configuration. In addition, the coordination compound 1 forms a 3D supramolecular structure, and the coordination compound 2 forms a 0D dimer structure by the inter-molecular hydrogen bond interactions. Meanwhile, the fluorescence spectra of the coordination compounds 1 and 2 were also measured and discussed.


Assuntos
Cobalto/química , Complexos de Coordenação/química , Oximas/química , Zinco/química , Cristalografia por Raios X , Dimerização , Ligação de Hidrogênio , Conformação Molecular , Espectrometria de Fluorescência , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta
12.
Molecules ; 23(4)2018 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-29614741

RESUMO

[Co2(L)Ce(OAc)3(CH3CH2OH)]·1.5CH3OH∙0.5CH2Cl2, a heterotrinuclear Co(II)-Ce(III) bis(salamo)-type complex with a symmetric bi(salamo)-type ligand H4L and an acyclic naphthalenediol moiety, was designed, synthesized and characterized by elemental analyses, FT-IR, UV-Vis and fluorescence spectroscopy and X-ray crystallography. The X-ray crystallographic investigation revealed the heterotrinuclear complex consisted of two Co(II) atoms, one Ce(III) atom, one (L)4‒ unit, three µ2-acetate ions, one coordinated ethanol molecule, one and half crystallization methanol molecule and half crystallization dichloromethane molecule. Two Co(II) atoms located in the N2O2 coordination spheres, are both hexacoordinated, with slightly distorted octahedral geometries. The Ce(III) atom is nine-coordinated and located in the O6 cavity possesses a single square antiprismatic geometry. In addition, supramolecular interactions exist in the Co(II)-Ce(III) complex. Two infinite 2D supramolecular structures are built via intermolecular O-H···O, C-H···O and C-H···π interactions, respectively.


Assuntos
Cério/química , Cobalto/química , Complexos de Coordenação/síntese química , Oximas/química , Complexos de Coordenação/química , Cristalografia por Raios X , Fluorescência , Ligação de Hidrogênio , Ligantes , Espectrometria de Fluorescência
14.
Nanotechnology ; 27(32): 325501, 2016 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-27347850

RESUMO

Many biological materials can readily modulate their mechanical properties and shape by interacting with water in the surrounding environment, which is essential to their high performance in application. In contrast, typical inorganic materials (such as the metals) cannot change their strength and shape without involving thermal/mechanical treatments. By introducing nano-scale porous structure and exploiting a simple physical concept-the water-capillarity in nanopores, here we report that a 'dead' metal can be transformed into a 'smart' material with water-responsive properties. We demonstrate that the apparent strength, volume and shape of nanoporous Au and Au(Pt) can be modulated in situ, dramatically and recoverably, in response to water-dipping and partial-drying. The amplitude of strength-modulation reaches 20 MPa, which is nearly 50% of the yield strength at initial state. This approach also leads to reversible length change up to 1.3% in nanoporous Au and a large reversible bending motion of a bi-layer strip with tip displacement of ∼20 mm, which may be used for actuation. This method is simple and effective, occurring in situ under ambient conditions and requiring no external power, analogous to biological materials. The findings may open up novel applications in many areas such as micro-robotics and bio-medical devices.

