Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Cell Death Dis ; 14(1): 64, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707511

RESUMO

The pregnane X receptor (PXR) is an important regulator of hepatocellular carcinoma cellular resistance to antitumor drugs. Activation of PXR was modulated by the co-regulators. The target protein for the Xenopus plus end-directed kinesin-like protein (Xklp2) known as TPX2 that was previously considered as a tubulin regulator, also functions as the regulator of some transcription factors and pro-oncogenes in human malignances. However, the actions of TPX2 on PXR and HCC cells are still unclear. In the present study, our results demonstrate that the high expression of endogenous mRNA level of TPX2 not only correlated with the poor prognosis of advanced HCC patients who received sorafenib treatment but also with expression of PXR's downstream genes, cyp3a4 and/or mdr-1. Results from luciferase and real-time polymerase chain reaction (qPCR) showed that TPX2 leads to enhancement of the transcription factor activation of PXR. Protein-protein interactions between PXR and TPX2 were identified using co-immunoprecipitation. Mechanically, overexpression of TPX2 led to enhancement of PXR recruitment to its downstream gene cyp3a4's promoter region (the PXRE region) or enhancer region (the XREM region). Treatment of HCC cells with paclitaxel, a microtubule promoter, led to enhancement of the effects of TPX2, whereas vincristine, a microtubule depolymerizing agent caused a decrease in TPX2-associated effects. TPX2 was found to cause acceleration of the metabolism or clearance of sorafenib, a typical tyrosine kinase inhibitor (TKI) in HCC cells and in turn led to the resistance to sorafenib by HCC cells. By establishing novel actions of TXP2 on PXR in HCC cells, the results indicate that TPX2 could be considered a promising therapeutic target to enhance HCC cells sensitivity to antitumor drugs.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Receptor de Pregnano X/genética , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Fatores de Transcrição/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Citocromo P-450 CYP3A/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proteínas Associadas aos Microtúbulos/genética , Proteínas de Ciclo Celular/genética
2.
Front Oncol ; 12: 959151, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936699

RESUMO

Background: Orthotopic liver transplantation (OLT) is a life-saving option for patients with hepatocellular carcinoma (HCC), but the expanded OLT criteria remain controversial. Objective: The study aimed to explore whether expanded OLT criteria can be applied to Chinese cirrhotic patients with HCC. Methods: This retrospective study analyzed risk factors for HCC recurrence and death and compared patients' tumor characteristics and outcomes in groups of Milan, "Up-to-seven," and Hangzhou criteria, and groups between met and unmet the combinative criteria of "Up-to-seven" and AFP of < 1000 ng/mL. Results: Among 153 patients who underwent OLT for HCC from January 2015 to February 2019 in 4 years of follow-up, 20 (13.1%) patients had HCC recurrence, and 11 (7.2%) had HCC-related death. Multivariate Cox regression analysis showed that preoperative alpha-fetoprotein (AFP) of > 1000 ng/mL (hazard ratio [HR]: 10.05, 95% confidence interval [CI]: 2.45-41.13, P = 0.001) was an independent risk factor for HCC recurrence and HCC-related death (HR: 6.63, 95%CI: 1.31-33.52, P = 0.022). Patients who did not meet Milan criteria but satisfied the "Up-to-seven" criteria had no differences in overall survival (OS) (P = 0.69) and disease-free survival (DFS) (P = 0.35) than patients who met the Milan criteria. The combination of "Up-to-seven" criteria and AFP of < 1000 ng/mL differed significantly (HR: 18.9; 95% CI: 4.0-89.2; P < 0.001). Patients with HCC who met the "Up-to-seven" criteria and AFP of < 1000 ng/mL (n = 121) had excellent survival with 4-year OS of 91.6% (P < 0.001) and DFS of 90.8% (P < 0.001), which is significantly better compared to the other group (n = 32) (OS of 67.5% and DFS of 46.5%) and patients who met the Milan criteria (n = 108, OS of 89.8%, DFS of 89.6%), allowing 28.9% (13/45) of patients who did not meet the Milan criteria to benefit from OLT. Conclusion: Chinese cirrhotic patients with HCC who met the combinative criteria of "Up-to-seven" and AFP of < 1000 ng/mL had better survival than those who met the Milan criteria, and these combinative criteria benefited more patients and may become a better option for OLT.

