G-quadruplexes in MTOR and induction of autophagy

Sci Rep. 2024 Jan 30;14(1):2525. doi: 10.1038/s41598-024-52561-y.

Abstract

G-quadruplex (G4) structures have emerged as singular therapeutic targets for cancer and neurodegeneration. Autophagy, a crucial homeostatic mechanism of the cell, is often dysregulated in neurodegenerative diseases and cancers. We used QGRS mapper to identify 470 G4 sequences in MTOR, a key negative regulator of autophagy. We sought to identify a functional context by leveraging the effect of G4-targeting ligands on MTOR G4 sequences. The effect of Bis-4,3, a G4 selective dimeric carbocyanine dye, was compared with the known G4-stabilizing activity of the porphyrin, TMPyP4 in HeLa and SHSY-5Y cells. Our results show that treatment with G4-selective ligands downregulates MTOR RNA and mTOR protein expression levels. This is the first report describing G4 motifs in MTOR. This study indicates a possible role of G4 stabilizing ligands in induction of autophagy by downregulation of mTOR levels, albeit not precluding MTOR independent pathways.

MeSH terms

  • Autophagy
  • G-Quadruplexes*
  • HeLa Cells
  • Humans
  • Ligands
  • RNA
  • TOR Serine-Threonine Kinases

Substances

  • RNA
  • TOR Serine-Threonine Kinases
  • Ligands
  • MTOR protein, human