Effects of psoralens as anti-tumoral agents in breast cancer cells

Figure 2 Estrogens and growth factor signaling in breast cancer. Mitogenic signals from estrogens and growth factors activate PI3K/AKT-Ras-Erk pathway to target estrogen receptor (ER). The phosphorylation cascade promotes ER activation. The receptor is recruited to a transcription factor (TF) that binds to responsive elements on DNA for the corresponding transcriptional responses. Antagonistic actions of tamoxifen on ER are shown. Psoralens may act by inhibiting aromatase enzyme, metalloproteinases (MMPs) and CYP enzymes. They address antagonistic effects on PI3K/AKT survival signals and apoptotic response with the involvement of p53 and p21 waf. Estrogens also bind the GPER, a member of the seven-transmembrane G protein-coupled receptor family, to trigger proliferative responses.