EUTOPS publishes new research showing that e-cigarette users with a limited smoking history experience similar DNA changes to specific cheek cells as smokers.

The study, led by Dr Chiara Herzog and published in Cancer Research, analysed the epigenetic effects of tobacco and e-cigarettes on DNA methylation on cells that are directly exposed to tobacco, such as the cells lining the cheek, and those that are not directly exposed, including blood and cervical cells. The research is the one of the most comprehensive studies to date to investigate the impact of smoking on the epigenome of various cell types including data from more than 3,500 individual samples.

Epithelial cells in the mouth showed substantial epigenomic changes in smokers. Importantly, these epigenomic changes were increased in lung cancers or pre-cancers when compared to the normal lung tissue, supporting the idea that the epigenetic changes associated with smoking allow cells to grow more quickly.

While it was known previously that smoking can modulate the epigenome, it was not known how smoking influences different cell types, and whether responses would be similar or impacting different genes and biological pathways. Our findings indicate that smoking changes the epigenome in different cell types across the body in different ways.

We also present new data showing similar epigenomic changes in the cells of e-cigarette users who had smoked less than 100 tobacco cigarettes in total in their lives, meaning that they are essentially ‘never-smokers’.

This study is an incremental step in helping researchers to build a deeper understanding of the long-term effects of e-cigarettes on health. Although it does not show that e-cigarettes cause cancer, studies with long-term follow up are important to assess whether e-cigarettes have harmful effects and, if so, what they are.