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1.
Proc Natl Acad Sci U S A ; 118(18)2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33931505

RESUMO

Active matter comprises individually driven units that convert locally stored energy into mechanical motion. Interactions between driven units lead to a variety of nonequilibrium collective phenomena in active matter. One of such phenomena is anomalously large density fluctuations, which have been observed in both experiments and theories. Here we show that, on the contrary, density fluctuations in active matter can also be greatly suppressed. Our experiments are carried out with marine algae ([Formula: see text]), which swim in circles at the air-liquid interfaces with two different eukaryotic flagella. Cell swimming generates fluid flow that leads to effective repulsions between cells in the far field. The long-range nature of such repulsive interactions suppresses density fluctuations and generates disordered hyperuniform states under a wide range of density conditions. Emergence of hyperuniformity and associated scaling exponent are quantitatively reproduced in a numerical model whose main ingredients are effective hydrodynamic interactions and uncorrelated random cell motion. Our results demonstrate the existence of disordered hyperuniform states in active matter and suggest the possibility of using hydrodynamic flow for self-assembly in active matter.


Assuntos
Alveolados/fisiologia , Movimento Celular/fisiologia , Flagelos/fisiologia , Hidrodinâmica , Modelos Biológicos , Movimento (Física) , Fenômenos Físicos , Natação/fisiologia
2.
Proc Natl Acad Sci U S A ; 118(40)2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34593647

RESUMO

Patterned ground, defined by the segregation of stones in soil according to size, is one of the most strikingly self-organized characteristics of polar and high-alpine landscapes. The presence of such patterns on Mars has been proposed as evidence for the past presence of surface liquid water. Despite their ubiquity, the dearth of quantitative field data on the patterns and their slow dynamics have hindered fundamental understanding of the pattern formation mechanisms. Here, we use laboratory experiments to show that stone transport is strongly dependent on local stone concentration and the height of ice needles, leading effectively to pattern formation driven by needle ice activity. Through numerical simulations, theory, and experiments, we show that the nonlinear amplification of long wavelength instabilities leads to self-similar dynamics that resemble phase separation patterns in binary alloys, characterized by scaling laws and spatial structure formation. Our results illustrate insights to be gained into patterns in landscapes by viewing the pattern formation through the lens of phase separation. Moreover, they may help interpret spatial structures that arise on diverse planetary landscapes, including ground patterns recently examined using the rover Curiosity on Mars.

3.
BMC Vet Res ; 18(1): 386, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329508

RESUMO

BACKGROUND: Salmonella infection in livestock and poultry causes salmonellosis, and is mainly treated using antibiotics. However, the misuse use of antibiotics often triggers the emergence of multi-drug-resistant Salmonella strains. Currently, Salmonella phages is safe and effective against Salmonella, serving as the best drug of choice. This study involved 16 Salmonella bacteriophages separated and purified from the sewage and the feces of the broiler farm. A phage, vB_SalP_LDW16, was selected based on the phage host range test. The phage vB_SalP_LDW16 was characterized by the double-layer plate method and transmission electron microscopy. Furthermore, the clinical therapeutic effect of phage vB_SalP_LDW16 was verified by using the pathogenic Salmonella Enteritidis in the SPF chicken model. RESULTS: The phage vB_SalP_LDW16 with a wide host range was identified to the family Siphoviridae and the order Caudoviridae, possess a double-stranded DNA and can lyse 88% (22/25) of Salmonella strains stored in the laboratory. Analysis of the biological characteristics, in addition, revealed the optimal multiplicity of infection (MOI) of vB_SalP_LDW16 to be 0.01 and the phage titer to be up to 3 × 1014 PFU/mL. Meanwhile, the phage vB_SalP_LDW16 was found to have some temperature tolerance, while the titer decreases rapidly above 60 ℃, and a wide pH (i.e., 5-12) range as well as relative stability in pH tolerance. The latent period of phage was 10 min, the burst period was 60 min, and the burst size was 110 PFU/cell. Furthermore, gastric juice was also found to highly influence the activity of the phage. The clinical treatment experiments showed that phage vB_SalP_LDW16 was able to significantly reduce the bacterial load in the blood through phage treatment, thereby improving the pathological changes in the intestinal, liver, and heart damage, and promoting the growth and development of the chicken. CONCLUSIONS: The phage vB_SalP_LDW16 is a highly lytic phage with a wide host range, which can be potentially used for preventing and treating chicken salmonellosis, as an alternative or complementary antibiotic treatment in livestock farming.


