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1.
J Cell Biochem ; 119(2): 2440-2449, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28926119

RESUMO

DNA hypermethylation and the silencing of tumor suppressor genes caused by DNA hypermethylation is considered as a molecular hallmark of many kinds of cancers. Procaine, a local anesthetic, has been shown as a potential DNA methylation inhibitor in some types of cancers. However, the influence of procaine on DNA methylation regulation as well as the biological function in gastric cancer is still unknown. We report here that procaine represses the DNA-methylation level and promotes the proliferation arrest and apoptosis of gastric cancer cells. Global DNA methylation measurement demonstrates that procaine significantly reduces the global DNA methylation level. Analyses of the DNMTs expression and activity show procaine represses the activity, but not the expression, of DNMT1/DNMT3A. Further evidence on specific genes shows that procaine reduces the DNA methylation level in the promoter regions of CDKN2A and RARß genes through abrogating the binding of DNMT1/DNMT3A toward these regions. This repression would not be reversed by the overexpression of DNMT1/DNMT3A. Moreover, RT-qPCR and luciferase report assays demonstrate that procaine leads to the upregulation of CDKN2A and RARß due to the activation of the promoter of these genes. In the end, we test the function of procaine toward gastric cancer cells and find that procaine has the growth inhibitory and apoptosis inducement effect toward gastric cancer cells. Collectively, our data not only uncovers the regulation mechanisms of procaine to DNA methylation but also suggests an anti-tumor potential of procaine specific to the gastric carcinoma and provides a new therapeutic strategy for gastric carcinoma.


Assuntos
Antineoplásicos/farmacologia , Metilação de DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Procaína/farmacologia , Neoplasias Gástricas/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ilhas de CpG/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p18/genética , DNA (Citosina-5-)-Metiltransferase 1/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , DNA Metiltransferase 3A , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Regiões Promotoras Genéticas/efeitos dos fármacos , Receptores do Ácido Retinoico/genética , Neoplasias Gástricas/tratamento farmacológico
2.
Cell Physiol Biochem ; 50(1): 196-213, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30278464

RESUMO

BACKGROUND/AIMS: Since the combined actions of lncRNAs and miRNAs have been considered to be involved in the occurrence and development of various neoplasms, the main purpose of this study was to discover whether and how lncRNA H19 and miR-194 influenced the epithelial-mesenchymal transition (EMT) process of colorectal adenocarcinoma (CRA). METHODS: Totally 214 pairs of CRA and adjacent normal tissues were collected, and 5 human CRA cell lines (i.e. HCT116, HT-29, RKO SW280 and Lovo) were purchased. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was adopted to quantify the H19 and miR-194-5p expressions in cells and tissues. The expressions of FoxM1, E-cadherin, vimentin, N-cadherin were determined using western blot. On the side, si-H19, si-NC, miR-194-5p mimic, miR-194-5p inhibitor and negative control (NC) were transfected into CRA cell lines. Meanwhile, the invasive, migratory and proliferative conditions of the cells were assessed through transwell, wound healing and colony-forming experiments, with final verification of the relationship between H19 and miR-194-5p employing dual-luciferase reporter gene assay. RESULTS: Highly-expressed H19, lowly-expressed miR-194-5p, low-grade differentiation and lymph node metastasis appeared as the independent predictors of unfavorable prognosis in CRA patients' (all P< 0.05). It indicated that FoxM1 expression displayed positive correlations with H19 expression, yet negative associations with miR-194-5p expression within CRA tissues (P< 0.05). In addition, transfection of H19-siRNA and miR-145-5p mimic triggered a conspicuous increase in E-cadherin expression, as well as an evidently down-regulation in vimentin and N-cadherin expressions within HT29 and RKO cells (P< 0.05). On the other hand, the invasive and migratory capacities of CRA cells were significantly hindered (P< 0.05). Moreover, the luciferase reporter gene assay confirmed that H19 modified miR-194-5p expression through directly targeting at it (P< 0.05). Ultimately, FoxM1 could reverse the role of miR-194-5p in inhibiting invasion, migration and EMT of CRA cells (P< 0.05). CONCLUSION: LncRNA H19/miR-194/FoxM1 axis could serve as a profound target for the diagnosis and treatment of CRA.


