Search

A novel electrochemiluminescence (ECL) biosensor was fabricated for miRNA-162a detection by using silver nanoclusters/molybdenum disulfide (AgNCs@MoS2) as an ECL material, peroxodisulfate (S2O82−) as a co-reactant, and semicarbazide (Sem) as a co-reaction accelerator. Firstly, hairpin probe Ha modified on AgNCs@MoS2/GCE was unfolded based on its hybridization with target microRNA. Then, the unfolded Ha can further be hybridized with another hairpin DNA of Hb on (AuNPs-semicarbazide)@Cu-MOF, resulting in the release of target microRNA, which further causes a cyclic hybridization. This creates more (AuNPs-semicarbazide)@Cu-MOF on the electrode surface, achieving cyclic hybridization signal amplification. Strikingly, due to the presence of Sem, accelerating the reduction of S2O82− and resulting in the generation of more oxidant intermediates of SO42−, the amount of excited states of Agincreases to further amplify the ECL signal. The biosensor exhibited high sensitivity with a low LOD of 1.067 fM, indicating that the introduction of co-reaction accelerators can provide an effective method for signal amplification. The applicability of this method was assessed by investigating the effect of Pb(II) ion on miRNA-162a expression level in maize seedling leaves. [ABSTRACT FROM AUTHOR]

Abstract Herein, a novel photoelectrochemical (PEC) biosensor was developed for the ultrasensitive detection of microRNA-396a based on a MoS 2 /g-C 3 N 4 /black TiO 2 heterojunction as the photoactive material and gold nanoparticles carrying Histostar antibodies (Histostar@AuNPs) for signal amplification. Briefly, MoS 2 /g-C 3 N 4 /black TiO 2 was deposited on an indium tin oxide (ITO) electrode surface, after which gold nanoparticles (AuNPs) and probe DNA were assembled on the modified electrode. Hybridization with miRNA-396a resulted in a rigid DNA: RNA hybrid being formed, which was recognized by the S9.6 antibody. The captured antibody can further conjugate with the secondary IgG antibodies of Histostar@AuNPs, thereby leading to the immobilization of horse radish peroxidase (HRP). In the presence of HRP, the oxidation of 4-chloro-1-naphthol (4-CN) by H 2 O 2 was accelerated, producing the insoluble product benzo-4-chlorohexadienone on the electrode surface and causing a significant decrease in the photocurrent. The developed biosensor could detect miRNA-396a at concentrations from 0.5 fM to 5000 fM, with a detection limit of 0.13 fM. Further, the proposed method can also be used to investigate the effect of heavy metal ions on the expression level of miRNAs. Results suggest that the biosensor developed herein offers a promising platform for the ultrasensitive detection of miRNA. Graphical abstract fx1 Highlights • A novel PEC strategy was developed for sensitive detection of microRNA. • It was based on the MoS 2 /g-C 3 N 4 /black TiO 2 heterojunction and Histostar@AuNPs. • This is the first time that black TiO 2 and Histostar were used in biosensing. • The low detection limits of 0.13 fM was achieved. [ABSTRACT FROM AUTHOR]

The present study investigated the role of microRNA-137-regulated AKT serine/threonine kinase 2 (AKT2) on tumor growth and cisplatin sensitivity in patients with non-small cell lung cancer (NSCLC). The results demonstrated that the expression of microRNA-137 in cisplatin- treated NSCLC patient tissue samples was markedly lower than that in healthy tissue samples. The disease-free survival and overall survival rates of patients with NSCLC exhibiting a high microRNA-137 expression were higher than the survival rates of patients with NSCLC exhibiting a low expression of microRNA-137. Overexpression of microRNA-137 inhibited the proliferation of A549 and H520 cells treated with cisplatin. Overexpression of miR-137 suppressed the protein expression of AKT2, increased caspase-3 activity, increased Bax protein expression and suppressed Cyclin D1 protein expression in A549 and H520 cells treated with cisplatin. MK2206, an AKT2 inhibitor, inhibited AKT2 protein expression and suppressed the proliferation of A549 and H520 cells treated with cisplatin following overexpression of miR-137. The inhibition of AKT2 also increased caspase-3 activity and Bax protein expression, and suppressed Cyclin D1 protein expression in A549 and H520 cells treated with cisplatin following overexpression of miR-137. Taken together, the results of the present study suggested that microRNA-137-regulated AKT2 inhibits tumor growth and sensitizes cisplatin in patients with NSCLC. [ABSTRACT FROM AUTHOR]

