Lipid peroxidation--DNA damage by malondialdehyde

摘要

Malondialdehyde is a naturally occurring product of lipid peroxidation and prostaglandin biosynthesis that is mutagenic and carcinogenic. It reacts with DNA to form adducts to deoxyguanosine and deoxyadenosine. The major adduct to DNA is a pyrimidopurinone called M sub(1)G. Site-specific mutagenesis experiments indicate that M sub(1)G is mutagenic in bacteria and is repaired by the nucleotide excision repair pathway. M sub(1)G has been detected in liver, white blood cells, pancreas, and breast from healthy human beings at levels ranging from 1-120 per 10 super(8) nucleotides. Several different assays for M sub(1)G have been described that are based on mass spectrometry, super(32) P -postlabeling, or immunochemical techniques. Each technique offers advantages and disadvantages based on a combination of sensitivity and specificity. Application of each of these techniques to the analysis of M sub(1)G is reviewed and future needs for improvements are identified. M sub(1)G appears to be a major endogenous DNA adduct in human beings that may contribute significantly to cancer linked to lifestyle and dietary factors. High throughput methods for its detection and quantitation will be extremely useful for screening large populations.