Limited mutagenicity of electronic cigarettes in mouse or human cells in vitro

Abstract

Objectives Electronic cigarettes (e-cig), which are promoted as safe alternatives to tobacco cigarettes or as aides to smoking cessation, are becoming increasingly popular among adult chronic smokers and adolescents experimenting with tobacco products. Despite the known presence of toxicants and carcinogens in e-cig liquid and vapor, the possible carcinogenic effects of e-cig use in humans are unknown. Materials and Methods We have utilized two validated in vitro model systems to investigate whether e-cig vapor induces mutation in mouse or human cells. We have exposed transgenic mouse fibroblasts in vitro to e-cig vapor extracts prepared from three popular brands, and determined the induction of mutagenesis in a reporter gene, the cII transgene. Furthermore, we have treated the pSP189 plasmid with e-cig vapor extract, transfected human fibroblast cells with the e-cig-treated plasmid, and screened for the induced mutations in the supF gene. Results and Conclusion We observed no statistically significant increases in relative mutant frequency in the cII transgene or supF gene in the e-cig treated mouse or human cells, respectively. Our data indicate that e-cig vapor extracts from the selected brands and at concentrations tested in this study have limited mutagenicity in both mouse and human cells in vitro.

Electronic cigarettes disrupt lung lipid homeostasis and innate immunity independent of nicotine

“…Further, terms such as "popcorn lung" have become synonymous with ENDS among their opponents for the deleterious diacetyls detected in ENDS-associated flavorings (12). In contrast, other reports have advocated the safety of the products over traditional tobacco cigarettes (13,14), thus emphasizing the unmet need to better understand the health-related consequences of exposure to e-cigarette components.…”

Mutation Analysis in Cultured Cells of Transgenic Rodents

“…The Big Blue ® rodent cell culture model and the λ Select cII Mutation Detection System (Stratagene Corp., La Jolla, CA, USA, acquired by Agilent Technologies Inc., Santa Clara, CA, USA, BioReliance/Sigma-Aldrich Corp., Darmstadt, Germany) have been successfully employed for mutagenicity testing of carcinogens by many research groups throughout the world [ 2 , 4 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. For the past 16 years, our laboratory has investigated the mutagenic effects of a wide range of chemical and/or physical carcinogens using cultures of the Big Blue ® mouse embryonic fibroblasts and the λ Select cII assay [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. The genome of transgenic Big Blue ® mouse houses multiple copies of a λLIZ shuttle vector containing two mutational reporter genes, namely the cII and lacI transgenes, that are integrated, at a single locus, into chromosome 4 in a head-to-tail arrangement [ 2 , 4 , 6 , 28 ].…”

The Lambda Select <em>cII</em> Mutation Detection System

“…Of these, transgenic Big Blue (referred to hereafter as BB) mice and the λ Select cII Mutation Detection System have been employed for mutagenicity experiments by this group and many other research groups worldwide 1,2,3,4,5,6,7,8,9 . For the past 16 years, we have investigated the mutagenic effects of various chemical and/or physical agents using these transgenic animals or their corresponding embryonic fibroblast cell cultures treated with a test compound, and subsequently analyzed the phenotype and genotype of the cII transgene by the λ Select cII assay and DNA sequencing, respectively 10,11,12,13,14,15,16,17,18,19,20,21,22,23,24 . The genome of these transgenic animals contains a bacteriophage λ shuttle vector (λLIZ) integrated on chromosome 4 as a multi-copy head-to-tail concatemer 1,2,25 .…”