Interaction analysis of RNA G-quadruplex with ligands and in situ imaging application.

RNA G4, as an integral branch of G4 structure, possesses distinct interactions with ligands compared to the common DNA G4, thus the investigation of RNA G4/ligand interactions might be considered as a fresh breakthrough to improve the biosensing performance of G4/ligand system. In this study, we comparatively explored the structural and functional mechanisms of RNA G4 and DNA G4 in the interaction with ligands, hemin and thioflavin T (ThT), utilizing the classical PS2.M sequence as a model.

A one-pot CRISPR-Cas12a-based toolbox enables determination of terminal deoxynucleotidyl transferase activity for acute leukemia screening.

An isothermal, one-pot toolbox (called OPT-Cas) based on CRISPR-Cas12a collateral cleavage capability is proposed for highly sensitive and selective determination of terminal deoxynucleotidyl transferase (TdT) activity. Oligonucleotide primers with 3'-hydroxyl (OH) terminal were randomly introduced for TdT-induced elongation. In the presence of TdT, dTTP nucleotides polymerized at the 3' terminals of the primers to generate abundant polyT-tails, which function as triggers for the synchronous activation of Cas12a proteins.

Dual-aptamer-engineered M1 macrophage with enhanced specific targeting and checkpoint blocking for solid-tumor immunotherapy.

Chimeric antigen receptor T (CAR-T) cell therapy has faced a series of challenges and has shown very little efficacy in solid tumors to date. Although genetically engineered macrophages have achieved definite therapeutic effect in solid tumors, heterogeneous expression of engineered proteins and the potential for toxicity limit further applications. Herein, we propose a nongenetic and simple macrophage cell engineering strategy through glycan metabolic labeling and click reaction for the treatment of solid tumors.

Light up multiple protein dimers on cell surface based on proximity-induced fluorescence activation of DNA-templated sliver nanoclusters.

Efficient and multiple analysis of receptor protein dimers is highly necessary, due to their important role in the occurrence and development of cancer. Herein, we report a turn-on strategy to visualize human epidermal growth factor receptor (HER) dimers on cell surfaces. By taking advantages of specific aptamer recognition and proximity-induced fluorescence activation of DNA-templated sliver nanoclusters (DNA/AgNCs) by guanine (G)-rich sequence, we attached the two kind of DNA/AgNCs sequence with different fluorescence properties to the corresponding HER aptamer to form aptamer-functionalized AgNCs probes, and attached G-rich sequence to the corresponding HER aptamer as enhancer.

Recent advances in rolling circle amplification-based biosensing strategies-A review.

Rolling circle amplification (RCA) is an efficient enzymatic isothermal reaction that using circular probe as a template to generate long tandem single-stranded DNA or RNA products under the initiation of short DNA or RNA primers. As a simplified derivative of natural rolling circle replication which synthesizes copies of circular nucleic acids molecules such as plasmids, RCA amplifies the circular template rapidly without thermal cycling and finds various applications in molecular biology. Compared with other amplification strategies, RCA has many obvious advantages.

Highly sensitive fluorescence biosensing of BCR-ABL1 fusion gene based on exponential transcription-triggered hemin catalysis.

Simple, sensitive and specific detection of the transcription level of BCR-ABL1 mRNA possesses vital clinical significance in diagnosis and treatment of chronic myeloid leukemia (CML). In this study, an innovative fluorescence biosensing methodology has been developed for sensitive and specific detection of BCR-ABL1 mRNA by integrating high-efficiency of exponential transcription and superior catalytic performance of DNA-grafted hemin. Exponential transcription was triggered by BCR-ABL1 mRNA to produce plenty of RNA products.

One-step discrimination of BCR/ABL transcript isoforms directly from RNA extraction with fusion-triggered rolling circle amplification.

BCR/ABL fusion gene, the characteristic biomarker of chronic myelogenous leukemia (CML), contains two different transcription isoforms, e13a2 and e14a2, which lead to differences in the pathological features and response to targeted drug. At present, there is short of simple and fast technology to distinguish these two transcript isoforms. In this paper, RNA fusion-triggered rolling circle amplification (RF-RCA) strategy was developed to distinguish e13a2 and e14a2 transcripts directly from RNA extraction in one step.

High-sensitive immunosensing of protein biomarker based on interfacial recognition-induced homogeneous exponential transcription.

A novel and versatile immunosensing strategy was developed for ultrasensitive and specific detection of proteins by organically integrating interfacial specific target recognition and homogeneous transcription amplification. In principle, classic antigen-antibody sandwich structure on the microplate could realize the specific identification of target protein. Biotinylated DNA probe was subsequently introduced by streptavidin-biotin system as a bridge linking interfacial and homogeneous reaction.

Target-triggered DNA nanoassembly on quantum dots and DNAzyme-modulated double quenching for ultrasensitive microRNA biosensing.

Herein, a simple and novel fluorescence biosensing strategy has been developed for ultrasensitive determination of microRNA (miRNA) by combining target-triggered DNA nanoassembly on quantum dots (QDs) with DNAzyme-modulated double quenching of QDs. In presence of miRNA target, the target triggered catalytic hairpin assembly (CHA) amplification and powered highly efficient DNA nanoassembly on the surface of QDs, leading to exhibition of numerous G-quadruplexes close to the QDs. The G-quadruplex folded properly and bound hemin to form a stable G-quadruplex/hemin complex.