Expression and Function of Stromal Androgen Receptor in Prostate Cancer

Prostate cancer has the highest incidence in the United States and the second highest in the world among cancers in the male population. It is also one of the leading causes of cancer deaths in males in the United States. Like other glandular organs, benign prostate has an epithelial compartment containing mainly secretory luminal cells outlined with basal cells and a stromal compartment including fibroblasts and smooth muscle cells. The development and function of the prostate is mediated by circulating androgens which act via androgen receptor (AR). Amongst the epithelial cells, AR is expressed only in secretory luminal cells, while in the stroma, AR is expressed primarily by fibroblasts and smooth muscle cells in adulthood. In the past, investigators mainly focused on studying epithelial AR function in prostate cancer, defined the involved mechanisms and developed numerous hypotheses which have been published and are widely accepted. However, limited data is available which can be used to describe the function of stromal AR in prostate cancer. This review of the literature examines the current knowledge and understanding of stromal AR function in prostate cancer and endeavors to illustrate its translational significance.