Immunopathogenesis of Colitis-Associated Cancer in an Animal Model

Chronic inflammation, such as that seen in patients with inflammatory bowel disease (IBD), greatly increases the risk of developing colon cancer. Growing evidence supports a role for T cell-mediated immune response and release of various cytokines in the pathogenesis of colitis-associated cancer (CAC). In fact, CD4(+) effector T cells promote chronic inflammation associated with IBD through release of proinflammatory cytokines, which leads to initiation and progression of colon cancer. Furthermore, CD8(+) T cells reduce tumor growth through cancer immunosurveillance, which can also contribute to intestinal inflammation and thereby might promote tumor growth. In contrast, regulatory T cells (Tregs) release the immunosuppressive cytokines IL-10, TGF-beta, and thus have protective effects in CAC. In addition, dendritic cells (DCs) are important components of antitumor immunity. Recently, a novel mouse model that was associated with repeated inflammation was established for investigating the immunopathogenesis of CAC. This review discusses the role of T cell-mediated immune response, and DCs and involved cytokines in the immunopathogenesis of CAC in an animal model, which may also provide future therapeutic targets in CAC.