Like a set of bookends, cellular, molecular, and genetic changes of the beginnings of life mirror those of one of the most common cause of death--metastatic cancer. Epithelial to mesenchymal transition (EMT) is an important change in cell phenotype which allows the escape of epithelial cells from the structural constraints imposed by tissue architecture, and was first recognized by Elizabeth Hay in the early to mid 1980's to be a central process in early embryonic morphogenesis. Reversals of these changes, termed mesenchymal to epithelial transitions (METs), also occur and are important in tissue construction in normal development. Over the last decade, evidence has mounted for EMT as the means through which solid tissue epithelial cancers invade and metastasize. However, demonstrating this potentially rapid and transient process in vivo has proven difficult and data connecting the relevance of this process to tumor progression is still somewhat limited and controversial. Evidence for an important role of MET in the development of clinically overt metastases is starting to accumulate, and model systems have been developed. This review details recent advances in the knowledge of EMT as it occurs in breast development and carcinoma and prostate cancer progression, and highlights the role that MET plays in cancer metastasis. Finally, perspectives from a clinical and translational viewpoint are discussed.
The Sacred Grove of Oshogbo was one place I had been looking forward to visiting in Nigeria. As prevalent as indigenous religions still are in West Africa, it is often hard to find public expressions of them in towns and cities; the Christianity brought by European slavers and colonialists has taken root and pushed most of these religions out of mainstream life. But in the Sacred Grove shrines honor all the local deities, including Obatala, the god of creation, Ogun, the god of iron, and Oshun, the goddess of water, whose aqueous essence is made manifest by the river running through the trees. The place is unique in the Yoruba religion, and that intrigued me.