Title:An Update on Poly(ADP-ribose) Polymerase I-A Brief Review
Volume: 23
Issue: 18
Author(s): Preeya Negi, Kaviarasan Lakshmanan, Praveen Kumar Patel, Kalirajan Rajagopal and Gowramma Byran*
Affiliation:
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, Tamil Nadu, India
Keywords:
Anti-cancer, poly (ADP-ribose) polymerase 1 inhibitor, PARP-1 enzyme, breast cancer, prostate cancer, DNA repair.
Abstract: Poly (ADP-ribose) polymerase 1 (PARP1) plays important roles in both DNA repair and
transcription, and the interplay of these processes in relation to cellular function and disease states has
not been well defined. The tumor-suppressor effects of PARP inhibitors have attracted significant interest
in the development of novel cancer therapies. As PARP1 binding motifs may be readily found
in promoter elements of DNA repair genes, the expanding role of PARP1 in DNA repair does not
have to be independent of transcription. The discovery of ADP-ribose binding modules that bind to
various forms of mono- and poly-ADP-ribose has provided important insights into how ADPribosylation
regulates different cellular pathways. Among the four distinct PAR-binding modules discovered
so far, it is the macrodomain alone that, in addition to possessing binding activity, in some
instances, also supports a catalytic activity toward ADP-ribose derivatives. However, the development
of PARP inhibitors as chemopotentiating agents has been limited by an increase in observed toxicity,
mainly myelosuppression, necessitating dose reduction of the cytotoxic chemotherapeutic agent and
the PARP inhibitor. Hence, it presents an opportunity to rationally develop combinations of PARP
inhibitors with new classes of DNA repair inhibitors that are on the horizon and classical cytotoxic
agents. Clinical trials of PARP inhibitors are investigating various uses of these approaches in cancer.
Recent studies on the clinical significance of PARP1 inhibitors are discussed in this review. These
recent research advances will inform the selection of patient populations who can benefit from the
PARP inhibitor treatment and the development of effective drug combination strategies.