Steroid receptors and cell cycle in normal mammary epithelium.

摘要: The ovarian steroids estrogen and progesterone (E(2) P) are essential for normal mammary gland growth development; however, the mechanisms by which they influence proliferative activity of epithelium remain unclear. Mammary epithelial cells expressing receptors E(2) P (ER PR respectively) separate from, although often adjacent to, those capable proliferating, implying that act indirectly via paracrine or juxtacrine factors to stimulate entry into cell cycle. A large number candidate have been identified in a variety different experimental systems, it appears transforming factor beta may play role preventing proliferation steroid receptor-containing cells. Dysregulation strict inverse relationship between ERalpha expression is detectable premalignant human breast lesions, indicating might be tumorigenic process. Challenges future include determining candidates as being mediators effects physiologically clinically relevant well finding out how ERalpha-containing become during tumorigenesis. Answering these questions could greatly increase our understanding controlling development processes leading cancer formation.