Prostate cancer is a leading cause of death in men. Treatment involves reducing production of di-hydro-testosterone (DHT) or blocking the interaction of this hormone with the androgen receptor (AR), a transcription factor responsible to drive expression of genes responsible for tumour growth. This treatment is unfortunately temporary and tumours eventually undergo genetic changes to become castration-resistant and able to grow in the absence of DHT.
This research project aims to use drugs to block AR activity in castration-resistant prostate cancer. Within the nucleus, two androgen receptor molecules must self-associate (“dimerize”) before binding DNA and initiating transcription. Dr. Dalal hypothesizes that slowing tumour growth can be achieved by preventing the AR-DNA interaction directly or by interfering with AR dimerization.
Cell biology and biochemistry approaches will allow Dr. Dalal to study the molecular mechanism of DNA-blocking or dimer-interfering compounds. Several compounds targeting both processes have been optimized to show potent and specific inhibition of the androgen receptor in cultured prostate cancer cells. Gel shift assays, calorimetry methods and confocal microscopy are now being used to gauge the effects of drugs on both DNA binding and AR dimerization. Site-directed mutagenesis of amino acids on the AR protein surface will validate the binding location of inhibitors. Promising compounds will be tested in mice to show effects on the size of prostate tumours.
Targeting transcription factor dimerization and DNA binding is a novel strategy that holds great promise to treat advanced forms of prostate and other cancers.