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1.
Gastric Cancer ; 24(2): 402-416, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33159601

RESUMO

BACKGROUND: Aberrant activation of Wnt/ß-catenin signaling by dysregulated post-translational protein modifications, especially ubiquitination is causally linked to cancer development and progression. Although Lys48-linked ubiquitination is known to regulate Wnt/ß-catenin signaling, it remains largely obscure how other types of ubiquitination, such as linear ubiquitination governs its signaling activity. METHODS: The expression and regulatory mechanism of linear ubiquitin chain assembly complex (LUBAC) on Wnt/ß-catenin signaling was examined by immunoprecipitation, western blot and immunohistochemical staining. The ubiquitination status of ß-catenin was detected by ubiquitination assay. The impacts of SHARPIN, a core component of LUBAC on malignant behaviors of gastric cancer cells were determined by various functional assays in vitro and in vivo. RESULTS: Unlike a canonical role in promoting linear ubiquitination, SHARPIN specifically interacts with ß-catenin to maintain its protein stability. Mechanistically, SHARPIN competes with the E3 ubiquitin ligase ß-Trcp1 for ß-catenin binding, thereby decreasing ß-catenin ubiquitination levels to abolish its proteasomal degradation. Importantly, SHARPIN is required for invasiveness and malignant growth of gastric cancer cells in vitro and in vivo, a function that is largely dependent on its binding partner ß-catenin. In line with these findings, elevated expression of SHARPIN in gastric cancer tissues is associated with disease malignancy and correlates with ß-catenin expression levels. CONCLUSIONS: Our findings reveal a novel molecular link connecting linear ubiquitination machinery and Wnt/ß-catenin signaling via SHARPIN-mediated stabilization of ß-catenin. Targeting the linear ubiquitination-independent function of SHARPIN could be exploited to inhibit the hyperactive ß-catenin signaling in a subset of human gastric cancers.


Assuntos
Carcinogênese/genética , Neoplasias Gástricas/genética , Ubiquitinação/genética , Ubiquitinas/genética , beta Catenina/genética , Humanos , Via de Sinalização Wnt/genética
2.
Med Sci Monit ; 26: e919896, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32090983

RESUMO

BACKGROUND Angiogenic factor with G patch and FHA domains 1 (AGGF1) is a novel identified initiator of angiogenesis through promoting the proliferation of endothelial cells. The continuous angiogenesis plays a key role in the growth, invasion, and metastasis of hepatocellular carcinoma (HCC), while the diagnostic and prognostic roles of AGGF1 for HCC need to be further studied. MATERIAL AND METHODS The mRNA sequencing datasets and clinical features of HCC patients were extracted from The Cancer Genome Atlas database. The relationship between clinical features and AGGF1 expression was analyzed by Wilcoxon test. Further validation explorations were carried out using online database Oncomine. The diagnostic receiver operating characteristic curves of AGGF1 and alpha-fetoprotein were compared to examine the diagnostic efficacy of AGGF1. Survival analysis and Gene Set Enrichment Analysis were performed to explore the prediction value and potential mechanism of AGGF1 dysregulation in HCC. RESULTS Comprehensive overexpression of AGGF1 was observed in HCC, correlating with poor overall survival. Upregulated level of AGGF1 was statistically associated with poor differentiated histological grade, advanced cancer stage and T classification. AGGF1 was a more effective diagnostic marker than alpha-fetoprotein in HCC. Several important pathways related to HCC including pathway in cancer and P53 signaling pathway were differentially enriched in the high AGGF1 expression phenotype. CONCLUSIONS AGGF1 was a potential diagnostic and prognostic marker for poor clinical outcomes in HCC patients. Moreover, vital pathways regulated by AGGF1 in HCC may include regulation of autophagy, Wnt signaling pathway, pathway in cancer, cell cycle, and P53 signaling pathway.