Assuntos
Bacteriófagos , Intoxicação Alimentar por Salmonella , Infecções por Salmonella , Animais , Bacteriófagos/genética , Galinhas/genética , Salmonella enteritidis/genética , Intoxicação Alimentar por Salmonella/veterinária , Antibacterianos , Genoma Viral
4.
Anaerobe ; 52: 115-121, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29936108

RESUMO

Clostridium perfringens is one of the leading causes of food poisoning worldwide. The aims of this study were to investigate the presence of C. perfringens in food supplied to school cafeterias, to assess the presence of toxin genes in the isolates, and to investigate the biofilm formation and antibiotic susceptibility of the isolates. A total of 30 C. perfringens strains (12.9%) from 232 samples of beef, pork, chicken, and duck meat were isolated. Toxin genes, including cpa, cpe, cpb2, and netB, were detected, while the cpb, etx, iap and tpeL genes were absent. Biofilm formation was analyzed, and all the isolates were able to form biofilm. Antibiotic resistance was observed against penicillin (97%), lincomycin (20%), bacitracin (97%), oxytetracycline (73%), trimethoprim (7%), gentamicin (10%), tetracycline (93%), erythromycin (83%), ampicillin (100%), amikacin (7%), and streptomycin (3%). In conclusion, the results showed that students are exposed to a potentially high risk of food poisoning by C. perfringens; therefore, precaution is required for these types of catering services.


Assuntos
Biofilmes/efeitos dos fármacos , Infecções por Clostridium/veterinária , Clostridium perfringens/isolamento & purificação , Farmacorresistência Bacteriana , Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/microbiologia , Carne/microbiologia , Animais , Antibacterianos/farmacologia , Toxinas Bacterianas , Galinhas , Infecções por Clostridium/microbiologia , Clostridium perfringens/efeitos dos fármacos , Clostridium perfringens/genética , Clostridium perfringens/fisiologia , Patos , Genótipo , Humanos , República da Coreia , Instituições Acadêmicas/estatística & dados numéricos , Suínos
5.
IUBMB Life ; 68(5): 388-93, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27015848

RESUMO

Reactive oxygen species (ROS) are at the center of many physiological and pathological processes. ROS generated due to oxidative stress can potentiate both cancer initiation and progression. Rotenone, which is an inhibitor of the mitochondrial electron transport chain complex I, results in the activation of NOX2 and release of ROS, and has been shown to display anticancer activity through the induction of apoptosis in various cancer cells. The mechanistic link between rotenone-dependent activation of NOX2 and induction of apoptosis is still elusive. In this study, we used the human lung cancer A549 cells to study the molecular mechanism(s) involved between rotenone-dependent activation of NOX2 and impairment of autophagic machinery. We report that acute exposure to rotenone induced mild NOX2-dependnet oxidative stress, which impaired the autophagic flux, resulting in cytosolic accumulation of LC3 and p62/STSQM1. We further show that this induction occurs through the PI3K/Akt/mTORC1 signaling pathway. We furthermore show that chronic exposure to rotenone lead to excessive NOX2-dependent ROS generation, increases autophagy, and decreases p62 level via increased-autophagic flux. Taken together, this study is the first mechanistic elucidation of how rotenone can be used to potently target cancer cells without overhauling the entire cellular machinery. © 2016 IUBMB Life 68(5):388-393, 2016.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Rotenona/farmacologia , Células A549 , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Pulmonares , Alvo Mecanístico do Complexo 1 de Rapamicina , Glicoproteínas de Membrana/metabolismo , Complexos Multiproteicos/metabolismo , NADPH Oxidase 2 , NADPH Oxidases/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Serina-Treonina Quinases TOR/metabolismo
6.
Acta Biochim Biophys Sin (Shanghai) ; 45(2): 115-22, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23343746