MicroRNAs play crucial role in regulating gene expression in organism, thus it is very necessary to exploit an efficient method for the sensitive and specific detection of microRNA. Herein, a signal-on electrochemiluminescence biosensor was fabricated for microRNA-319a detection based on two-stage isothermal strand-displacement polymerase reaction (ISDPR). In the presence of target microRNA, amounts of trigger DNA could be generated by the first ISDPR. Then, the trigger DNA and the primer hybridized simultaneously with the hairpin probe to open the stem of the probe, and then the ECL signal will be emitted. In the presence of phi29 DNA polymerase and dNTPs, the trigger DNA could be displaced to initiate a new cycle which was the second ISDPR. Due to the two-stage amplification, this method presented excellent detection sensitivity with a low detection limit of 0.14 fM. Moreover, the applicability of the developed method was demonstrated by detecting the change of microRNA-319a content in the leaves of rice seedlings after the rice seeds were incubated with chemical mutagen of ethyl methanesulfonate. [ABSTRACT FROM AUTHOR]

Background: As one of the most common types of co-regulatory motifs, feed-forward loops (FFLs) control many cell functions and play an important role in human cancers. Therefore, it is crucial to reconstruct and analyze cancer-related FFLs that are controlled by transcription factor (TF) and microRNA (miRNA) simultaneously, in order to find out how miRNAs and TFs cooperate with each other in cancer cells and how they contribute to carcinogenesis. Current FFL studies rely on predicted regulation information and therefore suffer the false positive issue in prediction results. More critically, FFLs generated by existing approaches cannot represent the dynamic and conditional regulation relationship under different experimental conditions. Methodology/Principal Findings: In this study, we proposed a novel filter-wrapper feature selection method to accurately identify co-regulatory mechanism by incorporating prior information from predicted regulatory interactions with parallel miRNA/mRNA expression datasets. By applying this method, we reconstructed 208 and 110 TF-miRNA co-regulatory FFLs from human pan-cancer and prostate datasets, respectively. Further analysis of these cancer-related FFLs showed that the top-ranking TF STAT3 and miRNA hsa-let-7e are key regulators implicated in human cancers, which have regulated targets significantly enriched in cellular process regulations and signaling pathways that are involved in carcinogenesis. Conclusions/Significance: In this study, we introduced an efficient computational approach to reconstruct co-regulatory FFLs by accurately identifying gene co-regulatory interactions. The strength of the proposed feature selection method lies in the fact it can precisely filter out false positives in predicted regulatory interactions by quantitatively modeling the complex co-regulation of target genes mediated by TFs and miRNAs simultaneously. Moreover, the proposed feature selection method can be generally applied to other gene regulation studies using parallel expression data with respect to different biological contexts. [ABSTRACT FROM AUTHOR]

A photoelectrochemical biosensor is described for sensitive detection of microRNA-162a. A multiple amplification strategy is employed that involves (a) isothermal strand displacement polymerase reaction; (b) terminal deoxynucleotidyl transferase-mediated extension, (c) amplification of streptavidin-coated gold nanoparticles, and (d) biotin functionalized alkaline phosphatase. Graphite-like C3N4 (g-C3N4) nanosheets were used as photoactive material. By using these amplification strategies, the detection limit is as low as 0.18 fM of microRNA, and the photocurrent increases linearly with the concentration of microRNA-162a in the range from 0.5 fM to 1 pM. The method was successfully applied to quantify the expression level of microRNA-162a in total RNA extracted from the leaves of maize seedlings after incubation with the chemical mutagen ethyl methanesulfonate. The results confirmed the applicability of the method to the analysis of practical biological samples.Schematic of a photoelectrochemical microRNA assay based on a multiple amplification strategy involving (a) isothermal strand displacement polymerase reaction; (b) terminal deoxynucleotidyl transferase-mediated extension, (c) amplification of streptavidin-coated gold nanoparticles, and (d) biotin functionalized alkaline phosphatase. [ABSTRACT FROM AUTHOR]

