Abstract 4473: Tumorigenesis by deregulation of CRAD-controlled cytoskeleton dynamics

Abstract

Abstract Epithelial cell behavior and homeostasis are mainly modulated by the cytoskeleton and cell adhesion. However, much concerning epithelial cell deregulation in cancer remains unknown. We identified Cancer-related Regulator of Actin Dynamics (CRAD) as frequently mutated or transcriptionally downregulated in colorectal cancer. We found that CRAD is a capping protein inhibitor and stabilizes the cadherin-catenin-actin (CCA) complex. CRAD inactivation disrupts the CCA complex via inhibiting actin polymerization, liberating β-catenin and aberrantly activating Wnt pathway. In mice, CRAD knockout induces the loss of epithelial cell integrity and hyperactivates Wnt signaling, resulting in intestinal adenoma development. With APC mutation, CRAD knockout induces and accelerates mucinous and invasive adenoma development in the colorectum. These results define CRAD as a new tumor suppressor, of which inactivation deregulates the cytoskeleton and hyperactivates Wnt signaling, initiating mucinous intestinal tumorigenesis. Our study reveals the unexpected roles of an actin cytoskeletal regulator in maintaining epithelial cell integrity. Citation Format: Youn-Sang Jung, Wenqi Wang, Sohee Jun, Jie Zhang, Mrianl Srivastava, Moon Jong Kim, Esther M. Lien, Joan Shang, Pierre D. McCrea, Songlin Zhang, Junjie Chen, Jae-Il Park. Tumorigenesis by deregulation of CRAD-controlled cytoskeleton dynamics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4473.