Assuntos
Proteínas Angiogênicas/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Biologia Computacional , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Fenótipo , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais
3.
Neurochem Res ; 42(2): 360-374, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27743286

RESUMO

Temporal lobe epilepsy (TLE) is one of the most refractory types of adult epilepsy, and treatment options remain unsatisfactory. Gastrodin (GAS), a phenolic glucoside used in Chinese herbal medicine and derived from Gastrodia elata Blume, has been shown to have remarkable anticonvulsant effects on various models of epilepsy in vivo. However, the mechanisms of GAS as an anticonvulsant drug remain to be established. By utilizing a combination of behavioral surveys, immunofluorescence and electrophysiological recordings, the present study characterized the anticonvulsant effect of GAS in a pilocarpine-induced status epilepticus (SE) rat model of TLE and explored the underlying cellular mechanisms. We found that GAS pretreatment effectively reduced the severity of SE in the acute phase of TLE. Moreover, GAS protected medial entorhinal cortex (mEC) layer III neurons from neuronal death and terminated the SE-induced bursting discharge of mEC layer II neurons from SE-experienced rats. Furthermore, the current study revealed that GAS prevented the pilocarpine-induced enhancement of Nav1.6 currents (persistent (INaP) and resurgent (INaR) currents), which were reported to play a critical role in the generation of bursting spikes. Consistent with this result, GAS treatment reversed the expression of Nav1.6 protein in SE-experienced EC neurons. These results suggest that the inhibition of Nav1.6 sodium currents may be the underlying mechanism of GAS's anticonvulsant properties.


Assuntos
Álcoois Benzílicos/uso terapêutico , Epilepsia do Lobo Temporal/tratamento farmacológico , Glucosídeos/uso terapêutico , Canal de Sódio Disparado por Voltagem NAV1.6/fisiologia , Pilocarpina/toxicidade , Bloqueadores dos Canais de Sódio/uso terapêutico , Estado Epiléptico/tratamento farmacológico , Animais , Álcoois Benzílicos/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Epilepsia do Lobo Temporal/fisiopatologia , Glucosídeos/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Bloqueadores dos Canais de Sódio/farmacologia , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/fisiopatologia
4.
Front Med (Lausanne) ; 9: 834159, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35252265

RESUMO

BACKGROUND: There is an urgent need for non-invasive methods for predicting portal hypertensive gastropathy (PHG). This study aims to develop and validate a non-invasive method based on clinical parameters for predicting PHG in patients with liver cirrhosis (LC). METHODS: The overall survival (OS) and hepatocellular carcinoma (HCC)-free survival were evaluated in LC patients, both with and without PHG. A prediction model for PHG was then constructed based on a training dataset that contained data on 492 LC patients. The discrimination, calibration, and clinical utility of the predicting nomogram were assessed using the C-index, calibration plot, and decision curve analysis. Internal validation was conducted using a bootstrapping method, and further external validation using data on the 208 other patients. RESULTS: LC patients with PHG had a worse prognosis compared with those without PHG. A nomogram was constructed using clinical parameters, such as age, hemoglobin content, platelet count and Child-Pugh class. The C-index was 0.773 (95% CI: 0.730-0.816) in the training cohort, 0.761 after bootstrapping and 0.745 (95% CI: 0.673-0.817) in the validation cohort. The AUC values were 0.767, 0.724, and 0.756 in the training, validation and total cohorts, respectively. Well-fitted calibration curves were observed in the training and validation cohorts. Decision curve analysis demonstrated that the nomogram was clinically useful at a threshold of 15%. CONCLUSION: The nomogram constructed to predict the risk of developing PHG was found to be clinically viable. Furthermore, PHG is an independent risk factor for OS of LC, but not for the occurrence of HCC.

5.
Gastroenterol Res Pract ; 2020: 2357840, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32328093

RESUMO

AIM: To develop and validate a simple-to-use nomogram for prediction of 3-/5-year survival in patients with N0M0 hepatocellular carcinoma after curative liver resection. Patients and Methods. Patients diagnosed HCC with hepatic resection in the Surveillance, Epidemiology, and End Results (SEER) database were included to identify prognostic factors of overall survival. Multivariate Cox regression were used to create a nomogram. RESULTS: We identified 4856 HCC with hepatic resection from the SEER database. A nomogram to predict long-term survival with a C-index 0.667 (95% CI, 0.653 to 0.681) is more efficient than TNM staging with a lower C-index 0.613 (95% CI, 0.597 to 0.629). The C-index was confirmed to be 0.663 (95% CI, 0.640 to 0.686) through validation, suggesting a good discrimination and a good prediction capability. CONCLUSIONS: The nomogram is a simple and effective screening tool for assessing the prognosis of HCC with hepatic resection and assists with the planning of individual postoperative surveillance protocols.

