Simultaneous Enzyme-Free Detection of Multiple Long Noncoding RNAs in Cancer Cells at Single-Molecule/Particle Level

Abstract

Aberrant change in long noncoding RNA (lncRNA) is associated with various diseases and cancers. So far, simultaneous detection of lncRNAs has remained a great challenge due to their large size and extensive secondary structure. Herein, we develop an enzyme-free single-molecule/particle detection method for simultaneous detection of multiple lncRNAs in cancer cells based on target-catalyzed strand displacement. We designed the magnetic bead–capture probe–multiple Cy5/Cy3-modified reporter unit complexes to isolate and identify lncRNA MALAT1 and lncRNA HOTAIR. The target-catalyzed strand displacement reactions lead to the release of Cy5 and Cy3 fluorescent molecules from the complexes, which can be subsequently quantified by single-molecule/particle detection. The dual-targetability, good selectivity and high sensitivity of this method enables simultaneous detection of multiple lncRNAs in even single cancer cell. Importantly, this method can discriminate cancer cells from normal cells and has significant advantages in the simple sequence design and in being free of enzymes, holding great potential in living cell imaging and early clinical diagnosis.

Mismatched fluorescent probes with an enhanced strand displacement reaction rate for intracellular long noncoding RNA imaging

“…3a), suggesting the upregulated expression of lncRNA HOTAIR in cancer cells. 18 The lncRNA HOTAIR level is further quantified by quantitative reverse transcription PCR (qRT-PCR) (Fig. S8, ESI†), and the obtained results are in good agreement with those obtained by the mismatched probe 5 for the direct lncRNA assay (Fig.…”

Target-Initiated Cascade Signal Amplification Lights up a G-Quadruplex for a Label-Free Detection of Circular Ribonucleic Acids

“…In contrast to the detection of linear nucleic acids (e.g., long noncoding RNAs and miRNAs), − the enrichment and identification of circRNAs remain a great challenge due to their lack of capping and poly-adenylation, ultralong sequence, structure complexity, and the lower levels than linear species. , Herein, we construct a label-free fluorescent biosensor for an ultrasensitive analysis of circRNAs based on the integration of a target-initiated cascade signal amplification strategy with a light-up G-quadruplex. The combination of G-quadruplex with small fluorogenic molecules may function as signal indicators for biosensing. − This assay does not need any complicated steps, large sample consumption, and specific labeled probes and possesses distinct features of simple operation, high sensitivity, and excellent specificity.…”

Identification and ultrasensitive photoelectrochemical detection of LncNR_040117: a biomarker of recurrent miscarriage and antiphospholipid antibody syndrome in platelet-derived microparticles

“…The photocurrent stabilized at 1.5 h at the hybridization temperature of 37℃, thus 1.5 h was determined to be the ideal optimal hybridization time (Fig. 7 f) [ 58 ]. The photocurrent decreased with the increase of LncNR_040117 concentration due to the increase of steric hindrance (Fig.…”