This is the second report by Dr. Tang directly linking a chemical in cigarette smoke to mutations in a crucial gene associated with cancer. In 1996, he published a study in the journal Science showing that a carcinogen found in cigarette smoke caused mutations in a gene called P53.
The new study is published in the October 16 issue of the Journal of the National Cancer Institute.
"With this new study, we are now providing concrete proof that smoking causes lung cancer," says Dr. Tang.
RAS is a family of genes that have many biological functions, but mainly control cell growth and development. Mutations in a RAS gene can lead to uncontrolled cell growth, and more than 30 percent of lung cancers, 90 percent of pancreatic cancers, and 50 percent of colon cancers are associated with mutations at a specific site in the gene K-RAS.
Scientists, however, didn't know why these mutations were occurring at this particular site in the gene. The new study provides an answer to this longstanding question by using a mapping technique that Dr. Tang pioneered. The technique pinpoints the exact sites on DNA where damage occurs due to environmental carcinogens.
Dr. Tang and colleagues from NYU and M.D. Anderson Cancer Center, in Houston, introduced the carcinogen benzo(a)pyrene diol expoxide (BPDE), a known cancer-causing chemical in cigarette smoke, to normal human lung epithelial cells and fibroblasts, another type of cel
Contact: Pam McDonnell
New York University Medical Center and School of Medicine