RESUMO

Metastasis-associated protein 1 (MTA1) high expression has been detected in a wide variety of human aggressive tumors and plays important roles in the malignant biological behaviors such as invasion, metastasis, and angiogenesis. However, the specific roles and mechanisms of MTA1 protein in regulating the malignant behaviors of non-small-cell lung cancer (NSCLC) cells still remain unclear. To elucidate the detailed functions of MTA1 protein, we down-regulated the MTA1 protein expression in NSCLC cell line by RNA interference (RNAi) in vitro, and found that down-regulation of MTA1 protein significantly inhibited the migration and invasion potentials of 95D cells. Further research revealed that down-regulation of MTA1 protein significantly decreased the activity of matrix metalloproteinase-9, which could be the mechanism responsible for the inhibition of 95D cells migration and invasion. In addition, the tube formation assay demonstrated that the number of complete tubes induced by the conditioned medium of MTA1-siRNA 95D cells was significantly smaller than that of 95D cells. These findings demonstrate that MTA1 protein plays important roles in regulating the migration, invasion, and angiogenesis potentials of 95D cells, suggesting that MTA1 protein down-regulation by RNAi might be a novel therapeutic approach to inhibit the progression of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Histona Desacetilases/metabolismo , Neovascularização Patológica/complicações , Neovascularização Patológica/fisiopatologia , Proteínas Repressoras/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Regulação para Baixo , Histona Desacetilases/genética , Humanos , Invasividade Neoplásica , Proteínas Repressoras/genética , Transativadores
7.
World J Surg ; 36(3): 623-31, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22270988

RESUMO

BACKGROUND: The purposes of the present study were to detect the expression of metastasis-associated protein 1 (MTA1) in patients with esophageal squamous cell cancer (ESCC), and to evaluate the relevance of MTA1 protein expression to the tumor progression, angiogenesis, and prognosis. METHODS: Both MTA1 protein and intratumoral microvessels were examined by immunohistochemical staining in 131 ESCC patients who successfully underwent subtotal esophagectomy and esophagogastric anastomosis at Qilu Hospital between Jan 2004 and Dec 2005. Intratumoral microvessel density (MVD) was recorded by counting CD-34 positive immunostained endothelial cells. All statistical analyses were performed with SPSS 13.0 statistical software. RESULTS: High expression of MTA1 protein was detected in 57 cases and significantly correlated with tumor invasion depth (P = 0.041), lymph node metastasis (P = 0.021), pathologic stage (P = 0.003), and MVD (P = 0.044). Survival analysis showed that patients with MTA1 protein high expression had significantly poor overall 5-year survival (P = 0.002), and the factor found on multivariate analysis to significantly affect overall survival was only pathologic stage (P = 0.040). Further stratified survival analysis split by pathologic stage demonstrated that MTA1 protein high expression significantly predicted unfavorable prognosis among patients with pathologic stage II disease (P = 0.006). CONCLUSIONS: High expression of the MTA1 protein is common in ESCC, and is closely associated with tumor progression, increased tumor angiogenesis, and poor survival. These findings indicate that MTA1 protein has clinical potentials as a useful indicator of progressive phenotype, a promising prognostic predictor to identify patients with poor prognosis, and a potential novel therapeutic target of antiangiogenesis for patients with ESCC.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Histona Desacetilases/metabolismo , Neovascularização Patológica/metabolismo , Proteínas Repressoras/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Masculino , Microvasos/patologia , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço , Transativadores
8.
Acta Biochim Biophys Sin (Shanghai) ; 44(7): 577-83, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22595511

RESUMO

Lung cancer is the leading cause of cancer-related mortality all over the world. In recent years, pulmonary adenocarcinoma has surpassed squamous cell carcinoma in frequency and is the predominant form of lung cancer in many countries. Epidemiological investigations have shown an inverse relationship between garlic (Allium sativum) consumption and death rate from many cancers. Diallyl trisulfide (DATS) is one of the garlic-derived compounds (also known as: organosulfer compounds, OSC). DATS can induce apoptosis and inhibit the growth of many cancer cell lines. Our study demonstrated that the apoptotic incidents induced by DATS were a mitochondria-dependent caspase cascade through a significant decrease of the anti-apoptotic Bcl-2 that resulted in up-regulation of the ratio of Bax/Bcl-2 and the activity of caspase-3, -8, and -9. Eventually, DATS induced the apoptosis and inhibited the proliferation in a concentration- and time-dependent manner. Furthermore, by establishing an animal model of female BALB/c nude mice with A549 xenografts, we found that oral gavage of DATS significantly retarded growth of A549 xenografts in nude mice without causing weight loss or any other side effects compared with the control group. All the evidence both in vitro and in vivo suggested that DATS could be an ideal anti-cancer drug.


Assuntos
Compostos Alílicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Pulmonares/prevenção & controle , Sulfetos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antioxidantes/farmacologia , Western Blotting , Caspases/genética , Caspases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Alho/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga Tumoral/efeitos dos fármacos , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
9.
J Bacteriol ; 193(16): 4302-3, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21642450

RESUMO

Mycoplasma fermentans is a microorganism commonly found in the genitourinary and respiratory tracts of healthy individuals and AIDS patients. The complete genome of the repetitive-sequence-rich M. fermentans strain M64 is reported here. Comparative genomics analysis revealed dramatic differences in genome size between this strain and the recently completely sequenced JER strain.


