5a-Pregnane-3,20-dione is a biologically active 5-alpha-reduced metabolite of plasma progesterone

内源性孕酮代谢产物5α-Pregnane-3,20-dione可能通过影响粘附分子和细胞骨架分子，促进乳腺肿瘤和转移的发生。

MCF-7 cells were grown without or with 5a-Pregnane-3,20-dione (10(-9)-10(-5) M), and the effects on cell and nuclear morphology, adhesion plaques, vinculin and actin expression, actin polymerization, and microfilament distribution were examined by immunohistochemistry, morphometry (using confocal microscopy and digital computer imaging analysis), and Western blotting.?Treatment of cells with 10(-9)-10(-6) M 5a-Pregnane-3,20-dione resulted in dose-dependent decreases in cell area, cell-to-cell contacts, and attachment to the substratum, and increases in variation in nuclear area.?These changes in the 5alphaP-treated cells were accompanied by decreases in vinculin-containing adhesion plaques, vinculin expression, polymerized actin stress fibers, and decreases in insoluble and increases in soluble actin fractions.