Abstract 1437: E-cigarette vape promotes cell cycle progression and inflammation in 3D pre-clinical oral spheroid models
Authors: Almeda Jasmine , Chinnaiyan Vikram , Andl Claudia 
Published: June 2023

Abstract
E-cigarettes have become a popular alternative to conventional cigarettes among middle and high school students. Electronic nicotine delivery systems (ENDs) vaporize a liquid into an aerosol that is inhaled by the user. Although they do not burn tobacco, e-cigarettes contain potential carcinogens as well as nicotine, a highly addictive substance. E-cigarette exposure has been reported to promote inflammation. Furthermore, our prior research indicates that e-cigarette aerosol dysregulates the oral microbiome by suppressing commensal bacteria and promoting the biofilm formation of cariogenic pathogens, which induces oral inflammation. With the recent rise in e-cigarette usage, it is important to investigate the carcinogenic risks of these devices. In this study, we use oral epithelial spheroids as a 3D pre-clinical model to assess the effect of e-cigarette vape on cell cycle progression, cell proliferation, and inflammation. Oral epithelial cells were directly (air-liquid interface) or indirectly (pre-exposed media) exposed to nicotine-free vape, nicotine-rich (3 mg) vape, or no vape. Indirect exposure with 6 puffs resulted in the upregulation of pro-inflammatory cytokines, such as TNFα and IL-8 by RT-PCR. TNFα is reportedly overexpressed in oral cancer while IL-8 is has been shown to be induced in oral pre-cancers and associated with progression. Indirect exposure of vape also promoted greater cell viability in spheroids as shown by the CellTiter assay, indicating that the vape enhanced proliferation and cell cycle progression. Assessment of sphere diameter before repeated exposures showed an increase over the course of treatment. More so, repeated indirect exposure with 12 puffs of vape compared to 6 puffs resulted in increased sphere diameters over time after exposure with both, nicotine-free or nicotine-rich vape, indicating a dose-dependent effect of the vape on cell proliferation. Survival and proliferation pathways such as pAKT and pERK were assessed by Western Blotting, identifying that indirect exposure does not show a significant difference in the expression of those proteins. We are currently evaluating signaling pathway activation after repeated direct exposures as well as cell cycle progression using FLOW cytometry. Additional markers of cell proliferation and stemness are being interrogated for their role in the observed increased cell proliferation. This study has demonstrated the effect of e-cigarette aerosol on inflammation and cell proliferation. As the risks of e-cigarette become clearer with the emergence of future studies, it is important to inform the public, especially young people, about the impact on oral health and implement policies to mitigate the recent surge in e-cigarette usage.
Citation Format: Jasmine Almeda, Vikram Chinnaiyan, Claudia Andl. E-cigarette vape promotes cell cycle progression and inflammation in 3D pre-clinical oral spheroid models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1437.