TABLE 1.

Studies investigating DNA damage and related effects in electronic cigarette (e-cigarette)-exposed oral cells

Cell types	e-Cigarette types	DNA damage	Reference
Normal human oral keratinocytes	e-Cigarette aerosol	Oxidative stress and cytotoxicity	Ji et al. 201615
Human gingival epithelial cells	e-Cigarette vapor	Altered cellular morphology, cytotoxicity, increased apoptosis, and lactate dehydrogenase activity	Rouabhia et al. 201716
Human gingival fibroblasts	Nicotine-containing and nicotine-free fluids of e-cigarettes	Increased reactive oxidation species production and cytotoxicity, followed by apoptosis	Sancilio et al. 201617
Human periodontal ligament fibroblasts, human gingival epithelium progenitors pooled, and epigingival 3D epithelium	e-Cigarettes with flavorings	Increased oxidative stress, carbonyl stress, inflammatory response, and DNA damage along with histone deacetylase 2 reduction via receptor for advanced glycation end products-dependent mechanisms	Sundar et al. 201618
Healthy oropharyngeal mucosa	Flavored e-cigarette liquids	Cytotoxicity, DNA fragmentation, and mutation	Welz et al. 201619
Normal epithelial and head and neck squamous cell carcinoma cell lines	Nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands	Increased DNA strand breaks, reduced cell viability, and clonogenic survival, along with increased rates of apoptosis and necrosis	Yu et al. 201620
Human epithelial normal bronchial cells and human premalignant dysplastic oral mucosal keratinocyte cells	e-Cigarette aerosol	Oxidative DNA damage	Ganapathy et al. 201721
Human oral keratinocyte cell line	Condensate of e-cigarette aerosol	Induced CYP1A1/1B1 and enhanced benzo[a]pyrene metabolism by activating the aryl hydrocarbon receptor	Sun et al. 201922
Human oral squamous cell carcinoma cells and normal human gingival fibroblast cells	e-Cigarette aerosol	Induced cytotoxicity and intracellular oxidative stress	Ureña et al. 202023
Human gingival fibroblasts	e-Cigarette vapor	Higher metabolic activity, no caspase 3/7 activation, and no significant differences in the amount of apoptosis/necrosis	Vermehren et al. 202024
Gingival fibroblast/gingival mesenchymal stem cells (GF/G-MSCs)	e-Cigarette aerosol	No significant effects on DNA damage, cellular dedifferentiation, cellular proliferation, or viability of GF/G-MSCs	El-Mouelhy et al. 202225
3 immortalized oral epithelial cell lines	e-Cigarette-generated aerosols from 10 flavored e-liquid products with and without nicotine	Cell toxicity, oxidative stress, lipid peroxidation, and genotoxicity in terms of micronuclei formation	Tellez et al. 202126
Human epithelial oral cells	e-Cigarette aerosol	Enhanced cytotoxicity and cell death in a dose-dependent manner and expressed upregulation of inflammatory cytokines up to 3.0-fold	Ramenzoni et al. 202227