Utilization of Gene Profiling and Proteomics to Determine Mineral Pathogenicity in a Human Mesothelial Cell Line (LP9/TERT-1)

• Published in: Journal of Toxicology and Environmental Health, Part A Vol. 73; no. 5-6; pp. 423 - 436
• Main Authors: Hillegass, Jedd M., Shukla, Arti, MacPherson, Maximilian B., Bond, Jeffrey P., Steele, Chad, Mossman, Brooke T.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01-01-2010; Taylor & Francis Ltd
• Subjects: Asbestos; Asbestos, Crocidolite - toxicity; Cell Line; Cells; Cytokines; Epithelium - drug effects; Epithelium - metabolism; Fibroblast Growth Factor 2 - genetics; Fibroblast Growth Factor 2 - metabolism; Gene expression; Gene Expression - drug effects; Gene Expression Profiling - methods; Granulocyte Colony-Stimulating Factor - genetics; Granulocyte Colony-Stimulating Factor - metabolism; Humans; Interleukin-13 - genetics; Interleukin-13 - metabolism; Particulate Matter - toxicity; Principal components analysis; Proteomics; Talc - toxicity; Telomerase - genetics; Titanium - toxicity; TNF inhibitors; Toxicity Tests - methods; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Vascular Endothelial Growth Factor A - genetics; Vascular Endothelial Growth Factor A - metabolism
• ISSN: 1528-7394; 1087-2620; 2381-3504
• DOI: 10.1080/15287390903486568

Identifying and understanding the early molecular events that underscore mineral pathogenicity using in vitro screening tests is imperative, especially given the large number of synthetic and natural fibers and particles being introduced into the environment. The purpose of the work described here was to examine the ability of gene profiling (Affymetrix microarrays) to predict the pathogenicity of various materials in a human mesothelial cell line (LP9/TERT-1) exposed to equal surface area concentrations (15 × 10
6
or 75 × 10
6
μm
2
/cm
2
) of crocidolite asbestos, nonfibrous talc, fine titanium dioxide (TiO
2
), or glass beads for 8 or 24 h. Since crocidolite asbestos caused the greatest number of alterations in gene expression, multiplex analysis (Bio-Plex) of proteins released from LP9/TERT-1 cells exposed to crocidolite asbestos was also assessed to reveal if this approach might also be explored in future assays comparing various mineral types. To verify that LP9/TERT-1 cells were more sensitive than other cell types to asbestos, human ovarian epithelial cells (IOSE) were also utilized in microarray studies. Upon assessing changes in gene expression via microarrays, principal component analysis (PCA) of these data was used to identify patterns of differential gene expression. PCA of microarray data confirmed that LP9/TERT-1 cells were more responsive than IOSE cells to crocidolite asbestos or nonfibrous talc, and that crocidolite asbestos elicited greater responses in both cell types when compared to nonfibrous talc, TiO
2
, or glass beads. Bio-Plex analysis demonstrated that asbestos caused an increase in interleukin-13 (IL-13), basic fibroblast growth factor (bFGF), granulocyte colony-stimulating factor (G-CSF), and vascular endothelial growth factor (VEGF). These responses were generally dose-dependent (bFGF and G-CSF only) and tumor necrosis factor (TNF)-α independent (except for G-CSF). Thus, microarray and Bio-Plex analyses are valuable in determining early molecular responses to fibers/particles and may directly contribute to understanding the etiology of diseases caused by them. The number and magnitude of changes in gene expression or "profiles" of secreted proteins may serve as valuable metrics for determining the potential pathogenicity of various mineral types. Hence, alterations in gene expression and cytokine/chemokine changes induced by crocidolite asbestos in LP9/TERT-1 cells may be indicative of its increased potential to cause mesothelioma in comparison to the other nonfibrous materials examined.