IADR Abstract Archives
E-Liquid Impact on Oral Cancer: in Vitro and Epidemiological Insights
Objectives: To investigate e-liquid exposure's role in oral carcinogenesis through epidemiological and in vitro approaches. The epidemiological component identifies key risk factors and gaps in the association between e-cigarette use and oral cancer. In vitro experiments explore the effects of nicotine and flavouring agents, particularly cinnamon, on oral epithelial cells, focusing on changes in cell morphology, viability, and epithelial-mesenchymal transition (EMT). The goal is to provide mechanistic insights to inform public health strategies for oral cancer prevention.
Methods: An epidemiological review synthesised data on the association between e-cigarettes and oral cancer. For laboratory experiments, OKF6 cells were cultured in keratinocyte growth medium (KGM) before exposure to commercial e-liquids (cinnamon-flavoured and unflavoured) containing nicotine concentrations of 0, 3, and 18 mg/mL at dilutions of 0.1%, 1%, and 5% (v/v) in a glycerine-propylene glycol solution (70–30%). Cells were also treated with 4NQO (0.001–0.06 µg/mL) for 4, 24, and 48 hours, followed by recovery in fresh media. Morphological changes were assessed via light microscopy, viability quantified using DAPI staining and flow cytometry, and EMT markers were analysed through flow cytometry and immunofluorescence.
Results: The review highlighted emerging evidence linking e-cigarettes to oral carcinogenesis, with concerns about risks from their components and flavouring agents. Laboratory findings revealed dose- and time-dependent changes in OKF6 cells upon e-liquid exposure. Morphological changes included cell detachment and loss of confluency, with viability loss most pronounced with 5% cinnamon-flavoured e-liquid at 18 mg/mL nicotine. Unflavoured e-liquids induced less cytotoxicity. 4NQO caused significant viability loss even at low concentrations, with no recovery across exposure durations. Preliminary EMT marker analysis is ongoing, with anticipated findings suggesting EMT induction.
Conclusions: E-liquid exposure alters oral epithelial cell morphology, viability, and potentially EMT marker expression. Epidemiological evidence underscores the need to assess e-cigarette risks alongside mechanistic studies to inform public health strategies for oral cancer prevention.
Methods: An epidemiological review synthesised data on the association between e-cigarettes and oral cancer. For laboratory experiments, OKF6 cells were cultured in keratinocyte growth medium (KGM) before exposure to commercial e-liquids (cinnamon-flavoured and unflavoured) containing nicotine concentrations of 0, 3, and 18 mg/mL at dilutions of 0.1%, 1%, and 5% (v/v) in a glycerine-propylene glycol solution (70–30%). Cells were also treated with 4NQO (0.001–0.06 µg/mL) for 4, 24, and 48 hours, followed by recovery in fresh media. Morphological changes were assessed via light microscopy, viability quantified using DAPI staining and flow cytometry, and EMT markers were analysed through flow cytometry and immunofluorescence.
Results: The review highlighted emerging evidence linking e-cigarettes to oral carcinogenesis, with concerns about risks from their components and flavouring agents. Laboratory findings revealed dose- and time-dependent changes in OKF6 cells upon e-liquid exposure. Morphological changes included cell detachment and loss of confluency, with viability loss most pronounced with 5% cinnamon-flavoured e-liquid at 18 mg/mL nicotine. Unflavoured e-liquids induced less cytotoxicity. 4NQO caused significant viability loss even at low concentrations, with no recovery across exposure durations. Preliminary EMT marker analysis is ongoing, with anticipated findings suggesting EMT induction.
Conclusions: E-liquid exposure alters oral epithelial cell morphology, viability, and potentially EMT marker expression. Epidemiological evidence underscores the need to assess e-cigarette risks alongside mechanistic studies to inform public health strategies for oral cancer prevention.