SBE 13 is a potent inhibitor of polo-like kinase 1 (Plk1) (IC50 = 0.2 nM) that targets the inactive conformation of the enzyme . It exhibits no activity against aurora A kinase and less effectively inhibits Plk2 (IC50 > 66 μM) and Plk3 (IC50 = 875 nM). SBE 13 induces cell cycle arrest, reduces cell proliferation (EC50 = 5-60 μM), and induces apoptosis in a broad range of human cancer cell lines.
to determine its ability to induce cell death in cancer cells, we applied kinase assays, western blot analyses, facs can analyses, caspase assays and immunofluorescence studies. we detected decreased cell proliferation, delayed progression through the cell cycle in lower sbe13 concentrations, a g2/m arrest using higher sbe13 concentrations followed by apoptosis, and abnormal mitotic figures. notably, sbe13 did not influence activity of other kinases (plk2, plk3, aurora a), indicating the selectivity of this type ii plk1 inhibitor [1].