The Effect of Selenate Ions on Formation of Oxidative Damage Markers in DNA

Indianapolis, IN

The breakage and damage of DNA strands is strongly linked to the development of several serious diseases, including cancers, Parkinson's, AIDS, and cystic fibrosis. Under the right conditions, certain metals have been shown to cause formation of "reactive oxygen species", radical oxygen compounds that readily react with DNA to cause this strand breakage, called oxidative damage. Certain selenium compounds have been shown to reduce signs of oxidative damage in DNA. Both selenite ions and selenium dioxide have been shown to prevent strand breakage in DNA when oxidatively damaged DNA is analyzed by gel electrophoresis. Selenate ions, however, have been shown to have no effect on damage. While this suggests that DNA is still being physically broken down in the presence of selenate, there are other ways to look at how much damage the DNA is suffering. Oxidative reactions were performed with DNA in the presence of Cr³⁺, Fe²⁺, and Cu²⁺ ions with and without selenate ions, then analyzed by HPLC to measure the formation 8-hydroxy-2'-deoxyguanosine, as an indicator of oxidative damage.