Co-opted integrin signaling in ErbB2-induced mammary tumor progression.

Although almost two decades of study point to a central role for aberrant ErbB2 activation in breast cancer, many cellular and biochemical mechanisms underlying ErbB2-induced tumor initiation and progression remain to be resolved. A study by Guo et al. published recently in Cell indicates that the signaling function of beta4 integrin actively contributes to the initiation, growth, and invasion of ErbB2-induced mammary tumors in transgenic mice by promoting the activation of c-Jun and STAT3. These observations offer novel mechanistic insight into ErbB2 action and highlight the notion that ErbB2 co-opts the functions of other signaling proteins to elicit tumor progression.