Epithelial-Mesenchymal Transition in Metastatic Colorectal Cancer

Epithelial-mesenchymal transition (EMT) is a morphogenetic event during which cells lose their epithelial characteristics, such as apicobasal polarity, and gain mesenchymal features with an increased migratory and invasive potential. A wide range of studies have shown that this event plays a crucial role in tumor progression and metastasis. The results of the studies also demonstrate participation of EMT in therapy resistance and in the development and maintenance of stemness potential in colorectal cancer. In addition, evidence from preclinical and early clinical studies have shown that EMT markers might serve as outcome predictors and potential therapeutic targets in colorectal cancer. In this chapter, we discuss the fundamentals of EMT, including cell-cell adhesion disruption and cell polarity loss, actin cytoskeleton reorganization, transcription factors, and post translational modifications associated with EMT. We also discuss EMT-mediated mechanisms of resistance to radiotherapy and chemotherapy. Finally, we provide a summary of EMT components and their use as potential markers or therapeutic targets for metastasis inhibition, along with the obstacles in the development of drugs targeting EMT.