Bifunctional Pdots-Based Novel ECL Nanoprobe with Qualitative and Quantitative Dual Signal Amplification Characteristics for Trace Cytokine Analysis.

In this work, a novel methodology to design bifunctional ECL-luminophores with self-enhanced and TSA-amplified characteristics was proposed for improving the sensing performance of ECL-immunosensor toward trace cytokine analysis. Thanks to the qualitative- and quantitative- dual signal amplification technique, the as-prepared ECL biosensor demonstrated excellent detection performance. By analyzing the prospective cytokine biomarkers (IL-6), the ECL immunosensor exhibited a broad examination range with quite low detection limit and quite high selectivity, which was far superior to commercial ELISA kits and ever reported works. In particular, the novel ECL nanoprobe developed here could also be applied to monitor other immune toxicities or disease-related cytokines by using the respective antibodies corresponding to these targets. Moreover, the concept and construction strategy of self-amplified ECL-luminophores presented here could be further extended to design a series of Pdots-derived multicolored ECL probes to meet the needs of multipathway detection applications.

PER-CRISPR/Cas14a system-based electrochemical biosensor for the detection of ctDNA EGFR L858R.

The detection of epidermal growth factor receptor (EGFR) mutation L858R in circulating tumor DNA (ctDNA) is beneficial for the clinical diagnosis and personalized therapy of non-small cell lung cancer (NSCLC). Herein, for the first time, the combination of the primer exchange reaction (PER) and clustered regularly interspaced short palindromic repeats (CRISPR) and its associated nucleases (Cas) 14a was used in electrochemical biosensor construction for the detection of ctDNA EGFR L858R. EGFR L858R, as the target, induced the isothermal amplification of the PER reaction, and then the CRISPR/Cas14a system was activated; subsequently, the substrate ssDNA-MB was cleaved and the electron on the surface of the gold electrode transferred, resulting in the fluctuation of the electrochemical redox signal on the electrode surface, whereas the electrochemical signal will be stable when EGFR L858R is absent. Therefore, the concentration of EGFR L858R can be quantified by electrochemical signal analysis. The low detection limit is 0.34 fM and the dynamic detection range is from 1 fM to 1 µM in this work. The PER-CRISPR/Cas14a electrochemical biosensor greatly improved the analytical sensitivity. In addition, this platform also exhibited excellent specificity, reproducibility, stability and good recovery. This study provides an efficient and novel strategy for the detection of ctDNA EGFR L858R, which has great potential for application in the diagnosis and treatment of NSCLC.

A General Strategy for Developing Ultrasensitive "Transistor-Like" Thermochromic Fluorescent Materials for Multilevel Information Encryption.

Thermochromic fluorescent materials (TFMs) exhibit great potential in information encryption applications but are limited by low thermosensitivity, poor color tunability, and a wide temperature-responsive range. Herein, a novel strategy for constructing highly sensitive TFMs with tunable emission (450-650 nm) toward multilevel information encryption is proposed, which employs polarity-sensitive fluorophores with donor-acceptor-donor (D-A-D) type structures as emitters and long-chain alkanes as thermosensitive loading matrixes. The structure-function relationships between the performance of TFMs and the structures of both fluorescent emitters and phase-change molecules are systematically studied. Benefiting from the above design, the obtained TFMs exhibit over 9500-fold fluorescence enhancement toward the temperature change, as well as ultrahigh relative temperature sensitivity up to 80% K-1 , which are first confirmed. Thanks to the superior transducing performance, the above-prepared TFMs can be further developed as information-storage platforms within a relatively narrow interval of temperature variation, including temperature-dominated multicolored information display and multilevel information encryption. This work will not only provide a novel perspective for designing superior TFMs for information encryption but also bring inspiration to the design and preparation of other response-switching-type fluorescent probes with ultrahigh conversion efficiency.

PIWI-Interacting RNAs (piRNAs): Promising Applications as Emerging Biomarkers for Digestive System Cancer.

