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1.
Mikrochim Acta ; 191(8): 494, 2024 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073465

RESUMO

Hyperproliferative  diseases are the first step for tumor formation; thymidine kinase 1 (TK1) mRNA is closely related to cell proliferation. Therefore, the risk of malignant proliferation can be identified by sensitively detecting the variance in TK1 mRNA concentration, which can be used for tumor auxiliary diagnosis and monitoring tumor treatment. Owing to the low abundance and instability of TK1 mRNA in real samples, the development of a sensitive and fast mRNA detection method is necessary. A DNA nanosensor that can be used for detecting TK1 mRNA based on bipedal 3D DNA walker-driven proximal catalytic hairpin assembly (P-CHA) was developed. P-CHA hairpins were hybridized to a linker DNA strand coupled with magnetic nanoparticles to increase their local concentrations. The bipedal DNA walking on the surface of NPs accelerates reaction kinetics using the proximity effect. Taking advantage of the signal amplification of P-CHA as well as the rapid reaction rate of the DNA walker in 80 min, the proposed sensor detects TK1 mRNA with a low detection limit of 14 pM and may then be applied to clinical diagnosis.


Assuntos
Técnicas Biossensoriais , DNA , Limite de Detecção , RNA Mensageiro , Timidina Quinase , RNA Mensageiro/genética , RNA Mensageiro/química , Timidina Quinase/genética , Humanos , Técnicas Biossensoriais/métodos , DNA/química , DNA/genética , Hibridização de Ácido Nucleico , Nanopartículas de Magnetita/química
2.
Pharmacol Res ; 205: 107216, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38761883

RESUMO

Gastric cancer (GC) is the leading cause of cancer-related death worldwide, and it is associated with a combination of genetic, environmental, and microbial risk factors. Helicobacter pylori (H. pylori) is classified as a type I carcinogen, however, the exact regulatory mechanisms underlying H. pylori-induced GC are incompletely defined. MicroRNAs (miRNAs), one of small non-coding RNAs, negatively regulate gene expression through binding to their target genes. Dysregulation of miRNAs is crucial in human cancer. A noteworthy quantity of aberrant miRNAs induced by H. pylori through complex regulatory networks have been identified. These miRNAs substantially affect genetic instability, cell proliferation, apoptosis, invasion, metastasis, autophagy, chemoresistance, and the tumor microenvironment, leading to GC development and progression. Importantly, some H. pylori-associated miRNAs hold promise as therapeutic tools and biomarkers for GC prevention, diagnosis, and prognosis. Nonetheless, clinical application of miRNAs remains in its infancy with multiple issues, including sensitivity and specificity, stability, reliable delivery systems, and off-target effects. Additional research on the specific molecular mechanisms and more clinical data are still required. This review investigated the biogenesis, regulatory mechanisms, and functions of miRNAs in H. pylori-induced GC, offering novel insights into the potential clinical applications of miRNA-based therapeutics and biomarkers.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , MicroRNAs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Helicobacter pylori/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/genética , Infecções por Helicobacter/complicações , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica
3.
J Transl Med ; 22(1): 41, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200523

RESUMO

As more is learned about lactate, it acts as both a product and a substrate and functions as a shuttle system between different cell populations to provide the energy for sustaining tumor growth and proliferation. Recent discoveries of protein lactylation modification mediated by lactate play an increasingly significant role in human health (e.g., neural and osteogenic differentiation and maturation) and diseases (e.g., tumors, fibrosis and inflammation, etc.). These views are critically significant and first described in detail in this review. Hence, here, we focused on a new target, protein lactylation, which may be a "double-edged sword" of human health and diseases. The main purpose of this review was to describe how protein lactylation acts in multiple physiological and pathological processes and their potential mechanisms through an in-depth summary of preclinical in vitro and in vivo studies. Our work aims to provide new ideas for treating different diseases and accelerate translation from bench to bedside.


