Nicolò Dal Ponte
OC19 – Nicolò Dal Ponte
Department of Pharmaceutical and Pharmacological Science, University of Padova, Italy
| Targeting the vimentin-G4 repeats axis to disrupt EMT and cancer cell invasion |
| Dal Ponte Nicolò1, Cozzaglio Marta1, Rotondo Martina2, Biondi Barbara2, Rigo Riccardo1, and Sissi Claudia1 1 Department of Pharmaceutical and Pharmacological Science, University of Padova, via Marzolo 5, 35131, Padova, Italy; 2 Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy. |
| Abstract G-quadruplexes (G4s) are non-canonical nucleic acid secondary structures that can arise at guanine-rich tracts, mainly enriched at telomeres and gene promoters. When multiple G4 units are located nearby, an intramolecular crosstalk can occur, leading to the formation of higher-order structures called G4 repeats (G4rps). Despite their biological relevance, only a few proteins have been identified as G4rps binding partners. We recently showed that the cytoskeletal protein vimentin selectively recognizes these arrangements over single G4s and other DNA structures [1]. Vimentin is a type III intermediate filament protein, mainly present in the cytoplasm, where it is arranged into filaments. In some cancer cells, it can also be found in the nucleus as soluble tetramers. Beyond its structural role, vimentin is a key regulator of the Epithelial-to-Mesenchymal Transition (EMT), a process that promotes cell invasion and supports metastasis in several tumor types. In these malignant cells, vimentin is generally overexpressed, highlighting its potential as a therapeutic target for preventing cancer development [2]. Although no structural data of the vimentin-G4rps complex are currently available, this system represents a novel and attractive pharmaceutical target. Here, we investigate the molecular basis of the vimentin-G4rps interaction using a “divide and conquer” approach, targeting both the protein and DNA domains involved in this interaction. By combining Hydrogen-Deuterium Exchange Mass Spectrometry and Surface Plasmon Resonance, we identified a region within the vimentin N-terminal domain that is actively responsible for G4rps binding [3]. A subsequent alanine-scanning approach revealed key residues driving this interaction, enabling the design of mutated vimentin variants with tuned affinity for G4rps. Regarding the DNA counterpart, screening a series of novel G4 binders led to the identification of a promising G4 ligand that will serve as a scaffold to develop new derivatives selective for G4rps over single G4s [4]. In parallel, a panel of vimentin binders was evaluated for their ability to modulate its polymerization state, potentially stabilizing one of its structural forms (i.e., filaments or tetramers), and to impair the vimentin-G4rps interaction. Overall, this work sheds light on a previously unexplored protein-DNA interaction and paves the way to innovative strategies to interfere with EMT-related processes. |
| References [1] Ceschi, S.; Berselli, M.; Cozzaglio, M.; Giantin, M.; Toppo, S.; Spolaore, B.; Sissi, C. Vimentin binds to G-quadruplex repeats found at telomeres and gene promoters. NAR 2022, 50(3), 1370-1381. DOI: 10.1093/nar/gkab1274. [2] Strouhalova, K.; Přechová, M.; Gandalovičová, A.; Brábek, J.; Gregor, M.; Rosel, D. Vimentin Intermediate Filaments as Potential Target for Cancer Treatment. Cancers 2020, 12(1), 184. DOI: 10.3390/cancers12010184. [3] Cozzaglio, M.; Dal Ponte, N.; Rotondo, M.; Biondi, B.; Rigo, R.; Spolaore, B.; Sissi, C. Unraveling the molecular mechanisms of vimentin interaction with G-quadruplex repeats. NAR, 2026, 54(6). DOI: 10.1093/nar/gkag247. [4] Giannangeli, M.; Ponte, ND.; Anyanwu, M.; Romanello, MB.; Mucenji, E.; Rigo, R.; Ribaudo, G.; Sissi, C.; Gianoncelli, A..Enhancing G-Quadruplex Binding: Rational Design and Biophysical Evaluation of Dimeric Ligands. Chem, 2025, 31(72), e03128. DOI: 10.1002/chem.202503128. |