Mesenchymal mechanisms in prostate organogenesis.

The development of the prostate is dependent upon androgens and stromal-epithelial interactions. Understanding the molecules and mechanisms by which androgens control prostate organogenesis has been a considerable challenge over the past few decades. Similarly, identifying the molecular signals passing between stromal and epithelial cells has been difficult, and consequently understanding how androgens and stromal-epithelial signalling interact is poorly understood. There remains significant uncertainty regarding how androgens control the growth of the prostate, although several pathways have been identified that are required for prostate development or which alter prostate growth. This review will summarize past findings relating to the pathways that might mediate the effects of androgens as well as molecules that act as stromal to epithelial signals in the prostate. It will also examine the approaches used to identify pathways of importance and the historical concepts that have informed these studies. In particular, the question of which mechanisms might be involved in early prostate organogenesis as well as anatomic aspects of organ induction will be described. Finally, models of prostatic development will be proposed and discussed.