Assuntos
Ácido Láctico , Osteogênese , Humanos , Diferenciação Celular , Inflamação , Processamento de Proteína Pós-Traducional
4.
Anal Chim Acta ; 1277: 341633, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37604619

RESUMO

Tumor-related mRNA detection is significant and interesting. The current mRNA detection method has the challenge of quantifying long mRNA sequences. Herein, a Y-shaped DNA probe with three target-binding segments was developed to detect tumor-related mRNA. This Y-shaped DNA probe (Y-probe) was assembled by six single DNA strands. Among these DNA strands, two DNA strands contained the split G-quadruplex sequence, and two DNA strands were modified with a pair of fluorophore and quencher, which were used to produce the detectable signal. In the presence of a long target mRNA sequence, target mRNA was hybridized with the three target-binding segments of the Y-probe, resulting in the increased fluorescence of G-quadruplex specific dye Thioflavin T and the decreased fluorescence of fluorophore, which could achieve the ratio detection of target mRNA. The Y-probe exhibited a low detection limit of 17.53 nM. Moreover, this probe showed high accuracy due to the benefits of three target-binding segments.


Assuntos
Corantes Fluorescentes , Quadruplex G , Sondas de DNA/genética , Fluorescência , Ionóforos , RNA Mensageiro/genética
6.
BMC Med Genomics ; 16(1): 123, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277853

RESUMO

BACKGROUND: Glycosylation involved in various biological function, aberrant glycosylation plays an important role in cancer development and progression. Glycosyltransferase 8 domain containing 1 (GLT8D1) and GLT8D2, as members of the glycosyltransferase family proteins, are associated with transferase activity. However, the association between GLT8D1/2 and gastric cancer (GC) remains unclear. We aimed to investigate the potential prognostic value and oncogenic role of GLT8D1/2 in GC. METHODS: The relationship between GLT8D1/2 and GC was evaluated through comprehensive bioinformatics approaches. A series of factors like gene expression patterns, Kaplan-Meier survival analyses, Cox regression analyses, prognostic nomogram, calibration curves, ROC curves, function enrichment analyses, tumor immunity association, genetic alterations, and DNA methylation were included. Data and statistical analyses were performed using R software (v3.6.3). RESULTS: Both GLT8D1 and GLT8D2 expression were significantly upregulated in GC tissues(n = 414) compared with normal tissues(n = 210), and high expression of GLT8D1/2 was remarkably correlated with poor prognosis for GC patients. Cox regression analyses implied that GLT8D1/2 could act as independent prognostic factors in GC. Furthermore, gene function analyses indicated that multiple signaling pathways involving tumor oncogenesis and development enriched, such as mTOR, cell cycle, MAPK, Notch, Hedgehog, FGF, and PI3K-Akt signaling pathways. Moreover, GLT8D1/2 was significantly associated with immune cell infiltration, immune checkpoint genes, and immune regulators TMB/MSI. CONCLUSION: GLT8D1/2 may serve as potential prognostic markers of poor prognosis in GC correlated with tumor immunity. The study provided an insight into identifying potential biomarkers and targets for prognosis, immunotherapy response, and therapy in GC.


Assuntos
Neoplasias Gástricas , Humanos , Biomarcadores Tumorais/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Transdução de Sinais , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
8.
Eur J Intern Med ; 114: 23-34, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37330315