Assuntos
Mycoplasma fermentans/classificação , Mycoplasma fermentans/genética , Genoma Bacteriano , Dados de Sequência Molecular
10.
Antimicrob Agents Chemother ; 55(8): 3829-37, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21646491

RESUMO

Significant increases in STM3031, STM1530, and AcrD protein levels and significant decreases in OmpC and OmpD protein levels are present when the ceftriaxone-resistant Salmonella enterica serovar Typhimurium R200 strain is compared with the ceftriaxone-susceptible strain 01-4. AcrD is known to be involved in drug export, and STM3031 seems to play a key role in ceftriaxone resistance. Here, we examine the roles of STM1530, OmpC, and OmpD in ceftriaxone resistance. An ompD gene deletion mutant showed 4-fold higher ceftriaxone resistance than 01-4. An ompC gene deletion mutant showed 4-fold higher cephalothin and erythromycin resistance than 01-4, but there was no effect on ceftriaxone resistance. However, a stm1530 deletion mutant did show >64-fold lower ceftriaxone resistance than R200. Moreover, the STM3031 protein was significantly decreased in R200(Δstm1530) compared to R200. STM3031 expression has been shown to be influenced by the two-component system regulator gene baeR. CpxR seems to modulate BaeR. A cpxA-cpxR gene deletion mutant showed >2,048-fold lower ceftriaxone resistance than R200. The outer membrane protein profile of R200(ΔcpxAR) showed significant decreases in STM3031 and STM1530 compared to R200, while OmpD had returned to the level found in 01-4. Furthermore, the stm3031, stm1530, and ompD mRNA levels were correlated with their protein expression levels in these strains, while decreases in the mRNA levels of the efflux pump acrB, acrD, and acrF genes were found in R200(ΔcpxAR). Findings similar to those for R200(ΔcpxAR) were found for R200(ΔbaeSR). These results, together with those for STM3031 and the fact that STM1530 is an outer membrane protein, suggest that STM1530 and OmpD are influenced by the CpxAR and BaeSR two-component systems and that this contributes to S. enterica serovar Typhimurium ceftriaxone resistance.


Assuntos
Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/biossíntese , Ceftriaxona/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/metabolismo , Resistência às Cefalosporinas , Regulação Bacteriana da Expressão Gênica , Testes de Sensibilidade Microbiana , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Porinas/biossíntese , Porinas/genética , Proteínas Quinases/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Salmonella typhimurium/metabolismo , Deleção de Sequência , Transativadores/metabolismo
11.
BMC Microbiol ; 11: 33, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21314918

RESUMO

BACKGROUND: BtuB (B twelve uptake) is an outer membrane protein of Escherichia coli. It serves as a receptor for cobalamines uptake or bactericidal toxin entry. A decrease in the production of the BtuB protein would cause E. coli to become resistant to colicins. The production of BtuB has been shown to be regulated at the post-transcriptional level. The secondary structure of 5' untranslated region of btuB mRNA and the intracellular concentration of adenosylcobalamin (Ado-Cbl) would affect the translational efficiency and RNA stability of btuB gene. The transcriptional regulation of btuB expression is still unclear. RESULTS: To determine whether the btuB gene is also transcriptionally controlled by trans-acting factors, a genomic library was screened for clones that enable E. coli to grow in the presence of colicin E7, and a plasmid carrying gadX and gadY genes was isolated. The lacZ reporter gene assay revealed that these two genes decreased the btuB promoter activity by approximately 50%, and the production of the BtuB protein was reduced by approximately 90% in the presence of a plasmid carrying both gadX and gadY genes in E. coli as determined by Western blotting. Results of electrophoretic mobility assay and DNase I footprinting indicated that the GadX protein binds to the 5' untranslated region of the btuB gene. Since gadX and gadY genes are more highly expressed under acidic conditions, the transcriptional level of btuB in cells cultured in pH 7.4 or pH 5.5 medium was examined by quantitative real-time PCR to investigate the effect of GadX. The results showed the transcription of gadX with 1.4-fold increase but the level of btuB was reduced to 57%. CONCLUSIONS: Through biological and biochemical analysis, we have demonstrated the GadX can directly interact with btuB promoter and affect the expression of btuB. In conclusion, this study provides the first evidence that the expression of btuB gene is transcriptionally repressed by the acid responsive genes gadX and gadY.


