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Genes Chromosomes Cancer ; 53(4): 277-88, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24488757


Stress-induced phosphoprotein1 (STIP1) is a candidate biomarker in epithelial ovarian cancer (EOC). In this study, we investigated in detail the expression of STIP1, as well as its functions, in EOC. STIP1 expression was assessed by immunohistochemistry (IHC) and the results were compared with clinicopathologic factors, including survival data. The effects of STIP1 gene silencing via small interfering RNA (siRNA) were examined in EOC cells and a xenograft model. The expression of STIP1 protein in EOC was significantly higher than in the other study groups (P < 0.001), and this increase of expression was significantly associated with tumor stage (P = 0.005), tumor grade (P = 0.029), and lymph node metastasis (P = 0.020). In multivariate analysis, overall survival in EOC was significantly shorter in cases with high STIP1 expression (HR = 2.78 [1.01-7.63], P = 0.047). STIP1 silencing in EOC cells resulted in inhibition of cell proliferation and invasion. In addition, in vivo experiments using STIP1 siRNA clearly showed a strong inhibition of tumor growth and a modulation of expression of prosurvival and apoptotic genes, further suggesting that STIP1 silencing can prevent cell proliferation and invasion. In conclusion, increased STIP1 expression is associated with poor survival outcome in EOC, and STIP1 may represent a useful therapeutic target in EOC patients.

Proteínas de Choque Térmico/genética , Neoplasias Epiteliais e Glandulares/diagnóstico , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genética , Adulto , Idoso , Animais , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Feminino , Proteínas de Choque Térmico/metabolismo , Xenoenxertos , Humanos , Proteínas Inibidoras de Diferenciação/genética , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Prognóstico , Proteína Smad1/metabolismo , Proteína Smad5/metabolismo
Talanta ; 119: 262-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24401413


Highly sensitive biosensor with 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) detection was developed to rapidly quantify Vibrio (V) parahaemolyticus without time-consuming procedures such as multiple long-incubations and washings. When V. parahaemolyticus in Tris-HCl (pH 7) and hairpin DNA aptamer conjugated with TEX615 in DNA free deionized water were consecutively added in PBS buffer (pH 7.4) containing graphene oxides (GOs), V. parahaemolyticus and GOs bind competitively to hairpin DNA aptamer conjugated with TEX615 during 10 min of incubation at room temperature. Brightness of light immediately emitted with the addition of ODI-CL reagents (e.g., ODI, H2O2) after the incubation was dependent on the concentration of V. parahaemolyticus in a sample. The dynamic range of linear calibration curve for the quantification of V. parahaemolyticus in a sample was from 4375 to 70,000 cells/ml. The limit of detection (LOD = background + 3 × standard deviation, 2230 cells/ml) of the biosensor operated with good accuracy, precision, and recovery was lower than those of conventional assay methods such as time-consuming and expensive enzyme-linked immunosorbent assays.

Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Grafite/química , Imidazóis/química , Vibrio parahaemolyticus/química , Limite de Detecção , Luminescência , Óxidos
Biosens Bioelectron ; 52: 310-6, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24080210


Cost-effective and sensitive aptasensor with guanine chemiluminescence detection capable of simply quantifying thrombin in human serum was developed using thrombin aptamer (TBA), one of the G-quadruplex DNA aptamers, without expensive nanoparticles and complicated procedures. Guanines of G-quadruplex TBA-conjugated carboxyfluorescein (6-FAM) bound with thrombin do not react with 3,4,5-trimethoxylphenylglyoxal (TMPG) in the presence of tetra-n-propylammonium hydroxide (TPA), whereas guanines of free TBA- and TBA-conjugated 6-FAM immobilized on the surface of graphene oxide rapidly react with TMPG to emit light. Thus, guanine chemiluminescence in 5% human serum with thrombin was lower than that without thrombin when TBA-conjugated 6-FAM was added in two samples and incubated for 20 min. In other words, the brightness of guanine chemiluminescence was quenched due to the formation of G-quadruplex TBA-conjugated 6-FAM bound with thrombin in a sample. High-energy intermediate, capable of emitting dim light by itself, formed from the reaction between guanines of TBA and TMPG in the presence of TPA, transfers energy to 6-FAM to emit bright light based on the principle of chemiluminescence energy transfer (CRET). G-quadruplex TBA aptasensor devised using the rapid interaction between TBA-conjugated 6-FAM and thrombin quantified trace levels of thrombin without complicated procedures. The limit of detection (LOD = background + 3 × standard deviation) of G-quadruplex TBA aptasensor with good linear calibration curve, accuracy, precision, and recovery was as low as 12.3 nM in 5% human serum. Using the technology reported in this research, we expect that various types of G-quadruplex DNA aptasensors capable of specifically sensing a target molecule such as ATP, HIV, ochratoxin, potassium ions, and thrombin can be developed.

Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Quadruplex G , Guanina/isolamento & purificação , Transferência de Energia , Grafite , Guanina/química , Humanos , Limite de Detecção , Luminescência
Talanta ; 116: 403-8, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24148422


The use of Triton X surfactants in developing 1,1'-oxalylimidazole chemiluminescent enzyme immunoassays (ODI CEIs) with extended linear response range for the quantification of unconjugated estriol (uE3), alpha-fetoprotein (AFP), and human chorionic gonadotropin (hCG) is reported for the first time. The wider linear dynamic range in ODI CLEIA results from Triton X series (e.g., Triton X-100, -114, -405, -705) acting as an inhibitor in the interaction between Amplex Red (hydrophobic substrate) and horseradish peroxidase (hydrophilic enzyme) to produce resorufin (hydrophobic fluorescent dye). Triton X-100 acts as the appropriate inhibitor in ODI CLEIA. The maximum concentrations of AFP and hCG quantified with sandwich ODI CLEIA in the presence of Triton X-100 were 8 times higher than when analyzed with the same system in the absence of Triton X-100. In addition, the lowest concentration of uE3 determined using competitive ODI CLEIA in the presence of Triton X-100 was 20 times lower than that measured with competitive ODI CLEIA in the absence of Triton X-100. These results indicate that rapid quantification of AFP, uE3, and hCG using cost effective and highly sensitive ODI CLEIAs in the presence of Triton X-100 can be applied as an accurate, precise, and reproducible method to diagnose genetic disorders (e.g., trisomy 18 and trisomy 21) in fetuses.

Gonadotropina Coriônica/sangue , Síndrome de Down/diagnóstico , Estriol/sangue , Técnicas Imunoenzimáticas , Octoxinol/química , Trissomia/diagnóstico , alfa-Fetoproteínas/metabolismo , Calibragem , Gonadotropina Coriônica/genética , Cromossomos Humanos Par 18/genética , Cromossomos Humanos Par 18/metabolismo , Síndrome de Down/genética , Síndrome de Down/metabolismo , Estriol/genética , Feto , Testes Genéticos , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Limite de Detecção , Medições Luminescentes , Oxazinas/química , Trissomia/genética , Síndrome da Trissomía do Cromossomo 18 , alfa-Fetoproteínas/genética
Talanta ; 116: 736-42, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24148468


One-step chemiluminescent aptasensor was developed using chemically initiated electron exchange luminescence (CIEEL) between high-energy intermediate formed from 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) reaction and G-quadruplex (ochratoxin A (OTA)-bound aptamer conjugated with TEX615) generated. The sensitivity of chemiluminescent aptasensor, optimized with various variables (e.g., property of microfibers fabricated with 3,4,9,10-perylenetetracarboxylic dimide, determination of fluorescent dye labeled with aptamer, physical properties of buffer solution), was dependent on the background (concentration of high-energy intermediate) generated in ODI-CL reaction. The limit of detection (LOD=background+3×standard deviation, 0.5 nM) of ODI-CL aptasensor with lower background was lower than that (3.7 nM) with 20 times higher background. Also, the ratio of signal to background (S/B) of ODI-CL aptasensor with low background was about 5-fold higher than that with high background. The sensitivities of ODI-CL aptasensors, with low as well as high background, capable of accurately and precisely quantifying OTA within 10 min, were better than those of fluorescent aptasensors and as good as those of highly sensitive but time-consuming competitive enzyme-linked immune-sorbent assays (ELISAs) using expensive antibody produced with the sacrifice of small animals.

Aptâmeros de Nucleotídeos/química , Imidazóis/química , Medições Luminescentes/normas , Micotoxinas/isolamento & purificação , Ocratoxinas/isolamento & purificação , Vinho/análise , Aptâmeros de Nucleotídeos/síntese química , Técnicas Biossensoriais , Tampões (Química) , Ensaio de Imunoadsorção Enzimática , Corantes Fluorescentes , Quadruplex G , Concentração de Íons de Hidrogênio , Imidas/química , Limite de Detecção , Medições Luminescentes/métodos , Perileno/análogos & derivados , Perileno/química , Razão Sinal-Ruído