Regulation of metastasis in colorectal adenocarcinoma: A collision between development and tumor biology

Metastases account for most fatalities caused by colon cancer. The metastatic phenotype, or the ability of normally polarized epithelial cells to separate from their tissue of origin, invade basement membrane, survive transit through the bloodstream, and recolonize at distal sites recapitulates a developmental process known as EMT. Regulators of EMT in adult epithelial cells, which includes the TGF-β and Wnt signal transduction systems, are important mediators of embryonic tissue development, tissue homeostasis, and wound healing. In addition, they have important roles in tumor cell behaviors that are still being defined. Research into the potential epigenetic and reversible nature of EMT, and the downstream effector signaling pathways that lead to EMT, may enable the identification of novel therapeutic interventions to disrupt the metastatic process. Through a better understanding of the biological mechanisms that contribute to metastasis lies the hope of translating these discoveries into new treatments that will improve the survival of cancer patients.