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is one of the leading chronic liver diseases with increased morbidity and mortality rates for extrahepatic diseases (including cardiovascular disease, portal vein thrombosis, etc.). There is an increased risk of thrombosis in both the portal and systemic circulation in patients with NAFLD, independent of traditional liver cirrhosis. However, increased portal pressure, the most critical factor, is frequently observed in NAFLD patients, predisposing them to portal vein thrombosis (PVT). It has been reported that there is an 8.5% incidence of PVT among patients with non-cirrhotic NAFLD in a prospective cohort study. Based on the prothrombotic status of NAFLD itself, patients combined with cirrhosis may accelerate the development of PVT and lead to a poor prognosis. Moreover, PVT has been shown to complicate the procedure and adversely affect the outcome during liver transplantation surgery. NAFLD is in a prothrombotic state, and its underlying mechanisms have not been fully understood so far. Particularly noteworthy is that gastroenterologists currently overlook the higher risk of PVT in NAFLD. We investigate the pathogenesis of NAFLD complicated with PVT from the perspective of primary, secondary, and tertiary hemostasis, and also summarize relevant studies in humans. Some treatment options that may affect NAFLD and its PVT are also explored to improve patient-oriented outcomes.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Trombose , Trombose Venosa , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Fatores de Risco , Veia Porta/patologia , Estudos Prospectivos , Trombose Venosa/complicações , Cirrose Hepática/complicações
9.
Front Oncol ; 13: 1123638, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007062

RESUMO

Discoidin domain receptors (DDRs) are receptor tyrosine kinases on the membrane surface that bind to extracellular collagens, but they are rarely expressed in normal liver tissues. Recent studies have demonstrated that DDRs participate in and influence the processes underlying premalignant and malignant liver diseases. A brief overview of the potential roles of DDR1 and DDR2 in premalignant and malignant liver diseases is presented. DDR1 has proinflammatory and profibrotic benefits and promotes the invasion, migration and liver metastasis of tumour cells. However, DDR2 may play a pathogenic role in early-stage liver injury (prefibrotic stage) and a different role in chronic liver fibrosis and in metastatic liver cancer. These views are critically significant and first described in detail in this review. The main purpose of this review was to describe how DDRs act in premalignant and malignant liver diseases and their potential mechanisms through an in-depth summary of preclinical in vitro and in vivo studies. Our work aims to provide new ideas for cancer treatment and accelerate translation from bench to bedside.

10.
Front Microbiol ; 14: 1134254, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007498

RESUMO

Helicobacter pylori is a pathogenic microorganism that mainly resides in the human stomach and is the major cause of chronic gastritis, peptic ulcer and gastric cancer. Up to now, the treatment of Helicobacter pylori has been predominantly based on a combination of antibiotics and proton pump inhibitors. However, the increasing antibiotic resistance greatly limits the efficacy of anti-Helicobacter pylori treatment. Turning to non-antibiotic or non-pharmacological treatment is expected to solve this problem and may become a new strategy for treating Helicobacter pylori. In this review, we outline Helicobacter pylori's colonization and virulence mechanisms. Moreover, a series of non-pharmacological treatment methods for Helicobacter pylori and their mechanisms are carefully summarized, including probiotics, oxygen-rich environment or hyperbaric oxygen therapy, antibacterial photodynamic therapy, nanomaterials, antimicrobial peptide therapy, phage therapy and modified lysins. Finally, we provide a comprehensive overview of the challenges and perspectives in developing new medical technologies for treating Helicobacter pylori without drugs.

11.
Front Cell Infect Microbiol ; 13: 1121947, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36968116

RESUMO

As a confirmed carcinogen, Helicobacter pylori (H. pylori) is the main cause of inflammatory diseases of the upper digestive tract and even gastric cancer. There is a high prevalence of H. pylori infection among the elderly population, which may cause adverse clinical outcomes. Particularly noteworthy is that guidelines or expert consensus presently available on H. pylori infection overlook the management of the elderly population as a special group. A brief overview of H. pylori in the elderly is as follows. The detection of H. pylori infection can be divided into invasive and non-invasive techniques, and each technique has its advantages and shortcomings. There may be more side effects associated with eradication treatment in elderly individuals, especially for the frail population. Physical conditions and risk-benefit assessments of the elderly should be considered when selecting therapeutic strategies for H. pylori eradication. Unless there are competing factors, elderly patients should receive H. pylori eradication regimens to finally reduce the formation of gastric cancer. In this review, we summarize the latest understanding of H. pylori in the elderly population to provide effective managements and treatment measures.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Idoso , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/diagnóstico , Neoplasias Gástricas/epidemiologia , Antibacterianos/uso terapêutico
12.
Talanta ; 255: 124179, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36566555

