Chromatin repair after oxidative stress: role of PARP-mediated proteasome activation.

Oxidative stress is an inevitable process in the nucleus, especially in antitumor chemotherapy, and adaptation by defense mechanisms seems to be one element in the development of long-term resistance to many chemotherapeutic drugs. In this study, a potential chromatin repair mechanism during oxidative stress was investigated in HT22 cells. The 20S proteasome has been shown to be largely responsible for the degradation of oxidatively modified histone proteins in the nucleus.