Analysis of the transcriptional profile of mononuclear cells from e-cigarette users

E-cigarettes contain nicotine, propylene glycol, glycerol, and flavorings. The use of e-cigarettes has increased worldwide, especially among young people. Although the chemical compounds present in aerosols affect epigenetic mechanisms such as DNA methylation and generate genotoxicity, additional studies are needed to demonstrate their impact on human health. We evaluated the transcriptomic profile of peripheral blood mononuclear cells from users of electronic nicotine delivery systems. A cross-sectional observational study was conducted in which transcriptomes of peripheral blood mononuclear cells from e-cigarette users were sequenced, analyzed and classified according to their use into exclusive users (n = 4), mixed users (n = 4), and controls (n = 7). The analysis of differentially expressed genes was performed with DESeq2. The differentially expressed genes identified were experimentally validated by qPCR in a cohort of 64 research subjects. Four differentially expressed genes were detected in the exclusive users, and 44 genes were detected in the mixed users. No common differentially expressed genes between the two groups of users were identified. Among the differentially expressed genes detected in the exclusive and mixed users, tumor suppressor genes and different oncogenes whose functions are associated with relevant biological processes, such as cell adhesion, cell attachment, the endoplasmic reticulum, epithelialmesenchymal transition, neuronal development, the immune response, and carcinogenesis, were identified. Electronic cigarette consumption significantly impacts gene expression, with relevant biological functions in normal and pathological contexts. These findings provide new evidence on the health effects of vaping and the short-term impact resulting from the consumption of these products.