Oxidative DNA damage is a biologically important and chemically complex process. A large variety (>50) of chemical modifications (lesions) are produced when DNA is exposed to oxidative conditions. DNA lesions are associated with aging and the development of disease. Consequently, they are of interest as "biomarkers" to help predict the onset of disease and progression of the aging process. The goal of this project is to develop facile, sensitive chemical methods for detecting lesions in cellular DNA. In addition, the PI will create chemical methods for lesion detection that will be employed by other scientists using commonly available instrumentation and reagents that can be produced by other laboratories and/or commercial suppliers. This chemistry will also enable a determination of whether there is a correlation between specific DNA damage and mutational hotspots. It is particularly challenging to detect specific lesions in telomeres or at exact positions in cellular DNA, because unlike single nucleotide polymorphisms it is not possible to produce more of DNA containing a lesion using the polymerase chain reaction. Hence, a very sensitive detection method is required. Broader Impact. Cell biologists, toxicologists, pharmacologists, and medicinal chemists will use the reagents developed during the course of this research. In addition, the potential use of such tools for identifying DNA lesion biomarkers would benefit society directly by potentially detecting genetically based diseases, such as cancer at an early stage where it is most treatable. The undergraduate students, graduate students, and postdoctoral fellows participating in this research will receive broad training in biochemistry, synthetic organic, physical organic and analytical chemistry. In addition, they will be exposed to biochemically important problems through their reading of the background literature related to DNA damage and the significance of its detection. The PI is actively involved in broadening the participation of groups that have traditionally been underrepresented in chemistry. He has been involved in creating a new undergraduate major in Chemical Biology at Morgan State University, and participates in a variety of undergraduate research symposia (e.g., Annual Biomedical Research Conference for Minority Students) where members of these groups are well represented.
This project involved the discovery and application of molecules designed to detect specific forms of damaged DNA, the carrier of genetic information in all cells. The structure of DNA is modified (damaged) by a variety of agents that humans are exposed to in the environment and even endogenously. The damaged DNA can give rise to a variety of health problems, including cancer, if not repaired via the formation of mutations. Detecting damaged DNA is difficult and routine methods are needed to aid a variety of research scientists and health professionals. We developed a method for detecting extremely small amounts (10-18 mole) of a specific type of DNA damage using 1 ´ 10-9 g of DNA, a quantity far too small to see with the naked eye. The method uses instrumentation commonly found in life scientists' laboratories. We also applied this chemistry to detecting DNA damage at specific positions within a sequence of DNA. This is important to society because the human genome in one cell contains more than 3 billion base pairs, and would be 6 feet long if unraveled from the cell. However, there are specific nucleotide locations that are hotspots for disease development. The chemistry developed by us is moving us closer to being able to probe for the presence of specific forms of DNA damage at such mutational hotspots.
