CD44+ or CD44– tumor cells isolated from K19-Wnt1/C2mE mice

We hypothesized that CD44+ tumor cells might have an increased capacity for reactive oxygen species (ROS) defense in the gastric tumors of K19-Wnt1/C2mE mice. To address this possibility, we examined the expression of antioxidant genes in tumor cells isolated from K19-Wnt1/C2mE mice by fluorescence-activated cell sorting (FACS). Lineage marker (Lin)–negative cells that were CD44+ or CD44– were thus isolated from the gastric tumors of 30-week-old K19-Wnt1/C2mE mice and subjected to cDNA microarray analysis. The expression of several key antioxidant genes, including those for glutathione peroxidase (GPX) and peroxiredoxin (PRDX) isoforms, was found to be increased in CD44+ tumor cells compared with that in CD44– cells. Lineage marker (Lin)–negative cells that were CD44+ or CD44– were isolated from the gastric tumors of 30-week-old K19-Wnt1/C2mE mice. Total RNA was isolated and subjected to cDNA microarray analysis. Two CD44+ replicates and two CD44- replicates were examined.