B-DIM Inhibits Androgen Receptor Activation and Potentiates Radiation Effect in Hormone Refractory Prostate Cancer

Abstract

Increased consumption of cruciferous vegetables is associated with decreased risk in prostate cancer (PCa). Two active compounds in cruciferous vegetables are indole-3-carbinol (I3C) and its dimeric derivative, 3,3'-diindolylmethane (DIM). Nutritional grade B-DIM (absorption-enhanced) has proven safe in a Phase I trial for PCa. We have investigated the anti-cancer activity of B-DIM as a new biological approach to improve the clinical outcome of radiotherapy (RT) for hormone refractory PCa. This approach was tested in vitro using human PCa cell lines positive or negative for androgen receptor (AR) expression and in vivo in an orthotopic model of PCa.