B4 androgen ablation: attacking the prostate cancer stem cell.

There is increasing evidence that prostate cancers in rodent models and in men contain a cellular subpopulation that displays stem cell properties. These prostate cancer stem cells (PCSCs) lack androgen receptor expression and are increased in castration-resistant disease. In this issue of the JCI, a study from Yoshioka et al. demonstrates that PCSCs are regulated by a pathway in which α6β4 integrin amplifies signaling through ErbB2 and c-Met receptors. Targeting this pathway provides a novel therapeutic strategy for hormone refractory prostate cancer.