Figure 4. RAP administration delays development of dysplasia in CDX2P-CreER^T2 Apc^fl/fl mice.

CDX2P-CreER^T2 Apc^fl/fl mice were treated with TAM to induce polyposis and then treated with either vehicle or RAP. A.) Histology of vehicle and RAP treated mice. A group of mice were euthanized at 7, 16 and 20 weeks to compare histology. Arrows indicate areas of low and high grade dysplasia (LGD and HGD, respectively). B.) The second group of mice were allowed to continue until they became ill or beyond 20 weeks of treatment and then were euthanized. Mean number of weeks to visible high grade dysplasia in colonic polyps after TAM induction were recorded for individual mice treated with vehicle (circle) or RAP (square). We found that HGD was seen significantly earlier in the vehicle treated mice vs the RAP treated mice (5.1 vs 15.8 weeks, p = 0.003, N = 7 and 4 in vehicle and RAP group respectively).