The authors describe a fluorometric assay for microRNA. It is based on two-step amplification involving (a) strand displacement replication and (b) rolling circle amplification. The strand displacement amplification system is making use of template DNA (containing a sequence that is complementary to microRNA-21) and nicking enzyme sites. After hybridization, the microRNA strand becomes extended by DNA polymerase chain reaction and then cleaved by the nicking enzyme. The DNA thus produced acts as a primer in rolling circle amplification. Then, the DNA probe SYBR Green II is added to bind to ssDNA to generate a fluorescent signal which increases with increasing concentration of microRNA. The method has a wide detection range that covers the10 f. to 0.1 nM microRNA concentration range and has a detection limit as low as 1.0 fM. The method was successfully applied to the determination of microRNA-21 in the serum of healthy and breast cancer patients. [ABSTRACT FROM AUTHOR]

Purpose: Osteosarcoma is a type of bone malignancy that mainly occurred in teenagers. This investigation is aimed to clarify the effect of long non-coding RNA (lncRNA) LINC00662 on the proliferation, migration, and invasion in osteosarcoma and explore the underlying action mechanisms. Methods: The mRNA expression of LINC00662 was determined by real-time quantitative polymerase chain reaction. Cell proliferation, migration, and invasion were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, and transwell assays, respectively. A dual-luciferase reporter assay was used to validate the target relationships Between microRNA (miR)-30b-3p and LINC00662/ ETS domain-containing protein 1 (ELK1). Western blotting was performed to determine the protein expression of ELK1. Xenograft model was established to evaluate the effects of LINC00662 silencing on tumor growth in vivo. Results: LncRNA LINC00662 and ELK1 were significantly increased, while miR-30b-3p was reduced in osteosarcoma tissues. The results of functional experiments indicated that transfection of small hairpin (sh)-LINC00662 and miR-30b-3p mimics repressed the migration, invasion, and proliferation of osteosarcoma cells. LncRNA LINC00662 also appeared to sponge miR-30b-3p in order to affect the expression of ELK1. Simultaneously, there were weak negative correlations between the expression of miR-30b-3p and LINC00662/ELK1 in osteosarcoma tissues. Rescue experiments suggested that ELK1 overexpression and downregulation of miR-30b-3p reversed the suppressive effects of sh-LINC00662 on the cell migration, invasion, and proliferation in osteosarcoma. Conclusions: The current study indicated that knockdown of LINC00662 repressed cell migration, invasion, and proliferation through sponging miR-30b-3p to regulate the expression of ELK1 in osteosarcoma. These results may uncover a promising target for the treatment of osteosarcoma. [ABSTRACT FROM AUTHOR]

Accumulating evidence indicates that CCL18 and the long non-coding RNA, HOTAIR, have critical roles in cancer progression and metastasis, but the correlation between CCL18 and HOTAIR in esophageal squamous cell carcinoma (ESCC) and their downstream molecular mechanisms remain unclear. Overexpression of CCL18 in ESCC tissues was associated with a worse survival in patients with ESCC. CCL18 enhanced the invasiveness of ESCC cells in a dose-dependent manner, whereas CCL18 knockdown inhibited their invasiveness. In particular, CCL18 expression was positively associated with HOTAIR expression in ESCC tissues. Furthermore, CCL18 upregulated the expression of HOTAIR, and knockdown of HOTAIR alleviated the CCL18-induced invasiveness of ESCC cells. HOTAIR may act as a competing endogenous RNA and could effectively becoming a sponge for miR-130a-5p, thereby modulating the derepression of ZEB1 and promoting epithelial-mesenchymal transition in ESCC. Our study suggests that CCL18 contributes to the malignant progression of esophageal cancer by upregulating HOTAIR expression. HOTAIR overexpression may promote tumor invasiveness and progression in ESCC, given that HOTAIR functions as a miR-130a-5p sponge, positively regulating ZEB1. This provides new therapeutic targets for early diagnosis and treatment of ESCC. [ABSTRACT FROM AUTHOR]

