399 Aberrant Epithelial GREM1 Expression Promotes Stem-Cell Plasticity and Ectopic Crypt Formation in the Pathogenesis of Familial and Sporadic Human Polyps

Conclusions: Gpsm2 controls mitotic spindle orientation in colon stem cells.Loss of Gpsm2 in normal colon causes increased apoptosis and proliferation without affecting overall tissue architecture.Future studies will determine how this affects susceptibility to injury or tumorigenesis.In human colon cancer, reduction of Gpsm2 increases the fraction of tumorigenic CD44+ cells and leads to larger tumors.Colon cancer patients whose tumors express lower levels of Gpsm2 exhibit worse clinical outcomes.