Mesenchyma

Unspecialized early connective tissue of animals that may give rise also to blood and lymphatic vessels. The epithelial–mesenchymal transition is mediated by transcription factors that repress E-cadherin expression. As a consequence embryonic morphogenesis can proceed. The transition also plays a part in the initiation of metastasis. Mesenchymal stem cells are pluripotent and a balance between Runx2 and PPARγ determine whether osteoblasts or adipocytes develop from the stem cells. The transcriptional activator with PDZ-binding domain (TAZ), a 14–3–3-binding protein coactivates Runx-dependent gene transcription and represses PPAR and functions like a rheostat (Hong J-H et al 2005 Science 309:1074). osteoblast, adipocyte, RUNX, PPAR, PDZ, mesoderm, metastasis, cadherins, Kang Y, Massagué J 2004 Cell 118:277.