15.
Inorg Chem ; 54(21): 10316-22, 2015 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-26473654

RESUMO

Three isostructural cyano-bridged 3d-4f compounds, [YFe(CN)6(hep)2(H2O)4] (1), [DyFe(CN)6(hep)2(H2O)4] (2), and [DyCo(CN)6(hep)2(H2O)4] (3), were successfully assembled by site-targeted substitution of the 3d or rare-earth ions. All compounds have been structurally characterized to display slightly distorted pentagonal-bipyramidal local coordination geometry around the rare-earth ions. Magnetic analyses revealed negligible magnetic coupling in compound 1, antiferromagnetic intradimer interaction in 2, and weak ferromagnetic coupling through dipolar-dipolar interaction in 3. Under an applied direct-current (dc) field, 1 (Hdc = 2.5 kOe, τ0 = 1.3 × 10(-7) s, and Ueff/kB = 23 K) and 3 (Hdc = 2.0 kOe, τ0 = 7.1 × 10(-11) s, and Ueff/kB = 63 K) respectively indicated magnetic relaxation behavior based on a single [Fe(III)]LS ion and a Dy(III) ion; nevertheless, 2 (Hdc = 2.0 kOe, τ0 = 9.7 × 10(-8) s, and Ueff/kB = 23 K) appeared to be a single-molecule magnet based on a cyano-bridged DyFe dimer. Compound 1, which can be regarded as a single-ion magnet of the [Fe(III)]LS ion linked to a diamagnetic Y(III) ion in a cyano-bridged heterodimer, represents one of the rarely investigated examples based on a single Fe(III) ion explored in magnetic relaxation behavior. It demonstrated that the introduction of intradimer magnetic interaction of 2 through a cyano bridge between Dy(III) and [Fe(III)]LS ions negatively affects the energy barrier and χ″(T) peak temperature compared to 3.

16.
Biochim Biophys Acta ; 1829(2): 239-47, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23201159

RESUMO

MicroRNA-145 (miR-145) is downregulated in various tumor types. However, its mechanism in inhibiting tumor growth and angiogenesis remains to be elucidated. In this study, we found that miR-145 was significantly downregulated in the plasma and cancer tumor tissues of colorectal cancer (CRC) patients, and overexpression of miR-145 inhibited cell proliferation, migration and invasion. To understand the potential mechanism of miR-145 in inhibiting tumor growth, we showed that miR-145 blocked the activation of AKT and ERK1/2 pathways, and the expression of HIF-1 and VEGF via directly targeting N-RAS and IRS1, and VEGF is an important effector for tumor growth. Forced expression of N-RAS and IRS1 restored VEGF expression via transcriptional activation. MiR-145 also inhibited N-RAS and IRS1 expression to suppress AKT and ERK1/2 activation, and VEGF expression in mouse xenograft tumors. To test the clinical relevance of these results, we used 60 pairs of colorectal cancer tissues and adjacent normal tissues, analyzed the levels of miR-145, N-RAS and IRS1 expression in these tissues, and found that miR-145 levels were significantly inversely correlated with N-RAS and IRS1 levels in these colorectal cancer tissues, suggesting the important implication of our findings in translational application for colorectal cancer diagnostics and treatment in the future.


Assuntos
Neoplasias Colorretais , Proteínas Substratos do Receptor de Insulina , MicroRNAs , Fator A de Crescimento do Endotélio Vascular , Proteínas ras , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Transformação Celular Neoplásica , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Camundongos , MicroRNAs/sangue , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Neovascularização Patológica , Proteína Oncogênica v-akt/metabolismo , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
17.
Biochim Biophys Acta ; 1833(12): 3375-3385, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24113386

RESUMO

Excessive generation of reactive oxygen species (ROS) in cancer cells is associated with cancer development, but the underlying mechanisms and therapeutic significance remain elusive. In this study, we reported that levels of ROS and p22(phox) expression are greatly increased in human prostate cancer tissues, and knockdown of p22(phox) by specific small interfering RNA (siRNA) decreased ROS levels in prostate cancer cells. We also showed that stable downregulation of p22(phox) in prostate cancer cells inhibited cell proliferation and colony formation, which was mediated by AKT and extracellular signal-regulated kinase (ERK)1/2 signaling pathways and their downstream molecules hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF). The NADPH oxidase subunit NOX1 was also elevated in prostate cancer cells, and was involved in activation of AKT/ERK/HIF-1/VEGF pathway and regulation of cell proliferation. Knockdown of p22(phox) resulted in inhibition of tumor angiogenesis and tumor growth in nude mice. These findings reveal a new function of p22(phox) in tumor angiogenesis and tumor growth, and suggest that p22(phox) is a potential novel target for prostate cancer treatment.


Assuntos
Sistema de Sinalização das MAP Quinases , NADPH Oxidases/metabolismo , Neovascularização Patológica/enzimologia , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/enzimologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Técnicas de Silenciamento de Genes , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Nus , Neovascularização Patológica/patologia , Neoplasias da Próstata/patologia , Ensaio Tumoral de Célula-Tronco , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
EMBO Rep ; 13(12): 1116-22, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23146892

RESUMO

Overexpression of ERBB2 or ERBB3 is associated with cancer development and poor prognosis. In this study, we show that reactive oxygen species (ROS) induce both ERBB2 and ERBB3 expression in vitro and in vivo. We also identify that miR-199a and miR-125b target ERBB2 and/or ERBB3 in ovarian cancer cells, and demonstrate that ROS inhibit miR-199a and miR-125b expression through increasing the promoter methylation of the miR-199a and miR-125b genes by DNA methyltransferase 1. These findings reveal that ERBB2 and ERBB3 expression is regulated by ROS via miR-199a and miR-125b downregulation and DNA hypermethylation.


Assuntos
MicroRNAs , Neoplasias Ovarianas , Espécies Reativas de Oxigênio , Receptor ErbB-2 , Receptor ErbB-3/genética , Alantoide/crescimento & desenvolvimento , Animais , Linhagem Celular Tumoral/efeitos dos fármacos , Galinhas , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA/efeitos dos fármacos , Feminino , Fluoresceínas/química , Fluoresceínas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo
19.
Nucleic Acids Res ; 40(2): 761-74, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21917858

RESUMO

MiR-145 can regulate cell apoptosis, proliferation, neural development and stem cell differentiation. Previous studies indicate that miR-145 is downregulated in human colon cancer cells. However, the molecular mechanisms of miR-145 used to regulate colon carcinogenesis and angiogenesis remain to be clarified. Here, we show that the expression of miR-145 is downregulated in colon and ovarian cancer tissues and cell lines. MiR-145 inhibits p70S6K1 post-transcriptional expression by binding to its 3'-UTR. The angiogenic factors hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF), which are downstream molecules of p70S6K1, are decreased by miR-145 overexpression. P70S6K1 rescues miR-145-suppressed HIF-1 and VEGF levels, tumorigenesis and tumor angiogenesis. Furthermore, the miR-145 level is inversely correlated with the amount of p70S6K1 protein in colon cancer tissues. Taken together, these studies suggest that miR-145 serves as a tumor suppressor which downregulates HIF-1 and VEGF expression by targeting p70S6K1, leading to the inhibition of tumor growth and angiogenesis. The miR-145 rescue could be a rationale for therapeutic applications in colon cancer in the future.


Assuntos
Neoplasias do Colo/genética , MicroRNAs/metabolismo , Neovascularização Patológica/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Regiões 3' não Traduzidas , Animais , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/metabolismo , Regulação para Baixo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Nus , Neovascularização Patológica/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Food Chem ; 441: 138357, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38199109

RESUMO

Neonicotinoids, the fastest-growing class of insecticides, have posed a multi-media residue problem with adverse effects on environment, biodiversity and human health. Herein, covalent organic framework-sodium alginate-Ca2+-polyacrylic acid composite beads (CACPs), facilely prepared at room temperature, were used in convenient dispersive solid-phase extraction (dSPE) and combined with high-performance liquid chromatography (HPLC) for the detection of five neonicotinoid insecticides (thiamethoxam, acetamiprid, dinotefuran, clothianidin, imidacloprid). CACPs can be completely separated within 1 min without centrifugation. After seven adsorption/desorption cycles, it maintained high extraction efficiencies (>90%). The developed method exhibited a wide linear range (0.01 âˆ¼ 10 µg mL-1), low limits of detection (LODs, 0.0028 âˆ¼ 0.0031 mg kg-1), and good repeatability (RSD ≤ 8.11%, n = 3). Moreover, it was applied to the determination of five neonicotinoids in fruit and vegetables (peach, pear, lettuce, cucumber, tomato), and recoveries ranged from 73.6% to 116.2%.


Assuntos
Resinas Acrílicas , Inseticidas , Estruturas Metalorgânicas , Humanos , Inseticidas/análise , Verduras/química , Estruturas Metalorgânicas/análise , Frutas/química , Neonicotinoides/análise , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão/métodos
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