Synthesis, biological activity and structural study of new benzotriazole-based protein kinase CK2 inhibitors

A new series of 4,5,6,7-tetrabromobenzotriazole (TBB) derivatives was synthesized and characterized as CK2 inhibitors. They were readily synthesized using a click chemistry approach based on a Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC). Some of the synthesized compounds present interesting inhibitory activities using an in vitro assay, with K-i values in the low micro molar range and a high degree of selectivity against a panel of 24 kinases. Selected compounds were tested for their antiproliferative effect on several cancer cell lines, and for their proapoptotic activity towards human Jurkat T-leukemia and MCF-7 breast adenocarcinoma cells, showing that they can be proposed as promising anticancer agents. Docking studies as well as crystallographic analysis allowed us to identify ligand-CK2 interactions that account for the molecular recognition process, and can help to further optimize this family of compounds as CK2 inhibitors.