Dietary linoleic acid-stimulated human breast cancer cell growth and metastasis in nude mice and their suppression by indomethacin, a cyclooxygenase inhibitor.
Growth and metastasis to the lung of the human breast cancer cell line MDA-MB-435 in nude mice fed a high-fat (20% wt/wt) high-linoleic acid (LA; 12% wt/wt) diet were significantly reduced by the addition of the cyclooxygenase inhibitor indomethacin to the drinking water at a dose of 10 micrograms/ml (approximately 1 mg/kg body wt). No toxicity was observed in these mice; at 20 micrograms/ml indomethacin, gastric ulcerations occurred. After necropsy, tumor eicosanoids were measured by radioimmunoassay in the control and 10 micrograms/ml indomethacin treatment groups. Levels of the cyclooxygenase products prostaglandin (PG) E (PGE), 6-keto-PGF1 alpha, and thromboxane B2 (TxB2) were significantly reduced in indomethacin-treated mice compared with controls; however, the 6-keto-PGF1 alpha-to-TxB2 ratio was significantly increased. Two lipoxygenase products, 5-hydroxyeicosatetraenoic acid (5-HETE) and 15-HETE, were unaffected, but the 12-HETE levels were increased compared with the untreated high-LA-fed group. Metastases to the lungs in mice fed a high-fat low-LA (2% wt/wt) diet were also reduced compared with those in the high-LA-fed control mice, but whereas tumor cyclooxygenase and lipoxygenase product levels were reduced, no change in the 6-keto-PGF1 alpha-to-TxB2 ratio was observed. The use of selective cyclooxygenase inhibitors may prevent LA-mediated progression of breast cancer at several levels of the metastatic cascade, among which may be interference with tumor cell-vascular endothelial cell interaction and with angiogenesis.
Connolly
J M
JM
Division of Nutrition and Endocrinology, American Health Foundation, Valhalla, NY 10595, USA.
Liu
X H
XH
Rose
D P
DP
D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology*; D015777:Eicosanoids / Q000378:metabolism; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000556:secondary; D051379:Mice; D008819:Mice, Nude; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured
D016861:Cyclooxygenase Inhibitors; D004041:Dietary Fats; D015777:Eicosanoids; D008041:Linoleic Acids; D019787:Linoleic Acid; D007213:Indomethacin