Pathological analysis of lung tissues showed that, with extended exposure time, carcinogenesis and injury in the lungs of WT mice was progressively worse; however, the injury was minimal and carcinogenesis was not detected in the lungs of PARG<sup>+/-</sup> mice.
In addition, we examined the role of a related regulatory protein of PARP-1, called Poly(ADP-ribose) glycohydrolase (PARG), in prostate carcinogenesis.
This was the first study that reported evidences to support an oncogenic role of PARG in BaP induced carcinogenesis, which provided a new perspective for our understanding in BaP exposure induced cancer.
Recent development of a selective inhibitor of poly(ADP-ribose) glycohydrolase (PARG), the enzyme primarily responsible for degradation of poly(ADP-ribose), and PARG-deficient animals should facilitate studies of the relationship of poly(ADP-ribose) with carcinogenesis.