Gene expression data from the LEC rat model with naturally occuring and oxidative stress induced liver tumorigenesis

ABSTRACT: To elucidate the fundamental molecular mechanisms responsible for multistep hepatotumorigenesis, this study investigated genes that were upregulated in a stepwise manner from the naïve liver condition through to chronic oxidative stress-induced hepatitis and liver tumor by time-series microarray analysis. The time-dependent gene expression profile should reflect the multistep process of hepatotumorigenesis, and might identify genes that function specifically in hepatotumorigenesis. We reduced several clinicopathological variables by using the Long-Evans Cinnamon rat, a model with naturally occurring and oxidative stress-induced hepatotumorigenesis. Gene expression patterns were analyzed serially by profiling liver tissue from naïve status (4 weeks old) rats through to those with chronic hepatitis (26 and 39 weeks old) to tumor development (67 weeks old). This study represents a normal versus diseased comparison with different time points of spontaneously developed liver tumor and normal liver tissue. In the first series of experiments, equivalent amounts of RNA from 2 pairs randomly selected from 8 paired liver tumor and adjacent nontumor tissue specimens were mixed and analyzed in order to normalize variations among mice. Average gene expression levels for tumor and non-tumor tissue samples were calculated using the 4 Affymetrix microarray datasets, respectively. In the following experiments, a mixture of equivalent amounts of RNA isolated from LEC rats at 4, 26, and 39 weeks of age and controls, respectively, was exploited as an RNA pool for Affymetrix microarray analyses. A total of 12 samples (4 sets of tumor-non-tumor pairs and a normal control, and 3 serial samples) were hybridized to Affymetrix Rat Expression 230 2.0 Arrays.

ORGANISM(S): Rattus norvegicus

SUBMITTER: Akihito Tsubota 

PROVIDER: E-GEOD-17384 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress