Long-term exposures to low doses of titaniumx dioxide nanoparticles induce cell transformation, but not genotoxic damage in BEAS-2B cells

Gerard Vales, Laura Rubio, Ricard Marcos

Research output: Contribution to journalArticleResearchpeer-review

47 Citations (Scopus)

Abstract

© 2014 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted. There is a great interest in a better knowledge of the health effects caused by nanomaterials exposures and, in particular to those induced by titanium dioxide nanoparticles (nano-TiO2) due to its high use and increasing presence in the environment. To add new information on its potential genotoxic/carcinogenic risk, we have carried out experiments using chronic exposures (up to 4 weeks), low doses, and the BEAS-2B cell line that, as a human bronchial epithelium cells, can be considered a good cell target. Cell uptake has been assessed by transmission electron microscopy (TEM) and flow cytometry (FC); genotoxicity was evaluated using the comet and the micronucleus (MN) assays; and cell-transforming ability was evaluated using the soft-agar assay to detect anchorage-independent cell growth. Results show an important cell uptake at all the tested doses and sampling times used (except for 1g/mL and 24-h exposure). Nevertheless, no genotoxic effects were observed in the comet and in the MN assays. This lack of genotoxic effect agrees with the FC results showing no induction of intracellular reactive oxygen species (ROS), the data from the comet assay with formamidopyrimidine DNA glycosylase (FPG) enzyme showing no induction of oxidized bases, and the lack of induction of expression of heme-oxygenase (HO-1) gene both at the RNA and protein level. On the contrary, significant increases in the number of clones growing in an anchorage-independent way were observed. This study would indicate a potential carcinogenic risk associated to nano-TiO2 exposure, not mediated by a genotoxic mechanism.
Original languageEnglish
Pages (from-to)568-578
JournalNanotoxicology
Volume9
Issue number5
DOIs
Publication statusPublished - 1 Jan 2015

Keywords

  • Cell transformation
  • Chronic exposure
  • Comet
  • Micronucleus
  • Titanium dioxide

Fingerprint Dive into the research topics of 'Long-term exposures to low doses of titaniumx dioxide nanoparticles induce cell transformation, but not genotoxic damage in BEAS-2B cells'. Together they form a unique fingerprint.

Cite this