Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 123
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Liver Int ; 44(4): 979-995, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38293784

RESUMO

BACKGROUND & AIMS: Accumulating evidences suggest tumour microenvironment (TME) profoundly influence clinical outcome in hepatocellular carcinoma (HCC). Existing immune subtypes are susceptible to batch effects, and integrative analysis of bulk and single-cell transcriptome is helpful to recognize immune subtypes and TME in HCC. METHODS: Based on the relative expression ordering (REO) of 1259 immune-related genes, an immuno-prognostic signature was developed and validated in 907 HCC samples from five bulk transcriptomic cohorts, including 72 in-house samples. The machine learning models based on subtype-specific gene pairs with stable REOs were constructed to jointly predict immuno-prognostic subtypes in single-cell RNA-seq data and validated in another single-cell data. Then, cancer characteristics, immune landscape, underlying mechanism and therapeutic benefits between subtypes were analysed. RESULTS: An immune-related signature with 29 gene pairs stratified HCC samples individually into two risk subgroups (C1 and C2), which was an independent prognostic factor for overall survival. The machine learning models verified the immune subtypes from five bulk cohorts to two single-cell transcriptomic data. Integrative analysis revealed that C1 had poorer outcomes, higher CNV burden and malignant scores, higher sensitivity to sorafenib, and exhibited an immunosuppressive phenotype with more regulators, e.g., myeloid-derived suppressor cells (MDSCs), Mø_SPP1, while C2 was characterized with better outcomes, higher metabolism, more benefit from immunotherapy, and displayed active immune with more effectors, e.g., tumour infiltrating lymphocyte and dendritic cell. Moreover, both two single-cell data revealed the crosstalk of SPP1-related L-R pairs between cancer and immune cells, especially SPP1-CD44, might lead to immunosuppression in C1. CONCLUSIONS: The REO-based immuno-prognostic subtypes were conducive to individualized prognosis prediction and treatment options for HCC. This study paved the way for understanding TME heterogeneity between immuno-prognostic subtypes of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Transcriptoma , Microambiente Tumoral/genética , Neoplasias Hepáticas/genética , Prognóstico
2.
J Stroke Cerebrovasc Dis ; 33(7): 107738, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38701940

RESUMO

OBJECTIVES: Edaravone dexborneol is neuroprotective against ischemic stroke, with free radical-scavenging and anti-inflammatory effects, but its effects in hemorrhagic stroke remain unclear. We evaluated whether edaravone dexborneol has a neuroprotective effect in intracerebral hemorrhage, and its underlying mechanisms. MATERIALS AND METHODS: Bioinformatics were used to predict the pathway of action of edaravone dexborneol. An intracerebral hemorrhage model was established using type IV collagenase in edaravone dexborneol, intracerebral hemorrhage, Sham, adeno-associated virus + edaravone dexborneol, and adeno-associated virus + intracerebral hemorrhage groups. The modified Neurological Severity Score was used to evaluate neurological function in rats. Brain water content was measured using the dry-wet weight method. Tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide synthase, and γ-aminobutyric acid levels were determined by enzyme-linked immunosorbent assay. The expression levels of neurofilament light chain and γ-aminobutyric acid transaminase were determined by western blot. Nissl staining was used to examine neuronal morphology. Cognitive behavior was evaluated using a small-animal treadmill. RESULTS: Edaravone dexborneol alleviated neurological defects, improved cognitive function, and reduced cerebral edema, neuronal degeneration, and necrosis in rats with cerebral hemorrhage. The expression levels of neurofilament light chain, tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide synthase, and γ-aminobutyric acid were decreased, while γ-aminobutyric acid transaminase expression was up-regulated. CONCLUSIONS: Edaravone dexborneol regulates γ-aminobutyric acid content by acting on the γ-aminobutyric acid transaminase signaling pathway, thus alleviating oxidative stress, neuroinflammation, neuronal degeneration, and death caused by excitatory toxic injury of neurons after intracerebral hemorrhage.


