( osite effect: it triggers a cascade of ...)Who gives stem cells their marching orders?

In an article appearing in the September issue of the journal Developmental Cell, the researchers explain how cleaved and uncleaved forms of the Nodal protein act together to let the stem cells know where to move and what to become, once the embryo has reached a critical size. "Whole blocks of chemical "programs" are triggered in a cascading fashion, with Nodal there to maintain the source of a concentration gradient," explains EPFL (Ecole Polytechnique Fédérale de Lausanne) professor Daniel Constam, lead researcher on the project. Constam adds that cells respond differently depending on the amount of time they have been exposed to the Nodal signal.

One hallmark of aggressive cancer cells is their unspecified nature, similar to that of embryonic stem cells. Constam and his colleagues think that the signaling pathways used by tumor cells to migrate and invade new territory might be similar to those used in the embryonic development of the organism. Recent research from Northwestern University seems to confirm this, showing that aggressive melanoma cells secrete the Nodal protein. Understanding the activity of this gene in embryonic development may hold the key to finding a way to control its activity in tumor cells. "We need to separate the aspects of Nodal function, and how this protein is regulated by the cell at the molecular level," says Constam. "The embryo holds the key to this understanding."
'"/>

Source:Ecole Polytechnique F茅d茅rale de Lausanne