Assuntos
Fator de Transcrição AraC/metabolismo , Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Proteínas de Membrana Transportadoras/biossíntese , Proteínas Repressoras/metabolismo , Antibacterianos/metabolismo , Antibacterianos/toxicidade , Fusão Gênica Artificial , Western Blotting , Colicinas/metabolismo , Colicinas/toxicidade , Pegada de DNA , DNA Bacteriano/metabolismo , Farmacorresistência Bacteriana , Ensaio de Desvio de Mobilidade Eletroforética , Genes Reporter , Regiões Promotoras Genéticas , Ligação Proteica , Transcrição Gênica , beta-Galactosidase/análise , beta-Galactosidase/genética
12.
Ann Surg Oncol ; 18(7): 2048-56, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21290196

RESUMO

BACKGROUND: The aims of this work are to detect the expression levels of metastasis-associated protein 1 (MTA1) in patients with early-stage non-small cell lung cancer (NSCLC), and to investigate the relationship of MTA1 protein with clinicopathologic factors, tumor angiogenesis, and prognosis. METHODS: One hundred and two patients with pathologic stage I NSCLC who successfully underwent curative surgical resection were enrolled in this study. Immunohistochemical staining for MTA1 and CD34 was performed using the streptavidin-peroxidase method, and intratumoral microvessel density (MVD) was recorded by counting CD34-positive immunostained endothelial cells. All statistical analyses were performed with SPSS statistical software to determine the effects of MTA1 protein on clinicopathologic factors, tumor angiogenesis, and prognosis. RESULTS: MTA1 protein overexpression was detected in 41 cases and was significantly associated with MVD (P = 0.008). MTA1 protein overexpression and high MVD were significantly associated with tumor relapse (P = 0.004 and 0.007) and poor 5-year disease-free survival (P = 0.001 and 0.004). Patients with MTA1 protein overexpression and high MVD had significantly poor overall survival (P = 0.005 and 0.043) and disease-specific survival (P = 0.006 and 0.031) at 5 years after operation. Multivariate analysis demonstrated that MTA1 protein overexpression was an independent prognosticator for unfavorable disease-free, overall, and disease-specific survival (P = 0.011, 0.024, and 0.046). CONCLUSIONS: MTA1 protein overexpression is common in early-stage NSCLC and is significantly associated with tumor angiogenesis and poor survival. These findings suggest that MTA1 may have clinical potential as a promising predictor to identify individuals with poor prognostic potential and as a possible novel target molecule of antiangiogenic therapy for patients with early-stage NSCLC.


Assuntos
Adenocarcinoma/mortalidade , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma de Células Escamosas/mortalidade , Histona Desacetilases/metabolismo , Neovascularização Patológica , Proteínas Repressoras/metabolismo , Adenocarcinoma/irrigação sanguínea , Adenocarcinoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/metabolismo , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Taxa de Sobrevida , Transativadores , Resultado do Tratamento
13.
Front Pharmacol ; 12: 684545, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603016

RESUMO

Esophageal cancer is the ninth most common malignancy worldwide, ranking sixth in mortality. Platinum-based chemotherapy is commonly used for treating locally advanced esophageal cancer, yet it is ineffective in a large portion of patients. There is a need for reliable molecular markers with direct clinical application for a prospective selection of patients who can benefit from chemotherapy and patients in whom toxicity is likely to outweigh the benefit. The cytotoxic activity of platinum derivatives largely depends on the uptake and accumulation into cells, primarily by organic cation transporters (OCTs). The aim of the study was to investigate the impact of OCT expression on the clinical outcome of patients with esophageal cancer treated with oxaliplatin. Twenty patients with esophageal squamous cell carcinoma (SCC) were prospectively enrolled and surgical specimens used for screening OCT expression level by western blotting and/or immunostaining, and for culture of cancer cells. Sixty-seven patients with SCC who received oxaliplatin and for whom follow-up was available were retrospectively assessed for organic cation/carnitine transporter 2 (OCTN2) expression by real time RT-PCR and immunostaining. OCTN2 staining was also performed in 22 esophageal adenocarcinomas. OCTN2 function in patient-derived cancer cells was evaluated by assessing L-carnitine uptake and sensitivity to oxaliplatin. The impact of OCTN2 on oxaliplatin activity was also assessed in HEK293 cells overexpressing OCTN2. OCTN2 expression was higher in tumor than in normal tissues. In patient-derived cancer cells and HEK293 cells, the expression of OCTN2 sensitized to oxaliplatin. Patients treated with oxaliplatin who had high OCTN2 level in the tumor tissue had a reduced risk of recurrence and a longer survival time than those with low expression of OCTN2 in tumor tissue. In conclusion, OCTN2 is expressed in esophageal cancer and it is likely to contribute to the accumulation and cytotoxic activity of oxaliplatin in patients with esophageal carcinoma treated with oxaliplatin.

