Carbon Nanotube- and Asbestos-Induced DNA and RNA Methylation Changes in Bronchial Epithelial Cells.
Esra EmerceManosij GhoshDeniz ÖnerRadu-Corneliu DucaJeroen VanoirbeekBram BekaertPeter H M HoetLode GodderisPublished in: Chemical research in toxicology (2019)
Carbon nanotubes (CNTs) are nanoscale tube-shaped carbon materials used in many industrial areas. Their fiber shape has caused concerns about their toxicity given their structural similarity with asbestos. The aim here was to elucidate the effect of CNTs and asbestos exposure on global DNA and RNA methylation and the methylation of genes associated with cell cycle, inflammation, and DNA damage processes in human lung cells. Human bronchial epithelial cells (16HBE14o-) were exposed for 24 h to 25 and 100 μg/mL CNTs (single-walled CNTs [SWCNTs] and multiwalled CNTs [MWCNTs]) and 2.5 μg/mL asbestos (chrysotile, amosite, and crocidolite). Global DNA and RNA (hydroxy)methylation to cytosines was measured by a validated liquid chromatography tandem-mass spectrometry method. Global RNA methylation to adenines was measured by a colorimetric ELISA-like assay. Gene-specific DNA methylation status at certain cytosine-phosphate-guanine (CpG) sites of cyclin-dependent kinase inhibitor 1A ( CDKN1A), serine/threonine kinase ( ATM), and TNF receptor-associated factor 2 ( TRAF2) were analyzed by using bisulfite pyrosequencing technology. Only MWCNT-exposed cells showed significant global DNA hypomethylation of cytosine and global RNA hypomethylation of adenosine. SWCNT, MWCNT, and amosite exposure decreased DNA methylation of CDKN1A. ATM methylation was affected by chrysotile, SWCNT, and MWCNT. However, SWCNT exposure led to DNA hypermethylation of TRAF2. These findings contribute to further understanding of the effect of CNTs on different carcinogenic pathways.
Keyphrases
- dna methylation
- genome wide
- carbon nanotubes
- nucleic acid
- circulating tumor
- cell cycle
- dna damage
- cell free
- single molecule
- liquid chromatography tandem mass spectrometry
- gene expression
- induced apoptosis
- oxidative stress
- cell cycle arrest
- copy number
- protein kinase
- cell proliferation
- simultaneous determination
- dna repair
- endothelial cells
- ms ms
- diabetic rats
- endoplasmic reticulum stress
- heavy metals
- atomic force microscopy
- dna damage response
- transcription factor
- risk assessment
- solid phase extraction
- nitric oxide
- high speed
- mass spectrometry
- high resolution
- high glucose