In Silico and in vitro evaluation of the anticancer effect of a 1,5-Benzodiazepin-2-One derivative (3b) revealing potent dual inhibition of HER2 and HDAC1

Benzodiazepines are widely recognized for their therapeutic benefits in the treatment of anxiety and insomnia. However, in the pursuit of innovative anticancer agents, they have gained attention as a possible pharmacophore. One of those promising anticancer benzodiazepines is 3b which was demonstrated to exert good antiproliferative effects. To investigate the anticancer effect of 3b, in silico prediction of the possible targets were performed. Then, the predicted targets were investigated through in vitro study. Furthermore, 3b was evaluated for its effects on cell cycle suppression and induction of apoptosis. Molecular docking was used to study the possible types of interactions while molecular dynamics simulations were conducted to estimate the protein-ligand complex's stability and dynamic behavior. Results demonstrated that 3b is a potent dual inhibitor of HER2 and HDAC1 with IC₅₀ values of 0.023 and 0.041 nM, respectively. Moreover, 3b was found to suppress cell cycle progression in G2/M phase and induce early and late apoptosis in HepG2 cancer cells. Further analysis of apoptotic markers revealed an induction of Caspase 3 and BAX proapoptotic proteins along with a suppression of the antiapoptotic protein (Bcl-2). Molecular docking of 3b into the active site of HER2 and HDAC1 displayed significant types of interactions with active sites of these target proteins while molecular dynamics simulations demonstrated the overall structural stability of HER2 and HDAC1 is maintained or even enhanced upon ligand binding. In conclusion, 3b is a powerful anticancer agent that exerts its effects by inhibiting HDAC1 and HER2, resulting in cell cycle arrest and cancer cell death through apoptosis. Nonetheless, additional investigations are needed to explore its mechanisms and therapeutic efficacy in more detail.