'Epigenetic' changes from cigarette smoke may be first step in lung cancer development
An illustration of how cigarette smoke triggers epigenetic changes in airway cells. Credit: Jennifer Fairman Scientists at the Johns Hopkins Kimmel Cancer Center say they have preliminary evidence in laboratory-grown, human airway cells that a condensed form of cigarette smoke triggers so-called "epigenetic" changes in the cells consistent with the earliest steps toward lung cancer development. Epigenetic processes are essentially switches that control a gene's potentially heritable levels of protein production but without involving changes to underlying structure of a gene's DNA. One example of such an epigenetic change is methylation -- when cells add tiny methyl chemical groups to a beginning region of a gene's DNA sequence, often silencing the gene's activation. "Our study suggests that epigenetic changes to cells treated with cigarette smoke sensitize airway cells to genetic mutations known to cause lung cancers," says Stephe...