Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Cancer ; 10(19): 4488-4498, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31528213

RESUMO

Cyclin-dependent kinase 5 regulatory subunit-associated protein 3 (CDK5RAP3) was identified as a tumor suppressor in gastric cancer, while, minichromosome maintenance complex component 6 (MCM6), which is closely related to the initiation of DNA replication, was reported to be upregulated in multiple malignancies. However, the interaction between these two proteins has not been investigated in gastric cancer. Here, we evaluate the connection between CDK5RAP3 and MCM6 using mass spectrometry and immunoprecipitation. In cells, cell growth and invasiveness indicate that CDK5RAP3 acts as a tumor suppressor by preventing the effects of MCM6. The potential mechanism was revealed using immunofluorescence and nuclear protein extraction. In patients, immunohistochemistry and immunofluorescence show that the protein levels of CDK5RAP3 were markedly decreased in most gastric tumor tissues compared with adjacent nontumor tissues, and the expression levels of MCM6 in the nucleus showed the opposite trend. Prognostic analysis showed that the combined expression of CDK5RAP3 and MCM6 was an independent prognostic factor correlating with the overall survival of gastric cancer patients. Cox regression analysis indicated that the expression of CDK5RAP3 and MCM6 corresponded to T, N, and M stages. Our results demonstrate that CDK5RAP3 can interact with MCM6 and prevent MCM6 from translocating into the nucleus, which may be a potential mechanism through which CDK5RAP3 negatively regulates the proliferation of gastric cancer.

2.
J Exp Clin Cancer Res ; 37(1): 59, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540196

RESUMO

BACKGROUND: CDK5RAP3 was initially isolated as a binding protein of the CDK5 activator p35. Although CDK5RAP3 has been shown to negatively regulate the Wnt/ß-catenin signaling pathway in gastric cancer by repressing GSK-3ß phosphorylation, its in-depth mechanism has not been determined. METHODS: Following CDK5RAP3 overexpression or knock down, CDK5RAP3 signaling pathways were investigated in gastric cancer cells by Western Blotting. Cell growth, invasion and migration were also evaluated in gastric cancer cell lines. We analyzed CDK5RAP3, AKT, p-AKT (Ser473), GSK-3ß and p-GSK-3ß (Ser9) expression in gastric tumor samples and adjacent non-tumor tissues from 295 patients using immunohistochemistry and Western Blotting. The prognostic significance of CDK5RAP3 and p-AKT (Ser473) was confirmed by a Log-rank test. RESULTS: Our study demonstrated that the expression of p-AKT (Ser473) and p-GSK-3ß (Ser9) was negatively correlated with CDK5RAP3 in stable gastric cancer cell lines. CDK5RAP3 repressed AKT phosphorylation, which promoted GSK-3ß phosphorylation, thereby suppressing ß-catenin protein expression and, consequently, gastric cancer. The protein level of CDK5RAP3 was markedly decreased in most gastric tumor tissues compared with adjacent non-tumor tissues, and the levels of p-AKT (Ser473) and p-GSK-3ß (Ser9) were also negatively correlated with those of CDK5RAP3. The prognostic value of CDK5RAP3 for overall survival was found to be dependent on AKT phosphorylation. CONCLUSION: Our results demonstrated that CDK5RAP3 negatively regulates the Wnt/ß-catenin signaling pathway by repressing AKT phosphorylation, which leads to better survival of patients with gastric cancer.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Via de Sinalização Wnt , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Feminino , Inativação Gênica , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fosforilação , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise Serial de Tecidos , Carga Tumoral , beta Catenina/genética , beta Catenina/metabolismo
3.
Ying Yong Sheng Tai Xue Bao ; 27(4): 1053-1060, 2016 Apr 22.
Artigo em Chinês | MEDLINE | ID: mdl-29732759

RESUMO

Water is a major limiting factor for plant growth in arid and semi-arid regions. To find out the main sources of water for two artificial sand-fixation plants (Caragana korshinskii and Artemisia ordosica), we analyzed the characteristics of hydrogen and oxygen stable isotopes in water molecules of rainfall, soil water and xylem water. To analyze water sources of these two plants, we used a direct comparison method and a multi-variate mixed linear model. The results showed that an equation of local meteoric water line in Shapotou was δD=7.83δ18O+5.64 (R2=0.91). The value for rainfall δ18O varied during plant-growing season, which was higher in the beginning and end of growing season, and lower in the peak of growing season. The value for soil water δ18O in the upper layers changed dramatically. The change range became smaller in the deeper soil layer. C. korshinskii had a greater efficiency (56.1%) in utilizing soil water in 40-80 cm soil layer. A. ordosica had a utilizing efficiency of 56.4% in 20-60 cm soil layer. A week after rain event, C. korshinskii and A. ordosica showed a higher efficiency in upper soil water. C. korshinskii showed an increase of 12.5% in utilizing soil water in 0-40 cm soil layer and A. ordosicas showed an increase of 10% in utilizing soil water in 0-20 cm layer. These results suggested that C. korshinskii and A. ordosica changed their water use strategy after large rainfall events, which might enable them to more easily adapt to arid environment.


