Cigarette smoke, revealed a recent study, has a negative influence on gene expression - the process by which a gene's information is converted into the structures and functions of a cell.
These alterations in response to smoking appear to have a wide-ranging negative influence on the immune system, and a strong involvement in processes related to cancer, cell death and metabolism.
Scientists at the Southwest Foundation for Biomedical Research (SFBR) identified 323 unique genes whose expression levels were significantly correlated with smoking behaviour in their study of 1,240 people. The changes were detected by studying the activity of genes within white blood cells of study participants.
"Our results indicate that not only individual genes but entire networks of gene interaction are influenced by cigarette smoking," said Jac Charlesworth, the lead author.
"Previous studies of gene expression as influenced by smoking have been seriously limited in size with the largest of the in vivo studies including only 42 smokers and 43 non-smokers," Charlesworth added.
As many as 1,240 individuals, including 297 current smokers were studied.
"Never before has such a clear link between smoking and transcriptomics been revealed, and the scale at which exposure to cigarette smoke appears to influence the expression levels of our genes is sobering, he added.
"Our results indicate that not only individual genes but entire networks of gene interaction are influenced by cigarette smoking
It is likely that this observed effect of smoking on transcription has 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," he added.
The findings of the study were published in BMC Medical Genomics.