RESUMO

Fluorescence detection of multiple mRNAs has attracted great attention for disease diagnosis. In this work, a stimulus-responsive strategy for highly sensitive and accurate multiple mRNAs detection was proposed. This stimulus-responsive detection system was prepared by mesoporous silica nanoparticles (MSN), manganese dioxide (MnO2) nanosheets, and DNA probes. DNA probes were loaded into the pores of MSN, which were closed with MnO2 nanosheets. In the presence of glutathione (GSH) and target mRNAs, MnO2 nanosheets were degraded by GSH, resulting in the release of DNA probes. These DNA probes hybridized to the corresponding target mRNA, thereby changing the fluorescence intensity of fluorophores of DNA probes, which could achieve the quantification of target mRNA. This system could simultaneously detect survivin mRNA and Thymidine kinase 1 mRNA at low background levels with relative limits of detection of 0.9 nM and 0.7 nM, respectively. Moreover, this assay has been successfully applied to detect multiple mRNAs with adequate anti-interference ability in the biological sample.


Assuntos
Nanopartículas , Dióxido de Silício , Óxidos , Compostos de Manganês , Glutationa
13.
Front Public Health ; 10: 937877, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091512

RESUMO

Objective: We investigated the association between cancer incidence and body mass index (BMI) variability calculated from the recall of weight at decades of age by participants in the USA Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Methods: A total of 89,822 individuals' BMI were recorded as recalled the participant's aged 30, 40, 50, 60, 70 years, and baseline. BMI variability was assessed using four indices: SD, coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV). The multivariate Cox regression analysis was performed to calculate hazard ratios (HRs) of these measures for incident cancers and corresponding 95% CIs. Results: During the median follow-up of 11.8 years, there were newly diagnosed 5,012 cases of prostate cancer, 792 cases of lung cancer, 994 cases of colon cancer, and 132 cases of ovarian cancer. Compared with the lowest quartile (Q1) group, the highest quartile (Q4) group of BMI variability indices was associated with increased lung cancer risk, including BMI_SD (HR, 1.58; 95% CI, 1.17-2.12), BMI_CV (HR, 1.46; 95% CI, 1.10-1.94), BMI_VIM (HR, 1.73; 95% CI, 1.33-2.25), and BMI_ARV (HR, 2.17; 95% CI, 1.62-2.91). Associations between BMI variability and prostate, colon, and ovarian cancer incidences were of limited significance. Conclusion: The findings imply that maintaining a stable weight across adulthood is associated with a decreased incidence of lung cancer.


Assuntos
Neoplasias Pulmonares , Neoplasias Ovarianas , Adulto , Índice de Massa Corporal , Colo , Feminino , Humanos , Pulmão , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/epidemiologia , Masculino , Obesidade/epidemiologia , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/epidemiologia , Próstata
14.
Mikrochim Acta ; 189(7): 266, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35776208

RESUMO

MicroRNA (miRNA) imaging has been employed to distinguish cancer cells from normal cells by exploiting the overexpression of miRNA in cancer. Inspired by the acidic extracellular tumor microenvironment, we designed a pH-activated DNA nanomachine to enable the specific detection of cancer cells using miRNA imaging. The DNA nanomachine was engineered by assembling two hairpins (Y1 and Y2) onto the surface of a ZIF-8 metal-organic framework (MOF), which decomposed under acidic conditions to release the adsorbed DNA hairpin molecules in situ. The released hairpins were captured by the target miRNA-21 and underwent catalytic hairpin assembly amplification between Y1 and Y2. The detection limit for miRNA assays using the DNA nanomachine was determined to be 27 pM, which is low enough for sensitive detection in living cells. Living cell imaging of miRNA-21 further corroborated the application of the DNA nanomachine in the identification of cancer cell.


