The Role of Dietary Long-Chain N-3 Fatty Acids in Anti-Cancer Immune Defense and R3230AC Mammary Tumor Growth in Rats: Influence of Diet Fat Composition
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- 作者：Lindsay E. Robinson ; M. Thomas Clandinin and Catherine J. Field
- 关键词：diet ; immune ; interleukin ; 2 ; long ; chain n ; 3 fatty acids ; natural killer cell ; phospholipids ; polyunsaturated/saturated fat ratio ; R3230AC mammary tumor ; rats
- 刊名：Breast Cancer Research and Treatment
- 出版年：2002
- 出版时间：2002
- 年：2002
- 卷：73
- 期：2
- 页码：145-160
- 全文大小：197 KB
文摘
We determined if long-chain n-3 fatty acids fed as part of a: (1) high polyunsaturated fat diet (currently recommended by several health agencies) or (2) low polyunsaturated fat diet (representative of that consumed by a large segment of the North American population) improved antitumor immune defense and inhibited tumor growth. Rats were fed one of four semi-purified diets (20 % w/w fat) for 21days pre- and 17days post- R3230AC mammary tumor implantation. The polyunsaturated to saturated fatty acid (P/S) ratio was either 1 (high P/S diet) or 0.35 (low P/S diet). At each P/S ratio, diets provided long-chain n-3 fatty acids at 0 or 5 % w/w of total fat. Long-chain n-3 fatty acids fed in a high P/S diet did not affect tumor growth or host immune responses. In contrast, feeding long-chain n-3 fatty acids in a low P/S diet increased natural killer cell cytotoxicity, splenocyte nitric oxide and interleukin-2 production, and the proportion of activated (CD25+) CD8+ and CD28+ cells, but did not significantly inhibit tumor growth. For both P/S diets, tumor cells from rats fed long-chain n-3 fatty acids had a higher n-3 content and n-3/n-6 ratio in phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Furthermore, the magnitude of increase in n-3 fatty acid incorporation into tumor phospholipids was greater when fed in a low P/S diet. We demonstrated that the dietary P/S ratio significantly influences the effect of long-chain n-3 fatty acids on host immune responses and n-3 fatty acid incorporation into tumor cells. These findings warrant further consideration when designing dietary recommendations.