Title
Tandem application of ligand-based virtual screening and G4-OAS assay to identify novel G-quadruplex-targeting chemotypes
Author
Domenica Musumeci, Jussara Amato, Pasquale Zizza, Chiara Platella, Sandro Cosconati, Chiara Cingolani, Annamaria Biroccio, Ettore Novellino, Antonio Randazzo, Concetta Giancola, Bruno Pagano, Daniela Montesarchio
Year
2017
Journal
Biochimica et Biophysica Acta (BBA) - General Subjects
Abstract
G-quadruplex (G4) structures are key elements in the regulation of cancer cell proliferation and their targeting is deemed to be a promising strategy in anticancer therapy. A tandem application of ligand-based virtual screening (VS) calculations together with the experimental G-quadruplex on Oligo Affinity Support (G4-OAS) assay was employed to discover novel G4-targeting compounds. The interaction of the selected compounds with the investigated G4 in solution was analysed through a series of biophysical techniques and their biological activity investigated by immunofluorescence and MTT assays. A focused library of 60 small molecules, designed as putative G4 groove binders, was identified through the VS. The G4-OAS experimental screening led to the selection of 7 ligands effectively interacting with the G4-forming human telomeric DNA. Evaluation of the biological activity of the selected compounds showed that 3 ligands of this sub-library induced a marked telomere-localized DNA damage response in human tumour cells. The combined application of virtual and experimental screening tools proved to be a successful strategy to identify new bioactive chemotypes able to target the telomeric G4 DNA. These compounds may represent useful leads for the development of more potent and selective G4 ligands.
Instrument
J-715
Keywords
Circular dichroism, DNA structure, Thermal stability, Ligand binding, Thermodynamics, Biochemistry