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BACKGROUND: Chemoresistance is associated with tumor relapse and unfavorable prognosis. Multiple mechanisms underlying chemoresistance have been elucidated, including stemness and DNA damage repair. Here, the involvement of the WNT receptor, FZD5, in ovarian cancer (OC) chemoresistance was investigated. METHODS: OC cells were analyzed using in vitro techniques including cell transfection, western blot, immunofluorescence and phalloidin staining, CCK8 assay, colony formation, flowcytometry, real-time PCR, and tumorisphere formation. Pearson correlation analysis of the expression levels of relevant genes was conducted using data from the CCLE database. Further, the behavior of OC cells in vivo was assessed by generation of a mouse xenograft model. RESULTS: Functional studies in OC cells showed that FZD5 contributes to epithelial phenotype maintenance, growth, stemness, HR repair, and chemoresistance. Mechanistically, FZD5 modulates the expression of ALDH1A1, a functional marker for cancer stem-like cells, in a ß-catenin-dependent manner. ALDH1A1 activates Akt signaling, further upregulating RAD51 and BRCA1, to promote HR repair. CONCLUSIONS: Taken together, these findings demonstrate that the FZD5-ALDH1A1-Akt pathway is responsible for OC cell survival, and targeting this pathway can sensitize OC cells to DNA damage-based therapy.
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Aldeído Desidrogenase , Neoplasias Ovarianas , Humanos , Animais , Camundongos , Feminino , Aldeído Desidrogenase/genética , Resistencia a Medicamentos Antineoplásicos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Linhagem Celular Tumoral , Células-Tronco Neoplásicas/metabolismoRESUMO
In recent years, all-inorganic perovskites CsPbX3 (X = Cl, Br, I) have emerged as excellent candidates for solar cells due to their remarkable thermal stability and suitable bandgaps. Among them, CsPbI2Br is a hotspot in perovskite material research currently. Non-radiative electron-hole recombination often leads to significant energy losses, impacting the efficiency of solar cells, so a thorough understanding of carrier recombination mechanisms is crucial. Our work investigated the carrier recombination dynamics in detail and proved that strains can effectively reduce nonradiative recombination. In this study, using first-principles calculations combined with nonadiabatic (NA) molecular dynamics (MD), we demonstrate that applying 2% tensile and 2% compressive strains to CsPbI2Br can modify the bandgap, induce moderate disorder, reduce the overlap of electron-hole wavefunctions, decrease NA coupling, and shorten decoherence time, thereby minimizing non-radiative recombination and extending the carrier lifetime. Especially the 2% tensile strain exhibits more effective control performance, significantly reducing non-radiative electron-hole recombination and extending the charge carrier lifetime to 14.59 ns, nearly five times that of the pristine CsPbI2Br system (3.12 ns). This study reveals the impact mechanism of strain on carrier behavior in perovskite solar cells, providing a new non-chemical strategy for modulating the lifetime of photo-generated carriers and enhancing the efficiency of all-inorganic perovskite solar cells.
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Photonic integrated circuits with compact design have opened possibilities for the development of optical computing systems; however, the overuse of photonic components in optical designs has slowed the progress of dense integration. In this paper, we propose an ultra-compact optical full-adder based on directed logic and microring resonators. To the best of our knowledge, the proposed structure requires fewer optical components than any other current designs, resulting in a significantly reduced footprint 59.2µm×29.2µm. Also, the proposed structure exhibits a maximum delay time of approximately 10 ps, implying a minimum date rate of 100 GHz. Simulation results by finite-difference time-domain (FDTD) demonstrate the effectiveness and feasibility of the proposed optical full-adder.
