TUESDAY, June 22, 2004 (HealthDayNews) -- Lung cell gene expression in smokers appears to differ from that of nonsmokers and former smokers, and may help predict a smoker's likelihood of developing lung cancer or other chronic airway diseases, researchers say.
Researchers at Boston University Medical Center examined gene expression profiles of bronchial (airway) cells from 93 smokers and nonsmokers.
Genes in smokers exhibited increased expression of several oncogenes -- genes that have been altered by mutation and may contribute to tumor development. The cells also showed a decreased expression of several tumor suppressor genes and genes that regulate airway inflammation.
Moreover, the scientists identified genes that changed expression depending on the cumulative number of years a person smoked. In former smokers, it took about two years free of the habit for expression levels in most genes to begin to resemble those of people who had never smoked.
However, several genes -- including potential oncogenes and tumor suppressor genes -- did not return to "never-smoker" status, the researchers say.
The study also found that some smokers appeared to express genes differently from other smokers. One of the smokers in this subset developed lung cancer within six months of undergoing gene expression profiling.
Airway gene expression of smokers may serve as a biomarker for lung cancer, the researchers concluded. The study will be published in the June 21-25 online edition of the Proceedings of the National Academy of Sciences.
More information
The American Cancer Society has more about lung cancer.