3.
Biochem Biophys Res Commun ; 521(2): 485-491, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31677784

RESUMO

Oxidative stress and cardiomyocyte apoptosis contributed to the progression of doxorubicin (Dox)-induced cardiotoxicity. Recent studies identified microRNA-22 (miR-22) as a cardiac- and skeletal muscle-enriched microRNA that functioned as a key regulator in stress-induced cardiac injury. The present study aimed to investigate the role and possible mechanism of miR-22 on Dox-induced oxidative stress and cardiomyocyte apoptosis. Mice were exposed to reduplicative injections of Dox (i.p., 4 mg/kg) weekly for consecutive 4 weeks to generate Dox-induced cardiotoxicity. Herein, we found that miR-22 level was significantly increased in murine hearts subjected to chronic Dox treatment. MiR-22 inhibition attenuated oxidative stress and cardiomyocyte apoptosis in vivo and in vitro, thereby preventing Dox-induced cardiac dysfunction. Mechanistically, we observed that miR-22 directly bound to the 3'-UTR of Sirt1 and caused SIRT1 downregulation. Conversely, miR-22 antagomir upregulated SIRT1 expression and SIRT1 inhibitor abolished the beneficial effects of miR-22 antagomir. In conclusion, miR-22 inhibition prevented oxidative stress and cardiomyocyte apoptosis via upregulating SIRT1 and miR-22 might be a new target for treating Dox-induced cardiotoxicity.


Assuntos
Cardiotoxicidade/prevenção & controle , Doxorrubicina/efeitos adversos , MicroRNAs/antagonistas & inibidores , Sirtuína 1/metabolismo , Regiões 3' não Traduzidas , Animais , Antagomirs/farmacologia , Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Camundongos , MicroRNAs/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Sirtuína 1/genética , Regulação para Cima
4.
Angew Chem Int Ed Engl ; 54(41): 12127-33, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26305271

RESUMO

Healable, electrically conductive materials are highly desirable and valuable for the development of various modern electronics. But the preparation of a material combining good mechanical elasticity, functional properties, and intrinsic self-healing ability remains a great challenge. Here, we design composites by connecting a polymer network and single-walled carbon nanotubes (SWCNTs) through host-guest interactions. The resulting materials show bulk electrical conductivity, proximity sensitivity, humidity sensitivity and are able to self-heal without external stimulus under ambient conditions rapidly. Furthermore, they also possess elasticity comparable to commercial rubbers.


Assuntos
Elastômeros/química , Nanotubos de Carbono/química , Elasticidade , Condutividade Elétrica , Nanotecnologia/métodos , Nanotubos de Carbono/ultraestrutura
5.
Chem Commun (Camb) ; 51(29): 6377-80, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25761433

RESUMO

A self-healable conductive composite is developed by combining the small molecules and nanotubes through host-guest interactions. This material shows uniform conductivity, microwave absorption and humidity sensing properties, and can be rapidly healed to over 90% electrical and mechanical properties with the aid of water multiple times. In addition, the produced material is also remouldable and recyclable.


Assuntos
Condutividade Elétrica , Nanocompostos/química , Nanotubos de Carbono/química , Polietilenoimina/química , Estresse Mecânico , beta-Ciclodextrinas/química
6.
Pharmazie ; 69(3): 163-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24716403

RESUMO

We synthesized eight tanshinone anhydrides and the alcoholytic derivatives through a mild oxygen-insertion under Pd/C catalytic hydrogenation conditions. The suppressive effects of the anhydrides on the oxidized low-density lipoprotein (oxLDL) uptake and the oxLDL-induced macrophage-derived foam cell formation were studied. Our results revealed that both anhydrides 1a and 2a could significantly suppress the oxLDL uptake in macrophages and the foam cell formation at micromolar level, which might be partially attributed to their inhibition of oxLDL-induced LOX-1 expression in macrophages.


Assuntos
Abietanos/síntese química , Antineoplásicos Fitogênicos/síntese química , Células Espumosas/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Anidridos/síntese química , Animais , Compostos Azo , Catálise , Linhagem Celular Tumoral , LDL-Colesterol/metabolismo , Corantes , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Camundongos , Sais de Tetrazólio , Tiazóis
7.
Bioorg Chem ; 52: 24-30, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24300390

RESUMO

A series of diacyltanshinol derivatives were synthesized by esterifying the corresponding o-hydroquinones of tanshinones. The suppressive effects of the synthesized compounds on oxidized low-density lipoprotein (oxLDL) uptake and oxLDL-induced macrophage-derived foam cell formation were evaluated. Our results indicated that the nicotinate derivatives 1a and 2a, modified from tanshinone IIA and cryptotanshinone, showed stronger suppressive activity on oxLDL uptake and the resultant foam cell formation relative to tanshinone IIA. Western Blot analysis indicated that derivatives 1a and 2a could dose-dependently inhibit the expression of oxLDL-induced LOX-1, implying that the suppressive effects of 1a and 2a on oxLDL uptake and foam cell formation could be at least partially attributed to the inhibition of LOX-1 expression in macrophages.