Assuntos
Estruturas Metalorgânicas , MicroRNAs , Neoplasias , DNA/genética , Concentração de Íons de Hidrogênio , Imidazóis , MicroRNAs/genética , Neoplasias/diagnóstico por imagem , Neoplasias/genética
15.
J Biophotonics ; 14(9): e202100140, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34089571

RESUMO

Polarized light scattering spectroscopy (PLSS) is a promising optical technique developed for the detection of cancer, which extracts the single scattering light to infer morphological information of epithelial cells. However, traditional PLSS uses either a rotatable polarizer or two orthogonal polarizers to purify the single scattering light, which makes it complicated and challenged to build a PLSS endoscope. Herein, we propose a snapshot PLSS with a single optical path to directly get the single scattering light for the first time. The single scattering light is encoded using the spectrally-modulated polarimetry and decoded using the continuous slide iterative method. Both the polystyrene microsphere solutions and the ex vivo gastric cancer samples are used to verify the method. The experimental results of the snapshot PLSS are consistent well with that of the traditional PLSS. The proposed method has a potential for the building of snapshot PLSS endoscope systems in future.


Assuntos
Neoplasias Gástricas , Detecção Precoce de Câncer , Humanos , Luz , Espalhamento de Radiação , Análise Espectral , Neoplasias Gástricas/diagnóstico
16.
Chemistry ; 26(19): 4246-4250, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32012367

RESUMO

The radical-radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical-radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy.

17.
Mikrochim Acta ; 186(1): 30, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30564958

RESUMO

A DNA-templated copper nanoparticle (CuNP) probe has been developed for the determination of the human immunodeficiency virus oligonucleotide (HIV-DNA). The function of the probe relies on affinity binding-induced DNA hybridization associated with the use of double G-quadruplexes. Double-stranded DNA (dsDNA) with poly(AT-TA) bases was used as a template for synthesis of dsDNA-CuNPs. These have weak fluorescence. In the next step, two G-rich sequences that are linked to both sides of the ds-DNA are locked by HIV complementary DNA (cDNA). If HIV-DNA is introduced, it will hybridize with cDNA, thereby transforming the two G-rich sequences into G-quadruplexes. This enhances the fluorescence of the adjacent dsDNA-CuNPs. Fluorescence increases linearly in the 1 to 200 and 250-1000 nM HIV-DNA concentration range, and the detection limit is 13 pM. This enzyme-free fluorometric assay is time-saving, easily operated, and therefore has large potential in biosensing because it may be extended to various other DNA targets. Graphic abstract Double-strand DNA-templated copper nanoparticles (DNA-CuNPs) have weak fluorescence. When Human Immunodeficiency Virus oligonucleotide (HIV-DNA) is added, it completely hybridized with HIV complementary DNA (cDNA). As a result, the two exposed G-rich sequences are transformed into G-quadruplexes, and an apparent increase in the fluorescence intensity can be observed. (AA: ascorbic acid).


Assuntos
Cobre/química , DNA Viral/análise , Corantes Fluorescentes/química , Quadruplex G , HIV/genética , Técnicas Biossensoriais , Humanos , Nanopartículas Metálicas
18.
Talanta ; 178: 974-979, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29136926

RESUMO

Based on 2-aminopurine (2-AP) probe in conjunction with a G-quadruplex structure and signal amplification technique, a simple and highly sensitive fluorescence sensor for detecting microRNA (miRNA) is developed for high signal-to-background ratio and wide linear range. The proposed sensor contains two hairpins DNA: H1 and H2. H1 is labeled by 2-AP incorporated into a G-rich sequence. Upon the addition of a target miRNA, H1 is unfolded and forms DNA/RNA complexes that contain a G-quadruplex, thereby significantly enhancing 2-AP fluorescence due to the protection provided by the G-quadruplex. Subsequently, H2 can displace the miRNA from the DNA/RNA complexes and induce signal amplification, resulting in further enhanced fluorescence intensity. Hence, the sensor is highly sensitive and its low limit of detection (L.O.D.) can reach as low as 1.48pM. Furthermore, the proposed sensor is used to detect overexpressed miRNA-21 from human breast cancer cell lysate. The result demonstrates the potential of the proposed sensor to monitor different miRNA biomarkers for the early diagnosis of various cancers.