Assuntos
Adenocarcinoma/patologia , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Vimentina/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Antagomirs/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Regulação para Baixo , Feminino , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Humanos , Masculino , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Pessoa de Meia-Idade , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Taxa de Sobrevida , Vimentina/genética
3.
BMC Public Health ; 18(1): 986, 2018 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-30089451

RESUMO

BACKGROUND: The prevalence of childhood obesity is increasing and psychological disorder is a common comorbidity of obesity. We investigated the associations of physical activity (PA) and fruit and vegetable (FV) intake with well-being and depressive symptoms among obese schoolchildren. METHODS: Participants included 188 obese children aged 9.8 ± 0.7 years living in Wuhan, China. Self-administered questionnaires were used to collect the children's PA and FV intake information. PA was considered to be high if the child participated in sport and/or vigorous free play at least 3 days per week with 60 min per day, while sufficient FV intake was defined as consuming FV 5 times per day. Children's well-being and depressive symptoms were assessed by standard questionnaires. Multiple logistic regression was performed to determine the odds ratios (ORs) and 95% confidence intervals (CIs) of the relationships of PA and FV intake with well-being and depressive symptoms. RESULTS: High PA and sufficient FV intake were independently associated with significantly decreased risks for depressive symptoms (for PA, OR: 0.39, 95% CI: 0.16-0.92; for FV, OR: 0.21, 95% CI: 0.08-0.55) and poor well-being (for PA, OR: 0.35, 95% CI: 0.16-0.74), respectively. Furthermore, interactive inverse associations were observed between combined high PA and sufficient FV intake with poor well-being and depressive symptoms. Compared to their counterparts, children with high PA and sufficient FV intake had significantly reduced risk for poor well-being (OR: 0.16, 95%CI: 0.05-0.55) and depressive symptoms (OR: 0.12, 95% CI: 0.03-0.48). CONCLUSIONS: High PA and sufficient FV intake are inversely associated with the risks of poor well-being and depressive symptoms among obese Chinese schoolchildren.


Assuntos
Depressão/prevenção & controle , Ingestão de Alimentos/fisiologia , Ingestão de Alimentos/psicologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Obesidade/prevenção & controle , Índice de Massa Corporal , Criança , China , Estudos Transversais , Feminino , Frutas , Humanos , Modelos Logísticos , Masculino , Prevalência , Inquéritos e Questionários , Verduras
4.
RSC Adv ; 12(43): 27963-27969, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36320274

RESUMO

In this study, we report a one-pot synthesis and enzyme-responsiveness of polyethylene glycol (PEG) and glutamic acid (Glu)-based amphiphilic doxorubicin (DOX) prodrug nanomicelles for cancer therapeutics. The nanomicelles were accomplished by esterification and amidation reactions. The nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) data confirmed the structure of nanomicelles. The DOX-loaded nanomicelles showed a DLS-measured average size of 107 nm and excellent stability in phosphate-buffered saline (PBS) for 7 days. The drug loading and cumulative release rates were measured by ultraviolet-visible (UV-vis) spectrophotometry at 481 nm. The cumulative release rate could reach 100% in an enzyme-rich environment. Further, the therapeutic efficiency of nanomicelles to cancer cells was determined by cell viability and cellular uptake and distribution using HeLa cells. The cell viability study showed that the DOX-loaded nanomicelles could effectively inhibit the HeLa cell proliferation. The cellular uptake study confirmed that the nanomicelles could be effectively ingested by HeLa cells and distributed into cell nuclei. Based on the collective experimental data, this study demonstrated that the synthesized nanomicellar prodrug of DOX is a potential candidate for cancer therapeutics.

5.
Analyst ; 136(20): 4168-73, 2011 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-21858296

RESUMO

A validated, simple, and sensitive fluorescence quenching method for the determination of ranitidine, nizatidine, and cimetidine in tablets and biological fluids is presented. This is the first single fluorescence method reported for the analysis of all three H(2) antagonists. The competitive reaction between the investigated drug and the palmatine probe for the occupancy of the cucurbit[7]uril (CB[7]) cavity was studied using spectrofluorometry. CB[7] was found to react with the probe to form a stable complex. The fluorescence intensity of the complex was also enhanced greatly. However, the addition of the drug dramatically quenched the fluorescence intensity of the complex. Accordingly, a new fluorescence quenching method for the determination of the studied drugs was established. The different experimental parameters affecting the fluorescence quenching intensity were studied carefully. At optimum reaction conditions, the rectilinear calibration graphs between the fluorescence quenching values (ΔF) and the medicament concentration were obtained in the concentration range of 0.04-1.9 µg mL(-1) for the investigated drugs. The limits of detection ranged from 0.013 to 0.030 µg mL(-1) at 495 nm using an excitation wavelength of 343 nm. The proposed method can be used for the determination of the three H(2) antagonists in raw materials, dosage forms and biological fluids.


Assuntos
Corantes Fluorescentes/química , Antagonistas dos Receptores H2 da Histamina/análise , Espectrometria de Fluorescência , Hidrocarbonetos Aromáticos com Pontes/química , Cimetidina/análise , Cimetidina/urina , Antagonistas dos Receptores H2 da Histamina/urina , Humanos , Concentração de Íons de Hidrogênio , Imidazóis/química , Nizatidina/análise , Nizatidina/urina , Ranitidina/análise , Ranitidina/urina , Temperatura
6.
Hum Cell ; 33(4): 1155-1164, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32504285

RESUMO

Hepatocellular carcinoma (HCC) remains a lethal cancer type for both males and females. MicroRNAs (miRNAs) contribute to the initiation, development and metastasis of cancer. Although several miRNAs have been identified as drivers or suppressors of HCC, the molecular mechanisms of many miRNAs have not been investigated. Currently, we discovered that miR-4270-5p was a significantly downregulated miRNA in HCC. We revealed that miR-4270-5p overexpression inhibited cell proliferation and invasion of HCC cells. The data manifested that miR-4270-5p directly targeted SATB2, a key regulator of epithelial mesenchymal transition (EMT), in HCC cells and reversed the EMT process. The rescue experiments suggested that SATB2 overexpression reversed the biological function of miR-4270-5p in HCC cells. Clinical data indicated that SATB2 expression was negatively correlated with miR-4270-5p levels in HCC patients. Our findings provided potential targets for prognosis and treatment of patients with HCC.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Expressão Gênica/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , MicroRNAs/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Neoplasias Hepáticas/terapia , Masculino , Terapia de Alvo Molecular
7.
J Food Biochem ; 44(5): e13171, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32150765

RESUMO

Three polysaccharide fractions from bamboo shoot (Chimonobambusa quadrangularis), CPS70, CPS75, and CPS80, were prepared using a final ethanol concentration of 70%, 75%, and 80% in the precipitation process. In vitro digestibility and the prebiotic activity of CPS70, CPS75, and CPS80 were evaluated and compared. The results indicated that all three of the CPS fractions exhibit a high degree of nondigestibility to human gastric juice (>98.5%) or α-amylase hydrolysis (>94.5%). Compared with the blank control, the three CPS fractions could not only significantly (p < .05) stimulate the proliferation of B. adolescentis, B. infantis, B. bifidum, and L. acidophilus, but also significantly (p < .05) enhance the production of lactic, acetic, propionic, and butyric acids when these polysaccharides were added as alternative carbon sources to glucose during the in vitro fermentation of four probiotics. Furthermore, when comparing the three CPS fractions, CPS75 displayed the strongest prebiotic potential, as this polysaccharide had the strongest effect on the proliferation of probiotic bacteria as well as the greatest effect on SCFAs production. These results demonstrated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. PRACTICAL APPLICATIONS: Ethanol precipitation is the first step when extracting polysaccharides from aqueous extracts as it is simple, rapid, and easy to carry out. This study focuses on how different concentrations of ethanol used in the precipitation process affect the prebiotic potential of bamboo shoot (Chimonobambusa quadrangularis) polysaccharides (CPS). The result indicated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. To our knowledge, it is the first to evaluate the effects of the concentration of ethanol during the process of precipitation on prebiotic potential of polysaccharides, which can subsequently be applied to the optimization of ethanol concentration when precipitating natural polysaccharides for the purpose of in vitro fermentation.


