COMPARATIVE-STUDIES ON THE ANTI-INVASIVE EFFECTS OF RETINOIC ACID ANDSTAUROSPORINE

Retinoic acid and the protein kinase C inhibitor staurosporine have be en reported to inhibit the invasiveness of tumor cells and may potenti ally be used to prevent metastatic disease. We report that retinoic ac id reduced the invasiveness of 6 of 6 ras-transformed rat fibroblast c ell lines and that inhibition did not require expression of the c-Jun component of AP-1. In contrast, staurosporine reduced the invasiveness of only 1 of 4 ras-transformed cell lines. The effect of staurosporin e on the invasiveness of human tumor cell lines varied with cell type and length of treatment. We conclude that retinoic acid, but not neces sarily staurosporine, decreases the invasiveness of ras-transformed fi broblasts.