A JAK/STAT invasion

Asignalingpathway that is critical in fly eggs might be a key to understanding cancer cell metastasis, according to Debra Silver and Denise Montell (Johns Hopkins School of Medicine, Baltimore, MD). They have found that activation of the JAK/STAT signaling pathway triggers the migration of border cells, which start off at the anterior end of the egg chamber, travel in between the nurse cells, and end up at the anterior end of the oocyte. Once they settle down, the border cells provide patterning information and help build an anterior eggshell structure that aids in fertilization.

In mammals, the same pathway is triggered by certain cytokines. Binding induces receptor dimerization, cross-phosphorylation of and by the receptor-bound JAK kinases, and docking and activation of STAT transcription factors. The pathway is constitutively activated in many...