Assuntos
Etanol , Prebióticos , Humanos , Peso Molecular , Poaceae , Polissacarídeos
8.
Nutrients ; 12(1)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31936767

RESUMO

This study aimed to evaluate the effectiveness of a school-based nutrition education and physical activity intervention on cardiovascular risk profile and mental health outcomes among Chinese children with obesity. Two primary schools were randomly allocated to the control group (CG) and the intervention group (IG). We selected children with obesity from 1340 students in the third and fourth grades as participants. The IG received 8 months of nutrition education and physical activity intervention, while the CG was waitlisted. A generalized estimating equation model was applied to assess repeated variables over time. A total of 171 children with obesity (99 IG and 72 CG) aged 9.8 ± 0.7 years completed the post-intervention stage. Compared with baseline, significant reductions were observed within the IG for depression and fasting plasma glucose at post-intervention. After adjusting for confounders, group and time interaction effects showed that the IG achieved improvements in the risk of poor well-being (p = 0.051) and social anxiety (p = 0.029), had decreased diastolic blood pressure (p = 0.020) and fasting plasma glucose (p < 0.001), and had significantly increased high-density lipoprotein (p < 0.001) from baseline to post-intervention relative to the CG. The effects of school-based nutrition education and physical activity intervention on children with obesity are diverse, including not only the improvement of metabolic health but also mental health promotion.


Assuntos
Ciências da Nutrição Infantil/educação , Exercício Físico , Obesidade Infantil/psicologia , Obesidade Infantil/terapia , Serviços de Saúde Escolar , Criança , China , Feminino , Educação em Saúde , Promoção da Saúde , Humanos , Masculino , Saúde Mental
9.
J Org Chem ; 74(2): 888-90, 2009 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-19049268

RESUMO

Palladium-catalyzed ring-opening thiocarbonylation of vinylcyclopropanes (VCPs) with thiols and carbon monoxide affords the corresponding unsaturated thioesters in moderate to excellent yields. This reaction provides a general method for the ring-opening thiocarbonylation of VCPs. It further demonstrates the utility of transition metal catalysts for the synthesis of organosulfur compounds.

10.
Org Lett ; 9(10): 1847-50, 2007 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-17428060

RESUMO

An enantioselective organocatalytic intramolecular ring-closing Friedel-Crafts-type alkylation of indolyl alpha,beta-unsaturated aldehydes has been developed. This powerful new strategy allows enantioselective access to THPIs and THBCs in a straightforward and atom-economical manner.


Assuntos
Indóis/química , Aldeídos/química , Alquilação , Catálise , Cristalografia por Raios X , Ciclização , Indóis/síntese química , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo
11.
Medicine (Baltimore) ; 96(5): e5521, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28151847

RESUMO

Th aim of this study was to develop a new facile chemical method for early screening of colorectal cancer.The -C(O)OH groups modified Carbon Quantum Dots (CQDs) were prepared by an facile innovative route of acid attacking on carbon nanotubes (CNTs). The -C(O)OH groups were further transported into -C(O)Cl groups by SOCl2 treating. The obtained ClCQDs were conjugated onto the anti-Desmin, which were applied for testing the Desmin concentration in serum by using linearly fitted relationship with photoluminescence (PL) intensity.The obtained carbon quantum dots are quasispherical graphite nanocrystals with photoluminescence at about 455 nm. The Desmin with concentration of 1 ng/mL can lead to a decrease of PL intensity for anti-Desmin conjugated CQDs with good linearity. This assay had good specificity for Desmin with in interferential substances of immunoglobulin G (IgG), alpha fetoprotein (AFP), and carcinoembryoic antigen (CEA).A new facile acid attack method was developed to prepare ClCQDs, which could conjugate onto the anti-Desmin for detection of Desmin in serum with high sensitivity and specificity. As the detection limit is lower than 1 ng/ mL, this work provides a promising strategy for the evaluation of colorectal cancer risk with low cost and excellent sensing performance.


