A new technique from UNC School of Medicine scientists led by Nobel Prize winner Aziz Sancar reveals the genome–wide DNA damage that a major carcinogen causes.
Scientists have known for decades that smoking cigarettes causes DNA damage, which leads to lung cancer. Now, for the first time, UNC School of Medicine scientists created a method for effectively mapping that DNA damage at high resolution across the genome.

The innovation comes from the laboratory of Nobel laureate Aziz Sancar, MD, PhD, the Sarah Graham Kenan Professor of Biochemistry and Biophysics at UNC’s School of Medicine. In a study published in the Proceedings of the National Academy of Sciences journal, Sancar and his team developed a useful technique for mapping sites on the genome that are undergoing repair following a common type of DNA damage. They then used that technique to map all damage caused by the major chemical carcinogen – benzoalphapyrene.

“This is a carcinogen that accounts for about 30 percent of the cancer deaths in the United States, and we now have a genome–wide map of the damage it causes,” said Sancar, who is also a member of the UNC Lineberger Comprehensive Cancer Center.

Maps like these will help scientists better understand how smoking–induced cancers originate, why some people are more vulnerable or resistant to cancers, and how these cancers might be prevented. Sancar also hopes that providing such stark and specific evidence of smoking’s harm at the cellular level might induce some smokers to kick the habit. There are about 40 million smokers in the United States and a billion worldwide.

“It would be good if this helps raise awareness of how harmful smoking can be,” he said. “It also would be helpful to drug developers if we knew exactly how DNA damage is repaired throughout the entire genome.”