Global and gene-specific DNA methylation effects of different asbestos fibres on human bronchial epithelial cells

Abstract

Inhalation exposure to asbestos is associated with lung and pleural diseases in humans and remains a major public health issue worldwide. Human bronchial epithelial cells (16HBE) were exposed to UICC amosite, crocidolite and chrysotile. Cytotoxicity, genotoxicity, global DNA methylation on cytosine residues (using LC-MS/MS) were investigated at different doses (2.5-100 μg/ml). Gene-specific DNA methylation alterations at the whole genome were investigated using a microarray that interrogates >450 thousand CpG sites. Subsequently, gene functional analyses (KEGG pathway, Gene Ontology and functional classification) were performed on genes with differentially methylated gene promoters. At non-cytotoxic doses, global DNA methylation was altered after 24 h exposure to amosite and crocidolite (>2.5 μg/ml). Exposure to amosite and crocidolite (amphibole type asbestos) induced both hypomethylation and hypermethylation at single CpG site and gene promoter levels whereas exposure to chrysotile (serpentine type asbestos) induced hypomethylation at the gene promoter level. Gene functional classification analyses revealed that all types of asbestos fibres induce alterations on GO-clusters i.e. on regulation of Rho-protein signal transduction, nucleus, (e.g. homeobox genes), ATP-binding function and extracellular region (e.g. WNT-group of genes). These differentially methylated genes might contribute to asbestos-related diseases in bronchial cells.

50‐Hz MF does not affect global DNA methylation of SH‐SY5Y cells treated with the neurotoxin MPP+

“…This result did not conflict with ours, as those authors focused on a single gene analysis, while we looked at the whole genome, global DNA methylation level. The extent of global DNA methylation and its possible changes do not necessarily overlap with DNA methylation changes occurring at gene‐specific promoters [Sharma et al, ; Öner et al, ]. Indeed, we recently reported that ELF‐MFs (applied to both proliferating and differentiated SH‐SY5Y under the same experimental conditions used in this study) trigger hypermethylation of the miR‐34b/c promoter [Consales et al, ].…”

Dysregulated Glutamate Transporter SLC1A1 Propels Cystine Uptake via Xc− for Glutathione Synthesis in Lung Cancer

“…Human embryonic kidney cells, HEK293T, and NSCLC cells (H292G, Calu-1 and HCC827) were tested and authenticated by DNA typing at Shanghai Jiao Tong University Analysis Core. The 16HBE (Human bronchial epithelial cells) cells were as described previously (19). HBEC cells were cultured in serum-free medium, and all other cells were cultured in DMEM essential medium with 10% fetal calf serum, at 37℃ in a humidified incubator in an atmosphere of 95% air and 5% CO 2 .…”

Carbon Nanotube- and Asbestos-Induced DNA and RNA Methylation Changes in Bronchial Epithelial Cells

“…63 Union Internationale Centre le Cancer (UICC) standard reference samples were used for asbestos, which has been used in our study previous study. 64 Asbestos of amphibole (Amosite South African, NB #4173-111-4 and Crocidolite South African, NB #4173-111-3) and serpentine (Chrysotile "A" Rhodesian, NB #4173-111-2) type were supplied from SPI Supplies (Structure Probe Inc., West Chester, USA).…”

“…For amosite, crocidolite, and chrysotile; a final concentration of 2.5 g/ml (noncytotoxic but genotoxic) was selected based on our previously published study. 64 For CNTs and asbestos, three independent experiments performed in duplicate were used for each concentration.…”

“…The amount of m 6 A-RNA is calculated from equation defined in the kit manual. The genes selected for the present study were based on the enriched pathways from our previous studies 25,46,[62][63][64] and that presented by Mossman. 68 Primers for CDKN1A, ATM, and TRAF2 were ordered from Qiagen (PyroMark CpG Assays, #PM00025711, #PM00153622, #PM00141309).…”