Inactivation of Itf2 promotes intestinal tumorigenesis in ApcMin/+ mice

Deregulation of Wnt/β-catenin signaling following inactivation of the adenomatous polyposis coli (APC) tumor suppressor gene is frequently found in colorectal cancer. We have previously shown that levels of ITF-2B, encoded by the β-catenin target gene ITF2 that is located on the tumor suppressor gene locus 18q21, are increased in colonic adenomas with deregulated β-catenin activity. However, during tumor progression ITF-2B levels are reduced, suggesting that ITF-2B interferes with tumor development. To investigate the role of ITF2 in intestinal tumorigenesis, we specifically inactivated Itf2 in the intestinal epithelium of ApcMin/+ mice. We found that genetic disruption of Itf2 on the ApcMin/+ background results in earlier death and a significant increase in tumor number and size in the small intestine. Based on these data Itf2 acts as a tumor suppressor gene of the intestinal tract that inhibits tumor initiation and growth.