- Full (HTML) - Full (PDF) - Related EHP Articles - PubMed:Related Articles - PubMed:Citation - Cited in PMC - Purchase This Issue

Matthew S. Forrest,¹ Qing Lan,² Alan E. Hubbard,¹ Luoping Zhang,¹ Roel Vermeulen,² Xin Zhao,¹ Guilan Li,³ Yen-Ying Wu,¹ Min Shen,² Songnian Yin,³ Stephen J. Chanock,² Nathaniel Rothman,² and Martyn T. Smith¹

¹School of Public Health, University of California, Berkeley, California, USA; ²Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA; ³National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China

Abstract
Benzene is an industrial chemical and component of gasoline that is an established cause of leukemia. To better understand the risk benzene poses, we examined the effect of benzene exposure on peripheral blood mononuclear cell (PBMC) gene expression in a population of shoe-factory workers with well-characterized occupational exposures using microarrays and real-time polymerase chain reaction (PCR) . PBMC RNA was stabilized in the field and analyzed using a comprehensive human array, the U133A/B Affymetrix GeneChip set. A matched analysis of six exposed-control pairs was performed. A combination of robust multiarray analysis and ordering of genes using paired t-statistics, along with bootstrapping to control for a 5% familywise error rate, was used to identify differentially expressed genes in a global analysis. This resulted in a set of 29 known genes being identified that were highly likely to be differentially expressed. We also repeated these analyses on a smaller subset of 508 cytokine probe sets and found that the expression of 19 known cytokine genes was significantly different between the exposed and the control subjects. Six genes were selected for confirmation by real-time PCR, and of these, CXCL16, ZNF331, JUN, and PF4 were the most significantly affected by benzene exposure, a finding that was confirmed in a larger data set from 28 subjects. The altered expression was not caused by changes in the makeup of the PBMC fraction. Thus, microarray analysis along with real-time PCR confirmation reveals that altered expressions of CXCL16, ZNF331, JUN, and PF4 are potential biomarkers of benzene exposure. Key words: Affymetrix, benzene, biomarkers, blood, expression profiling, leukemia, lymphocyte, microarray, molecular epidemiology, occupational exposure, real-time PCR. Environ Health Perspect 113: 801-807 (2005) . doi:10.1289/ehp.7635 available via http://dx.doi.org/ [Online 14 March 2005]

Address correspondence to M.T. Smith, School of Public Health, 140 Warren Hall, University of California, Berkeley, CA 94720-7360 USA. Telephone: (510) 642-8770. Fax: (510) 642-0427. E-mail: martynts@berkeley.edu

We thank H. Asahara for assistance with the Affymetrix GeneChip hybridizations.

This work was supported by National Institutes of Health grants RO1ES006721 and P30ES001896 to M.T.S.

The authors declare competing financial interests. M.T.S. has received consulting and expert testimony fees from law firms representing both plaintiffs and defendants in cases involving exposure to benzene. G.L. has received funds from the American Petroleum Institute for consulting on benzene-related health research.

Received 5 October 2004 ; accepted 14 March 2005.