Genotoxicity and hypomethylation of LINE-1 induced by electronic cigarettes

Currently, the marketing of electronic cigarettes as a safe alternative to smoking has increased, which is associated with greater use of these devices, especially among young people and smokers interested in quitting tobacco cigarettes. Given the growing use of this type of product, there is a need to determine the consequences of electronic cigarettes on human health, especially since many of the compounds contained in the aerosol and liquid of these devices have a high potential to be carcinogenic and genotoxic. Additionally, many of these compounds' aerosol concentrations exceed the safe limits. We have evaluated the levels of genotoxicity and changes in DNA methylation patterns associated with vaping. We analyzed a total of 90 peripheral blood samples from a population of vapers (n = 32), smokers (n = 18), and controls (n = 32), in which the frequencies of genotoxicity were determined by the cytokinesis-blocking micronuclei (CBMN) assay and the patterns of methylation of the repetitive elements of LINE-1 through the Quantitative Methylation Specific PCR (qMSP) assay. Here we show an increase in genotoxicity levels associated with vaping habits. Additionally, the group of vapers showed changes at the epigenetic level specifically associated with the loss of methylation of the LINE-1 elements. These changes in LINE-1 methylation patterns were reflected in its representative RNA expression detected in vapers.