Minimizing DNA trapping while maintaining activity inhibition via selective PARP1 degrader

Cell Death Dis. 2024 Dec 18;15(12):898. doi: 10.1038/s41419-024-07277-2.

Abstract

Poly (ADP-ribose) polymerase 1 (PARP1) catalyzes poly (ADP) ribosylation reaction, one of the essential post-translational modifications of proteins in eukaryotic cells. Given that PARP1 inhibition can lead to synthetic lethality in cells with compromised homologous recombination, this enzyme has been identified as a potent target for anti-cancer therapeutics. However, the clinical application of existing PARP1 inhibitors is restrained by side effects associated with DNA trapping and off-target effects, highlighting the need for improved therapeutic strategies. By integrating protein degradation technology, we synthesized a PROTAC molecule 180055 based on the Rucaparib junction and VHL ligand, which efficiently and selectively degraded PARP1 and inhibited PARP1 enzyme activity without a noticeable DNA trapping effect. Furthermore, 180055 kills tumor cells carrying BRCA mutations with a minor impact on the growth of normal cells both in vitro and in vivo. This suggests that 180055 is a PARP1-degrading compound with excellent pharmacological efficacy and extremely high biological safety that deserves further exploration and validation in clinical trials.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • DNA / metabolism
  • Female
  • Humans
  • Indoles
  • Mice
  • Mice, Nude
  • Poly (ADP-Ribose) Polymerase-1* / antagonists & inhibitors
  • Poly (ADP-Ribose) Polymerase-1* / metabolism
  • Poly(ADP-ribose) Polymerase Inhibitors* / pharmacology
  • Proteolysis / drug effects

Substances

  • Poly(ADP-ribose) Polymerase Inhibitors
  • Poly (ADP-Ribose) Polymerase-1
  • PARP1 protein, human
  • DNA
  • rucaparib
  • Indoles