PARP

\ua9 Springer Science+Business Media New York 2017. All rights reserved. PARP enzymes synthese poly(ADP-ribose) (PAR) using nicotinamide adenine dinucleotide (NAD+) as a substrate. PARP-1 is the most extensively studied of a family of PARP enzymes. It is a highly abundant nuclear protein that is activated by DNA breaks and facilitates their repair. PARP inhibitors (PARPis), originally designed to enhance the activity of DNA damaging chemo- and radiotherapy can exploit defects in homologous recombination DNA repair (HRR) by a process termed synthetic lethality. This potential for tumour-selective non-toxic therapy with PARPi has proved the impetus to progress the development of these compounds further