2. Academic Validation
  3. Cellular modulation of a G-quadruplex structure found in the lung cancer-related microRNA-3196

Cellular modulation of a G-quadruplex structure found in the lung cancer-related microRNA-3196

  • Int J Biol Macromol. 2025 Jul;318(Pt 4):145263. doi: 10.1016/j.ijbiomac.2025.145263.
Daniela Alexandre 1,  Joana Polido 2,  André Miranda 2,  Robert H E Hudson 3,  David Monchaud 4,  Pedro V Baptista 5,  Carla Cruz 6
Affiliations

Affiliations

  • 1 RISE-Health, Department of Chemistry, Faculty of Sciences, University of Beira Interior, Rua Marquês d'Ávila e Bolama, 6201-001 Covilhã, Portugal; UCIBIO, Department of Life Sciences, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
  • 2 RISE-Health, Department of Chemistry, Faculty of Sciences, University of Beira Interior, Rua Marquês d'Ávila e Bolama, 6201-001 Covilhã, Portugal.
  • 3 Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7.
  • 4 Institut de Chimie Moléculaire, ICMUB CNRS UMR 6302, Université Bourgogne Europe (UBE) Dijon, France.
  • 5 UCIBIO, Department of Life Sciences, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; i4HB, Associate Laboratory - Institute for Health and Bioeconomy, FCT-NOVA, Portugal. Electronic address: pmvb@fct.unl.pt.
  • 6 RISE-Health, Department of Chemistry, Faculty of Sciences, University of Beira Interior, Rua Marquês d'Ávila e Bolama, 6201-001 Covilhã, Portugal; Department of Chemistry, University of Beira Interior, Rua Marquês d'Ávila e Bolama, 6201-001 Covilhã, Portugal. Electronic address: carlacruz@fcsaude.ubi.pt.
PMID: 40527376 DOI: 10.1016/j.ijbiomac.2025.145263
Abstract

RNA G-quadruplexes (G4s) are promising drug targets due to their high cellular abundance. G-rich RNA regions inherently form G4 structures, while GC-rich sequences adopt stem-loop conformations, and their dynamic equilibrium critically influences RNA function. MicroRNAs (miRs), key regulators of protein expression, undergo processing by Dicer, which specifically recognizes stem-loop structures in precursor miRs (pre-miRs). Notably, some pre-miRs containing G4-forming sequences influence Dicer cleavage, suggesting that G4s can directly regulate miR production. Moreover, pre-miRs with G4 structures present promising targets for small molecules. This research focuses on identifying and modulating G4 structure in pre-miR-3196 to restore normal lung Cancer (LC) levels, offering a potential therapeutic strategy. Firstly, bioinformatic analyses indicated the presence of G4 motifs in pre-miR-3196. We then demonstrated in vitro that this RNA sequence folds into stable G4s by a combination of biophysical and biochemical assays. Then, we demonstrated the formation of these G4s in human Cancer cells by confocal imaging before showing that these G4s can be modulated using the RNA G4 destabilizer PhpC, which impacts the miR-3196 biogenesis. These findings highlighted the possibility of using G4s to control the expression of mature miR-3196 and revealed the potential of using the destabilizer PhpC to adjust its G4 structure.

Keywords

G-quadruplex microRNA-3196; In vitro assays; PhpC ligand.

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