GW-2974 and SCH-442416 modulators of tyrosine kinase and adenosine receptors can also stabilize human telomeric G-quadruplex DNA

by Selleckchem | Apr 13 2023

GW-2974 is a potent tyrosine kinase receptor inhibitor while SCH-442416 is a potent adenosine receptors' antagonist with high selectivity towards human adenosine A2A receptor over other adenosine receptors. The two compounds were reported to possess anti-cancer properties. This study aimed to investigate whether stabilization of human telomeric G-quadruplex DNA by GW-2974- and SCH-442416 is a plausible fundamental mechanism underlying their anti-cancer effects. Human telomeric G-quadruplex DNA with sequence AG3(TTAGGG)3 was used. The study used ultraviolet-visible (UV-Vis), fluorescence, fluorescence quenching, circular dichroism (CD), melting temperatures (Tm) and molecular docking techniques to evaluate interactions. The results showed that GW-2974 and SCH-442416 interacted with G-quadruplex DNA through intercalation binding into two types of dependent binding sites. Binding affinities of 1.3 × 108-1.72 × 106 M-1 and 1.55 × 107-3.74 × 105 M-1 were obtained for GW-2974 and SCH-442416, respectively. An average number of binding sites between 1 and 2 was obtained. Additionally, the melting temperature curves indicated that complexation of both compounds to G-quadruplex DNA provided more stability (ΔTm = 9.9°C and 9.6°C, respectively) compared to non-complexed G-quadruplex DNA. Increasing the molar ratios over 1:1 (drug:G-quadruplex) showed less stabilization effect on DNA. Furthermore, GW-2974 and SCH-442516 have proven ≥ 4.0 folds better selective towards G-quadruplex over double-stranded ct-DNA. In silico molecular docking and dynamics revealed favorable exothermic binding for the two compounds into two sites of parallel and hybrid G-quadruplex DNA structures. The results supported the hypothesis that GW-2974 and SCH-442416 firmly stabilize human telomeric G-quadruplex DNA in additions to modulating tyrosine kinase and adenosine receptors. Consequently, stabilizing G-quadruplex DNA could be a mechanism underlying their anti-cancer activity.

Comments：

The study investigated the potential mechanism underlying the anti-cancer properties of GW-2974 and SCH-442416 by examining their interaction with human telomeric G-quadruplex DNA. The results indicated that both compounds could intercalate into G-quadruplex DNA through two types of dependent binding sites, with binding affinities ranging from 1.3 × 108-1.72 × 106 M-1 and 1.55 × 107-3.74 × 105 M-1 for GW-2974 and SCH-442416, respectively.

The study also found that complexation of both compounds to G-quadruplex DNA provided more stability compared to non-complexed G-quadruplex DNA, with an average number of binding sites between 1 and 2. The stabilization effect was observed up to a molar ratio of 1:1 (drug:G-quadruplex), with less effect observed at higher ratios.

Furthermore, the study found that GW-2974 and SCH-442516 were ≥ 4.0 folds better selective towards G-quadruplex over double-stranded ct-DNA. In silico molecular docking and dynamics showed that the two compounds could bind favorably into two sites of parallel and hybrid G-quadruplex DNA structures.

The results supported the hypothesis that the anti-cancer activity of GW-2974 and SCH-442416 could be attributed to their ability to stabilize human telomeric G-quadruplex DNA in addition to their known tyrosine kinase and adenosine receptor modulation properties. The findings suggest that stabilizing G-quadruplex DNA could be a potential mechanism underlying the anti-cancer activity of these compounds.