It was found that chloroauric acid (HAuCl(4)) could be directly reduced by the luminescent reagent luminol in aqueous solution to form gold nanoparticles (AuNPs), the size of which depended on the amount of luminol. The morphology and surface state of as-prepared AuNPs were characterized by transmission electron microscopy, UV/visible spectroscopy, X-ray photoelectron spectroscopy, FTIR spectroscopy, and thermogravimetric analysis. All results indicated that residual luminol and its oxidation product 3-aminophthalate coexisted on the surface of AuNPs through the weak covalent interaction between gold and nitrogen atoms in their amino groups. Subsequently, a luminol-capped AuNP-modified electrode was fabricated by the immobilization of AuNPs on a gold electrode by virtue of cysteine molecules and then immersion in a luminol solution. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The as-prepared modified electrode exhibited an electrochemiluminescence (ECL) response in alkaline aqueous solution under a double-step potential. H2O2 was found to enhance the ECL. On this basis, an ECL sensor for the detection of H2O2 was developed. The method is simple, fast, and reagent free. It is applicable to the determination of H2O2 in the range of 3x10(-7)-1x10(-3) mol L(-1) with a detection limit of 1x10(-7) mol L(-1) (S/N=3).
Balanced chromosomal rearrangement (or balanced chromosome abnormality, BCA) is a common chromosomal structural variation. Next-generation sequencing has been reported to detect BCA-associated breakpoints with the aid of karyotyping. However, the complications associated with this approach and the requirement for cytogenetics information has limited its application. Here, we provide a whole-genome low-coverage sequencing approach to detect BCA events independent of knowing the affected regions and with low false positives. First, six samples containing BCAs were used to establish a detection protocol and assess the efficacy of different library construction approaches. By clustering anomalous read pairs and filtering out the false-positive results with a control cohort and the concomitant mapping information, we could directly detect BCA events for each sample. Through optimizing the read depth, BCAs in all samples could be blindly detected with only 120 million read pairs per sample for data from a small-insert library and 30 million per sample for data from nonsize-selected mate-pair library. This approach was further validated using another 13 samples that contained BCAs. Our approach advances the application of high-throughput whole-genome low-coverage analysis for robust BCA detection-especially for clinical samples-without the need for karyotyping.
Compelling evidence has demonstrated the potential functions of circular RNAs (circRNAs) in breast cancer (BC) tumorigenesis. Nevertheless, the underlying mechanism by which circRNAs regulate BC progression is still unclear. The purpose of present research was to investigate the novel circRNA circRNF20 (hsa_circ_0087784) and its role in BC. CircRNA microarray sequencing revealed that circRNF20 was one of the upregulated transcripts in BC samples. Increased circRNF20 level predicted the poor clinical outcome in BC specimens. Functionally, circRNF20 promoted the proliferation and Warburg effect (aerobic glycolysis) of BC cells. Mechanistically, circRNF20 harbor miR-487a, acting as miRNA sponge, and then miR-487a targeted the 3'-UTR of hypoxia-inducible factor-1α (HIF-1α). Moreover, HIF-1α could bind with the promoter of hexokinase II (HK2) and promoted its transcription. In conclusion, this finding illustrates the vital roles of circRNF20 via the circRNF20/ miR-487a/HIF-1α/HK2 axis in breast cancer progress and Warburg effect, providing an interesting insight for the BC tumorigenesis.
Emerging evidence suggests that the long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) gene is involved in the pathogenesis of cervical cancer. However, the potential mechanism is rarely reported. Our study found that PVT1 was upregulated in cervical cancer tissue and cell lines. After transfecting PVT1 siRNA, the proliferation, migration, and invasion of cervical cancer cells were markedly decreased. miRNA expression profiles demonstrate that miR-424 was markedly downregulated in cervical cancer tissue. Bioinformatics analysis revealed that miR-424 was potentially targeted by PVT1, which was confirmed by dual-luciferase reporter assay. Pearson's correlation analysis showed that PVT1 expression was negatively related to miR-424 expression in glioma cancer tissues. Finally, lowered expression of miR-424 could recover the tumor-suppressive effects of PVT1 knockdown in cervical cancer cell lines. Our results reveal a tumor-promoting role for PVT1, acting as a competing endogenous RNA (ceRNA) or a molecular sponge in negatively modulating miR-424, which might provide a novel therapeutic target for cervical cancer.
GABAb receptor (GABAbR)-mediated suppression of glutamate release is critical for limiting glutamatergic transmission across the central nervous system. Here we show that, upon tetanic stimulation of afferents to lateral amygdala, presynaptic GABAbR-mediated inhibition only occurs in glutamatergic inputs to principle neurons (PNs), but not to interneurons (INs), despite the presence of GABAbR in terminals to both types of neurons. The selectivity is caused by differential local GABA accumulation; it requires GABA reuptake, and parallels distinct spatial distributions of presynaptic GABAbR in terminals to PNs and INs. Moreover, GABAbR-mediated suppression of theta-burst induced long-term potentiation (LTP) occurs only in the inputs to PNs, but not to INs. Thus, target cell-specific control of glutamate release by presynaptic GABAbR orchestrates the inhibitory dominance inside amygdala and may contribute to prevention of non-adaptive defensive behaviors.
Circular RNAs (circRNAs) are a type of non-coding RNAs that have been identified as critical regulators in various diseases, especially in cancers. However, the expression profiles and functions of circRNAs in cervical cancer are still unclear. In present study, human circRNAs microarray were performed to screen the circRNAs expression in cervical cancer tissue. Microarray analysis revealed 45 significantly expressed circRNAs with 4 fold change. Among these up-regulated circRNAs, hsa_circ_0018289 was validated to be significantly up-regulated in 35 pairs of cervical cancer tissue compared with adjacent normal tissue and cell lines. Loss-of-function experiments revealed that, in vitro and in vivo, hsa_circ_0018289 knockdown inhibited the proliferation, migration and invasion of cervical cancer cells. Via bioinformatics prediction program and luciferase reporter assays, hsa_circ_0018289 was observed to directly bind to miR-497. Taken together, the results indicate that hsa_circ_0018289 plays important role in cervical cancer proliferation, migration and invasion, suggesting the miRNA ‘sponge’ of hsa_circ_0018289 and its oncogenic role on cervical cancer tumorigenesis.
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