Assuntos
Ácidos Cafeicos/química , Células Espumosas/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Abietanos/química , Animais , Linhagem Celular , Técnicas de Química Sintética , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Células Espumosas/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Camundongos , Substâncias Protetoras/síntese química , Receptores Depuradores Classe E/antagonistas & inibidores
8.
Sensors (Basel) ; 13(7): 9070-84, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23860316

RESUMO

The measurement and control strategy of a piezo-based platform by using strain gauge sensors (SGS) and a robust composite controller is investigated in this paper. First, the experimental setup is constructed by using a piezo-based platform, SGS sensors, an AD5435 platform and two voltage amplifiers. Then, the measurement strategy to measure the tip/tilt angles accurately in the order of sub-µrad is presented. A comprehensive composite control strategy design to enhance the tracking accuracy with a novel driving principle is also proposed. Finally, an experiment is presented to validate the measurement and control strategy. The experimental results demonstrate that the proposed measurement and control strategy provides accurate angle motion with a root mean square (RMS) error of 0.21 µrad, which is approximately equal to the noise level.


Assuntos
Algoritmos , Sistemas Microeletromecânicos/instrumentação , Transdutores de Pressão , Desenho de Equipamento , Análise de Falha de Equipamento , Retroalimentação , Movimento (Física)
9.
Org Lett ; 15(6): 1162-5, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23452325

RESUMO

An oxygen-insertion reaction that transforms an o-quinone and a conjugated α-diketone substrate into an anhydride product or derivative under catalytic hydrogenation conditions is reported. The experiments and computations indicate that the oxygen insertion proceeds via a radical mechanism mediated by an acetoxyl radical.


Assuntos
Compostos Heterocíclicos/síntese química , Oxigênio/química , Quinonas/química , Compostos de Bifenilo/química , Catálise , Técnicas de Química Combinatória , Óxidos N-Cíclicos/química , Compostos Heterocíclicos/química , Hidrogenação , Estrutura Molecular , Picratos/química
10.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 8): o2548, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22904980

RESUMO

In the title mol-ecule, C(18)H(11)FN(2)O(4), the fused four- ring system is essentially planar, with an r.m.s. deviation of 0.032 Å. In the crystal, mol-ecules are connected by π-π stacking inter-actions [centroid-centroid distances = 3.5684 (9) and 3.8247 (9) Å] into chains along [100].

11.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 29(12): 1110-3, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20214334

RESUMO

OBJECTIVE: To investigate the effect of ginsenoside (GSS) in regulating level of sex hormone receptors in human liver cell line HL-7702. METHODS: The growth of HL-7702 were detected by MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay for choosing the available concentration of GSS; and the effect of GSS on sex hormone receptors in HL-7702 cells were detected by immuno-histochemistry, Western blot and RT-PCR. RESULTS: GSS significantly enhance the protein and mRNA expressions of estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) in HL7702 cell in a dose-dependent manner, the levels of expressions in the GSS treated group were higher than those in the solvent control group respectively (P < 0.05). CONCLUSION: GSS can up-regulate the protein and mRNA expressions of sex hormone receptors in HL-7702.


Assuntos
Ginsenosídeos/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Receptores de Estrogênio/metabolismo , Linhagem Celular , Hepatócitos/citologia , Humanos
12.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 22(3): 196-9, 2006 May.
Artigo em Chinês | MEDLINE | ID: mdl-16883893

RESUMO

OBJECTIVE: To study a new method of venous flap that is improved on its persistence and quality. METHODS: New Zealand white rabbits were subdivided randomly into 4 groups. All rabbits were operated by harvesting a flap from the latero-abdominal wall and then sutured it in the original position. Group A: the superficial epigastric vein in the pedicle was left open (only one inflow vein remained). Group B: the pedicle vein of the proximal and distant end were left open (keeping an inflow vein and a principal out). Group C: the pedicle vein and a tributary vein were left open (keeping an inflow vein and a tributary outflow vein). Group D: the pedicle vein and two tributary veins were left open (keeping an inflow vein and two tributary outflow veins). Survival rate, MDA of the tissue, histology and ultra-microstructure were examined. RESULTS: Survival rate of A, B, C, D were improved in order. Statistic difference is significant (P < 0.05) between group and group other than C and D. The content of MDA was heightened with statistically significant differences (A > B > C > D) among the four groups 8 hours postoperatively, but fell back to the normal level in group D and C and kept a high level in group A and B at 72 hour postoperatively. Histology and ultra-microstructure exam showed that degeneration of collagen fiber and karyopyknosis of cell is more obvious in Group A and Group B than Group C and Group D. CONCLUSIONS: The higher survival rate of venous flap is possible by designing the more reasonable venous flap outputs pedicles which can alleviate the high tension dropsy and maintain the valid equilibrium of pour with flow in the venous flap.


Assuntos
Sobrevivência de Enxerto , Retalhos Cirúrgicos , Veias/transplante , Animais , Coelhos , Retalhos Cirúrgicos/irrigação sanguínea
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA