RNA‐Selective Small‐Molecule Ligands: Recent Advances in Live‐Cell Imaging and Drug Discovery

Abstract

RNA structures, including those formed from coding and noncoding RNAs, alternative to protein‐based drug targets, could be a promising target of small molecules for drug discovery against various human diseases, particularly in anticancer, antibacterial and antivirus development. The normal cellular activity of cells is critically dependent on the function of various RNA molecules generated from DNA transcription. Moreover, many studies support that mRNA‐targeting small molecules may regulate the synthesis of disease‐related proteins via the non‐covalent mRNA‐ligand interactions that do not involve gene modification. RNA‐ligand interaction is thus an attractive approach to address the challenge of “undruggable” proteins in drug discovery because the intracellular activity of these proteins is hard to be suppressed with small molecule ligands. We selectively surveyed a specific area of RNA structure‐selective small molecule ligands in fluorescence live cell imaging and drug discovery because the area was currently underexplored. This state‐of‐the‐art review thus mainly focuses on the research published within the past three years and aims to provide the most recent information on this research area; hopefully, it could be complementary to the previously reported reviews and give new insights into the future development on RNA‐specific small molecule ligands for live cell imaging and drug discovery.

Live Cell Imaging and Real-Time Monitoring of Nucleolus Morphology and Mitophagy with a Red Fluorescent and Photostable rRNA-Specific Probe in Human Cancer Cells

“…Currently, SYTO RNA-Select is the only commercially available dye for RNA imaging; however, its molecular structure is not known, its excitation and emission are approximately 490/530 nm, and the photostability is low under cellular conditions . More importantly, with respect to the most recent reviews on the RNA-selective probe development, , only few probes have been developed at present and they commonly encounter some drawbacks of low water solubility, poor nuclear membrane permeability, short emission wavelength, low stability against photobleaching, and relatively high cytotoxicity. These adverse properties of most reported rRNA probes limit their potential applications in real-time live-cell imaging and in biomedical and clinical areas.…”