The Potential Contribution of Hexavalent Chromium to the Carcinogenicity of Chrysotile Asbestos

Author(s)
Martin Walter, Walter D. C. Schenkeveld, Maura Tomatis, Karin Schelch, Barbara Peter-Voroesmarty, Gerald Geroldinger, Lars Gille, Maria C. Bruzzoniti, Francesco Turci, Stephan M. Kraemer, Michael Grusch
Abstract

Chrysotile asbestos is a carcinogenic mineral that has abundantly been used in industrial and consumer applications. The carcinogenicity of the fibers is partly governed by reactive Fe surface sites that catalyze the generation of highly toxic hydroxyl radicals (HO

•) from extracellular hydrogen peroxide (H

2O

2). Chrysotile also contains Cr, typically in the low mass permille range. In this study, we examined the leaching of Cr from fibers at the physiological lung pH of 7.4 in the presence and absence of H

2O

2. Furthermore, we investigated the potential of cells from typical asbestos-burdened tissues and cancers to take up Cr leached from chrysotile in PCR expression, immunoblot, and cellular Cr uptake experiments. Finally, the contribution of Cr to fiber-mediated H

2O

2decomposition and HO

•generation was studied. Chromium readily dissolved from chrysotile fibers in its genotoxic and carcinogenic hexavalent redox state upon oxidation by H

2O

2. Lung epithelial, mesothelial, lung carcinoma, and mesothelioma cells expressed membrane-bound Cr(VI) transporters and accumulated Cr up to 10-fold relative to the Cr(VI) concentration in the spiked medium. Conversely, anion transporter inhibitors decreased cellular Cr(VI) uptake up to 45-fold. Finally, chromium associated with chrysotile neither decomposed H

2O

2nor contributed to fiber-mediated HO

•generation. Altogether, our results support the hypothesis that Cr may leach from inhaled chrysotile in its hexavalent state and subsequently accumulate in cells of typically asbestos-burdened tissues, which could contribute to the carcinogenicity of chrysotile fibers. However, unlike Fe, Cr did not significantly contribute to the adverse radical production of chrysotile.

Organisation(s)
Department of Environmental Geosciences
External organisation(s)
University of Turin, Medizinische Universität Wien, Veterinärmedizinische Universität Wien
Journal
Chemical Research in Toxicology
Volume
35
Pages
2335-2347
No. of pages
13
ISSN
0893-228X
DOI
https://doi.org/10.1021/acs.chemrestox.2c00314
Publication date
12-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
106026 Ecosystem research, 105906 Environmental geosciences
Keywords
ASJC Scopus subject areas
Toxicology
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/e125ab0e-72cd-4853-b206-aa0180be9dd9