Abstract Copper oxide nanoparticles (CuO NPs) are fabricated using Coleus aromaticus leaf extract with an environmental friendly method and studied using various microscopic and spectroscopic techniques. Also, a new aptamer-conjugated hybrid delivery system using green synthesized CuO NPs is developed to deliver miRNA-29b to A549 cells. This delivery system can effectively deliver miRNAs to cancer cells, with superior performance compared to traditionally available transfection agents, thus acting as an efficient platform for intracellular miRNA delivery and improving therapeutic outcomes for lung cancer. [ABSTRACT FROM AUTHOR]

MicroRNAs play a crucial role in regulating plant growth, such as involving in the pathways of phytohormons signaling, which function in broad range of important aspects in many stages of plant development and evolution. To figure out the components part of microRNA in phytohormone signaling network, a sensitive photoelectrochemical biosensor was developed to detect miRNA-319a specifically using CuO-CuWO 4 as photoactive material and in situ generation electron donor technique. Taking the advantage of rolling circle amplification, nicking endonuclease triggered exponential amplification of target molecule, specific interaction between phosphate group and phos-tag and between biotin and avidin, the developed strategy can greatly amplify the detection signal only using trace amount of target miRNA-319a. The wide linear range was obtained from 1 fM to 0.1 nM and the detection limit was estimated to be 0.47 fM (S/N = 3). The developed method also showed good detection specificity. The effect of five phytohormones on the expression level of miRNA-319a in rice leaves was also investigated. This will be a basal principle of investigating the signaling network of phytohormones. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. Here, we identified that miR-599 is up-regulated in non-small cell lung cancer (NSCLC) patients. It promoted NSCLC cell proliferation by negatively regulating SATB2. In NSCLC cell lines, CCK-8 proliferation assay indicated that the cell proliferation is promoted by miR-599 mimics. Transwell assay showed that miR-599 mimics promoted the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-599 directly binds to the 3'untranslated region of SATB2, and western blotting showed that miR-599 suppresses the expression of SATB2 at the protein level. This study indicates that miR-599 promotes proliferation and invasion of NSCLC cell lines via SATB2. The miR-599 may represent a potential therapeutic target for NSCLC treatment. [ABSTRACT FROM AUTHOR]

Objectives Worldwide, lung cancer accounts for the majority of cancer-related deaths. Aberrant expression of mi RNAs has increasingly been reported to be associated with tumour progression. This study aimed to explore the role of miR-301b in regulating apoptosis in lung cancer. Materials and methods Expression of miR-301b was assessed by real-time PCR in cell lines, human patient tissues and cells treated under hypoxia and DMOG. Scramble si RNA, miR-301b inhibitor and miR-301b mimics were transfected into lung cancer cells to determine their effects on apoptosis. Additionally, a mouse xenograft model was used to explore functions of miR-301b on apoptosis, in vivo. Finally, relationships between Bim and miR-301b levels were explored by luciferase reporter assay and Western blotting. Results We found that miR-301b was highly expressed in lung cancer tissues and cell lines. Expression of miR-301b was induced by hypoxia, and miR-301b suppressed expression of Bim by targeting its 3′UTR. Functionally, ectopic expression of miR-301b enhanced cell population growth, reduced apoptosis and reduced sensitivity of cells to chemotherapy. In the xenograft model, overexpression of miR-301b promoted tumour growth. Additionally, miR-301b and Bim expression were inversely correlated in clinical lung cancer samples. Conclusions This study provides new insights into the function of mi RNA-301b in lung cancer and suggests that mi RNA-301b could be a potential molecular target for chemotherapy. [ABSTRACT FROM AUTHOR]

