Role of dietary oleic acid in linoleic acid-enhanced metastasis of a mouse mammary tumor.
We have previously shown that a high fat diet (20% w/w) containing 12% linoleic acid (18:2) can significantly increase the metastasis of mammary tumor cells when compared with high fat diets that contain 8% or less 18:2 with a constant level of oleic acid (18:1). This effect may have been due to an alteration of eicosanoid metabolism because the cyclooxygenase inhibitor, indomethacin, abolished the increase. Because 18:1 may interfere with the metabolism of 18:2 to 20:4, we have now tested whether the 18:1 that supplements the 18:2 diet can have an effect on spontaneous or experimental metastasis of the line 4526 murine mammary tumor. For this, six 20% fat diets were formulated with 1%, 6%, and 12% 18:2 and either high or low levels of 18:1. Our results indicate that the amount of select fatty acids other than 18:2 at 12% has no significant effect on mouse growth, tumor growth, or tumor latency. When spontaneous metastatic burden was calculated, no significant differences between mice fed diets containing 1% and 6% 18:2 were observed. However, 4 to 5 times more of a metastatic burden was observed in mice fed diets containing 12% 18:2. No significant differences were observed between high and low 18:1 diets when the 18:2 content was 1 or 12%. However, at 6% 18:2, 18:1 significantly decreased metastatic burden. When experimental metastasis was assessed, relatively low levels of surface lung nodules were observed at 1% and 6% 18:2, but significantly higher levels were observed at 12% 18:2.(ABSTRACT TRUNCATED AT 250 WORDS)
Hubbard
N E
NE
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis 95616.
Erickson
K L
KL
D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis / Q000473:pathology*; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology*
D004041:Dietary Fats; D005227:Fatty Acids; D008041:Linoleic Acids; D009829:Oleic Acids; D019301:Oleic Acid; D019787:Linoleic Acid