Cannabis vaping elicits transcriptomic and metabolomic changes involved in inflammatory, oxidative stress, and cancer...

The increasing shift from cannabis smoking to cannabis vaping is largely driven by the perception that vaping to form an aerosol represents a safer alternative to smoking and is a form of consumption appealing to youth. Herein, we compared the chemical composition and receptor-mediated activity of cannabis smoke extract (CaSE) to cannabis vaping extract (CaVE) along with the biological response in human bronchial epithelial cells. Chemical analysis using HPLC and GC/MS revealed that cannabis vaping aerosol contained fewer toxicants than smoke; CaSE and CaVE contained teratogens, carcinogens, and respiratory toxicants. A bioluminescence resonance energy transfer (BRET)-based biosensor detected the receptor-mediated activity of the extracts, primarily driven by Δ⁹-tetrahydrocannabinol (Δ⁹-THC) concentration. RNA-sequencing showed both CaSE and CaVE induced similar transcriptional responses, significantly upregulating genes within pathways related to inflammation, cancer, and cellular stress. This was paralleled by downregulation of pathways related to lipid synthesis and metabolism from both CaSE and CaVE. Targeted metabolomics revealed significant changes in metabolites involved in lipid and membrane metabolism, energy production, nucleotide/DNA/RNA pathways, and oxidative stress response, suggesting potential impairment of lung epithelial cell repair and function. In addition, the upregulation of 5-hydroxymethylcytosine (5hmC) indicates epigenetic changes potentially contributing to inflammation, oxidative stress, and an increased risk of cancer. These findings challenge the notion that cannabis vaping is risk-free, highlighting an urgent need for comprehensive research into its respiratory health effects. This comparison of cannabis consumption methods offers insights that could inform public health policies and raise consumer awareness regarding the potential risks of inhaling cannabis aerosol.NEW & NOTEWORTHY Cannabis use is increasing worldwide amid broad acceptance and legalization. The prevalence of traditional smoking is diminishing in favor of vaping dry flower. This is the first study to provide initial evidence that cannabis aerosol contains carcinogenic, teratogenic, and respiratory toxicants that induce transcriptional responses in epithelial cells analogous to those from cannabis smoke, suggesting potential adverse pulmonary effects.