14.
J Cell Biochem ; 111(2): 402-11, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20503246

RESUMO

The Wnt/ß-catenin pathway has been implicated in leukemogenesis. We found ß-catenin abnormally accumulated in both human acute T cell leukemia Jurkat cells and human erythroleukemia HEL cells. ß-Catenin can be significantly down-regulated by the Janus kinase 2 specific inhibitor AG490 in these two cells. AG490 also reduces the luciferase activity of a reporter plasmid driven by LEF/ß-catenin promoter. Similar results were observed in HEL cells infected with lentivirus containing shRNA against JAK2 gene. After treatment with 50 µM AG490 or shRNA, the mRNA expression levels of ß-catenin, APC, Axin, ß-Trcp, GSK3α, and GSK3ß were up-regulated within 12-16 h. However, only the protein levels of GSK3ß and ß-Trcp were found to have increased relative to untreated cells. Knockdown experiments revealed that the AG490-induced inhibition of ß-catenin can be attenuated by shRNA targeting ß-TrCP. Taken together; these results suggest that ß-Trcp plays a key role in the cross-talk between JAK/STAT and Wnt/ß-catenin signaling in leukemia cells.


Assuntos
Regulação Neoplásica da Expressão Gênica , Janus Quinase 2/metabolismo , Leucemia Eritroblástica Aguda/metabolismo , Leucemia de Células T/metabolismo , beta Catenina/genética , Proteínas Contendo Repetições de beta-Transducina/fisiologia , Acetilcisteína/farmacologia , Humanos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Células Jurkat , Leucemia Eritroblástica Aguda/patologia , Leucemia de Células T/patologia , RNA Mensageiro/análise , Receptor Cross-Talk , Transdução de Sinais , beta Catenina/biossíntese
15.
J Biomed Sci ; 17: 52, 2010 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-20587027

RESUMO

Open reading frame l0045 in the pathogenic island of enterohemorrhagic Escherichia coli O157:H7 has been predicted to encode a lytic transglycosylase that is homologous to two different gene products encoded by the same bacteria at loci away from the island. To deduce the necessity of the presence in the island, we created an l0045-deleted strain of EHEC and observed that both the level of cytosolic EspA and that of the other type III secreted proteins in the media were affected. In a complementation assay, a low level-expressing L0045 appeared to recover efficiently the type III secretion (TTS). On the other hand, when l0045 was driven to express robustly, the intracellular levels of representative TTS proteins were severely suppressed. This suppression is apparently caused by the protein of L0045 per se since introducing an early translational termination codon abolished the suppression. Intriguingly, the authentic L0045 was hardly detected in all lysates of EHEC differently prepared while the same construct was expectedly expressed in the K-12 strain. A unique network must exist in EHEC to tightly regulate the presence of L0045, and we found that a LEE regulator (GrlA) is critically involved in this regulation.


Assuntos
Escherichia coli O157/genética , Ilhas Genômicas/genética , Glicosiltransferases/genética , Via Secretória/fisiologia , Primers do DNA/genética , Proteínas de Escherichia coli/metabolismo , Teste de Complementação Genética , Immunoblotting , Fases de Leitura Aberta/genética , Plasmídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Via Secretória/genética , Transativadores/metabolismo
16.
Antimicrob Agents Chemother ; 53(8): 3248-55, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19470505