Assuntos
Edema Encefálico , Modelos Animais de Doenças , Edaravone , Interleucina-1beta , Fármacos Neuroprotetores , Ratos Sprague-Dawley , Animais , Edaravone/farmacologia , Masculino , Fármacos Neuroprotetores/farmacologia , Interleucina-1beta/metabolismo , Edema Encefálico/patologia , Edema Encefálico/tratamento farmacológico , Edema Encefálico/metabolismo , Edema Encefálico/enzimologia , Edema Encefálico/prevenção & controle , 4-Aminobutirato Transaminase/metabolismo , 4-Aminobutirato Transaminase/antagonistas & inibidores , Comportamento Animal/efeitos dos fármacos , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/metabolismo , Hemorragia Cerebral/patologia , Hemorragia Cerebral/enzimologia , Anti-Inflamatórios/farmacologia , Cognição/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/metabolismo , Encéfalo/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Mediadores da Inflamação/metabolismo
3.
Molecules ; 29(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38675557

RESUMO

The design and synthesis of organic photocatalysts remain a great challenge due to their strict structural constraints. However, this could be mitigated by achieving structural flexibility by constructing permanent porosity into the materials. Conjugated microporous polymers (CMPs) are an emerging class of porous materials with an amorphous, three-dimensional network structure, which makes it possible to integrate the elaborate functional groups to enhance photocatalytic performance. Here, we report the synthesis of a novel CMP, named TAPFc-TFPPy-CMP, constructed by 1,1'3,3'-tetra(4-aminophenyl)ferrocene (TAPFc) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) monomers. The integration of the p-type dopant 7,7,8,8-tetracyanoquinodimethane (TCNQ) into the TAPFc-TFPPy-CMP improved the light adsorption performance, leading to a decrease in the optical bandgap from 2.00 to 1.43 eV. The doped CMP (TCNQ@TAPFc-TFPPy-CMP) exhibited promising catalytic activity in photocatalytic CO2 reduction under visible light, yielding 546.8 µmol g-1 h-1 of CO with a selectivity of 96% and 5.2 µmol g-1 h-1 of CH4. This represented an 80% increase in the CO yield compared to the maternal TAPFc-TFPPy-CMP. The steady-state photoluminescence (PL) and fluorescence lifetime (FL) measurements reveal faster carrier separation and transport after the doping. This study provides guidance for the development of organic photocatalysts for the utilization of renewable energy.

4.
Molecules ; 29(10)2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38792104

RESUMO

The effective capture and recovery of radioiodine species associated with nuclear fuel reprocessing is of significant importance in nuclear power plants. Porous materials have been proven to be one of the most effective adsorbents for the capture of radioiodine. In this work, we design and synthesize a series of conjugated microporous polymers (CMPs), namely, TPDA-TFPB CMP, TPDA-TATBA CMP, and TPDA-TECHO CMP, which are constructed based on a planar rectangular 4-connected organic monomer and three triangular 3-connected organic monomers, respectively. The resultant CMPs are characterized using various characterization techniques and used as effective adsorbents for iodine capture. Our experiments indicated that the CMPs exhibit excellent iodine adsorption capacities as high as 6.48, 6.25, and 6.37 g g-1 at 348 K and ambient pressure. The adsorption mechanism was further investigated and the strong chemical adsorption between the iodine and the imine/tertiary ammonia of the CMPs, 3D network structure with accessible hierarchical pores, uniform micromorphology, wide π-conjugated structure, and high-density Lewis-base sites synergistically contribute to their excellent iodine adsorption performance. Moreover, the CMPs demonstrated good recyclability. This work provides guidance for the construction of novel iodine adsorbent materials with high efficiency in the nuclear power field.

5.
Zhongguo Zhong Yao Za Zhi ; 49(1): 110-122, 2024 Jan.
Artigo em Zh | MEDLINE | ID: mdl-38403344

RESUMO

Studying the physicochemical properties and biological activities of Lycium barbarum polysaccharides(LBPs) is of great significance. The previous study had extracted LBPs(LBP-1, LBP-2, LBP-3, LBP-4, and LBP-5) by five different methods(cold water extraction, boiling water reflux extraction of the residue after cold water extraction, ultrasonic extraction with 50% ethanol, ultrasonic extraction with 25% ethanol of the residue after 50% ethanol extraction, and hot water extraction). In this study, the structures of the obtained five LBPs were characterized by UV spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Furthermore, the antioxidant, blood lipid-lowering, nitrosation-inhibting, acetylcholinesterase-inhibiting, and tyrosinase-inhibiting activities of the five LBPs were measured in vitro. The results showed that high-temperature extraction destroyed the polysaccharide structure, while ultrasound-assisted extraction ensured the structural integrity. The thermal stability and degradation behaviors differed among the five LBPs. However, the UV spectroscopic results of the five LBPs did not show significant differences, and all of the five LBPs showed the characteristic absorption peaks of proteins. LBP-3 and LBP-4 exhibited strong antioxidant activity, while LBP-3 had the strongest blood lipid-lowering activity. In addition, LBP-3 outperformed other LBPs in inhibiting nitrosation and acetylcholineste-rase, and LBP-2 showed the strongest inhibitory effect on tyrosinase. This study explored the effects of different extraction methods on the physicochemical properties and biological activities of LBPs, with a view to providing a basis for the selection of suitable extraction methods to obtain LBPs with ideal biological activities.


