Comparison of biological and transcriptomic effects of conventional cigarette and electronic cigarette smoke exposure at toxicological dose in BEaS-2B cells.

Introduction:
This text provides a detailed analysis of the biological and transcriptomic effects of conventional cigarette (CSC) and electronic cigarette (ECSC) smoke exposure at toxicological doses in BEaS-2B cells. The study aims to determine the IC50 of cell viability and morphological assessment for both CSC and ECSC. additionally, the study investigates inflammation, apoptosis, cell cycle analysis, and RNa-Seq transcriptome analysis to characterize the differences between CSC and ECSC.

Key Points:

* The study found that acute exposure of BEaS-2B cells to CSC at IC50 led to morphological changes, inflammatory cytokines production, and cell apoptosis, while ECSC did not exert such cell effects in equivalent nicotine levels.
* Transcriptome analysis showed that differentially expressed genes in CSC were far more than that in ECSC, and mainly enriched in cell cycle, DNa repair, cancer, and metabolic related pathways.
* The cell cycle arrest was further experimentally confirmed.
* The study determined the nicotine content of CSC and ECSC by UPLC.
* BEaS-2B cells were exposed to 0-32 μg/ml of CSC and ECSC for 24 hours to determine IC50 of cell viability and morphological assessment.
* Inflammation, apoptosis, cell cycle analysis, and RNa-Seq transcriptome analysis were performed to characterize the differences between CSC and ECSC.
* The study found that at toxicological doses, CSC had a higher cytotoxicity in BEaS-2B cells compared to ECSC in 24 hours acute exposure.
* The study suggests that toxicological dose of ECSC might be much higher than that of CSC.

Main Message:
The study provides a reference for safety studies of conventional cigarettes and e-cigarettes. Based on equivalent nicotine content, an acute exposure to CSC had significant impacts on cell effects and gene expression profile compared to ECSC. Therefore, it is essential to consider toxicological doses when comparing the safety of conventional cigarettes and e-cigarettes. The study's findings are crucial for regulatory matters, as they provide evidence that e-cigarettes may not be as safe as previously thought, especially at toxicological doses.

Wang L, Wang Y, Chen J, et al. Comparison of biological and transcriptomic effects of conventional cigarette and electronic cigarette smoke exposure at toxicological dose in BEaS-2B cells. Ecotoxicology and environmental safety. 2021;222:112472. doi:10.1016/j.ecoenv.2021.112472