RESUMO
In this study, carbazole (MC) and dibenzofuran (MD) derivatives were synthesized to examine their effect on the biomolecular recognition of G-quadruplex (G4) targets. Biophysical studies revealed that MC-4, a carbazole derivative, exhibits a specific affinity and effectively stabilizes the c-KIT 1 G4. Molecular modeling suggests a stable interaction of MC-4 with the terminal G-tetrad of c-KIT 1 G4. Biological studies demonstrate that MC-4 efficiently enters cells, reduces c-KIT gene expression, and induces cell cycle arrest, DNA damage, and apoptosis in cancer cells. These findings demonstrate MC-4 as a selective c-KIT G4 ligand with therapeutic potential, providing insight into the structural basis of its anticancer mechanisms.
RESUMO
We herein report the synthesis and biophysical evaluation of triazolyl dibenzo[a,c]phenazine derivatives as a novel class of G-quadruplex ligands. The aromatic core facilitates π-π interaction and the flexible, protonatable side chains interact with the phosphate backbone of DNA via electrostatic interactions. Förster resonance energy transfer (FRET) melting assay and isothermal titration calorimetry (ITC) studies suggest that these ligands show binding preference for the hTELO G-quadruplex over G-quadruplexes found in the promoter region of various oncogenes and duplex DNA. The in vitro telomeric repeat amplification protocol (Q-TRAP) assay reveals that these ligands reduce telomerase activity in cancer cells.
RESUMO
DNA sequences rich in cytosine have the propensity, under acidic pH, to fold into four-stranded intercalated DNA structures called i-motifs. Recent studies have provided significant breakthroughs that demonstrate how chemists can manipulate these structures for nanobiotechnology and therapeutics. The first section of this Minireview discusses the development of advanced functional nanostructures by synthetic conjugation of i-motifs with organic scaffolds and metal nanoparticles and their role in therapeutics. The second section highlights the therapeutic targeting of i-motifs with chemical scaffolds and their significance in biology. For this, first we shed light on the long-lasting debate regarding the stability of i-motifs under physiological conditions. Next, we present a comparative analysis of recently reported small molecules for specifically targeting i-motifs over other abundant DNA structures and modulating their function in cellular systems. These advances provide new insights into i-motif-targeted regulation of gene expression, telomere maintenance, and therapeutic applications.