Assuntos
Medicamentos de Ervas Chinesas , Lycium , Lycium/química , Monofenol Mono-Oxigenase , Acetilcolinesterase , Antioxidantes/farmacologia , Antioxidantes/química , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Lipídeos , Etanol , Água
6.
J Neurochem ; 166(2): 265-279, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37263975

RESUMO

Studies of the intracranial vasculature in patients with ischemic stroke caused by atherosclerosis (AS) and cardiac embolism have revealed significantly different degrees of AS, plaque, and vascular stenosis. And the endothelium has a great influence on the vasculature throughout the circulatory system, especially in the brain. This study aimed to investigate the mechanistic differences in endothelial injury between atrial fibrillation (AF)- and AS-induced ischemic stroke. All target genes of AF, AS, and the vascular endothelial cell (VC) were obtained from the GeneCards database; the differential genes of AF and AS separately associated with the VC were established by a Venn diagram. A protein-protein interaction network was created, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases were used to perform genomic enrichment and functional enrichment analysis. Hub genes were selected by Maximal Clique Centrality algorithm ranking and correlation linkage in the STRING database, and then, clinical serum samples were used to verify the quantitative expressions in the AF, AF stroke, AS, and AS stroke groups. Fifty-five AF-VC-related genes and ninety-three AS-VC-related genes were screened, which differed in biological function, cellular composition, and molecular function. The genes correlation between AF and vascular endothelial cells (VCs) was KRAS and PTPN11, and those correlation between AS and VCs was IL-4, IFNG, IL-17A, and CSF-2. IL-4 and CSF-2 may be relevant proteins involved in the differences in stroke mechanisms between AF and AS, and they may act by further influencing the function of their downstream cells. This study provides a preliminary theoretical basis for investigating the differences in mechanisms of endothelial injury between AF- and AS-induced ischemic stroke.


Assuntos
Aterosclerose , Fibrilação Atrial , Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/genética , Fibrilação Atrial/complicações , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Isquemia Encefálica/genética , Isquemia Encefálica/complicações , Células Endoteliais , Interleucina-4 , Fatores de Risco , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/complicações , Aterosclerose/genética , Aterosclerose/complicações , Biologia Computacional , Endotélio
7.
Opt Express ; 31(15): 24173-24182, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37475250

RESUMO

Direct epitaxial growth of group III-V light sources with excellently thermal performance on silicon photonics chips promises low-cost, low-power-consumption, high-performance photonic integrated circuits. Here, we report on the achievement of ultra-high thermal stability 1.3 µm InAs/GaAs quantum dot (QD) lasers directly grown on an on-axis Si (001) with a record-high continuous-wave (CW) operating temperature of 150 °C. A GaAs buffer layer with a low threading dislocation density (TDD) of 4.3 × 106 cm-2 was first deposited using an optimized three-step growth method by molecular beam epitaxy. Then, an eight-layer QD laser structure with p-type modulation doping to enhance the temperature stability of the device was subsequently grown on the low TDD Si-based GaAs buffer layer. It is shown that the QD laser exhibits the ultra-high temperature stability with a characteristic temperature T0=∞ and T1=∞ in the wide temperature range of 10-75 °C and 10-140 °C, respectively. Moreover, a maximum CW operating temperature of up to 150 °C and a pulsed operating temperature of up to 160 °C are achieved for the QD laser. In addition, the QD laser shows a high CW saturation power of 50 mW at 85 °C and 19 mW at 125 °C, respectively.

8.
Opt Express ; 31(12): 20449-20456, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37381439

RESUMO

We report the significantly enhanced performance of InAs/GaAs quantum dot (QD) lasers on Si(001) by spatially separated co-doping, including n-doping in the QDs and p-doping in the barrier layers simultaneously. The QD lasers are a ridge waveguide of 6 × 1000 µm2 containing five InAs QD layers. Compared with p-doped alone laser, the co-doped laser exhibits a large reduction in threshold current of 30.3% and an increase in maximum output power of 25.5% at room temperature. In the range of 15°C-115°C (under 1% pulse mode), the co-doped laser shows better temperature stability with higher characteristic temperatures of threshold current (T0) and slope efficiency (T1). Furthermore, the co-doped laser can maintain stable continuous-wave ground-state lasing up to a high temperature of 115°C. These results prove the great potential of co-doping technique for enhancing silicon-based QD laser performances towards lower power consumption, higher temperature stability, and higher operating temperature, to boost the development of high-performance silicon photonic chips.

9.
Acta Neurochir (Wien) ; 165(5): 1155-1160, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36534186

RESUMO

PURPOSE: To elucidate the anatomic relationship between the internal carotid artery (ICA) and the bony structures of the craniovertebral junction among "sandwich" atlantoaxial dislocation (AAD) patients, and to analyze the risks of injury during surgical procedures. METHODS: The distance from the medial wall of ICA to the midsagittal plane (D1), the shortest distance between the ICA wall and the anterior cortex of the lateral mass of atlas (LMA) (D2) on the most caudal and cranial levels of LMA and the angle (A) between the sagittal plane passing through the screw entry point of C1 lateral mass(C1LM) screw and the medial tangent line of the vessel passing through the entry point were measured. Besides, the location of ICA in front of the atlantoaxial vertebra was divided into 4 categories (Z1-Z4). RESULTS: There was a statistically difference between the male and female patients regarding D1, and the difference between D2 at level a and level b as well as angle A between the left and right sides were statistically different (p < 0.05). Ninety-two ICAs (57.5%) were anteriorly located in Z3, 50 (31.3%) were located in Z4, 17 were located in Z2, and only one ICA was located in Z1 in all 80 patients. CONCLUSIONS: In "sandwich" AAD patients, particular attention should be paid to excessively medialized ICA to avoid ICA injury during trans-oral procedures, and the risk of injuring the ICA with more cranially and medially angulated C1LM screw placement was relatively less during posterior fixation procedures. A novel classification of ICA location was used to describe the relationship between ICA and LMA.


Assuntos
Articulação Atlantoaxial , Lesões das Artérias Carótidas , Luxações Articulares , Lesões do Pescoço , Fusão Vertebral , Humanos , Masculino , Feminino , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/cirurgia , Fusão Vertebral/métodos , Vértebras Cervicais/cirurgia , Parafusos Ósseos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia
10.
J Enzyme Inhib Med Chem ; 37(1): 431-444, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34957906

RESUMO

Chromone has emerged as one of the most important synthetic scaffolds for antitumor activity, which promotes the development of candidate drugs with better activity. In this study, a series of nitrogen mustard derivatives of chromone were designed and synthesised, in order to discover promising anti-breast tumour candidates. Almost all target derivatives showed antiproliferative activity against MCF-7 and MDA-MB-231 cell lines. In particular, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed the most potent antiproliferative activity with IC50 values of 1.83 and 1.90 µM, respectively, and it also exhibited certain selectivity between tumour cells and normal cells. Further mechanism exploration against MDA-MB-231 cells showed that it possibly induced G2/M phase arrest and apoptosis by generating intracellular ROS and activating DNA damage. In addition, it also inhibited MDA-MB-231 cells metastasis, invasion and adhesion. Overall, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed potent antitumor activities and relatively low side effects, and deserved further investigation.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Cromonas/farmacologia , Desenho de Fármacos , Mecloretamina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromonas/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Mecloretamina/química , Estrutura Molecular , Relação Estrutura-Atividade
11.
Molecules ; 27(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36234750

RESUMO

Transforming CO2 into value-added chemicals has been an important subject in recent years. The development of a novel heterogeneous catalyst for highly effective CO2 conversion still remains a great challenge. As an emerging class of porous organic polymers, covalent organic frameworks (COFs) have exhibited superior potential as catalysts for various chemical reactions, due to their unique structure and properties. In this study, a layered two-dimensional (2D) COF, IM4F-Py-COF, was prepared through a three-component condensation reaction. Benzimidazole moiety, as an ionic liquid precursor, was integrated onto the skeleton of the COF using a benzimidazole-containing building unit. Ionization of the benzimidazole framework was then achieved through quaternization with 1-bromobutane to produce an ionic liquid-immobilized COF, i.e., BMIM4F-Py-COF. The resulting ionic COF shows excellent catalytic activity in promoting the chemical fixation of CO2 via reaction with epoxides under solvent-free and co-catalyst-free conditions. High porosity, the one-dimensional (1D) open-channel structure of the COF and the high catalytic activity of ionic liquid may contribute to the excellent catalytic performance. Moreover, the COF catalyst could be reused at least five times without significant loss of its catalytic activity.

