Figure 1.

Schematic representation of the steroid activity on prostate (PCa) or breast (BCa) cancer. Three various levels of control could be pointed out: i) steroid synthesis by inhibiting the enzymatic pathways leading to testosterone or 17β-estradiol production; ii) modulation of the androgen or estrogen receptor activity using specific antagonists; iii) modulation of the steroid receptor activity together with the induction of its degradation/down-regulation. Δ4, Δ4-androstenedion; 5⍺R, 5⍺-reductase; 17βE2, estradiol; 17βHSD, 17β-hydroxy-steroid dehydrogenase; AR, androgen receptor; BCa, breast cancer; E1, estrone; ER⍺, estrogen receptor ⍺; PCa, prostate cancer; T, testosterone.