The Epithelial-Mesenchymal Transition in Cancer: A Potentially Fatal Transformation?

 

Tumor cells from a highly aggressive ovarian cancer cell line are shown on the left. They have a mesenchymal shape (spindle-like) and express typical mesenchymal markers. On the right, cells from the same cell line reverted to an epithelial shape (rounded) and expressed epithelial cell markers after researchers introduced microRNA-429. (Images courtesy of Dr. John McDonald, Georgia Institute of Technology

National Cancer Institute (March 8, 2011)

The question remains one of cancer biology’s most perplexing: How do cancer cells from a primary tumor navigate to other parts of the body to form metastatic tumors? Most solid tumors arise from epithelial cells, which normally stick together in tightly bound sheets to provide the structural foundations of many organs. In principle, epithelial cells lack the ability to escape those bonds and wiggle and jostle their way into nearby tissues, other organs, or the circulatory system. Yet, somehow cancerous epithelial cells-also known as carcinoma cells-do end up in other areas of the body, and the outcome is often dire: metastatic tumors are responsible for the vast majority of cancer-associated deaths. (full story…)