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Breheny D, Thorne D, Baxter A, Bozhilova S, Jaunky T, Santopietro S, Taylor M, Terry A, Gaça M. The in vitro assessment of a novel vaping technology. Toxicol Rep 2020; 7:1145-1156. [PMID: 32983902 PMCID: PMC7494588 DOI: 10.1016/j.toxrep.2020.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/26/2020] [Accepted: 08/18/2020] [Indexed: 11/17/2022] Open
Abstract
We have developed a novel vaping product (NVP) IS1.0(TT), which utilises a stainless-steel mesh to transfer and vaporise the e-liquid, mitigating some of the potential sources of toxicants that can be generated using the more traditional 'wick and coil' approach. The emissions from IS1.0(TT) have previously been found to have lower levels of toxicants overall when directly compared with a commercial wick and coil e-cig. This current study assessed the toxicological responses to aerosols from this NVP. Responses induced by IS1.0(TT)were compared to those from a 3R4F reference cigarette, using in vitro test methods which included regulatory genetic toxicological assays as well as some more contemporary screening approaches. The experimental conditions were designed to facilitate the testing of aerosol from this vaping product at doses that in most cases greatly exceeded those of the 3R4F comparator showed little to no toxicological responses and demonstrated significantly reduced effects in these in vitro assays when compared to 3R4F. Furthermore, the extreme doses tested in the present study indicate that the toxicant profile of this NVP translates to lower biological activity in vitro, and suggests that the absolute risk hazard level associated with electronic cigarettes can be reduced through continuous improvement as the technology evolves.
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Key Words
- ACM, aerosol collected mass
- ALI, air-liquid interface
- ANOVA, analysis of variance
- ARE, antioxidant response element
- Aerosol
- AqE, aerosol aqueous extract
- AqE, aqueous aerosol extracts
- CRM81, CORESTA recommended method number 81
- Cigarette
- DCF, 2′,7′ dichlorodihydrofluorescein
- DMSO, dimethyl sulfoxide
- DSB, double-strand break
- Electronic cigarette
- FDA, US Food and Drug Administration
- GEF, global evaluation factor
- GSH, glutathione (reduced form)
- HCI, Health Canada Intense
- HUVEC, human umbilical vein endothelial cell
- ISO, International Organisation for Standardisation
- IVMn, in vitro micronucleus
- In vitro
- MF, mutant frequency
- MLA, mouse lymphoma assay
- NASEM, US National Academy of Sciences, Engineering and Medicine
- NHBE, normal human bronchial epithelial
- NRU, neutral red uptake
- NVP, new vapour product
- RWD, relative wound density
- S9, post-mitochondrial supernatant
- TPA, 12-O-tetradecanoylphorbol-13-acetate
- TPM, total particulate matter
- TobReg, WHO Study Group on Tobacco Product Regulation
- WA, whole aerosol
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Breheny D, Adamson J, Azzopardi D, Baxter A, Bishop E, Carr T, Crooks I, Hewitt K, Jaunky T, Larard S, Lowe F, Oke O, Taylor M, Santopietro S, Thorne D, Zainuddin B, Gaça M, Liu C, Murphy J, Proctor C. A novel hybrid tobacco product that delivers a tobacco flavour note with vapour aerosol (Part 2): In vitro biological assessment and comparison with different tobacco-heating products. Food Chem Toxicol 2017; 106:533-546. [PMID: 28595930 DOI: 10.1016/j.fct.2017.05.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/05/2017] [Accepted: 05/11/2017] [Indexed: 01/10/2023]
Abstract
This study assessed the toxicological and biological responses of aerosols from a novel hybrid tobacco product. Toxicological responses from the hybrid tobacco product were compared to those from a commercially available Tobacco Heating Product (c-THP), a prototype THP (p-THP) and a 3R4F reference cigarette, using in vitro test methods which were outlined as part of a framework to substantiate the risk reduction potential of novel tobacco and nicotine products. Exposure matrices used included total particulate matter (TPM), whole aerosol (WA), and aqueous aerosol extracts (AqE) obtained after machine-puffing the test products under the Health Canada Intense smoking regime. Levels of carbonyls and nicotine in these matrices were measured to understand the aerosol dosimetry of the products. The hybrid tobacco product tested negative across the in vitro assays including mutagenicity, genotoxicity, cytotoxicity, tumour promotion, oxidative stress and endothelial dysfunction. All the THPs tested demonstrated significantly reduced responses in these in vitro assays when compared to 3R4F. The findings suggest these products have the potential for reduced health risks. Further pre-clinical and clinical assessments are required to substantiate the risk reduction of these novel products at individual and population levels.
