earticle

영어

This study was designed to investigate the differential effects of tumor promotors on prostaglandinproduction and COX-2 expressionin raw264.7 macrophage cells. Tumor promotors such as thapsigargine, okadaic acidand PMA stimulated TXB2 synthesis at the doses of 1 ng/ml to 1 µg/ml. But staurosporine showed differential effectsat the same range of doses. At higher dose (>100 ng/ml) staurosporine significantly reduced TXB2 synthesis, but atlower doses, it stimulated TXB2 synthesis. When cotreated, thapsigargine and PMA reduced LPS-induced TXB2production. However okadaic acid and staurosporine showed dual effects depending on the concentration. The effectsof tumor promotors on COX-2 expression paralleled their effects on TXB2 synthesis. These results shows tumorpromotors affects COX-2 expression in a different way and thereby suggest differential contribution of COX-2 duringthe process of tumor promotion stimulated by particular agents.