You are here:
APPLICATION OF CDNA MICROARRAY TECHNOLOGY TO IN VITRO TOXICOLOGY AND THE SELECTION OF GENES FOR A REAL TIME RT-PCR-BASED SCREEN FOR OXIDATIVE STRESS IN HEP-G2 CELLS
Citation:
Morgan, K. T., H. Ni, H. R. Brown, L. Yoon, C. W. Qualls Jr., L. M. Crosby, R. Reynolds, B. Gaskill, S. P. Anderson, T. B. Kepler, T. Brainard, N. Liv, M. Easton, C. Merrill, D. Creech, D. Sprenger, G. Conner, P. R. Johnson, T. Fox, R. Tyler, M. Sartor, E. Richard, S. Kuruvilla, W. M. Casey, AND G. Benavides. APPLICATION OF CDNA MICROARRAY TECHNOLOGY TO IN VITRO TOXICOLOGY AND THE SELECTION OF GENES FOR A REAL TIME RT-PCR-BASED SCREEN FOR OXIDATIVE STRESS IN HEP-G2 CELLS. TOXICOLOGIC PATHOLOGY 30(4):435-451, (2001).
Description:
Large-scale analysis of gene expression using cDNA microarrays promises the
rapid detection of the mode of toxicity for drugs and other chemicals. cDNA
microarrays were used to examine chemically-induced alterations of gene
expression in HepG2 cells exposed to oxidative and nonoxidative toxicants.
Patterns of gene expression were correlated with morphologic and biochemical
indicators of toxicity, including oxidative stress assessed by the GSH:GSSG
ratio. These data indicated that, under the conditions of this test system,
oxidative stress upregulated 5 genes, HMOX1, p21waf1/cip1, GCLM, GR, TXNR1
while down regulating CYP1A1 and TOPO2A. Primers and probes for these genes
were incorporated into the design of a seven-gene plate for RT-PCR. The
plate design incorporated statistical analysis and allowed clear
discrimination between chemicals inducing oxidative versus non-oxidative
stress. A simple oxidative stress score (0-1) of the responses by the seven
genes on the RT-PCR plate, which incorporated statistical analysis (p-value),
was correlated with the GSH:GSSG ratio using linear regression and ranking
(Pearson product) procedures. These analyses yielded correlation
coefficients of -0.74 and -0.87, respectively, for the treatments tested
(when one outlier was excluded), indicating a good correlation between the
two measures of oxidative stress. These results indicate that gene
expression patterns provide an effective indicator of oxidative stress. We
conclude that it is essential to measure the mechanism of interest directly
in the test system being used when assessing gene expression as a tool for
toxicology.