Assuntos
Neoplasias Colorretais/sangue , Neoplasias Colorretais/diagnóstico , Desmina/sangue , Detecção Precoce de Câncer/métodos , Pontos Quânticos/química , Biomarcadores Tumorais , Carbono , Antígeno Carcinoembrionário/sangue , Humanos , Imunoglobulina G/sangue , Limite de Detecção , Medições Luminescentes/métodos , Nanotubos de Carbono , Sensibilidade e Especificidade , alfa-Fetoproteínas/análise
12.
Eur J Pharmacol ; 807: 168-173, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28433657

RESUMO

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Although the development of therapy approaches, the outcome of CRC patients still is poor, understanding the biological mechanism of CRC progression is critical to improve the treatment strategies. miRNAs regulate CRC progression, we found miR-938 was upregulated in CRC tissues and cells, MTT assay, colony formation assay and soft agar growth assay suggested miR-938 overexpression promoted CRC cell proliferation, miR-938 knockdown inhibited CRC cell proliferation. Tumor suppressor PH domain Leucine-rich-repeats Protein Phosphatase 2 (PHLPP2) was a target of miR-938, miR-938 inhibited PHLPP2, luciferase activity assay suggested miR-938 directly bound to the 3'UTR of PHLPP2, meanwhile, we found miR-938 promoted c-Myc and Cyclin D1 expression, confirming miR-938 promoted CRC cell proliferation. Double knockdown of miR-938 and PHLPP2 promoted CRC cell proliferation, suggesting miR-938 promoted CRC cell proliferation by inhibiting PHLPP2.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , MicroRNAs/genética , Fosfoproteínas Fosfatases/genética , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células/genética , Humanos , Regulação para Cima
13.
Ying Yong Sheng Tai Xue Bao ; 28(10): 3289-3296, 2017 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-29692148

RESUMO

In order to rapidly monitor chlorophyll content in cotton functional leaf, and establish the quantitative relationship between chlorophyll content and spectral characteristic parameter of single cotton leaf, cotton was pot cultivated in a rain shelter and subjected to waterlogging at squaring stage. Cotton leaf samples were taken and measured every 3 days after waterlogging. The correlation between chlorophyll content and spectral characteristic parameter was synthetically analyzed, and then the estimation model of chlorophyll content was established and verified. The results showed that the chlorophyll content decreased with increasing waterlogging stress. The original spectral reflectance and first order differential spectral reflectance was negatively correlated with the chlorophyll content in the band near 580 and 697 nm. The estimation model established by difference vegetation index and normalized difference vegetation index performed better than that established by linear model of single band. Furthermore, the estimation model with (DR697-DR738)/(DR697+DR738) as the independent variable fitted the best with the correlation coefficient of 0.814, which could be utilized to estimate chlorophyll content of single leaf under waterlogging stress.


Assuntos
Clorofila , Estresse Fisiológico , Folhas de Planta , Análise Espectral
14.
Int J Oncol ; 49(3): 1068-80, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27315344

RESUMO

Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumors, including gastric cancer. Aberrant miR-224 expression has been indicated in tumor growth, the mechanism of miR-224 promoting the proliferation and metastatic ability for gastric cancer remains unclear. Accumulating evidence reports that mTOR signal pathway plays an important role in the cellular process, such as apoptosis, cell growth and proliferation. The goal of the present study was to identify whether miR-224 could inhibit the growth, migration, invasion, proliferation and metastasis of gastric cancer through targeting mTOR expression. Real-time PCR (RT-PCR) was used to quantify miR-224 expression in vitro and in vivo experiments. Luciferase reporter assays were performed to confirm the activity of mTOR pathway, and immunofluorescence staining assay was conducted to observe apoptosis and cell proliferation ability. Bioinformatics as well as cell luciferase function studies distinguished the direct modulation of miR-224 on the 3'-UTR of the mTOR, which leads to the inactivation of apoptosis signaling and the activation of cell proliferation. In addition, inhibition of miR-224 significantly reduced the expression of mTOR and improved caspase-9/3 expression while decreased cyclin D1/2 levels, attenuating gastric cancer cell proliferation. Therefore, the present study revealed the mechanistic links between miR-224 and mTOR in the pathogenesis of gastric cancer through modulation of caspase-9/3 and cyclin D1/2. In addition, targeting miR-224 could serve as a novel strategy for future gastric cancer therapy.


