Monoclonal antibodies for the detection of a specific cyclic DNA adduct derived from ω-6 polyunsaturated fatty acids.

Lipid peroxidation of polyunsaturated fatty acids (PUFAs) is an endogenous source of alpha,beta-unsaturated aldehydes that react with DNA producing a variety of cyclic adducts. The mutagenic cyclic adducts, specifically those derived from oxidation of omega-6 PUFAs, may contribute to the cancer promoting activities associated with omega-6 PUFAs. (E)-4-Hydroxy-2-nonenal (HNE) is a unique product of omega-6 PUFAs oxidation. HNE reacts with deoxyguanosine (dG) yielding mutagenic 1,N-2 -propanodeoxyguanosine adducts (HNE-dG). Earlier studies showed HNE can also be oxidized to its epoxide (EH), and EH can react with deoxyadenosine (dA) forming the well studied epsilon dA and the substituted etheno adducts. Using a liquid chromatography-based tandem mass spectroscopic (LC-MS/MS) method, we previously reported the detection of EH-derived 7-(1',2'-dihydroxyheptyl)-1,N-6 -ethenodeoxyadenosine (DHH epsilon dA) as a novel endogenous background adduct in DNA from rodent and human tissues. The formation, repair, and mutagenicity of DHH epsilon dA and its biological consequences in cells have not been investigated. To understand the roles of DHH epsilon dA in carcinogenesis, it is important to develop an immuno-based assay to detect DHH epsilon dA in cells and tissues. In this study we describe the development of monoclonal antibodies specifically against DHH epsilon dA and its application to detect DHH epsilon dA in human cells.