Why Does Smoking Cause Lung Disease in Some, But Not Others?

After the analysis of over 50,000 genetic sequences – collected from volunteers by the UK’s Biobank project – researchers found striking differences between the DNA from smokers, with and without lung problems. According to the Medical Research Council, this discovery could lead to the development of novel therapies for those with lung disease.

The study compared DNA sequences taken from smokers and non-smokers, with and without chronic obstructive pulmonary disease (COPD). This condition causes coughing, breathlessness and recurring chest infections, and is thought to affect 3 million people in the UK.

The researchers found that some of the individuals studied had beneficial mutations which conferred a lower risk of developing COPD – regardless of whether they were a smoker or not. COPD also includes chronic conditions such as bronchitis and emphysema.

According to Professor Martin Tobin from the University of Leicester, and one of the study researchers, the genes that were found to be different in people with a reduced chance of COPD are involved in lung cell growth and injury response systems.

“There doesn’t appear to be any kind of magic bullet that would give anyone guaranteed protection against tobacco smoke – they would still have lungs that were unhealthier than they would be had they been a non-smoker,” said Tobin. “The strongest thing that people can do to affect their future health in terms of COPD and also smoking-related disease like cancer and heart disease is to stop smoking.”

As well as lung problems, cigarette smoking also increases a person’s risk of heart disease and development of cancer. The researchers involved in the study also identified sequences – or biomarkers – that were found more commonly in smokers, compared to non-smokers.

These genes are thought to be involved in brain function, and a person’s susceptibility to nicotine addiction. Though these results still need to be substantiated through further investigation, Tobin said that the findings provided “fantastic new clues about how the body works, that we really had little idea about before. It’s those things that are likely to lead to some really exciting breakthroughs for drug development.”

In addition to being presented at the European Respiratory Society meeting, the results of the study were also published in the journal, The Lancet Respiratory Medicine. “These findings represent a significant step forward in helping us achieve a clearer picture about the fascinating and intricate reality of lung health,” said Ian Jarrold, head of research at the British Lung Foundation. “Understanding genetic predisposition is essential in not only helping us develop new treatments for people with lung disease but also in teaching otherwise healthy people how to better take care of their lungs.”

Sources:

• Rare ‘healthy’ smokers’ lungs explained – http://www.bbc.com/news/health-34360865
• UK Biobank – http://www.ukbiobank.ac.uk/
• Wain, L., Shrine, N., Miller, S., Jackson, V., Ntalla, I., Artigas, M., Billington, C., Kheirallah, A., Allen, R., Cook, J., et al. (2015). Novel insights into the genetics of smoking behaviour, lung function, and chronic obstructive pulmonary disease (UK BiLEVE): a genetic association study in UK Biobank. Lancet Respiratory Medicine.