Assuntos
MicroRNAs/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Invasividade Neoplásica , Transplante de Neoplasias , Prognóstico , Neoplasias Gástricas/metabolismo
15.
Artigo em Inglês | MEDLINE | ID: mdl-26565339

RESUMO

Self-consistent direct numerical simulations of turbulent channel flows of dilute polymer solutions exhibiting friction drag reduction (DR) show that an effective Deborah number defined as the ratio of polymer relaxation time to the time scale of fluctuations in the vorticity in the mean flow direction remains O(1) from the onset of DR to the maximum drag reduction (MDR) asymptote. However, the ratio of the convective time scale associated with streamwise vorticity fluctuations to the vortex rotation time decreases with increasing DR, and the maximum drag reduction asymptote is achieved when these two time scales become nearly equal. Based on these observations, a simple framework is proposed that adequately describes the influence of polymer additives on the extent of DR from the onset of DR to MDR as well as the universality of the MDR in wall-bounded turbulent flows with polymer additives.


Assuntos
Fricção , Hidrodinâmica , Polímeros/química , Reologia , Rotação , Soluções
16.
Onco Targets Ther ; 8: 2981-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26543373

RESUMO

MicroRNAs (miRNAs) have emerged as important regulators of cancer-cell biological processes. Previous studies have shown that miR-766 plays an important role in a variety of biological processes in various human cancers. However, the underlying mechanism of miR-766 in colorectal cancer (CRC) cells remains unclear. In this study, we investigated miR-766's role in CRC cell proliferation. Polymerase chain reaction results showed that miR-766 expression was significantly upregulated in CRC tissues and cells. Ectopic expression of miR-766 promoted cell growth and anchorage-independent growth in CRC cells. Bioinformatic analysis predicted SOX6, a potential target of miR-766, acting as a tumor suppressor. Luciferase reporter assay results demonstrated that miR-766 directly bound to the 3'-untranslated region of SOX6. Overexpression of miR-766 suppressed SOX6 expression, resulting in the downregulation of p21 and upregulation of cyclin D1. In a further experiment, SOX6-silenced SW480 cells transfected with miR-766 promoted cell growth, suggesting that downregulation of SOX6 was required for miR-766-induced CRC cell proliferation. Taken together, these results suggested that miR-766 represents an onco-miRNA and participates in the development of CRC by modulating SOX6 expression.

17.
Talanta ; 132: 653-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25476359

RESUMO

In this work, the competitive interaction between dibucaine and three fluorescent probes (i.e., berberine, palmatine, and coptisine) for occupancy of the cucurbit[7]uril (CB[7]) cavity was studied by fluorescence spectra, UV-visible absorption spectra, (1)H NMR spectra, and theoretical calculations in acidic aqueous solution. Based on the fluorescence enhancement of berberine, palmatine, and coptisine upon binding with CB[7], respectively, a series of fluorescence detection methods for dibucaine were proposed. At the optimized conditions, the fluorescence intensity of berberine-CB[7], palmatine-CB[7], and coptisine-CB[7] complexes showed negative correlation to the concentration of dibucaine, which led to a series of simple and sensitive fluorescence methods for the determination of dibucaine for the first time. Linear ranges obtained in the detection of the dibucaine were 0.018-3.34 µmol L(-1), 0.032-4.47 µmol L(-1), and 0.079-4.42 µmol L(-1) with detection limits of 6.0 nmol L(-1), 12.0 nmol L(-1), and 25.0 nmol L(-1), respectively. Moreover, the proposed method was successfully applied for the determination of the drug in biological fluids. The competitive mode based on CB[7] superstructure provided a promising assay strategy for fluorescence detection in various potential applications.


Assuntos
Anestésicos Locais/urina , Hidrocarbonetos Aromáticos com Pontes/química , Dibucaína/urina , Corantes Fluorescentes/química , Imidazóis/química , Berberina/análogos & derivados , Berberina/química , Alcaloides de Berberina/química , Ligação Competitiva , Humanos , Concentração de Íons de Hidrogênio , Cinética , Limite de Detecção , Soluções , Espectrometria de Fluorescência , Termodinâmica
18.
Mol Med Rep ; 10(2): 1108-16, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24842518

RESUMO

The aim of this study was to construct an expression vector carrying the hypoxia/radiation dual­sensitive chimeric hypoxia response element (HRE)/early growth response 1 (Egr­1) promoter in order to overexpress the therapeutic second mitochondria­derived activator of caspases (Smac). Using this expression vector, the present study aimed to explore the molecular mechanism underlying radiotherapy­induced A549 human lung adenocarcinoma cell death and apoptosis under hypoxia. The plasmids, pcDNA3.1­Egr1­Smac (pE­Smac) and pcDNA3.1­HRE/Egr-1­Smac (pH/E­Smac), were constructed and transfected into A549 human lung adenocarcinoma cells using the liposome method. CoCl2 was used to chemically simulate hypoxia, followed by the administration of 2 Gy X­ray irradiation. An MTT assay was performed to detect cell proliferation and an Annexin V­fluorescein isothiocyanate apoptosis detection kit was used to detect apoptosis. Quantitative polymerase chain reaction and western blot analyses were used for the detection of mRNA and protein expression, respectively. Infection with the pE­Smac and pH/E­Smac plasmids in combination with radiation and/or hypoxia was observed to enhance the expression of Smac. Furthermore, Smac overexpression was found to enhance the radiation­induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis. The cytochrome c/caspase­9/caspase­3 pathway was identified to be involved in this regulation of apoptosis. Plasmid infection in combination with X­ray irradiation was found to markedly induce cell death under hypoxia. In conclusion, the hypoxia/radiation dual­sensitive chimeric HRE/Egr­1 promoter was observed to enhance the expression of the therapeutic Smac, as well as enhance the radiation­induced inhibition of cell proliferation and promotion of cycle arrest and apoptosis under hypoxia. This apoptosis was found to involve the mitochondrial pathway.


Assuntos
Apoptose/efeitos da radiação , Proteína 1 de Resposta de Crescimento Precoce/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Mitocondriais/metabolismo , Radiação Ionizante , Elementos de Resposta/genética , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Proteínas Reguladoras de Apoptose , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Citocromos c/genética , Citocromos c/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/patologia , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Análise de Sequência de DNA
20.
Exp Ther Med ; 5(6): 1770-1774, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23837071

RESUMO

The Akt/NF-κB pathways are involved in numerous anti-apoptotic and drug-resistance events that occur in non-small cell lung cancer (NSCLC). In the present study, the role of 7,8-dihydroxycoumarin in the regulation of the anti-apoptotic Akt and NF-κBp65 signaling pathways was explored. A549 human lung adenocarcinoma cells were exposed to 7,8-dihydroxycoumarin with a final concentration of 25, 50 and 100 µmol/l for 48 h. Quantitative polymerase chain reaction (PCR) and western blotting were performed to detect mRNA and protein expression, respectively. The MTT assay was performed to detect cell proliferation. The results demonstrated that anti-apoptotic phospho-Akt1 (pAkt1), phospho-IκBα (pIκBα), NF-κBp65 and Bcl-2 were inhibited and pro-apoptotic caspase-3 was upregulated in a concentration-dependent manner. At a concentration of 100 µmol/l, the anti-apoptotic NF-κBp65 and Bcl-2 mRNA expression levels decreased 0.12 (5.82/48.5, treated/control)-fold and 0.17 (6.7/39.4, treated/control)-fold, respectively. The pro-apoptotic caspase-3 mRNA was upregulated 4.43 (39.4/8.9, treated/control)-fold. The anti-apoptotic pAkt1, pIκBα, NF-κBp65 and Bcl-2 proteins were downregulated, with blot grayscale values of 7.3 (vs. 52.4 control), 4.3 (vs. 42.2 control), 5.08 (vs. 44.5 control) and 5.92 (vs. 38.5 control), respectively. The proapoptotic caspase-3 was upregulated to a blot grayscale value of 27.8 (vs. 5.8 control). The proliferative activity of A549 cells was reduced significantly compared with that of the control cells (83.7, 27.2 and 9.5 vs. 100%, respectively; P<0.05 for each). 7,8-Dihydroxycoumarin plays an important role in the induction of apoptosis via suppression of Akt/NF-κB signaling in A549 human lung adenocarcinoma cells in a concentration-dependent manner. 7,8-Dihydroxycoumarin may be a candidate naturally-occurring drug for the treatment and prevention of lung adenocarcinoma.

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