RESUMO

Previously, the putative outer membrane protein STM3031 has been correlated with ceftriaxone resistance in Salmonella enterica serovar Typhimurium. In this study, this protein was almost undetectable in the ceftriaxone-susceptible strain 01-4, but its levels were increased in 01-4 isogenic strains for which MICs were higher. The stm3031 gene deletion mutant, R200(Deltastm3031), was generated and showed >64-fold lower ceftriaxone resistance than R200, supporting a key role for STM3031 in ceftriaxone resistance. To investigate which outer membrane protein(s) was associated with resistance, the outer membrane protein profiles of 01-4, R200, and R200(Deltastm3031) were compared proteomically. Nine proteins were identified as altered. The expression levels of AcrA, TolC, STM3031, STM1530, VacJ, and Psd in R200 were increased; those of OmpC, OmpD, and OmpW were decreased. The expression levels of OmpD, OmpW, STM1530, VacJ, and Psd, but not those of OmpC, AcrA, and TolC, in R200(Deltastm3031) were returned to the levels in strain 01-4. Furthermore, the genes' mRNA levels correlated with their protein levels when the three strains were compared. The detection of higher AcrB levels, linked to higher acrB, acrD, and acrF mRNA levels, in strain R200 than in strains 01-4 and R200(Deltastm3031) suggests that AcrB, AcrD, and AcrF participate in ceftriaxone resistance. Taken together with the location of STM3031 in the outer membrane, these results suggest that STM3031 plays a key role in ceftriaxone resistance, probably by reducing permeability via a decreased porin OmpD level and enhancing export via increased AcrD efflux pump activity.


Assuntos
Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/fisiologia , Ceftriaxona/farmacologia , Farmacorresistência Bacteriana/fisiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Western Blotting , Farmacorresistência Bacteriana/genética , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Testes de Sensibilidade Microbiana , Mutação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salmonella typhimurium/genética
17.
J Microbiol Immunol Infect ; 52(2): 282-288, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30448437

RESUMO

BACKGROUND/PURPOSE: The outer membrane protein STM3031 had been shown to confer Salmonella enterica serovar Typhimurium resistance to ceftriaxone. In this study, the STM3030 was increased in strain R200 and decreased in strain R200(Δstm3031). How stm3030 and stm3031 contributing to antibiotic resistance was investigated. METHODS: The level of STM3030 protein in R200(Δstm3031) were compared between 01-4, R200, and R200(Δstm3031) by 2-DE analysis. The stm3030 gene deleted strain, R200(Δstm3030), was generated by the one-step inactivation chromosome gene method. The various antibiotic susceptibility of strains 01-4, R200, R200(Δstm3031) and R200(Δstm3030) were determined by agar dilutions assays and E-test. The co-transcription of stm3031 and stm3030 were determined by RT-PCR. The promoter activities of these two genes fused with LacZ were determined. The binding of the regulatory protein BaeR on the promoter of both genes was detected by EMSA. The interaction between STM3030 and STM3031 proteins was determined by GST pull-down assay. RESULTS: Strain R200(Δstm3030) displayed a 32- to 64-fold reduction in resistance to cephalosporin drugs. Transcription analyses revealed that stm3030 and stm3031 are independent genes and that the promoter of stm3030 is stronger than that of stm3031. The regulator BaeR binds to the promoter region of stm3031 but not that of stm3030. The STM3031 decreased in R200(Δstm3030) compared to R200 by western blot analysis. The pull-down assay revealed that STM3030 and STM3031 bind to each other. CONCLUSION: Our data indicate that STM3030 has a chaperone-like activity and may modulate or stabilize STM3031, leading to resistance of S. enterica serovar Typhimurium to cephalosporin drugs.


Assuntos
Proteínas de Bactérias/genética , Ceftriaxona/farmacologia , Resistência às Cefalosporinas/genética , Genes Bacterianos/genética , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Sorogrupo , Proteínas da Membrana Bacteriana Externa/genética , Cromossomos Bacterianos/genética , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Humanos , Testes de Sensibilidade Microbiana , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes
18.
Onco Targets Ther ; 12: 10739-10747, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31849482

RESUMO

OBJECTIVE: To investigate the expression of tumor suppressor protein ASK1-interacting protein-1 (AIP1) in cancer tissues of patients with early-stage non-small cell lung cancer (NSCLC) and its correlation with tumor progression, tumor angiogenesis and prognosis. METHODS: A total of 136 patients with stage I NSCLC who underwent radical resection of lung cancer in Qianfoshan Hospital of Shandong Province from January 2011 to December 2011 were enrolled. Immunohistochemistry was used to detect AIP1 protein in tumor tissues. Vascular endothelial CD34 immunohistochemical staining was used to count intratumoral microvessel density (MVD). SPSS 19.0 software was used to analyze the relationship between AIP1 protein expression and clinicopathological features, tumor angiogenesis and prognosis. RESULTS: Low expression of AIP1 was more common in tumor tissues with high MVD, and patients with low expression of AIP1 were more likely to have tumor recurrence. Multivariate analysis showed that low expression of AIP1 had predictive value for overall survival, disease-free survival, and disease-specific survival. CONCLUSION: Downregulation of AIP1 protein expression is associated with lung cancer progression, tumor angiogenesis and poor prognosis. Consequently, AIP1 may prove to be an important predictor of recovery from lung cancer and could become a new therapeutic target for lung cancer treatment.