12.
J Cell Mol Med ; 25(17): 8442-8453, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34337852

RESUMO

Osteosarcoma (OS) is a primary malignant bone tumour that mainly affects teenagers, with patients displaying poor prognosis. Budding uninhibited by benzimidazoles 1 (BUB1), a type of serine/threonine kinase that is linked to pro-tumorigenic phenomena, has not been well studied in OS. Hence, this study aimed to explore the role of BUB1 in OS. The expression of BUB1 in OS specimens and cell lines was assessed using immunohistochemistry and Western blot analysis. Univariate and multivariate analyses were applied to evaluate the impact of BUB1 on patient survival. Cell counting kit-8, wound-healing and Transwell assays, as well as flow cytometry, were used to investigate the influence of BUB1 inhibition on OS in vitro. Moreover, a tumour xenograft model was established to investigate the in vivo effect of BUB1 inhibition on OS tumour growth. Results showed that BUB1 was overexpressed in OS specimens and cell lines. Furthermore, BUB1 overexpression was closely associated with the poor clinical outcomes of patients with OS. Inhibition of BUB1 markedly suppressed cell proliferation and tumour growth, cell migration, invasion and induced cell apoptosis of OS by blocking the PI3K/Akt and ERK signalling pathways. Thus, our study suggested that overexpression of BUB1 protein contributed to poor survival of OS patients and that inhibition of BUB1 resulted in considerable anti-tumour activity associated with proliferation, migration, invasion and apoptosis of OS.


Assuntos
Neoplasias Ósseas/metabolismo , Carcinogênese/imunologia , Osteossarcoma/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Adolescente , Adulto , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Adulto Jovem
13.
J Exp Bot ; 72(7): 2463-2476, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33340036

RESUMO

Seeds are major vehicles of propagation and dispersal in plants. A number of transcription factors, including APETALA2 (AP2), play crucial roles during the seed development process in various plant species. However, genes essential for seed development and the regulatory networks that operate during seed development remain unclear in lettuce. Here, we identified a lettuce AP2 (LsAP2) gene that was highly expressed during the early stages of seed development. LsAP2 knockout plants obtained by the CRISPR/Cas9 system were used to explore the biological function of LsAP2. Compared with the wild type, the seeds of Lsap2 mutant plants were longer and narrower, and developed an extended tip at the seed top. After further investigating the structural characteristics of the seeds of Lsap2 mutant plants, we proposed a new function of LsAP2 in seed dispersal. Moreover, we identified several interactors of LsAP2. Our results showed that LsAP2 directly interacted with the lettuce homolog of BREVIPEDICELLUS (LsBP) and promoted the expression of LsBP. Transcriptome analysis revealed that LsAP2 might also be involved in brassinosteroid biosynthesis and signaling pathways. Taken together, our data indicate that LsAP2 has a significant function in regulating seed shape in lettuce.


Assuntos
Lactuca/genética , Proteínas de Plantas , Sementes/crescimento & desenvolvimento , Fatores de Transcrição , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fator de Transcrição AP-2 , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Acta Biochim Biophys Sin (Shanghai) ; 53(3): 317-324, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33432347

RESUMO

Osteosarcoma (OS) is the most common type of primary malignant tumors that originate in the bone. Resistance to chemotherapy confers a poor prognosis on OS patients. Dysregulation of the epidermal growth factor receptor (EGFR) signaling has been reported in sarcomas. However, the functional contribution of EGFR hyperactivation to the tumor biology and chemoresistance remains largely unexplored in OS. In this study, we aimed to investigate the role of EGFR in OS progression and in the response of OS to gemcitabine treatment. The EGFR expression was found to be upregulated in fibroblastic OS cell lines. EGFR knockdown suppressed OS cell proliferation, migration, and invasion in vitro and tumor formation in vivo. Conversely, EGFR overexpression promoted the growth and motility of OS cells. In terms of mechanism, the levels of phospho-Akt and phospho-ERK were decreased upon EGFR knockdown but increased as a result of EGFR overexpression, implying a possible involvement of PI3K/Akt and ERK pathways in mediating the effects of EGFR on OS cells. Moreover, the level of phospho-EGFR was increased in OS cells when exposed to gemcitabine treatment. A more profound proliferative inhibition and a higher rate of apoptosis were obtained in OS cells via inducing cell cycle arrest at G1 phase upon gemcitabine treatment combined with EGFR knockdown, as compared to gemcitabine alone. On the contrary, EGFR overexpression counteracted the growth-inhibiting and pro-apoptotic effects of gemcitabine in OS cells. The present study suggests that EGFR promotes tumor progression and contributes to gemcitabine resistance in OS.


