By Briga Mullin, Biochemistry and Molecular Biology, ’15

What do a smoker, a two week old embryo, a child with a broken wrist, and a metastatic tumor all have in common? While these are a diverse group of conditions, they all have cells that are experiencing the same process known as epithelial-mesenchymal transition (EMT). Mesenchymal cells are non-polarized, mobile, invasive, and their main function is to secrete extracellular  matrix. In contrast, epithelial cells form our skin and the linings of our internal organs. They are normally polarized which means they have a directional structure and are uniformly oriented and are attached to a membrane to form a layer of epithelial tissue.  Under certain conditions an EMT will occur and epithelial cells will change  their transcription patterns, produce new proteins, destroy the basal membrane they are attached to, and totally convert their phenotype to become motile  mesenchymal cells.  EMT can be triggered by a variety of conditions and can yield very beneficial or extremely detrimental results depending on the circumstances. (more…)