6.
Cancer Res ; 79(19): 4869-4881, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311807

RESUMO

Cancer metastasis, a leading cause of death in patients, is associated with aberrant expression of epigenetic modifiers, yet it remains poorly defined how epigenetic readers drive metastatic growth and whether epigenetic readers are targetable to control metastasis. Here, we report that bromodomain-containing protein 4 (BRD4), a histone acetylation reader and emerging anticancer therapeutic target, promotes progression and metastasis of gastric cancer. The abundance of BRD4 in human gastric cancer tissues correlated with shortened metastasis-free gastric cancer patient survival. Consistently, BRD4 maintained invasiveness of cancer cells in vitro and their dissemination at distal organs in vivo. Surprisingly, BRD4 function in this context was independent of its putative transcriptional targets such as MYC or BCL2, but rather through stabilization of Snail at posttranslational levels. In an acetylation-dependent manner, BRD4 recognized acetylated lysine 146 (K146) and K187 on Snail to prevent Snail recognition by its E3 ubiquitin ligases FBXL14 and ß-Trcp1, thereby inhibiting Snail polyubiquitination and proteasomal degradation. Accordingly, genome-wide transcriptome analyses identified that BRD4 and Snail regulate a partially shared metastatic gene signature in gastric cancer cells. These findings reveal a noncanonical posttranscriptional regulatory function of BRD4 in maintaining cancer growth and dissemination, with immediate translational implications for treating gastric metastatic malignancies with clinically available bromodomain inhibitors. SIGNIFICANCE: These findings reveal a novel posttranscriptional regulatory function of the epigenetic reader BRD4 in cancer metastasis via stabilizing Snail, with immediate translational implication for treating metastatic malignancies with clinically available bromodomain inhibitors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/19/4869/F1.large.jpg.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Invasividade Neoplásica/patologia , Fatores de Transcrição da Família Snail/metabolismo , Neoplasias Gástricas/patologia , Fatores de Transcrição/metabolismo , Acetilação , Animais , Progressão da Doença , Epigênese Genética/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Camundongos , Transcriptoma
7.
Opt Express ; 15(26): 18357-69, 2007 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-19551134

RESUMO

All-optical on-off keying (OOK) to binary phase-shift keying (BPSK) modulation format conversion based on gain-transparent semiconductor optical amplifier (GT-SOA) is simulated and analyzed, where GT-SOA is used as an all-optical phase-modulator (PM). Numerical simulation of the phase modulation effect of GT-SOA is performed using a wideband dynamic model of GT-SOA and the quality of the BPSK signal is evaluated using the differential-phase-Q factor. Performance improvement by holding light injection is analyzed and non-return-to-zero (NRZ) and return-to-zero (RZ) modulation formats of the OOK signal are considered.


Assuntos
Lasers , Fibras Ópticas , Refratometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Telecomunicações/instrumentação , Transdutores , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Semicondutores , Sensibilidade e Especificidade
8.
IEEE Trans Image Process ; 16(7): 1831-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17605381

RESUMO

With the development of numerous imaging sensors, many images can be simultaneously pictured by various sensors. However, there are many scenarios where no one sensor can give the complete picture. Image fusion is an important approach to solve this problem and produces a single image which preserves all relevant information from a set of different sensors. In this paper, we proposed a new image fusion method using the support value transform, which uses the support value to represent the salient features of image. This is based on the fact that, in support vector machines (SVMs), the data with larger support values have a physical meaning in the sense that they reveal relative more importance of the data points for contributing to the SVM model. The mapped least squares SVM (mapped LS-SVM) is used to efficiently compute the support values of image. The support value analysis is developed by using a series of multiscale support value filters, which are obtained by filling zeros in the basic support value filter deduced from the mapped LS-SVM to match the resolution of the desired level. Compared with the widely used image fusion methods, such as the Laplacian pyramid, discrete wavelet transform methods, the proposed method is an undecimated transform-based approach. The fusion experiments are undertaken on multisource images. The results demonstrate that the proposed approach is effective and is superior to the conventional image fusion methods in terms of the pertained quantitative fusion evaluation indexes, such as quality of visual information (Q(AB/F)), the mutual information, etc.


Assuntos
Algoritmos , Inteligência Artificial , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Reconhecimento Automatizado de Padrão/métodos , Técnica de Subtração
9.
Opt Express ; 14(24): 11839-47, 2006 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-19529607

RESUMO

A novel scheme for an ultrahigh-speed all-optical half adder based on four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is proposed. This scheme is free of pattern effect, due to using the polarization-shift-keying (PolSK) modulation format. By numerical simulation, the output power level of logic "1" dependence on the operating conditions, such as two input signal powers, injection current, and input signal wavelength, are investigated in detail using the broad-band model of this all-optical half adder.

