Effect of dietary linoleic acid level on lodgement, proliferation and survival of mammary tumor metastases.
High levels of dietary linoleic acid (18:2) have been shown to increase the spontaneous metastasis of line 4526 mouse mammary tumors. In this report, the influence of 18:2 on specific events of tumor metastasis, namely, lodgement, proliferation and survival, were studied using spontaneous and experimental metastasis assays with line 4526 cells. A significantly greater number of radiolabeled tumor cells lodged in the lungs of mice fed 4, 8 and 12% 18:2 when compared with mice fed lower levels of 18:2. The effect of dietary 18:2 appeared to be on the host tissue (lungs) and not the tumor cells. Lodgement of tumor cells first cultured in serum of mice fed 18:2 then injected into mice fed 1% 18:2 was not affected. There were no significant differences in the percentage of [3H]thymidine labeled metastatic cells from lungs of mice fed different levels of 18:2. However, the number of surface lung nodules that appeared in mice 21 days after injection of unlabeled line 4526 cells increased in mice fed 8 and 12% 18:2 compared with those fed lower levels of 18:2. Thus, dietary 18:2 may increase metastasis by influencing the lodgement, implantation and survival but not proliferation of line 4526 mouse mammary tumor cells.
Hubbard
N E
NE
Department of Human Anatomy, University of California, School of Medicine, Davis 95616.
Erickson
K L
KL
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000556:secondary; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation
D004041:Dietary Fats; D008041:Linoleic Acids; D019787:Linoleic Acid