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Affiliation(s)
- Damien Breheny
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK.
| | - Jason Adamson
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - David Azzopardi
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Andrew Baxter
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Emma Bishop
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Tony Carr
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Ian Crooks
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Katherine Hewitt
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Tomasz Jaunky
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Sophie Larard
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Frazer Lowe
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Oluwatobiloba Oke
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Mark Taylor
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Simone Santopietro
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - David Thorne
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Benjamin Zainuddin
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Marianna Gaça
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Chuan Liu
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - James Murphy
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Christopher Proctor
- Research and Development, British American Tobacco Investments Ltd, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
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Breheny D, Oke O, Pant K, Gaça M. Comparative tumor promotion assessment of e-cigarette and cigarettes using the in vitro Bhas 42 cell transformation assay. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:190-198. [PMID: 28444993 PMCID: PMC5435921 DOI: 10.1002/em.22091] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
In vitro cell transformation assays (CTA) are used to assess the carcinogenic potential of chemicals and complex mixtures and can detect nongenotoxic as well as genotoxic carcinogens. The Bhas 42 CTA has been developed with both initiation and promotion protocols to distinguish between these two carcinogen classes. Cigarette smoke is known to be carcinogenic and is positive in in vitro genotoxicity assays. Cigarette smoke also contains nongenotoxic carcinogens and is a tumour promoter and cocarcinogen in vivo. We have combined a suite of in vitro assays to compare the relative biological effects of new categories of tobacco and nicotine products with traditional cigarettes. The Bhas promotion assay has been included in this test battery to provide an in vitro surrogate for detecting tumor promoters. The activity of an electronic cigarette (e-cigarette; Vype ePen) was compared to that of a reference cigarette (3R4F) in the promotion assay, using total particulate matter (TPM)/aerosol collected matter (ACM) and aqueous extracts (AqE) of product aerosol emissions. 3R4F TPM was positive in this assay at concentrations ≥6 µg/mL, while e-cigarette ACM did not have any promoter activity. AqE was found to be a lesssuitable test matrix in this assay due to high cytotoxicity. This is the first study to use the Bhas assay to compare tobacco and nicotine products and demonstrates the potential for its future application as part of a product assessment framework. These data add to growing evidence suggesting that e-cigarettes may provide a safer alternative to traditional cigarettes. Environ. Mol. Mutagen. 58:190-198, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Damien Breheny
- British American Tobacco, Research and DevelopmentSouthamptonUK
| | | | - Kamala Pant
- Department of Genetic ToxicologyBioreliance CorporationRockvilleMaryland
| | - Marianna Gaça
- British American Tobacco, Research and DevelopmentSouthamptonUK
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Han SG, Pant K, Bruce SW, Gairola CG. Bhas 42 cell transformation activity of cigarette smoke condensate is modulated by selenium and arsenic. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:220-228. [PMID: 26924598 DOI: 10.1002/em.22000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 01/09/2016] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
