EFFECTS OF PIROXICAM AND ESCULETIN ON THE MDA-MB-231 HUMAN BREAST-CANCER CELL-LINE

We investigated the effects of piroxicam, esculetin, prostaglandin E(2 ) (PGE(2)) and leukotriene B-4 (LTB(4)) on a human breast cancer cell line (MDA-MB-231). Both piroxicam and esculetin suppressed cell growth and thymidine incorporation, though esculetin was more active in inhi biting cell growth in the presence of linoleic acid (LA), Esculetin re duced the secretion of LTB independent of LA, Piroxicam reduced the se cretion of PGE in the absence of LA but only at higher concentrations in the presence of LA, When the relationship between cell growth and P GE and LTB concentration was evaluated by multivariate regression anal ysis, cell growth was associated with the PGE and LTB concentrations w hen the cells were treated with esculetin alone or with esculetin and LA, Cell growth was associated only with the PGE concentration when th ey were treated with piroxicam alone or with piroxicam and LA, Therefo re, it appears that the growth of MDA-MB-231 cells in vitro is affecte d by both lipoxygenase and cyclooxygenase products, though lipoxygenas e inhibition is more active than cyclooxygenase inhibition on suppress ion of cell growth in the presence of LA.