ARH3, a Therapeutic Target for Cancer, Ischemia, and Inflammation

ADP-ribosylation is important in many cellular processes, including DNA replication and repair, maintenance of genomic stability, telomere dynamics, cell differentiation and proliferation, and necrosis and apoptosis. Poly-ADP-ribose is important in a number of critical physiological processes such as DNA repair, cellular differentiation, and carcinogenesis. Until recently, only one human enzyme, PARG, had been identified that degrades the ADP-ribose polymer. Another ADP-ribose, O-acetyl-ADP ribose, is formed via the deacetylation of proteins, such as acetyl-histone, by proteins in the Sir2 family. Sir2 proteins have been implicated in regulation of chromatin structure and longevity.

The NIH announces the discovery of a novel PARG-like enzyme, ARH3. ARH3 possesses PARG activity, yet is structurally distinct from PARG. ARH3 also hydrolyzes O-acetyl-ADP-ribose, and is the only protein recognized to date with such activity. ARH3 thus appears to function in two important signaling pathways, serving to regulate both poly-ADP-ribose and O-acetyl-ADP-ribose levels. It may affect chromatin structure through effects on both pathways. Since ARH3 structures differs from PARG or other enzymes that participate in these pathways, it may be possible to design specific inhibitors to target both the poly-ADP-ribose and Sir2 pathways. These drugs may be used as anticancer agents, radiosensitizers or antiviral agents, or for treating disorders involving oxidative damage, such as acute tissue injury, ischemia, and inflammation.

Potential Commercial Applications: Competitive Advantages:
  • Development of therapeutics for cancer or disorders associated with excessive DNA damage
  • Development of therapeutics for diseases involving oxidative damage, such as acute tissue injury, ischemia and inflammation

Development Stage:
Early stage


Joel Moss (NHLBI)  ➽ more inventions...

Intellectual Property:
U.S. Pat: 7,670,806 issued 2010-03-02

S Oka, J Kato, J Moss. Identification and characterization of a mammalian 39-kDa poly(ADP-ribose) glycohydrolase. J Biol Chem. 2006 Jan 13;281(2):705-713. PubMed: 16278211
T Ono, A Kasamatsu, S Oka, J Moss. The 39-kDa poly(ADP-ribose) glycohydrolase ARH3 hydrolyzes O-acetyl-ADP-ribose, a product of the Sir2 family of acetyl-histone deacetylases. Proc Natl Acad Sci USA 2006 Nov 7;103(45):16687-16691. PubMed: 17075046

Collaboration Opportunity:

The Pulmonary Critical Care Medicine Branch in the National Heart, Lung, and Blood Institute is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize the invention. Please contact Brian W. Bailey, Ph.D. at 301-594-4094 or for more information.

Licensing Contact:
Michael Shmilovich, J.D.
Phone: 301-435-5019

OTT Reference No: E-347-2004-1
Updated: Jun 1, 2010