Background and Objective: Evidence point out promising anticancer activities of Dihydropyrimidinones
(DHPM) and organoselenium compounds. This study aimed to evaluate the cytotoxic and antiproliferative
potential of DHPM-derived selenoesters (Se-DHPM), as well as their molecular mechanisms of action.
Methods: Se-DHPM cytotoxicity was evaluated against cancer lines (HeLa, HepG2, and MCF-7) and normal
cells (McCoy). HepG2 clonogenic assay allowed verifying antiproliferative effects. The propidium iodide/
orange acridine fluorescence readings showed the type of cell death induced after treatments (72h). Molecular
simulations with B-DNA and 49H showed docked positions (AutoDock Vina) and trajectories/energies
(GROMACS). In vitro molecular interactions used CT-DNA and 49H applying UV-Vis absorbance and fluorescence.
Comet assay evaluated DNA fragmentation of HepG2 cells. Flow cytometry analysis verified HepG2 cell
cycle effects. Levels of proteins (β-actin, p53, BAX, HIF-1α, γH2AX, PARP-1, cyclin A, CDK-2, and pRB)
were quantified by immunoblotting.
Results: Among Se-DHPM, 49H was selectively cytotoxic to HepG2 cells, reduced cell proliferation, and increased
BAX (80%), and p53 (66%) causing apoptosis. Molecular assays revealed 49H inserted in the CT-DNA
molecule causing the hypochromic effect. Docking simulations showed H-bonds and hydrophobic interactions,
which kept the ligand partially inserted into the DNA minor groove. 49H increased the DNA damage (1.5 fold)
and γH2AX level (153%). Besides, treatments reduced PARP-1 (60%) and reduced pRB phosphorylation (21%)
as well as decreased cyclin A (46%) arresting cell cycle at the G1 phase.
Conclusion: Together all data obtained confirmed the hypothesis of disruptive interactions between Se-DHPM
and DNA, thereby highlighting its potential as a new anticancer drug.