Dextran sodium sulfate treatment of Pirc rats alters colonic and tumor gene expression

Dextran sodium sulfate (DSS) causes inflammation in the gut similar to ulcerative colitis in humans. Patients with ulcerative colitis have increased risk of developing colon cancer. We sought to determine whether genes altered in the normal colonic epithelium or tumor differed between sporadic and inflammation-associated tumor development. 97 day old (ACIxF344)F1-Pirc male rats either untreated or given 4% DSS in the drinking water from 40-47 and 54-61 days of age, housed in 12 hour light:12 dark, ad lib feeding and drinking conditions. Normal colonic tissue and tumors were harvested from the distal colon at 97 days of age. A two color, reference design experiment hybridized according to Agilent protocols against a reference pool of RNA made up from colon tissue taken from pooled wild type rats which was labeled with Cy5.