Assuntos
Neoplasias Ósseas/metabolismo , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos , Proteínas de Neoplasias/metabolismo , Osteossarcoma/metabolismo , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Desoxicitidina/farmacologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Proteínas de Neoplasias/genética , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/patologia , Gencitabina
15.
Acta Biochim Biophys Sin (Shanghai) ; 53(12): 1670-1680, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34693451

RESUMO

Osteosarcoma (OS), the most common malignant bone tumor with high metastatic potential, frequently affects children and adolescents. Epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors exhibit encouraging anti-tumor activity for patients with solid tumors, whereas their effects on OS remain controversial. In the present study, we aimed to elucidate the anti-tumor activity of gefitinib for OS, as well as to explore the underlying mechanisms. Gefitinib inhibits cell viability, tumor growth, cell migration, and invasion and promotes cell apoptosis and G1 cycle arrest in OS at a relatively high concentration via suppressing the PI3K/Akt and ERK pathways. However, gefitinib treatment results in the feedback activation of signal transducer and activator of transcription 3 (STAT3) induced by interleukin 6 (IL-6) secretion. Combined treatment with gefitinib and stattic, an inhibitor for STAT3 phosphorylation, engenders more evident inhibitory effects on cell proliferation, migration, and invasion and promotive effects on cell apoptosis and G1 phase arrest in OS, compared with the single exposure to gefitinib or stattic. Western blot analysis demonstrates that stattic treatment in gefitinib-treated OS abrogates the IL-6-induced STAT3 activation and subsequently further restrains the activities of EGFR, Akt, and ERK pathways in tumor cells. This study confirms that the EGFR inhibitor of gefitinib has moderate anti-tumor effects on OS through IL-6 secretion-mediated STAT3 activation. Additional administration of stattic in EGFR-targeted therapies may contribute to improve the efficacy for OS.


Assuntos
Antineoplásicos/farmacologia , Óxidos S-Cíclicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Interleucina-6/metabolismo , Osteossarcoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Óxidos S-Cíclicos/uso terapêutico , Feminino , Gefitinibe/farmacologia , Gefitinibe/uso terapêutico , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Osteossarcoma/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Fator de Transcrição STAT3/metabolismo , Ensaio Tumoral de Célula-Tronco , Ensaios Antitumorais Modelo de Xenoenxerto
16.
BMC Musculoskelet Disord ; 22(1): 121, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514363

RESUMO

BACKGROUND: Treatment of atlantoaxial dislocation is aimed at reduction and stabilization of the atlantoaxial joint. 3D printing refers to a process where additive manufacturing is achieved under precise computer control. Literature on its utilization in anterior atlantoaxial fixation and fusion is rare. This study is the first report on a 3D-printed locking cage used in the anterior procedure for atlantoaxial dislocation. METHODS: A middle-aged male in his 40s presented with weakness and numbness of his extremities for 3 years and could only walk slowly with assistance. Imaging studies revealed severe anterior migration of C1, irreducible atlantoaxial dislocation, and severe cervical-medullary compression. A preoperative plan consisting of trans-oral soft tissue release and fixation using tailor-designed 3D-printed cages was devised. Following fluoroscopic confirmation of reduction of the atlantoaxial joints, two customized 3D-printed cages made of titanium alloy were inserted into the bilateral facet joints, which were then locked by six screws into the lateral masses of C1 and C2. The microstructure of the inserted cages was optimized for improved biomechanical stability and enhanced osseo-integration, without the need for bone grafting. In addition, a biomechanical test was performed on seven human cadaveric specimens comparing the novel implant with the conventional C1 lateral mass-C2 pedicle screw construct in three modes of motion (flexion-extension, lateral bending, axial rotation). RESULTS: Improvement of neurologic function in the patient was evident immediately after surgery. He was able to walk independently 1 month post-operatively. At the 12-month follow-up, coronal reconstruction of CT demonstrated properly-positioned 3D-printed cages, evidence of osseo-integration at the bone-implant interface, and no subsidence or displacement of the implant. Eighteen months out of surgery, the mJOA score improved to 15, and lateral X-ray confirmed reduction of atlanto-axial dislocation. Additionally, the new construct provided strong fixation comparable to that conferred by conventional constructs as there was no significant difference observed between the two groups in all three directions of motion. CONCLUSIONS: The novel implant represents a new option in the treatment of irreducible atlantoaxial dislocation. It can provide strong anterior support for solid fixation and fusion with a low profile and a microstructure that obviates the need for bone grafting.


Assuntos
Articulação Atlantoaxial , Luxações Articulares , Parafusos Pediculares , Fusão Vertebral , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia , Fenômenos Biomecânicos , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , Impressão Tridimensional
17.
BMC Surg ; 21(1): 84, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33579244

RESUMO

BACKGROUND: To explore the clinical safety and efficacy of single-stage posterior-only debridement, decompression, allograft bone using titanium mesh and interbody fusion combined for the treatment of thoracolumbar spinal tuberculosis complicated with psoas abscesses. METHODS: A total of 38 patients diagnosed with thoracolumbar spinal tuberculosis complicated with psoas abscesses underwent surgery via single-stage posterior-only debridement, decompression, allograft bone using titanium mesh and interbody fusion from January 2010 to September 2016 were enrolled in the study. The clinical efficacy of the approach was assessed based on parameters including operating time, blood loss, Cobb angle, visual analogue scale (VAS) scores, Frankel grade, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). RESULTS: The surgery duration was 224.4 ± 71.1 min with a blood loss of 731.8 ± 585.8 ml. The Cobb angle was corrected from 16.0 ± 15.4° preoperatively to 8.1 ± 7.4° postoperatively (P < 0.001, t = - 4.38), and returned to a level of 11.0 ± 8.5° at the final follow-up (P = 0.002, t = 3.38). Back pain was relieved, with the mean preoperative VAS of 3.5 ± 1.1 decreased to 0.7 ± 0.8 postoperatively (P < 0.001, t = 23.21) and then to 0.6 ± 0.5 at the final follow-up (P < 0.001, t = 17.07). Neurological function was improved in various degrees and psoas abscesses disappeared in all patients. The ESR and CRP decreased gradually after surgery and returned to normal at the final follow-up in all patients. All patients achieved bone fusion thoroughly and no recurrence of TB or surgical related complications was found at the final follow-up. CONCLUSION: Single-stage posterior-only debridement, decompression, allograft bone using titanium mesh and interbody fusion is a safe and effective approach for the management of thoracolumbar spinal tuberculosis complicated with psoas abscesses.


Assuntos
Desbridamento , Descompressão , Vértebras Lombares/cirurgia , Abscesso do Psoas/cirurgia , Fusão Vertebral , Vértebras Torácicas/cirurgia , Tuberculose da Coluna Vertebral/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Abscesso do Psoas/complicações , Estudos Retrospectivos , Resultado do Tratamento , Tuberculose da Coluna Vertebral/complicações
18.
J Orthop Sci ; 26(3): 466-472, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32402505

RESUMO

BACKGROUND: Osteosarcoma is the most common primary malignant bone tumor, particularly among children and adolescents, and the prognosis of osteosarcoma patients remains poor. The NADPH oxidase 2 (NOX2) has been found over-expressed in several human cancers, and closely associated with poor prognosis. Meanwhile the role of NOX2 in osteosarcoma patients has not been reported. This study aimed to investigate the clinicopathological and prognostic significance of NOX2 in osteosarcoma patients. METHODS: Immunohistochemistry (IHC), western blot (WB) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect the expression of NOX2 in 55 primary osteosarcoma specimens and in 20 non-neoplastic bone tissue specimens. The correlations between NOX2 expression and clinicopathological parameters were analysed by using the χ2 test or Fisher's exact test. Disease free survival and overall survival of osteosarcoma patients were assessed by using the Kaplan-Meier method and Cox proportional hazards model. RESULTS: NOX2 was over-expressed significantly in osteosarcoma compared with that in non-neoplastic bone tissue, and correlated with progression free survival (P < 0.001) and overall survival (P < 0.001). The over-expression of NOX2 was associated with tumor size (P < 0.001), tumor location (P < 0.001). The Cox analysed shown that the over-expression of NOX2 was predicted to be worse PFS (hazard ratio (HR) = 4.10, P = 0.004) and OS (hazard ratio (HR) = 3.50, P = 0.010) time in osteosarcoma patients. CONCLUSIONS: The results of our study suggest that the over-expression of NOX2 is related to adverse clinical outcome, and can be viewed as an independent prognostic marker in osteosarcoma. Further research is required to verify the predictive value of NOX2 in osteosarcoma patients.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Adolescente , Biomarcadores Tumorais/genética , Neoplasias Ósseas/genética , Criança , Intervalo Livre de Doença , Humanos , Estimativa de Kaplan-Meier , NADPH Oxidase 2/genética , Osteossarcoma/genética , Prognóstico , Modelos de Riscos Proporcionais
19.
J Orthop Sci ; 26(6): 1100-1106, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32972820

RESUMO

BACKGROUND: Osteosarcoma is a common primary malignant bone tumor susceptible to distant metastasis. The clinical outcome for patients remains poor due to the resistance to chemotherapy and lacking effective therapeutic targets. Recepteur d'origine nantais (RON), a transmembrane protein of the c-MET proto-oncogene family, has been reported to contribute to the malignant progression and bone metastasis in several tumors. The present study aimed to explore the prognostic significance of RON in primary high-grade osteosarcoma. METHODS: Immunohistochemistry (IHC) and western blotting (WB) were used to investigate the protein expression of RON in 80 surgically resected specimens (50 high-grade osteosarcoma specimens and 30 non-neoplastic bone tissues) and 6 cell lines. The χ2 test or independent-sample Student's t-test was used to assess the significance of RON difference between osteosarcoma and non-neoplastic bone tissues. The χ2 test and Fisher's exact test were used to analyze the association of RON with the clinicopathological features of osteosarcoma patients. Kaplan-Meier method and Cox proportional hazards model were used to assess the significance of RON for the survival of osteosarcoma patients. RESULTS: The results of IHC and WB observed significant overexpression of RON in osteosarcoma specimens (P < 0.001) and osteosarcoma cell lines. Moreover, immunohistochemical high expression of RON was associated with a poor response to chemotherapy (P = 0.032) as well as worse progression-free (P = 0.003) and overall (P < 0.001) survival of osteosarcoma patients. Multivariate analysis revealed that high expression of RON was independently associated with reduced progression-free (P = 0.027, HR = 2.31) and overall survival (P = 0.004, HR = 5.06) time of osteosarcoma patients. CONCLUSIONS: The present study demonstrated that high expression of RON held independent value for unfavorable survival in primary high-grade osteosarcoma. Its potential role as a therapeutic target for osteosarcoma treatment deserves further research.


Assuntos
Osteossarcoma , Humanos , Imuno-Histoquímica , Prognóstico , Proto-Oncogene Mas , Receptores Proteína Tirosina Quinases
20.
Acta Biochim Biophys Sin (Shanghai) ; 52(4): 345-362, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32181480

RESUMO

Osteosarcoma is the most common primary malignant bone tumor, which occurs in adolescents. As reported by our previous studies, HER4 indicates a poor prognosis of primary osteosarcoma. However, its mechanisms in the pathogenesis of osteosarcoma have not yet been studied. The purpose of this study was to investigate the role of HER4 in osteosarcoma and whether the PI3K/AKT pathway is involved. In this study, western blot analysis was used to investigate the expression of HER4 protein in osteosarcoma tissues and cell lines. CCK8 and transwell assays were used to detect the effects of HER4 on the proliferation, migration, and invasion of osteosarcoma cells in vitro. The effects of HER4 on the growth and metastasis of osteosarcoma in vivo were detected by tumor formation and immunofluorescence in nude mice. The role of the PI3K/AKT pathway in HER4 regulation of the growth and metastasis of osteosarcoma was examined by western blot analysis and immunofluorescence assay. We found that HER4 protein was highly expressed in clinical osteosarcoma specimens and osteosarcoma cells. HER4 markedly promoted the proliferation, migration, and invasion of osteosarcoma cells in vitro as well as the growth and metastasis of osteosarcoma in vivo. HER4 overexpression upregulated the expression of phosphorylated protein kinase B (pAKT), proliferation marker antigen Ki67, and metastasis cell marker matrix metalloproteinase 9 (MMP9). Notably, PI3K/AKT inhibitor LY294002 significantly inhibited the effects of HER4 via the downregulation of pAKT, Ki67, and MMP9. Moreover, LY294002 markedly blocked the effects of HER4-induced upregulation of tumor malignancy. The present study suggests that HER4 may promote the growth and metastasis of osteosarcoma via the PI3K/AKT pathway. The HER4/PI3K/AKT pathway could serve as a potential target for the treatment of osteosarcoma.


Assuntos
Neoplasias Ósseas/metabolismo , Proliferação de Células , Osteossarcoma/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-4/metabolismo , Transdução de Sinais , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Metástase Neoplásica , Osteossarcoma/genética , Osteossarcoma/patologia , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Receptor ErbB-4/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA