Characterisation of Androgen Receptor Signalling and Metabolism in Prostate Cancer

Prostate cancer (PCa) is a prevalent disease which affects men worldwide. The Androgen Receptor (AR) is responsible for driving disease progression, therefore therapies often target this signalling axis. Eventually, these treatments fail and the cancer progresses to an aggressive, incurable stage known as castrate-resistant prostate cancer (CRPC), for which very few therapies exist. Therefore, understanding and characterising AR signalling may aid in the development of novel therapeutics. Fused in Sarcoma (FUS) (a co-regulator protein of the AR) and Hox Transcript Antisense Intergenic RNA (HOTAIR) (a long noncoding RNA) can interact with the AR and are found to be elevated in CRPC. To investigate their effect on AR activity, luciferase reporter assays were performed. Results demonstrated that both factors can repress AR activity. The AR drives PCa growth through the regulation of genes and protein involved in, for example, the cell cycle and metabolism. Metabolism increases in cancer cells to support their elevated growth and division. One pathway includes haem synthesis, which supplies haem for several proteins that assist in maintaining cellular homeostasis and protecting against cellular stresses. Previously, using a small interfering RNA (siRNA) screen, haem synthesis was identified as a potential therapeutic target for prostate cancer and the pathway was therefore further investigated. The results demonstrated that inhibiting haem synthesis, using succinylacetone, significantly reduced PC3 cell proliferation in crystal violet growth assays. Furthermore, knockdown of aminolevulinate synthase-1, involved in the first step of the haem synthesis pathway, significantly reduced cell proliferation by approximately 60 %. Interestingly, inhibition of haem synthesis sensitised PC3 cells to ROS. In preparation for crystallography assays, ALAS1 and ALAS2 were cloned and expressed in Escherichia coli BL21(DE3). Further investigation of co-factors which interact with the AR and downstream metabolic pathways will aid in the development of novel therapeutic strategies for PCa patients in the future.