Plasminogen activator synthesis by cultured human embryonic lung cells: characterization of the suppressive effect of corticosteroids.

The synthesis of plasminogen activator (PA) by cultured human embryonic lung (HuEL) cells has been examined. The production of PA by these cells was found to be reversibly inhibited by physiological levels of glucocorticoids. The suppression of PA synthesis in HuEL cells was not accompanied by an inhibition of cell growth. Moreover, the glucocorticoid induced deinduction of plasminogen activator synthesis occurred in both growing and non-growing cells. The inhibition of PA production by corticosteroids appeared to have a requirement for DNA-dependent RNA synthesis since the inhibition of DNA-dependent RNA synthesis at the time of exposure of cells to corticosteroids prevented the deinduction of PA.