Cigarette smoking remains a major health risk worldwide. Development of newer tobacco products requires the use of quantitative toxicological assays. Recently, v-Ha-ras transfected BALB/c3T3 (Bhas 42) cell transformation assay was established that simulates the two-stage animal tumorigenesis model and measures tumor initiating and promoting activities of chemicals. The present study was performed to assess the feasibility of using this Bhas 42 cell transformation assay to determine the initiation and promotion activities of cigarette smoke condensate (CSC) and its water soluble fraction. Further, the modulating effects of selenium and arsenic on cigarette smoke-induced cell transformation were investigated. Dimethyl sulfoxide (DMSO) and water extracts of CSC (CSC-D and CSC-W, respectively) were tested at concentrations of 2.5-40 µg mL(-1) in the initiation or promotion assay formats. Initiation protocol of the Bhas 42 assay showed a 3.5-fold increase in transformed foci at 40 µg mL(-1) of CSC-D but not CSC-W. The promotion phase of the assay yielded a robust dose response with CSC-D (2.5-40 µg mL(-1)) and CSC-W (20-40 µg mL(-1)). Preincubation of cells with selenium (100 nM) significantly reduced CSC-induced increase in cell transformation in initiation assay. Co-treatment of cells with a sub-toxic dose of arsenic significantly enhanced cell transformation activity of CSC-D in promotion assay. The results suggest a presence of both water soluble and insoluble tumor promoters in CSC, a role of oxidative stress in CSC-induced cell transformation, and usefulness of Bhas 42 cell transformation assay in comparing tobacco product toxicities and in studying the mechanisms of tobacco carcinogenesis.
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Affiliation(s)
- Sung Gu Han
- Toxicology Laboratory, Department of Food Science and Biotechnology of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Kamala Pant
- Department of Genetic Toxicology, Bioreliance Corporation, Rockville, Maryland
| | - Shannon W Bruce
- Department of Genetic Toxicology, Bioreliance Corporation, Rockville, Maryland
| | - C Gary Gairola
- Department of Genetic Toxicology, Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
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Sasaki K, Umeda M, Sakai A, Yamazaki S, Tanaka N. Transformation assay in Bhas 42 cells: a model using initiated cells to study mechanisms of carcinogenesis and predict carcinogenic potential of chemicals. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2015; 33:1-35. [PMID: 25803194 DOI: 10.1080/10590501.2014.967058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transformation assays using cultured cells have been applied to the study of carcinogenesis. Although various cell systems exist, few cell types such as BALB/c 3T3 subclones and Syrian hamster embryo cells have been used to study chemically induced two-stage carcinogenesis. Bhas 42 cells were established as a clone by the transfection with the v-Ha-ras gene into mouse BALB/c 3T3 A31-1-1 cells and their subsequent selection based on their sensitivity to 12-O-tetradecanoylphorbol-13-acetate. Using Bhas 42 cells, transformed foci were induced by the treatment with nongenotoxic carcinogens, most of which act as tumor promoters. Therefore, Bhas 42 cells were considered to be a model of initiated cells. Subsequently, not only nongenotoxic carcinogens but also genotoxic carcinogens, most of which act as tumor initiators, were found to induce transformed foci by the modification of the protocol. Furthermore, transformation of Bhas 42 cells was induced by the transfection with genes of oncogenic potential. We interpret this high sensitivity of Bhas 42 cells to various types of carcinogenic stimuli to be related to the multistage model of carcinogenesis, as the transfection of v-Ha-ras gene further advances the parental BALB/c 3T3 A31-1-1 cells toward higher transforming potential. Thus, we propose that Bhas 42 cells are a novel and sensitive cell line for the analysis of carcinogenesis and can be used for the detection of not only carcinogenic substances but also gene alterations related to oncogenesis. This review will address characteristics of Bhas 42 cells, the transformation assay protocol, validation studies, and the various chemicals tested in this assay.
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Affiliation(s)
- Kiyoshi Sasaki
- a Laboratory of Cell Carcinogenesis, Division of Alternative Toxicology Tests , Hatano Research Institute, Food and Drug Safety Center , Hadano , Kanagawa , Japan
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