10.
Neuroscience ; 337: 355-369, 2016 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-27670903

RESUMO

Rhynchophylline (RIN) is a significant active component isolated from the Chinese herbal medicine Uncaria rhynchophylla. Several studies have demonstrated that RIN has a significant anticonvulsant effect in many types of epilepsy models in vivo. However, the mechanisms of the anticonvulsant effect remain elusive. Using combined methods of behavioral testing, immunofluorescence and electrophysiological recordings, we characterized the anticonvulsant effect of RIN in a pilocarpine-induced status epilepticus (SE) rat model of temporal lobe epilepsy (TLE) and investigated the underlying cellular mechanisms. In one set of experiments, rats received RIN treatment prior to pilocarpine injection. In a second set of experiments, rats received RIN treatment following the onset of stage 3 seizures. Pretreatment and posttreatment with RIN effectively reduced the seizure severity in the acute phase of TLE. Furthermore, RIN protected medial entorhinal cortex (mEC) layer III neurons from neuronal death and terminated spontaneous epileptiform discharge of mEC layer II neurons in SE-experienced rats. Whole-cell voltage-clamp recordings indicated that RIN inhibited neuronal hyperexcitability via inhibition of the persistent sodium current (INaP) and NMDA receptor current. Immunofluorescence experiments also demonstrated that RIN rectified the pilocarpine-induced upregulation of Nav1.6 and NR2B protein expression. In conclusion, our results identified RIN as an anticonvulsant agent that inhibited ictal discharge via INap and NMDA receptor current inhibition.


Assuntos
Anticonvulsivantes/farmacologia , Epilepsia do Lobo Temporal/tratamento farmacológico , Alcaloides Indólicos/farmacologia , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Sódio/metabolismo , Animais , Modelos Animais de Doenças , Córtex Entorrinal/efeitos dos fármacos , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Neurônios/metabolismo , Oxindóis , Pilocarpina/farmacologia , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Estado Epiléptico/induzido quimicamente
11.
Amyloid ; 22(1): 36-44, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25472656

RESUMO

Abnormal accumulation of soluble amyloid beta (Aß) is believed to cause malfunction of neurons in Alzheimer's disease (AD). The hippocampus is one of the earliest affected brain regions in AD. However, little effort has been made to investigate the effects of soluble Aß1-42 oligomers on discharge properties of hippocampal neurons in vivo. This study was designed to examine the effects of soluble Aß1-42 oligomers on the discharge properties of hippocampal CA1 neurons using extracellular single-unit recordings in vivo. The protective effects of riluzole (RLZ) were also investigated for the prevention of soluble oligomers of Aß1-42-induced alterations in the spontaneous discharge of hippocampal neurons. The results showed that (1) the mean frequency of spontaneous discharge was increased by the local application of 100 µM Aß1-42 oligomers; (2) Aß1-42 oligomers also induced alterations of the neuronal firing patterns in the hippocampal CA1 region; and (3) pretreatment with 20 µM RLZ effectively inhibited the Aß1-42-induced enhancement of spontaneous discharge and alterations of neuronal firing patterns in CA1 neurons. Our study suggested that Aß1-42 oligomers induced hyperactivity and perturbed the firing patterns in hippocampal neurons. RLZ may provide neuroprotective effects on the Aß1-42-induced perturbation of neuronal activities in the hippocampal region of rats.


Assuntos
Peptídeos beta-Amiloides/fisiologia , Região CA1 Hipocampal/fisiopatologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/fisiologia , Riluzol/farmacologia , Potenciais de Ação , Doença de Alzheimer/tratamento farmacológico , Animais , Região CA1 Hipocampal/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Masculino , Ratos Sprague-Dawley
12.
Comput Vis Image Underst ; 114(7): 827-834, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28250706

RESUMO

In this paper we propose a novel framework for contour based object detection from cluttered environments. Given a contour model for a class of objects, it is first decomposed into fragments hierarchically. Then, we group these fragments into part bundles, where a part bundle can contain overlapping fragments. Given a new image with set of edge fragments we develop an efficient voting method using local shape similarity between part bundles and edge fragments that generates high quality candidate part configurations. We then use global shape similarity between the part configurations and the model contour to find optimal configuration. Furthermore, we show that appearance information can be used for improving detection for objects with distinctive texture when model contour does not sufficiently capture deformation of the objects.

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