PIWI-interacting RNAs (piRNAs) are a novel type of small non-coding RNAs (sncRNAs), which are 26-31 nucleotides in length and bind to PIWI proteins. Although piRNAs were originally discovered in germline cells and are thought to be essential regulators for germline preservation, they can also influence gene expression in somatic cells. An increasing amount of data has shown that the dysregulation of piRNAs can both promote and repress the emergence and progression of human cancers through DNA methylation, transcriptional silencing, mRNA turnover, and translational control. Digestive cancers are currently a major cause of cancer deaths worldwide. piRNAs control the expression of essential genes and pathways associated with digestive cancer progression and have been reported as possible biomarkers for the diagnosis and treatment of digestive cancer. Here, we highlight recent advances in understanding the involvement of piRNAs, as well as potential diagnostic and therapeutic applications of piRNAs in various digestive cancers.

An emerging role of the 5' termini of mature tRNAs in human diseases: Current situation and prospects.

The fundamental biological roles of a class of small noncoding RNAs (sncRNAs), derived from mature tRNAs or pre-tRNAs, in human diseases have received increasing attention in recent years. These ncRNAs are called tRNA-derived fragments (tRFs) or tRNA-derived small RNAs (tsRNAs). tRFs mainly include tRF-1, tRF-5, tRF-3 and tRNA halves (tiRNAs or tRHs), which are produced by enzyme-specific cleavage of tRNAs. Here, we classify tRF-5 and 5' tiRNAs into the same category: 5'-tRFs and review the biological functions and regulatory mechanisms of 5'-tRFs in cancer and other diseases (metabolic diseases, neurodegenerative diseases, pathological stress injury and virus infection) to provide a new theoretical basis for the diagnosis and treatment of diseases.

A highly sensitive electrochemical cytosensor based on a triple signal amplification strategy using both nanozyme and DNAzyme.

The development of a sensitive cytosensor is beneficial for the early diagnosis and treatment of cancer. Herein, highly sensitive cytosensing was achieved by applying triple signal amplification strategies with Fe3O4@Au nanozymes and DNAzyme hybrids as electrochemical nanoprobes and toluidine blue (Tb) as the electron transfer medium. The Fe3O4@Au nanocomposites not only acted as nanozymes with excellent catalytic performance towards H2O2 reduction but also served as promising scaffolds to carry massive electroactive substances and DNA probes. The dual-functional DNA probes were designed with the sequence of hemin/G-quadruplex to serve as the DNAzyme and the sequence of aptamer to recognize cancer cells. Furthermore, Tb was also conjugated to the surface of the Fe3O4@Au nanohybrids, working as the electron transport medium to magnify the electrochemical response. With the above design, the Fe3O4@Au nanozymes and hemin/G-quadruplex DNAzyme efficiently co-catalyzed the reduction of H2O2 to accelerate the electron transfer of Tb, which realized triple signal amplification and finally improved the performance of the electrochemical cytosensor. The proposed cytosensor achieved a sensitive detection of HepG2 cells with a low detection limit of 20 cells mL-1, and could be potentially used as an effective analysis tool in early cancer diagnosis in the future.

Target Recognition- and HCR Amplification-Induced In Situ Electrochemical Signal Probe Synthesis Strategy for Trace ctDNA Analysis.

An electrochemical-DNA (E-DNA) sensor was constructed by using DNA metallization to produce an electrochemical signal reporter in situ and hybridization chain reaction (HCR) as signal amplification strategy. The cyclic voltammetry (CV) technique was used to characterize the electrochemical solid-state Ag/AgCl process. Moreover, the enzyme cleavage technique was introduced to reduce background signals and further improve recognition accuracy. On the basis of these techniques, the as-prepared E-DNA sensor exhibited superior sensing performance for trace ctDNA analysis with a detection range of 0.5 fM to 10 pM and a detection limit of 7 aM. The proposed E-DNA sensor also displayed excellent selectivity, satisfied repeatability and stability, and had good recovery, all of which supports its potential applications for future clinical sample analysis.

Hsa_circ_0000098 is a novel therapeutic target that promotes hepatocellular carcinoma development and resistance to doxorubicin.

