A Novel Method to Directly Observe the Effects of Histone Deacetylase Inhibition on the DNA Damage ResponseRaanan Y. Alter11Brookline, MA United States Keywords: neuropathology, experiment, radiation, radiation injury, molecular biology
One of the earliest indicators of chromatin-based DNA damage response (DDR) is ATM-mediated phosphorylation of histone H2AX, forming H2AX. H2AX formation is a signal that DNA damage has been detected and repair is underway.
Radiotherapy is frequently employed in the treatment of brain tumors, and relies on the formation of lethal DNA damage in tumor cells, and repair of DNA damage in normal tissues.
Prior work showed that treatment of cells with HDAC inhibitors prior to radiation exposure leads to dramatically increased and prolonged H2AX phosphorylation. However, H2AX is a marker of DNA damage and repair signaling and its relationship to actual physical DNA damage is unclear. In this investigation, we adapted a novel DNA damage assay to fully elucidate the correlation of H2AX as an indicator of DNA damage response signaling to physical damage in DNA using a human osteosarcoma cell model.The results strongly indicate that the redesigned CometChip assay is a functional and potentially powerful tool in cancer research.
We found that HDAC inhibitor pretreatment results in no significant change in physical DNA damage and the cellular repair response, despite the fact that our previous investigations discovered enhanced DNA damage signaling via .F NcH2AX.
This is a laboratory study.
This would indicate that elevated repair signaling is not a direct correlation to the amount of physical DNA damage.
More research must be done; however, to fully elucidate the effects of HDAC inhibition on DNA repair. Project Roles:
R. Alter ()