BI 2536

BI-2536 was originally reported as a potent (IC50’s Plk1=0.83 nM, Plk2=3.5 nM and Plk3=9.0 nM) and selective Polo-like kinase inhibitor that caused mitotic arrest and apoptosis induction in various human cancer cell lines. It was later found to be a potent inhibitor (IC50=100 nM) of BET family member BRD4 and able to potently suppress c-Myc expression in MM.1S multiple myeloma cells. BI-2536 destabilizes N-Myc by inhibiting the deactivation of the ubiquitin E3 ligase Fbw7 by Plk1.