Androgens and esophageal cancer: What do we know?

Figure 1 Biological actions of androgens via androgen receptors. Testosterone molecules translocate via the plasma membrane and are transformed into dihydrotestosterone (DHT) by 5α-reductase. The androgen receptor (AR) is located in cytoplasm and bound to heat shock protein (HSP). DHT binds to the AR and HSP is then released. Ligand-AR complexes can be phosphorylated (and/or are modified by other post-translational mechanisms). Two ligand-AR complexes form homodimers and move into the nucleus. AR nuclear translocation is facilitated by filamin A (FlnA). In the cell nucleus ligand-AR complexes bind to specific DNA elements - androgen-responsive elements (ARE), which are in target gene promoters. These regulate target gene expression at the transcriptional level. A large variety of co-factors and regulators can orchestrate AR-induced gene transcription.