Flavored E-cigarette product aerosols induce transformation of human bronchial epithelial cells.

Introduction:
This text reports a study on the effects of flavored e-cigarette aerosols on human bronchial epithelial cells (hBECs). The study aimed to evaluate the potency of e-liquid aerosols with respect to inducing transformation and gene expression profiles with comparison to cigarette smoke aerosol. The study also characterized the expressed cytochrome P450s (CYP) in selected hBEC lines and determined cytochrome P450 reductase activity in hBEC lines and the a549 adenocarcinoma cell line.

Key Points:

* The study used an aerosol generation system to expose hBEC lines to e-cigarette aerosols and the Kentucky reference cigarette.
* The aerosol exposure system accommodates culture dishes up to 100 mm and cells are attached to the surface of the plate covered with a small volume of serum free RPMI media during the exposure.
* The concentration in the exposure chamber is controlled by the flow rate of dilution air, while the puffing protocol is controlled by the solenoid valve and its relay.
* The aerosols were generated at 5 V using a puffing protocol based on the topography results of e-cigarette users consisting of ~52 ml puffs of 2.6 s duration at intervals of 18 s.
* The amount and concentration of aerosol delivered was quantified by collection of TPM onto a filter.
* Cells were exposed to hEPa-filtered air only or e-liquid for 20 min to a target aerosol dose of 450 mg TPM/m3.
* The Kentucky reference cigarette was used as a positive control for all assays with a target dose of 200 mg TPM/m3.
* The study used soft agar assays, ROS-Glo assays, the alkaline comet assay, and cytochrome P450 reductase assays to evaluate the effects of e-cigarette aerosols on hBECs.

Main Message:
The study found that exposure to e-cigarette aerosols can induce a pre-malignant phenotype in lung epithelial cells. The study used a pre-malignancy model to evaluate the potency of e-liquid aerosols with respect to inducing transformation and gene expression profiles with comparison to cigarette smoke aerosol. The study also characterized the expressed cytochrome P450s (CYP) in selected hBEC lines and determined cytochrome P450 reductase activity in hBEC lines and the a549 adenocarcinoma cell line. The study used soft agar assays, ROS-Glo assays, the alkaline comet assay, and cytochrome P450 reductase assays to evaluate the effects of e-cigarette aerosols on hBECs. The study found that exposure to e-cigarette aerosols can induce a pre-malignant phenotype in lung epithelial cells, highlighting the potential health risks associated with e-cigarette use.

Tellez CS, Grimes MJ, Juri DE, et al. Flavored E-cigarette product aerosols induce transformation of human bronchial epithelial cells. Lung cancer (amsterdam, Netherlands). 2023;179:107180. doi:10.1016/j.lungcan.2023.107180