Effects of protease inhibitors on nuclear binding of glucocorticoid hormones in C3H10T1/2 cells.

We have measured incorporation of the glucocorticoid hormone cortisone into nuclear hormone-receptor complexes in the C3H10T1/2 cell line. As we had found cortisone to be capable of malignantly transforming these cells in vitro, and certain protease inhibitors have been shown to suppress transformation in this cell line, we investigated the effects of these protease inhibitors (antipain, chymostatin and the Bowman-Birk inhibitor) on the formation of nuclear cortisone-receptor complexes. All 3 inhibitors were found to suppress wholly or partially formation of nuclear cortisone-receptor complexes, suggesting that such complexes may be involved in the process of glucocorticoid-enhanced transformation.