title: Cancer in inflammatory bowel disease:  lessons from animal models.
abstract: OBJECTIVE
  Human colitis-associated cancers (CAC) represent a heterogeneous group of conditions in which multiple oncogenic pathways are involved. In this article, we review the latest studies using genetic, chemical, bacterial and innate immune-mediated experimental models of CAC.
  
  
  RESULTS
  Using the azoxymethane-dextran sodium sulfate model, wound healing pathways seem to be required in the development of CAC. There is also an emerging understanding that commensal and/or pathogenic bacteria can promote tumorigenesis, through T cell and TLR-mediated inflammation. Using specific transgenic mice (villin-CD98, T cell SMAD7, villin-TLR4) or specific knockout mice, investigators have determined that derangements in epithelial or innate and adaptive immune pathways can result in CAC. Subtle perturbations in epithelial repair - both too little or too exuberant - can render mice susceptible to tumorigenesis.
  
  
  CONCLUSIONS
  With the aid of animal models, we have witnessed a rapid expansion of our knowledge of the molecular and immunologic mechanisms underlying inflammatory cancers. Though animal models have contributed a discrete amount of information to our understanding of tumorigenesis in the setting of intestinal inflammation, it is clear that no single animal model will be able to adequately recapitulate the pathogenesis of complex colorectal cancers, but each model gets us one step closer to comprehending the nature of CAC.
authors.affiliation: University of Miami Miller School of Medicine, Department of Medicine, Division of Gastroenterology, Miami, Florida 33101, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Sussman
authors.forename: Rebeca
authors.initials: R
authors.lastname: Santaolalla
authors.forename: Sebastian
authors.initials: S
authors.lastname: Strobel
authors.forename: Rishu
authors.initials: R
authors.lastname: Dheer
authors.forename: Maria T
authors.initials: MT
authors.lastname: Abreu
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000276:immunology; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D006801:Humans; D007113:Immunity, Innate; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000235:genetics / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains