Kentucky researchers identify, suppress gene responsible for one carcinogen in tobacco

While the addictive effects of nicotine are its best known properties, the nicotine produced by tobacco can also led to the creation of a key carcinogen. As part of research to reduce the risk of smoking or chewing tobacco, University of Kentucky researchers have identified a gene responsible for the process by which nicotine molecules are metabolized into nornicotine, a dangerous alkaloid, reports Carol Spence of UK's College of Agriculture. As tobacco cures, nornicotine can become nitrosonornicotine (NNN), a potent carcinogen.

The research is being conducted by Balazs Siminszky, assistant professor in the Department of Plant and Soil Sciences, working with UK postdoctoral research associate Lily Gavilano, in collaboration with researchers at North Carolina State University and with funding from cigarette manufacturer Philip Morris USA. Currently, tobacco-seed breeders use a screening process to identify and discard nornicotine-producing plants, but Siminszky said that system is imperfect. Siminszky has tried a different approach by attempting to suppress the activity of the gene responsible for nornicotine production.

About 5 percent of tobacco plants produce nornicotine, but less than 1 percent of the research team's transgenic plants did -- and had six times less NNN, the potent carcinogen, than commercial tobacco. Still, Siminszky emphasized that scientists have identified more than 60 cancer-causing compounds in tobacco smoke and at least 16 in unburned tobacco. “Nobody wants to give the message to people that now we’ve solved the cancer problem. That’s not true at all,” he told Spence. “All we are saying at this point is this particular carcinogen has been reduced.” (Read more)