Assuntos
Artemisia/fisiologia , Caragana/fisiologia , Chuva , Água/fisiologia , China , Clima Desértico , Isótopos de Oxigênio/análise , Estações do Ano , Dióxido de Silício , Solo , Xilema
4.
Sci China Life Sci ; 57(5): 539-48, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24699917

RESUMO

The main prevention and control area for wind-blown sand hazards in northern China is about 320000 km(2) in size and includes sandlands to the east of the Helan Mountain and sandy deserts and desert-steppe transitional regions to the west of the Helan Mountain. Vegetation recovery and restoration is an important and effective approach for constraining wind-blown sand hazards in these areas. After more than 50 years of long-term ecological studies in the Shapotou region of the Tengger Desert, we found that revegetation changed the hydrological processes of the original sand dune system through the utilization and space-time redistribution of soil water. The spatiotemporal dynamics of soil water was significantly related to the dynamics of the replanted vegetation for a given regional precipitation condition. The long-term changes in hydrological processes in desert areas also drive replanted vegetation succession. The soil water carrying capacity of vegetation and the model for sand fixation by revegetation in aeolian desert areas where precipitation levels are less than 200 mm are also discussed.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Plantas , China , Clima Desértico , Solo , Água , Vento
5.
Biomed Environ Sci ; 26(2): 138-47, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23336137

RESUMO

OBJECTIVE: To compare the nature of the metabolites formed from the phase I metabolism (hydroxylation and oxidation) and phase II metabolism (glutathionyl conjugation) of PCBs that have different chlorine substitution patterns. To discuss the structure-activity relationships and metabolic mechanisms of PCBs. METHODS: 4-Cl-biphenyl (PCB3), 4,4'-Cl-biphenyl (PCB15), 3,4,3',4'-Cl-biphenyl (PCB77) were used for in vitro metabolic study. LC/MS and UV-Vis studies were performed for metabolites identification. RESULTS: The cytochrome P-450 catalyzed hydroxylation rate decreased as the number of chlorine substitutions increased. In this reaction, PCB3 was fully metabolized, approximately half of the PCB15 was metabolized and PCB77 was not metabolized at all. The oxidation rate of PCB15-HQ was higher than that of PCB3-HQ under various oxidation conditions. The LC/MS and UV-Vis data suggest that in the conjugation reaction of PCB15-Q and GSH, the Michael addition reaction occurs preferentially over the displacement reaction. CONCLUSION: The metabolic profiles of polychlorinated biphenyls (PCBs) are dramatically affected by chlorine substitution patterns. It is suggested that the metabolic profiles of PCBs are related to their chlorine substitution patterns, which may have implications for the toxicity of PCB exposure.


Assuntos
Bifenilos Policlorados/química , Hidroxilação , Estrutura Molecular , Oxirredução
6.
Huan Jing Ke Xue ; 31(5): 1139-45, 2010 May.
Artigo em Chinês | MEDLINE | ID: mdl-20623843

RESUMO

A total of 30 samples of total suspended particles were collected at an urban site in western of Lhasa city, Tibet from August 2006 to July 2007 for investigating carbonaceous aerosol features. 14C was taken as a reference to quantitatively distinguish the fossil and biogenic-derived origins along with the characteristics of seasonal variations of all carbonaceous materials in Lhasa are discussed. The results showed that the f(c) values in Lhasa ranged from 0.357 to 0.702, with an average of 0.493, which is higher than Beijing and Tokyo, but are far lower than that of remote/rural regions such as Launceston, indicating a major biogenic influence in Lhasa. Values of f(c) displayed clear seasonal variations with higher mean value in winter, a decreasing trend in spring, while relatively lower values in summer and autumn. Higher f(C) values in winter demonstrate that carbonaceous aerosol is mainly dominated by wood burning and incineration of agricultural wastes during the winter. The lower f(c) values in summer and autumn might be caused by increased diesel engines, motor vehicles emissions, which are related to the tourism in Lhasa. delta13C values ranged from -26.40% per hundred to approximately -25.10% per hundred, with an average of -25.8% per hundred, and showed no clear seasonal variation. The relative higher values in summer reflected the increment of fossil carbon emissions. 13C(TC) values are relatively homogeneous at -25.8% per hundred, considering the characteristics of seasonal variations of f(c) values, it can be concluded that carbonaceous aerosol of Lhasa was mainly influenced by a constant mixing of several pollution sources such as motor vehicles and wood burning emissions.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Radioisótopos de Carbono/análise , Monitoramento Ambiental , Isótopos de Carbono/análise , Cidades , Estações do Ano , Tibet
7.
J Plant Res ; 122(1): 109-19, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19023645

RESUMO

A field experiment was conducted to investigate root distribution, biomass, and seasonal dynamics in a revegetated stand of Caragana korshinskii Kom. in the Tengger Desert. We used soil profile trenches, soil core sampling, and minirhizotron measurements to measure root dynamics. Results showed that the roots of C. korshinskii were distributed vertically in the uppermost portion of the soil profile, especially the coarse roots, which were concentrated in the upper 0.4 m. The horizontal distribution of the root length and weight of C. korshinskii coarse roots was concentrated within 0.6 and 0.4 m of the trunk, respectively. The lateral distribution of fine roots was more uniform than coarse roots. Total-root and fine-root biomasses were 662.4 +/- 45.8 and 361.1 +/- 10.3 g m(-2), accounting for about two-thirds and one-third of the total plant biomass, respectively. Fine-root turnover is closely affected by soil water, and both of these parameters showed synchronously seasonal trends during the growing season in 2004 and 2005. The interaction between fine-root turnover and soil water resulted in the fine-root length densities and soil water content in the 0- to 1.0-m soil layer having similar trends, but the soil water peaks occurred before those of the fine-root length densities.


Assuntos
Caragana/fisiologia , Clima Desértico , Raízes de Plantas/fisiologia , Biomassa , Ecossistema , Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA