Fig. 4.

Pathways of androgen synthesis in CRPC. Shown in this figure are the pathways contributing to androgen synthesis that occur in the testes, adrenals, and prostate tumor itself in men with CRPC. Expression of CYP17A1 in all three tissues produces androgens, and further metabolism of these androgenic substrates results in the synthesis of the potent androgen receptor agonists, testosterone and DHT. Highlighted in purple is the backdoor pathway to DHT synthesis that bypasses testosterone as an intermediate. Independent studies have shown evidence to support this particular pathway being intact in CRPC