AOM-DSS Colitis and Cancer Model

Azoxymethane (AOM, 10mg/kg, Sigma-Aldrich- A5486-25MG) in saline was injected intraperitoneally (IP) 2 days in advance of three cycles of 3.5% dextran sodium sulfate (DSS, MP Biomedicals- 160110, molecular weight: 36,000–50,000). Each cycle consisted of 5 days of 3.5% DSS in the drinking water, followed by 16 days of regular water. Mice were euthanized at various time points (“baseline”; at the end of each DSS treatment, designated as “colitis”; one week after each DSS cycle, designated as “recovery”, with the end of the 3^rd cycle being designated as “cancer”). This AOM-DSS colitis model leads to predictable and reproducible colitis and cancer [15 ]. Disease activity index (DAI) was recorded, a colonoscopy was performed 1 week after each DSS treatment, and mice were euthanized at various time points (colitis, recovery, cancer) with colon tissue either stored in liquid nitrogen or placed in formalin. Disease activity index was calculated based on weight loss (1 = 0–10%, 2 = 10–15%, 3 = 15–20%, 4 = >20%), stool consistency (1 = solid, 2 = loose, 3 = wet, 4 = diarrhea), and hematochezia (1 = no blood, 2 = slight blood, 3 = blood, 4 = significant hematochezia).