Effects of eicosanoid synthesis inhibitors on the in vitro growth and prostaglandin E and leukotriene B secretion of a human breast cancer cell line.

We investigated the effects of cyclooxygenase and lipoxygenase inhibitors on a human breast cancer cell line (MDA-MB-231) in culture. Indomethacin (INDO), piroxicam, esculetin, and nordihydroguaiaretic acid (NDGA) significantly suppressed cell growth, although piroxicam caused significant suppression only at high concentrations. Esculetin and NDGA caused significantly reduced secretion of leukotriene B (LTB), while INDO and piroxicam caused significantly reduced secretion of prostaglandin E (PGE). Consequently, cell growth was significantly correlated with the LTB concentration when the cells were treated with esculetin or NDGA, whereas it was significantly correlated with the PGE concentration when they were treated with INDO or piroxicam. Therefore, MDA-MB-231 cell growth in vitro was independently associated with both the PG and LTB concentrations.