Never tear us a-PARP: Dealing with DNA lesions during mitosis

Tumors defective in homologous recombination (HR) are highly sensitive to poly ADP-ribose polymerase (PARP) inhibition, however the cell biological mechanisms underlying this synthetic lethality remain elusive. We recently identified that PARP inhibitor-induced DNA lesions persist until mitosis, subsequently causing mitotic chromatin bridges, multinucleation and apoptosis. Here, we discuss the implications of these findings.