Open AccessApplication of Transcriptional Benchmark Dose Values in Quantitative Cancer and Noncancer Risk Assessment
Author(s) -
Russell S. Thomas,
Harvey J. Clewell,
Bruce C. Allen,
Scott C. Wesselkamper,
Nina Ching Y. Wang,
Jason C. Lambert,
Janet K. Hess-Wilson,
Qianqian Zhao,
Melvin E. Andersen
Publication year - 2010
Publication title -
toxicological sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.352
H-Index - 183
eISSN - 1096-6080
pISSN - 1096-0929
DOI - 10.1093/toxsci/kfq355
Subject(s) - cancer , bioassay , medicine , risk assessment , physiology , oncology , microarray analysis techniques , microarray , bioinformatics , biology , gene expression , gene , genetics , computer security , computer science
The traditional approach for estimating noncancer and cancer reference values in quantitative chemical risk assessment is time and resource intensive. The extent and nature of the studies required under the traditional approach has limited the number of chemicals with published risk assessments. In this study, female mice were exposed for 13 weeks to multiple concentrations of five chemicals that were positive in a 2-year cancer bioassay. Traditional histological and organ weight changes were evaluated, and gene expression microarray analysis was performed on the target tissues. The histological, organ weight changes, and the original tumor incidences in the original cancer bioassay were analyzed using standard benchmark dose (BMD) methods to identify noncancer and cancer points of departure, respectively. The dose-related changes in gene expression were also analyzed using a BMD approach and the responses grouped based on cellular biological processes. A comparison of the transcriptional BMD values with those for the traditional noncancer and cancer apical endpoints showed a high degree of correlation for specific cellular biological processes. For chemicals with human exposure data, the transcriptional BMD values were also used to calculate a margin of exposure. The margins of exposure ranged from 1900 to 54,000. Both the correlation between the BMD values for the transcriptional and apical endpoints and the margin of exposure analysis suggest that transcriptional BMD values may be used as potential points of departure for noncancer and cancer risk assessment.