Epithelial to Mesenchymal Transition in Breast Cancer and Drug Resistance

Abstract

Epithelial to mesenchymal transition (EMT) is the process by which epithelial cells lose their defining epithelial characteristics and begin to express mesenchymal markers, thus endowing them with a mesenchymal-like phenotype that is also often compared to the cancer stem cell-like (CSC) phenotype. Similar to the cancer stem cell phenotype, mesenchymal-like cells are considered to be more therapy resistant. In this review we discuss the defining characteristics of EMT, factors that promote EMT, the relationship between EMT, CSCs and mammary stem cells (MaSC), the role of EMT in drug resistance and finally, current mechanisms to target EMT to treat cancer and prevent drug resistance.