A novel versatile locked nucleic acid modified molecular beacon probe (LNA-MB) was developed for imaging intracellular precursor miRNAs (pre-miRNAs) and disturbing Dicer-mediated cleavage process. The target recognition reaction between the smart probe and pre-miRNA can not only induce the conformational changes of probe and block the Dicer cleavage site， but also inhibit the cleavage process， and then achieve down-regulation of miRNA expression. Simultaneously， the target recognition reaction broke the fluorescence resonance energy transfer (FRET) between fluorophore donor FAM and acceptor TAMRA， which were labelled on the LNA-MB probe， further induced the relevant change of fluorescence signal， an... More
A novel versatile locked nucleic acid modified molecular beacon probe (LNA-MB) was developed for imaging intracellular precursor miRNAs (pre-miRNAs) and disturbing Dicer-mediated cleavage process. The target recognition reaction between the smart probe and pre-miRNA can not only induce the conformational changes of probe and block the Dicer cleavage site， but also inhibit the cleavage process， and then achieve down-regulation of miRNA expression. Simultaneously， the target recognition reaction broke the fluorescence resonance energy transfer (FRET) between fluorophore donor FAM and acceptor TAMRA， which were labelled on the LNA-MB probe， further induced the relevant change of fluorescence signal， and then achieved imaging analysis of pre-miRNA and inhibition events in situ. Both in?vitro and in single living cell studies showed that the versatile probes exhibited a remarkable performance in targeting with pre-miRNA-21， and nearly 65% downregulation of mature miRNA-21 was achieved with 100?nM probes. All investigations demonstrate that the proposed strategy represents a promising alternative for regulating and inhibiting endogenous disease-associated RNAs， then further for achieving therapeutic outcomes in personalized treatments.