Assuntos
2-Aminopurina/química , Corantes Fluorescentes/química , Quadruplex G , Limite de Detecção , MicroRNAs/análise , MicroRNAs/química , Linhagem Celular Tumoral , Humanos
19.
ACS Sens ; 2(10): 1430-1434, 2017 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-28936869

RESUMO

A novel catalyzed hairpin assembly-based turn-on ratiometric fluorescence biosensor was constructed for the determination of microRNA-122 (miRNA-122) by using 2-aminopurine (2-AP) and thioflavin T (ThT) as detection signal sources. Hairpin DNA sequence (H1) includes the complementary strands of miRNA-122 and G-quadruplex-forming sequence. When miRNA-122 was presented, hybridization occurred between miRNA-122 and part of H1, causing a double-stranded DNA and a G-quadruplex formed. The formed double-stranded DNA significantly decreased the fluorescence intensity of 2-AP. Furthermore, after binding with ThT, the formed G-quadruplex led to the fluorescent enhancement. The hairpin DNA sequence (H2) hybridized with the unfolded H1 and displaced miRNA-122. Finally, the displaced miRNA-122 again hybridized with the H1 and initiated cycle amplification. This sensor showed a linear ranges of 0.5-50 nM and the limit of detection for miRNA-122 assay was 72 pM (with the lowest measured concentration of 500 pM) for determination of miRNA-122 when no other miRNA was present. Measurements on cell lysates from 100, 1000, and 10 000 cells of three different cell lines provided increasing signal ratios, which showed the application potential of the sensor for miRNA determination in real samples.


Assuntos
Técnicas Biossensoriais/métodos , Fluorescência , Quadruplex G , MicroRNAs/análise , Neoplasias/diagnóstico , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Células Cultivadas , Feminino , Hepatócitos/metabolismo , Humanos , Limite de Detecção , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Nanopartículas Metálicas/química , MicroRNAs/genética , Neoplasias/genética , Hibridização de Ácido Nucleico
20.
Talanta ; 174: 336-340, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28738589

RESUMO

A quencher-free and enzyme-free fluorescent sensor was proposed to simply and sensitively detect miRNA via the target catalyzed hairpin assembly (CHA) signal amplification in combination with 2-aminopurine (2-AP) molecular beacon (MBs). This sensor contains two DNA hairpins termed as H1 and H2. H1 labeled by 2-AP needs no quenchers because 2-AP can be quenched through its stacking interaction with the adjacent bases. H2 is partially complementary to H1. In the presence of the target microRNA (miRNA), H1 is unfolded and produces the DNA/RNA complexes, enhancing the fluorescent signal. Then, the RNA of the DNA/RNA complexes can be displaced by H2 and the free miRNA can interact with another H1, resulting in the significant fluorescence enhancement of the system. This signal amplification process is enzyme-free, making the sensor more simple and cost effective. The detection limit of this sensor could be as low as 3.5pM. We further applied this assay to monitor the overexpressed miRNA-21 from human breast cancer cells to confirm its applicability. The proposed sensor could be used as a simple and sensitive platform for target miRNA detection, holding great potential for convenient monitoring of different miRNA biomarkers for early diagnosis of various cancers.


Assuntos
2-Aminopurina/química , Técnicas Biossensoriais/métodos , Sequências Repetidas Invertidas , Limite de Detecção , MicroRNAs/análise , Sondas de Oligonucleotídeos/química , Catálise , Linhagem Celular Tumoral , Humanos , MicroRNAs/química , MicroRNAs/genética
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