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OBJECTIVE: To explore the effect of strontium in drinking water on blood pressure in hypertensive mice and its possible mechanism. METHODS: Establishment of mouse model of high blood pressure by drinking 2 mg/mL N'nitro-L-arginine methyl eater hydrochloride(L-NAME) for 4 weeks. One hundred ICR mice were randomly divided into normal control group(n=20) and model group(n=80) according to systolic blood pressure. Eighty hypertensive mice were randomly divided into model control group(n=20), 2.5 mg/L strontium water group(n=20), 5.0 mg/L strontium water group(n=20) and 10.0 mg/L strontium water group(n=20). The body weight and blood pressure of mice were measured every week. After 10 weeks, serum sodium(Na), potassium(K), calcium(Ca), magnesium(Mg), Chlorine(Cl), nitric oxide(NO), renin, angiotensin II(Ang II), aldosterone(ALD), endothelial nitric oxide synthase(eNOS), intercellular cell adhesion molecule-1(ICAM-1), heart interleukin-6(IL-6), interleukin-1 beta(IL-1ß) and tumor necrosis factor-α(TNF-α) were determined. RESULTS: After 10 weeks of intervention, the systolic blood pressure in the low, medium and high strontium water groups(129.60±4.90 mmHg vs.127.33±6.35 mmHg vs.124.70±3.91 mmHg) was significantly lower than that of the model control group(141.84±5.34 mmHg)(P<0.05). The diastolic blood pressure in the high strontium water group(84.74±5.49 mmHg) was significantly lower than that of the model control group(92.21±10.08 mmHg). The contents of serum potassium, calcium and magnesium in medium strontium gourp(8.06±0.80 mmol/L vs.2.34±0.13 mmol/L vs.0.57±0.12 mmol/L) and high strontium group(9.59±0.58 mmol/L vs. 2.37±0.17 mmol/L vs.0.58±0.09 mmol/L) were significantly higher than those in normal control group(6.64±0.57 mmol/L vs.2.07±0.15 mmol/L vs.0.46±0.10 mmol/L) and model control group(6.62±0.53 mmol/L vs.2.09±0.11 mmol/L vs.0.48±0.09 mmol/L)(P<0.05). Compared with model control group, the contents of renin(24.08±6.65 ng/mL vs.15.24±3.88 ng/mL), AngII(263.30±61.66 pg/mL vs.203.31±54.95 pg/mL), ALD(102.41±22.39 pg/mL vs. 60.31±10.83 pg/mL), ICAM-1(367.17±120.08 ng/mL vs.224.45±46.86 ng/mL), IL-6(5.90±0.66 ng/mL vs.3.88±1.08 ng/mL), IL-1ß(6.37±1.83 ng/mL vs.3.44±1.28 ng/mL) and TNF-α(9.35±1.41 ng/mL vs.5.68±2.11 ng/mL) in high strontium group were significantly decreased(P<0.05). CONCLUSION: Strontium can reduce the blood pressure of hypertensive mice by regulating the eNOS/NO pathway and reducing the production of inflammatory factors.
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Água Potável , Hipertensão , Animais , Camundongos , Camundongos Endogâmicos ICR , Pressão Sanguínea , Molécula 1 de Adesão Intercelular , Cálcio , Interleucina-6 , Magnésio , Renina , Fator de Necrose Tumoral alfa , Cálcio da DietaRESUMO
Carcinoembryonic antigens (CEAs) are known as one of the most common tumor markers. Their facile and affordable detection is critical for early diagnosis of malignant tumors, especially in resource-constrained settings. Here, we report a novel multimer-based surface-enhanced Raman scattering (SERS) aptasensor for a specific CEA assay. The aptasensor is fabricated through aptamer-assisted self-assembly of silver-coated gold nanoparticles (Au@Ag NPs), and the self-assembled multimeric structure possesses abundant hot-spots to provide high SERS response. When CEA is introduced, the specific recognition of CEA by aptamers will lead to the disassembly of Au@Ag multimers due to the lack of a bridging aptamer between Au@Ag NPs. As a result, the number of hot-spots in the multimeric system is decreased, and the intensity at 1585 cm-1 of the SERS reporter (4-mercaptobenzoic acid, 4-MBA) on the surface of NPs will also be decreased. The Raman intensity is proportional to the logarithm of the concentration of CEA. The detection sensitivity can be down to the pg mL-1 level. The analytical method only needs a droplet of 2 µL of sample, and the detection time is less than 20 min. The multimer-based SERS aptasensor can be applied in sensitive and inexpensive detection of CEA in serum samples.