The signal transducer and activator of transcription 3 (STAT3) signaling pathway was involved in regulation of endothelial cell survival/apoptosis and was regarded as a target for prevention of atherosclerosis or other cardiovascular diseases. Factors, regulating STAT3 expression and activity, have aroused a wide range of interest, such as miRNAs or transcription factors. The aim of this study is to explore the role of miR-351, a miRNA found not long before, in the regulation of STAT3 expression and endothelial cell survival in the model mice with atherosclerosis (AS). Expression of miR-351 in the serum and cardiac arterial endothelial cells of the WT mice and AS mice was detected. Real-time qPCR analysis showed that miR-351 was upregulated in the serum and endothelial cells of the AS mice, displaying an opposite expression pattern with STAT3. To explore the role and mechanism of miR-351 in the endothelial cell survival, the miR-351 mimic was transfected in to the endothelial cells. MTT and Trypan Blue assays showed miR-351 attenuated the survival of endothelial cells. Our results of the TargetScan output and the 3′UTR luciferase reporter assay indicated that STAT3 was target of miR-351. Additionally, miR-351 resisted the elevation of STAT3 protein level and promotion of endothelial cell survival caused by SD19. Finally, our in vitro angiogenesis assay revealed that miR-351 suppressed angiogenesis and resisted the promotion of angiogenesis caused by SD19. In conclusion, miR-351 was upregulated in the atherosclerotic mice. MiR-351 can attenuate the survival of endothelial cells and suppress angiogenesis through targeting STAT3 in vitro. [ABSTRACT FROM AUTHOR]

Following publication of the original article [1], the authors reported two errors in the article. In the caption of Figure 1c the sentence "The 20 most highly upregulated EBV BART miRNAs identified between NPC specimens and normal nasopharyngeal mucosal specimens" should be corrected as "The highly upregulated EBV BART miRNAs identified between NPC specimens and normal nasopharyngeal mucosal specimens". [ABSTRACT FROM AUTHOR]

Background: Epstein-Barr virus (EBV) is ubiquitously associated with nasopharyngeal carcinoma (NPC). EBV encodes two groups of microRNAs (miRNAs) which are divided into BamHI fragment H rightward open reading frame 1 (BHRF1) and BamHI-A rightward transcripts (BART) microRNAs. EBV miR-BART has been found to be involved in the development and progression of NPC. However, so far the role of EBV-miR-BART8-3p in NPC progression remains unknown. This study aimed to investigate the role of EBV-miR-BART8-3p in NPC and explore the underlying mechanisms. Methods: miRNA expression was profiled in NPC and normal nasopharyngeal mucosal specimens using miRNA sequencing. EBV-miR-BART8-3p and RNF38 expression was quantified with qPCR assay. The migration, invasion and metastasis of NPC cells were evaluated using CCK-8, colony-forming, wound-healing, and migration and invasion assays. The expression levels of epithelial-mesenchymal transition (EMT)-related markers,metastasis-related markers and NF-κB and Erk1/2 signaling proteins were determined using Western blotting. Tumorigenic assay was performed to evaluate the pulmonary metastatic ability of NPC cells in vivo. Results: EBV BART miRNAs were highly over-expressed and co-expressed in NPC and might be associated with deactivated immune response in NPC according to the sequencing analysis. EBV-miR-BART8-3p expression was significantly higher in human NPC specimens than in normal nasopharyngeal mucosal specimens. EBV-miR-BART8-3p was found to promote NPC migration, invasion and metastasis, drove an EMT process and upregulated expression of metastasis-related proteins expression in NPC cells. Our data showed EBV-miR-BART8-3p directly targeted RNF38 in NPC cells. Conclusion: The present study demonstrates that EBV-miR-BART8-3p plays a significant role in inducing EMT and promoting metastasis through directly targeting RNF38 in NPC cells via the activation of NF-κB and Erk1/2 signaling pathways. Our findings suggest that EBV-miR-BART8-3p is a potential therapeutic target for NPC. [ABSTRACT FROM AUTHOR]