Docking and molecular dynamics predicted B-DNA and dihydropyrimidinone selenoesters interactions elucidating antiproliferative effects on breast adenocarcinoma cells.

Dihydropyrimidinones have demonstrated different biological activities including anticancer properties. Cytotoxic potential and antiproliferative potential of new dihydropyrimidinone-derived selenoesters (Se-DHPM) compounds were assessed in vitro against the breast adenocarcinoma cells (MCF-7). Among the eight Se-DHPM compounds tested just 49A and 49F were the most cytotoxic for MCF-7 and the most selective for the non-tumor strain (McCoy) and reduced cell viability in a time- and concentration-dependent manner. Compounds 49A and 49F increased the rate of cell death due to apoptosis and necrosis comparatively to the control, however only the 49F showed antiproliferative potential, reducing the number of colonies formed. In the molecular assay 49A interacts with CT-DNA and caused hyperchromism while 49F caused a hypochromic effect. The intercalation test revealed that the two compounds caused destabilization in the CT-DNA molecule. This effect was evidenced by the loss of fluorescence when the compounds competed and caused the displacement of propidium iodide. Simulations (docking and molecular dynamics) using B-DNA brought a greater understanding of ligand-B-DNA interactions. Furthermore, they predicted that the compounds act as minor groove ligands that are stabilized through hydrogen bonds and hydrophobic interactions. However, the form of interaction foreseen for 49A was more energetically favorable and had more stable hydrogen bonds during the simulation time. Despite some violations foreseen in the ADMET for 49F, the set of other results point to this Se-DHPM as a promising leader compound with anti-tumor potential for breast cancer.Communicated by Ramaswamy H. Sarma.

Novel Dihydropyrimidinone-Derived Selenoesters as Potential Cytotoxic Agents to Human Hepatocellular Carcinoma: Molecular Docking and DNA Fragmentation.

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 (ß-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.