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Ouro , Nanopartículas Metálicas , Antígeno Carcinoembrionário , Prata , Análise Espectral RamanRESUMO
Statin exposure has been reported to improve survival in several cancers. However, studies evaluating the association between statins and prognostic outcomes in patients with lung cancer are conflicting and heterogeneous. Pubmed, EMBASE and reference lists of included studies were searched to identify studies investigating the association between statin exposure and lung cancer prognosis. The primary outcome measure was overall survival (OS) and secondary ones included cancer-specific survival (CSS) and recurrence-free survival (RFS). Hazard ratios (HRs) with 95% confidence intervals (95% CIs) of these outcomes were pooled using random-effects models. Thirteen studies with data from 99,297 individuals satisfying the inclusion criteria were identified. Studies were ranked to be at low to moderate risk of bias. Meta-analysis showed that statin exposure was significantly associated with improved OS (pooled HR 0.79, 95% CI 0.72-0.86), CSS (pooled HR 0.83, 95% CI 0.77-0.89) and RFS (pooled HR 0.85, 95% CI 0.81-0.89). Subgroup analyses showed that statin users after diagnosis of lung cancer had more survival benefit for OS (HR 0.68, 95% CI 0.51-0.92) than those before diagnosis (HR 0.86, 95% CI 0.81-0.90) and current users (HR 0.79, 95% CI 0.62-1.02) (P for interaction <0.001). Besides, statin users were likely to have more survival benefits in stage IV lung cancer patients (HR 0.77, 95% CI 0.74-0.79) than in mixed stage (I-IV or I-III) patients (P for interaction = 0.004). Statin exposure is associated with significantly improved survival in patients with lung cancer. Future studies are warranted to further demonstrate the therapeutic role of statins in specific lung cancer patients.
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Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Neoplasias Pulmonares/epidemiologia , Intervalo Livre de Doença , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Estudos Observacionais como Assunto , Prognóstico , Análise de SobrevidaRESUMO
OBJECTIVE: To compare the effect of three different surface zirconium oxide treatments on binding strength and fracture patterns between zirconia and veneering ceramics.â© Methods: A total of 40 zirconia specimens and 10 nickel-chromium alloy were divided into 5 groups (n=10 in each group): a treatment group by zirconium oxide sand-blaste (Group A), a zirconia bonded porcelain group (Group B), a hot-etching solution group (Group C), a non-treatment zirconia (Group D) and a non-treatment nickel-chromium alloy group (Group E). After all treatments, a veneering porcelain (4 mm×4 mm×2 mm) was formed onto the center of all substrate specimens by plastic coating method. Shear bond strength (SBS) test with a universal testing machine was used in each group. Scanning electron microscopy was used to observe the surface morphology of the damaged specimen interface, which was randomly selected from each group.â© Results: The SBS test showed that there was no significant difference in SBS results between the Group A, the Group B and the Group D (both P>0.05), and both of them were significant less than that in the group E (both P<0.05). The SBS results in the Group C were significantly higher than that in the Group D, the Group A, and the Group B (all P<0.05), but there were no significant difference compared with that in the Group E (P<0.05). â© Conclusion: Sand-blaste and liner application on zirconia ceramic contribute no effect to binding strength between zirconia and veneering ceramics, but hot-etching solution can increase the binding strength between zirconia and veneering ceramics.
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Colagem Dentária , Facetas Dentárias , Cerâmica , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , ZircônioRESUMO
A dual-emission ratiometric fluorometric aptasensor is presented for highly specific detection of adenosine. An adenosine binding aptamer (ABA) was split into two halves (termed as ABA1 and ABA2). ABA1 was covalently bound to blue-emitting carbon dots (with excitation/emission maxima at 365/440 nm) as responsive fluorophore (referred to as ABA1-CDs). ABA2 was linked to red-emitting silica-coated CdTe quantum dots (with excitation/emission maxima at 365/613 nm) acting as internal reference and referred to as ABA2-QDs@SiO2. Upon addition of graphene oxide, the fluorescence of ABA1-CDs is quenched. After subsequent addition of ABA2-QDs@SiO2 and different amounts of adenosine, the blue fluorescence is recovered and causes a color change from red to royal blue. The method represents a ratiometric turn-on assay for visual, colorimetric and fluorometric determination of adenosine. The limit of detection is as low as 2.4 nM in case of ratiometric fluorometry. The method was successfully applied to the determination of adenosine in (spiked) human urine. Recoveries range from 98.8% to 102%. Graphical abstract Adenosine binding aptamer1-carbon dots (ABA1-CDs) can absorb on graphene oxide (GO) via π stacking. This causes fluorescence to be quenched by fluorescence resonance energy transfer (FRET). After addition of ABA2-silica-coated quantum dots (ABA2-QDs@SiO2) and adenosine, binding of adenosine to two pieces of aptamers forms a complex (ABA1-CD/adenosine/ABA2-QD@SiO2) which dissociates from GO. As a result, fluorescence is recovered.
