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Comparative microarray analysis of basal gene expression in mouse Hepa-1c1c7 wild-type and mutant cell lines. C.J. Fong1,3,4, L.D. Burgoon2,3,4, M.D. Ramer1,4, T.R. Zacharewski1,3,4. 1Department of Biochemistry & Molecular Biology, 2Department of Pharmacology & Toxicology, 3Center for Integrative Toxicology, 4National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, 48824, USA. cDNA microarrays containing 4858 unique genes were used to examine differences in basal gene expression between mouse Hepa-1c1c7 wild-type and mutant (C1 – uninducible Cyp1a1, C4 – ARNT translocation deficient and C12 - reduced Ah receptor levels) cell lines. Using a model based t-test approach, 727 uniquely annotated genes were identified in the mutant cell lines that exhibited a significant (p < 0.01) difference in basal expression when compared to wild-type. Surprisingly C1 cells exhibited the greatest number (339 unique genes) of expression differences while 235 and 153 differences where identified in C4 and C12 cell lines, respectively, when compared to wild-type cells. Many genes found to be differentially regulated belong to pathways involving lipid metabolism and transport as well as xenobiotic metabolism. Multiple genes involved in iron transport and metabolism were uniquely differentially expressed in the C1 mutant line. Proliferation and energy synthesis pathway genes were also identified which may correlate to differences associated with cell line-specific growth rates. Quantitative RT-PCR was conducted on selected genes to verify microarray results where there appear to be discrepancies between the data sets. These studies further characterize Hepa-1c1c7 wild-type and mutant cell line properties and provide further insights into the endogenous role of the AhR as well as potential mechanisms of toxicity of TCDD and related compounds. Research supported through ES 11271. |
