Washington, July 14 (IANS) Scientists have found that exposure to cigarette smoke not only upsets gene expression - the process by which genetic information is converted into the structures and functions of a cell - but their entire networks as well.
These alterations seem to have a wide-ranging negative influence on the immune system, including processes bearing on cancer, cell death and metabolism.
Scientists of Southwest Foundation for Biomedical Research at San Antonio in the US, identified 323 unique genes whose expression levels were significantly correlated with smoking behaviour in their study of 1,240 volunteers.
The changes were detected by studying the activity of genes within white blood cells of volunteers, the BMC Medical Genomics journal reports.
'Our results indicate that not only individual genes, but entire networks of gene interaction are influenced by cigarette smoking,' said Jac Charlesworth, who led the study, according to a university release.
Charlesworth, formerly at Southwest Foundation, is now a research fellow at the Menzies Research Institute at the University of Tasmania in Australia.
The study is part of Southwest Foundation's San Antonio Family Heart Study which includes 40 families in the Mexican-American community.
'Previous studies of gene expression as influenced by smoking have been seriously limited in size, with the largest of the studies including only 42 smokers and 43 non-smokers. We studied 1,240 individuals, including 297 current smokers,' Charlesworth said.
'The findings have a larger implications for human disease risk, especially in relation to the increased risk of a wide variety of cancers throughout the body as a result of cigarette smoke exposure,' Charlesworth said.