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Adenosina/urina , Aptâmeros de Nucleotídeos , Técnicas Biossensoriais/métodos , Fluorescência , Cor , Transferência Ressonante de Energia de Fluorescência , Humanos , Pontos QuânticosRESUMO
Circulating lncRNAs have been defined as a novel biomarker for non-small cell lung cancer (NSCLC), MALAT-1 was first identified lncRNA that was related to lung cancer metastasis. However, the relationship between exosomal lncRNAs and the diagnosis and prognosis of NSCLC was poorly understood. The aim of this study is to evaluate the clinical significance of serum exosomal MALAT-1 as a biomarker in the metastasis of NSCLC. In this study, we firstly isolated the exosomes from healthy subjects and NSCLC patients. Then we measured the expression levels of MALAT-1 contained in exosomes, and found that exosomal MALAT-1 was highly expressed in NSCLC patients, more importantly, the levels of exosomal MALAT-1 were positively associated with tumor stage and lymphatic metastasis. In addition, we decreased MALAT-1 expression by short hairpin RNA and conducted a series of assays including MTT, cell cycle, colony formation, wound-healing scratch and Annexin/V PI by flow cytometry in human lung cancer cell lines. These in vitro studies demonstrated that serum exosome-derived long noncoding RNA MALAT-1 promoted the tumor growth and migration, and prevented tumor cells from apoptosis in lung cancer cell lines. Taken together, this study shed a light on utilizing MALAT-1 in exosomes as a non-invasive serum-based tumor biomarker for diagnosis and prognosis of NSCLC.
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Carcinoma Pulmonar de Células não Pequenas/patologia , Exossomos/patologia , Neoplasias Pulmonares/patologia , Pulmão/patologia , RNA Longo não Codificante/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Exossomos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Metástase Linfática/diagnóstico , Metástase Linfática/genética , Metástase Linfática/patologia , Prognóstico , RNA Longo não Codificante/genética , Regulação para CimaRESUMO
Tumor-stroma interactions contribute greatly to intratumoral estrogen biosynthesis in endometrial carcinoma, but the mechanisms involved remain largely unknown. Previous study demonstrated that intratumoral aromatase upregulation in stromal cells participated in this process, but the specific aromatase-regulators have not been reported. In the present study, we found that aromatase expression in intratumoral stroma, but not in tumor epithelium, correlated positively with interleukin 6 (IL-6) expression in cancer epithelial cells by immunohistochemistry, which was confirmed using laser capture microdissection/real-time reverse transcription-PCR. With stimulation by exogenous IL-6, aromarase expression was increased in stromal cells not but not in cancer cells. Aromatase mRNA levels in endometrial cancer cells were not influenced by cocultivation with intratumoral stromal cells. When cocultured with 17ß-estradiol (E2 )-treated cancer cells, aromatase mRNA in stromal cells was significantly elevated and increased IL-6 protein levels were detected in E2 -treated culture medium. Next, we demonstrated that E2 -induced IL-6 production was through cooperation between estrogen receptor α and nuclear factor-kappa B. Furthermore, an IL-6 receptor blocking antibody could attenuate the upregulation of aromatase expression in stromal cells and the E2 concentration in coculture systems of cancer and stromal cells. The results were confirmed by an orthotopic nude endometrial carcinoma model in vivo. These studies elucidated the activation of a positive feedback loop, that is, IL-6 stimulated by E2 in endometrial cancer cells induced aromatase expression in stromal cells, promoting enhanced intratumoral E2 synthesis. Blocking of this tumor-stroma interaction may be a therapeutic strategy to overcome in situ estrogen biosynthesis in endometrial carcinoma.