19.
Onco Targets Ther ; 11: 7699-7707, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30464518

RESUMO

OBJECTIVE: To investigate the expression of tumor suppressor protein ASK1-interacting protein-1 (AIP1) in human esophageal squamous cell carcinoma (ESCC) and its role in tumor progression, angiogenesis, and prognosis. METHODS: A total of 117 biopsy samples were obtained from ESCC patients. None of the patients had distant metastasis before surgery, and did not receive preoperative chemotherapy or radiotherapy. Immunohistochemistry was used to detect the expression of AIP1 protein and vascular endothelial growth factor receptor 2 (VEGFR2) in ESCC specimens collected from 117 patients who underwent esophageal cancer radical surgery. Microvessel density (MVD) was evaluated by immunohistochemical staining of vascular endothelial CD34. The correlation between AIP1 protein and clinicopathological characteristics, tumor angiogenesis, and prognosis was analyzed. RESULTS: The downregulation of AIP1 protein in esophageal carcinoma tissues was detected in 63 cases. This downregulation significantly correlated with lymph node metastasis, clinicopathological staging, and tumor MVD (P<0.05). Survival analysis showed that ESCC patients with a low expression of AIP1, a high expression of VEGFR2, and a high level of MVD had a lower 5-year survival rate (P<0.05). Multivariate analysis confirmed that the downregulation of AIP1 significantly affected patient survival. CONCLUSION: The downregulation of AIP1 correlated with ESCC progression, tumor angiogenesis, and poor prognosis. AIP1 could be a promising biomarker for predicting ESCC prognosis and a potential target for anti-angiogenic therapy.

20.
J Invest Surg ; 29(6): 335-342, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27050249

RESUMO

PURPOSE: To investigate the potential protective effects of Proanthocyanidins(PAs) on intestinal motility disturbance following intestinal ischemia/reperfusion (I/R). MATERIALS AND METHODS: Male rats were divided into four groups: Sham, I/R, I/R+PA100 and I/R+PA200. Sham group underwent laparotomy without ligation, the others were subjected to intestinal ischemia for 1 h and reperfusion 4 h. Rats in the I/R+PA100 group received PAs (100 mg/kg/d) for 5 days prior to I/R, while rats in the I/R+PA200 group received PAs (200 mg/kg/d). After reperfusion, using an electrophysiology instrument measured ileal slow wave. Ileal specimens were obtained to determine contractility, tissue levels of Bax, Bcl-2, and Caspase-3 and evaluate histopathological changes. In addition, blood sample was obtained to determine serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels. RESULTS: Intestinal I/R caused severe histopathological injury including mucosal erosions, inflammatory cell infiltration, necrosis, and hemorrhage. Both PAs treatment decreased mucosal pathological impairment in comparison with the I/R group (p < .05) in light microscopic evaluations. In both PAs-treated groups, Bax and Caspase-3 expression were decreased compared to I/R group, while the Bcl-2 expression increased (p < .05), which was similarly the case for serum SOD activity demonstrated significant enhance (p < .05) and decline in MDA levels in comparison with I/R group (both p < .05). Moreover, PAs treatment was more efficient in attenuating serum MDA levels of intestinal I/R (both p < .05). And the contractile amplitude and frequency of slow wave in I/R+PA100 and I/R+PA200 groups were higher than I/R group (both p < .05). CONCLUSIONS: PAs improve intestinal motility disturbance following intestinal I/R by alleviating oxidative stress and apoptosis.


Assuntos
Motilidade Gastrointestinal/efeitos dos fármacos , Íleo/efeitos dos fármacos , Proantocianidinas/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Caspase 3/metabolismo , Avaliação Pré-Clínica de Medicamentos , Íleo/irrigação sanguínea , Íleo/metabolismo , Íleo/patologia , Masculino , Malondialdeído/sangue , Proantocianidinas/farmacologia , Distribuição Aleatória , Ratos Sprague-Dawley , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/patologia , Circulação Esplâncnica , Superóxido Dismutase/sangue , Proteína X Associada a bcl-2/metabolismo
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