This Article Full Text Full Text (PDF) All Versions of this Article: 2008-0146OCv1 41/1/114    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Shukla, A. Articles by Mossman, B. T. PubMed PubMed Citation Articles by Shukla, A. Articles by Mossman, B. T.

Alterations in Gene Expression in Human Mesothelial Cells Correlate with Mineral Pathogenicity

Departments of ¹ Pathology, ² Medical Biostatistics, and ³ Microbiology and Molecular Genetics, University of Vermont College of Medicine, Burlington, Vermont; ⁴ Department of Cardiothoracic Surgery, NYU Langone Medical Center, New York, New York; and ⁵ Department of Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama

Correspondence and requests for reprints should be addressed to Arti Shukla, Ph.D., Department of Pathology, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405. E-mail: Arti.Shukla{at}uvm.edu

Human mesothelial cells (LP9/TERT-1) were exposed to low and high (15 and 75 µm²/cm² dish) equal surface area concentrations of crocidolite asbestos, nonfibrous talc, fine titanium dioxide (TiO₂), or glass beads for 8 or 24 hours. RNA was then isolated for Affymetrix microarrays, GeneSifter analysis and QRT-PCR. Gene changes by asbestos were concentration- and time-dependent. At low nontoxic concentrations, asbestos caused significant changes in mRNA expression of 29 genes at 8 hours and of 205 genes at 24 hours, whereas changes in mRNA levels of 236 genes occurred in cells exposed to high concentrations of asbestos for 8 hours. Human primary pleural mesothelial cells also showed the same patterns of increased gene expression by asbestos. Nonfibrous talc at low concentrations in LP9/TERT-1 mesothelial cells caused increased expression of 1 gene Activating Transcription Factor 3 (ATF3) at 8 hours and no changes at 24 hours, whereas expression levels of 30 genes were elevated at 8 hours at high talc concentrations. Fine TiO₂ or glass beads caused no changes in gene expression. In human ovarian epithelial (IOSE) cells, asbestos at high concentrations elevated expression of two genes (NR4A2, MIP2) at 8 hours and 16 genes at 24 hours that were distinct from those elevated in mesothelial cells. Since ATF3 was the most highly expressed gene by asbestos, its functional importance in cytokine production by LP9/TERT-1 cells was assessed using siRNA approaches. Results reveal that ATF3 modulates production of inflammatory cytokines (IL-1β, IL-13, G-CSF) and growth factors (VEGF and PDGF-BB) in human mesothelial cells.

Key Words: mesothelioma • crocidolite asbestos • talc • titanium dioxide • gene profiling

CLINICAL RELEVANCE Results of work here suggest that transcriptional profiling can be used to reveal molecular events by mineral dusts that are predictive of their pathogenicity in mesothelioma.