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Aromatase/metabolismo , Neoplasias do Endométrio/metabolismo , Estradiol/biossíntese , Interleucina-6/metabolismo , Microambiente Tumoral/fisiologia , Animais , Western Blotting , Técnicas de Cocultura , Ensaio de Imunoadsorção Enzimática , Retroalimentação Fisiológica , Feminino , Humanos , Imuno-Histoquímica , Imunoprecipitação , Microdissecção e Captura a Laser , Camundongos , Camundongos Nus , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/metabolismoRESUMO
Chemoresistance poses a significant obstacle to the treatment of breast cancer patients. The increased capacity of DNA damage repair is one of the mechanisms underlying chemoresistance. Bioinformatic analyses showed that E2F8 was associated with cell cycle progression and homologous recombination (HR) repair of DNA double-strand breaks (DSBs) in breast cancer. E2F8 knockdown suppressed cell growth and attenuated HR repair. Accordingly, E2F8 knockdown sensitized cancer cells to Adriamycin and Cisplatin. Centromere protein L (CENPL) is a transcriptional target by E2F8. CENPL overexpression in E2F8-knockdowned cells recovered at least in part the effect of E2F8 on DNA damage repair and chemotherapy sensitivity. Consistently, CENPL knockdown impaired DNA damage repair and sensitized cancer cells to DNA-damaging drugs. These findings demonstrate that targeting E2F8-CENPL pathway is a potential approach to overcoming chemoresistance.
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Neoplasias da Mama , Reparo de DNA por Recombinação , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Resistencia a Medicamentos Antineoplásicos/genética , Reparo do DNA , DNA , Proteínas Repressoras/genética , Proteínas Cromossômicas não Histona , Proteínas de Ciclo Celular/genéticaRESUMO
In this study, Brassica chinensis L seedlings after 6 weeks of soil cultivation were treated with foliar application of TiO2 NPs (20 mg/L) for different times. Transcriptomics analysis was employed to investigate the impact of TiO2 NPs on the physiology, growth, and yield of B. chinensis L. Results showed that TiO2 NPs' exposure significantly increased the biomass, total phosphorus, and catalase enzyme activity by 23.60, 23.72, and 44.01%, respectively, compared to the untreated ones (not bulk or ion).TiO2 NPs increased the leaf chlorophyll content by 4.9% and photosynthetic rate by 16.62%, which was attributed to the upregulated expression of seven genes (PetH, PetF, PsaF, PsbA, PsbB, PsbD, and Lhcb) associated with electron transport in photosystem I and light-harvesting in leaves. The water balance of B. chinensis was improved correlating with the altered expressions of 19 aquaporin genes (e.g., PIP2;1 and NIP6;1). The expressions of 58 genes related to plant hormone signaling and growth were dysregulated, with notable downregulations in GA20, SnRK2, and PP2C and upregulations of DELLAs, SAM, and ETR. Moreover, the 11 tricarboxylic acid cycle genes and 13 glycolysis genes appear to stimulate pathways involved in promoting the growth and physiology of B. chinensis. This research contributes valuable insights into new strategies for increasing the yield of B. chinensis.
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Drainage water quality is a crucial factor reflecting the regime of agricultural non-point source pollution in irrigation districts and is closely related to land use, soil texture, cropping pattern, fertilization, and irrigation and drainage conditions. However, the response of drainage water quality to various natural and anthropogenic factors needs further exploration in irrigation districts affected by shallow groundwater table. Spatiotemporal patterns of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), and ammonium nitrogen (NH4-N) were monitored and analyzed in ten agricultural drainage ditches in the arid region of China from 2011 to 2019. Spatially, water pollution in agricultural drainage ditches with small water quantity can be significantly exacerbated by urban sewage, whereas a large amount of agricultural drainage can effectively dilute the pollution of urban sewage. Severe soil salinization in the cropland increases the risk of water pollution due to easier losses of soil nutrient and organic matter. Soil salinization is a key factor in the crop distribution pattern based on the crop salt tolerance, and the maize/wheat field with a higher fertilizer application rate generally results in poorer drainage water quality. Temporally, for the agricultural drainage ditches, the monthly and annual COD, TP, TN, and NH4-N concentrations fluctuate inversely with drainage water quantity and are positively correlated with fertilizer application, among which the monthly COD concentration in drainage water has larger variation in severe salinized areas. There exist critical annual and monthly drainage amounts, above which the probabilities of higher concentrations of COD, TP, TN, and NH4-N reduce greatly.
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Água Subterrânea , Poluentes Químicos da Água , Qualidade da Água , Fertilizantes/análise , Esgotos , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Solo , China , Nitrogênio/análise , Fósforo/análise , Irrigação AgrícolaRESUMO
In comparison to metal complexes, organic photosensitive dyes employed in photocatalytic hydrogen production exhibit promising developmental prospects. Utilizing the organic dye molecule TA+0 as the foundational structure, a series of innovative organic dyes, denoted as TA1-1 to TA2-6, were systematically designed. Employing first-principles calculations, we methodically explored the modifying effects of diverse electron-donating groups on the R1 and R2 positions to assess their application potential. Our findings reveal that, relative to the experimentally synthesized TATA+03, the TA2-6 molecule boasts a spatial structure conducive to intramolecular electron transfer, showcasing the most negative reduction potential (Ered = -2.11 eV) and the maximum reaction driving force (â³G0 2 = -1.26 eV). This configuration enhances its compatibility with the reduction catalyst, thereby facilitating efficient hydrogen evolution. The TA2-6 dye demonstrates outstanding photophysical properties and a robust solar energy capture capacity. Its maximum molar extinction coefficient (ε) stands at 2.616 × 104 M-1·cm-1, representing a remarkable 292.8% improvement over TATA+03. In conclusion, this research underscores the promising potential of the TA2-6 dye as an innovative organic photosensitizer, positioning it as an efficacious component in homogeneous photocatalytic systems.
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Chemoresistance represents a major obstacle to the treatment of human cancers. Increased DNA repair capacity is one of the important mechanisms underlying chemoresistance. In silico analysis indicated that YTHDF1, an m6A binding protein, is a putative tumor promoter in breast cancer. Loss of function studies further showed that YTHDF1 promotes breast cancer cell growth in vitro and in vivo. YTHDF1 facilitates S-phase entry, DNA replication and DNA damage repair, and accordingly YTHDF1 knockdown sensitizes breast cancer cells to Adriamycin and Cisplatin as well as Olaparib, a PARP inhibitor. E2F8 is a target molecule by YTHDF1 which modulates E2F8 mRNA stability and DNA damage repair in a METTL14-dependent manner. These data demonstrate that YTHDF1 has a tumor-promoting role in breast cancer, and is a novel target to overcome chemoresistance.
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Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Dano ao DNA , Reparo do DNA , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
Methylglyoxal (MGO) is the primary material basis for the non-peroxide antibacterial activity (NPA) of manuka honey from New Zealand. Therefore, it is necessary to identify the quality or discriminate the grade of honey because no all manuka honeys on the market display the NPA. The current routine method employed for the detection of MGO involves high-performance liquid chromatography (HPLC) test. However, it requires long time (â¼8 h) for sample derivatization. Herein, we report an intrinsic Raman signal amplification strategy for the rapid identification and detection of MGO by using silver-coated gold nanoparticles (Au@Ag NPs) along with a high selective surface-enhanced Raman scattering (SERS) probe 8-thioguanosine (8-TG). 8-TG is synthesized via the derivatization of 8-bromoguanosine (8-BG) with thiourea, and its Raman peak assignments were confirmed by computer simulation. The detection is performed through the Raman intensity ratio (I631/I700) variation of N2-(1-carboxyethyl)-thioguanosine (CETG) formed by the reaction between 8-TG and MGO on surface of Au@Ag NPs, where one CETG Raman intensity at 631 cm-1 increases while the other one at 700 cm-1 decreases oppositely. The opposite change not only yields an intrinsic Raman signal amplification, but also provides built-in correction. As a result, the proposed SERS method exhibits high sensitivity and accuracy. In addition, the whole analytical test is achieved within â¼20 min. The method can be used for the fast detection of MGO in manuka honey and discrimination of the honey grade.
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Mel , Nanopartículas Metálicas , Simulação por Computador , Ouro , Mel/análise , Aldeído Pirúvico , Análise Espectral RamanRESUMO
The evaluation of true penicillin allergy is significant to reduce its occurrence and the overdiagnosis before anti-infective treatment. However, the currently available methods with high specificity still face the problem of low sensitivity, thereby easily leading to false negatives. Herein, an alkyne responsive surface-enhanced Raman scattering (SERS) immunosensor is reported for ultrasensitive detection of penicillin allergen penicilloyl protein (P-protein) by using Au-Ag alloy nanoparticles@(antibody + alkyne probe) (as SERS immunoprobe) together with Ag nanofilm modified by antibody (as SERS capture substrate). The SERS immunoassay integrates the interference-free Raman response of high wavenumber region (2212 cm-1) and specific capture antibody with high affinity to selectively recognize P-protein from complicated sample. Meanwhile, the target-induced near-field coupling effect between localized surface plasmon resonances of individual SERS immunoprobe and capture substrate enables the detection of P-protein as low as pg/mL level, and the limit of detection can reach 0.329 pg/mL that is about 6 orders of magnitude lower than the limit defined protein residue (causing penicillin allergy). With the ultrasensitivity and specific selectivity, the proposed SERS immunoassay platform can precisely evaluate the content of P-protein in blood sample or penicillin drugs. It will be a potential tool to monitor allergic reaction to penicillin and better understand the mechanism of penicillin hypersensitivity.
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Técnicas Biossensoriais , Hipersensibilidade , Nanopartículas Metálicas , Alcinos , Ouro , Humanos , Imunoensaio , Penicilinas , Prata , Análise Espectral RamanRESUMO
Cadmium (Cd), widely present in food and drinking water at low doses, can cause health risks. However, the mechanistic effects of long-term Cd exposure at low dose through dietary intake is poorly studied. The aim of this study is to elucidate whether the dysbiosis of gut microbiota caused by Cd at an environmental low dose can aggravate the injury of mice liver, and the possible mechanism is investigated. In order to explore the potential underlying mechanism, the analyses of the variation of gut microbiota composition, intestinal permeability, and hepatic transcriptome were conducted. Our results showed that gut microbiota was disturbed. The rise of intestinal permeability induced by the dysbiosis of gut microbiota resulted in more Cd ions accumulating in mice liver, but it could be restored partly through depleting gut microbiota by antibiotics cocktail. Transcriptomic analyses indicated that 162 genes were significantly differentially expressed including 59 up-regulated and 103 down-regulated in Cd treatment. These genes were involved in several important pathways. Our findings provide a better understanding about the health risks of cadmium in the environment.
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The fluorescence-based assay of iodide ion (I-) has been extensively studied by the use of different sensing probes and techniques, but it remains a tricky task to eliminate the interference of chloride ion (Cl-) for the analysis of low-level I- in complex genuine samples. Herein, we develop a redox pretreatment strategy for specific separating I- from human urine. Simultaneously, a novel ratiometric fluorescent probe is constructed by a simple mixing of dimer DNA silver nanoclusters (dDNA-AgNCs) and carbon dots (CDs) with the ratio of 5:1 in fluorescent intensity, and used for visual assay of I-. After addition of I-, the fluorescence of orange dDNA-AgNCs can be quenched by I- as the result of I--induced oxidative etching and aggregation of dDNA-AgNCs, while blue CDs as the stable internal standard are unresponsive to I-. With the increase of I-, the fluorescence intensity ratio (I577/I446) of binary-color probe gradually decreased, which leads to color variation from salmon pink to lighter salmon pink to lilac to light steel blue to final deep sky blue (under a UV lamp) with a sensitive detection limit of 19.8 nM. The assay for I- can also be convenient to implement for visual monitoring of I- by observing color change of test paper printed with the ratiometric probe, responding to 50 nM that is about 1 order of magnitude lower than the median urinary I- concentration defined by the World Health Organization (WHO) for school-age children. The sensitive test paper can provide an advanced platform for colorimetric and visual monitoring of I- in human urine.