BACKGROUND: Circular RNA (circRNA) is crucial to the progression of hepatocellular cancer (HCC). In addition, Mitochondrial calcium uniporter regulatory factor 1 (MCUR1) is commonly overexpressed in HCC to increase cellular ATP levels. Due to the highly aggressive characteristics of HCC, it is essential to identify new diagnostic biomarkers and therapeutic targets that may facilitate the diagnosis of HCC and the development of effective anti-HCC treatments. METHODS: A series of in vitro and in vivo experiments were undertaken to investigate the biological importance and underlying mechanisms of circ_0000098 in HCC. RESULTS: The expression of circ_0000098 was higher in HCC tissues compared to paired adjacent tissues. According to the receiver-operating characteristic curves, circ_0000098 functioned as a potential diagnostic tumor marker in HCC. Our experiments indicated that circ_0000098 served as a key oncogenic circRNA to increase HCC cell proliferation and invasion in vitro and HCC progression in vivo. Furthermore, mechanistic investigation demonstrated that by sequestering miR-383 from the 3'-UTR of MCUR1, circ_0000098 positively regulated MCUR1 expression in HCC cells and finally promoted HCC progression. On the other hand, inhibiting circ_0000098 in HCC cells could diminish doxorubicin (DOX) resistance by decreasing P-glycoprotein (P-gp, MDR1) expression and intracellular ATP levels. Either downregulation of MCUR1 or overexpression of miR-383 improved DOX sensitivity in HCC cells. Subsequently, a short hairpin RNA targeting circ_0000098 (referred to as sh-1) and doxorubicin (DOX) were encapsulated into platelets (PLTs), referred to as DOX/sh-1@PLT. Activated DOX/sh-1@PLT through HCC cells resulted in the creation of platelet-derived particles that were capable of delivering the DOX/sh-1 combination into HCC cells and promoting intracellular DOX accumulation. Furthermore, our in vivo experiments showed that DOX/sh-1@PLT can effectively reduce P-gp expression, promote DOX accumulation, and reverse DOX resistance. CONCLUSIONS: Our results demonstrated that circ_0000098 is an oncogenic circRNA that promotes HCC development through the miR-383/MCUR1 axis and targeting circ_0000098 with DOX/sh-1@PLT may be a promising and practical therapeutic strategy for preventing DOX resistance in HCC.

Methyltransferase-Like 3-Mediated m6A Methylation of Hsa_circ_0058493 Accelerates Hepatocellular Carcinoma Progression by Binding to YTH Domain-Containing Protein 1.

Circular RNAs (circRNAs) are highly correlated with the progression and prognosis of hepatocellular carcinoma (HCC). In addition, mounting evidence has revealed that N6-methyladenosine (m6A) methylation, a common RNA modification, is involved in the progression of malignancies. In this research, a novel circRNA, hsa_circ_0058493, was proven to be upregulated in HCC, which was correlated with the prognosis of HCC patients. Experimentally, hsa_circ_0058493 knockdown suppressed the growth and metastasis of HCC cells in vivo and in vitro. On the contrary, the overexpression of hsa_circ_0058493 in HCC cells had the opposite effect in vitro. Mechanistic experiments revealed that hsa_circ_0058493 contained m6A methylation sites and that methyltransferase-like 3 (METTL3) mediated the degree of methylation modification of hsa_circ_0058493. Furthermore, YTH domain-containing protein 1 (YTHDC1) could bind to hsa_circ_0058493 and promote its intracellular localization from the nucleus to the cytoplasm. In addition, both si-METTL3 and si-YTHDC1 suppressed HCC cell growth and metastasis, whereas rescue experiments confirmed that overexpression of hsa_circ_0058493 inverted the inhibitory effects of si-METTL3 and si-YTHDC1 on HCC cells. Taken together, this study explored the oncogenic role of m6A-modified hsa_circ_0058493 and found to accelerate HCC progression via the METTL3-hsa_circ_0058493-YTHDC1 axis, indicating a potential therapeutic target for this deadly disease.