Real-time and quantitative fluorescent live-cell imaging with quadruplex-specific red-edge probe (G4-REP)

• Published in: Biochimica et biophysica acta. General subjects Vol. 1861; no. 5; pp. 1312 - 1320
• Main Authors: Yang, Sunny Y., Amor, Souheila, Laguerre, Aurélien, Wong, Judy M.Y., Monchaud, David
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2017; Elsevier
• Subjects: Binding Sites; Biosensing Techniques; Cell imaging; Chemical Sciences; DNA; DNA, Neoplasm - chemistry; DNA, Neoplasm - metabolism; dyes; filters; fluorescence; Fluorescent Dyes - chemistry; Fluorescent Dyes - metabolism; G-Quadruplexes; Guanosine - chemistry; Guanosine - metabolism; HEK293 Cells; HT29 Cells; human cell lines; Humans; image analysis; Ligands; Live-cell analysis system; microscopy; Microscopy, Confocal; Microscopy, Fluorescence, Multiphoton; monitoring; Multiphoton microscopy; prototypes; Red-edge effect; RNA; Smart quadruplex probe; Structure-Activity Relationship; therapeutics; Time Factors; Twice-as-smart quadruplex ligands; wavelengths; Live-cell analysis system; Red-edge effect; Cell imaging; Smart quadruplex probe; Twice-as-smart quadruplex ligands; Multiphoton microscopy; visualization; rna-quadruplexes; biology; chemical sensors; water; Live-cell; ligand; dynamics; dna; molecular hydrophobic interfaces; microscopy
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/j.bbagen.2016.11.046

The development of quadruplex-directed molecular diagnostic and therapy rely on mechanistic insights gained at both cellular and tissue levels by fluorescence imaging. This technique is based on fluorescent reporters that label cellular DNA and RNA quadruplexes to spatiotemporally address their complex cell biology. The photophysical characteristics of quadruplex probes usually dictate the modality of cell imaging by governing the selection of the light source (lamp, LED, laser), the optical light filters and the detection modality. Here, we report the characterizations of prototype from a new generation of quadruplex dye termed G4-REP (for quadruplex-specific red-edge probe) that provides fluorescence responses regardless of the excitation wavelength and modality (owing to the versatility gained through the red-edge effect), thus allowing for diverse applications and most imaging facilities. This is demonstrated by cell images (and associated quantifications) collected through confocal and multiphoton microscopy as well as through real-time live-cell imaging system over extended period, monitoring both non-cancerous and cancerous human cell lines. Our results promote a new way of designing versatile, efficient and convenient quadruplex-reporting dyes for tracking these higher-order nucleic acid structures in living human cells. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio. •A new generation of quadruplex-selective fluorescent probes is studied, the G4-REP (for quadruplex-specific red-edge probes).•The photophysical properties of G4-REP are deciphered (red-edge effect versus multiphoton fluorescence).•The versatility of G4-REP is demonstrated via cell images collected through different imaging techniques and facilities.•Real-time live-cell imaging system is implemented to studied G4-REP over long incubation times.