Abstract The LAP (leucine-rich repeat (LRR) and PDZ domain) family protein, ERBIN, is basolaterally localized protein that has previously been identified as a regulator of epithelial cell polarity and an ERBB2/HER2 binding protein. In addition, ERBIN inhibits RAF activation by disrupting by the RAS/RAF interaction. However, the functional importance of ERBIN in cancer remains elusive. In this study, we examined the role of ERBIN in regulating colon cancer progression and metastasis. Stable colon cancer cell lines, including SW480, LIM2405, and Caco2, were generated using lentiviral shRNA to deplete endogenous ERBIN expression. Our results showed that knockdown of ERBIN induced epithelial-mesenchymal transition (EMT)-like phenotype as marked by spindle-like morphology, a decrease in E-cadherin and an increase in vimentin expression. Moreover, the overall rate of cell migration was significantly increased in ERBIN knockdown cells as determined using Transwell assays. When tracking the movement of individual cells using live cell imaging, we found that ERBIN knockdown cells were considerably more motile with faster migrating speed when compared to control cells. Mechanistically, knockdown of ERBIN expression resulted in an increase in both Akt and ERK signaling activation. Taken together, we have identified a novel role of ERBIN in suppressing EMT and cell motility in colon cancer cells. Citation Format: Payton D. Stevens, Mike Yang, Tianyan Gao. The role of ERBIN in suppressing migration in colon cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1478. doi:10.1158/1538-7445.AM2013-1478