Effects of different dietary fatty acids on the fatty acid compositions and the expression of lipid metabolic-related genes in mammary tumor tissues of rats

Nutr Cancer. 2008;60(6):810-25. doi: 10.1080/01635580802192858.


In this study, the effects of dietary fatty acids on the fatty acid compositions and lipid metabolic-related genes expression in N-methyl-N-nitrosourea (MNU)-induced rat mammary carcinogenesis were evaluated. The 50-day-old female Sprague-Dawley rats were intervened by different dietary fats (15% wt/wt), including saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), n-6 polyunsaturated fatty acid (PUFA), n-3 PUFA, 1:1 n-6/n-3, 5:1 n-6/n-3, 10:1 n-6/n-3, and 1:2:1 S/M/P (1:1 n-6/n-3), alone or in combination with MNU. There was no mammary tumor occurrence in the control and MNU-treated n-3 PUFA groups after 18 wk. n-3 PUFA diet retarded the weight growth of rats. 1:1 n-6/n-3 diet significantly reduced the MNU-induced tumor incidence and tumor multiplicity compared with SFA, MUFA, n-6 PUFA, 5:1 n-6/n-3, 10:1 n-6/n-3 and 1:2:1 S/M/P diets (42.86% vs. 83.33%-92.31%, 0.79 vs. 2.62-2.85, P < 0.01). Additionally, 1:1 n-6/n-3 diet substantially increased cis-5,8,11,14,17-eicosapentaenoic acid and cis-4,7,10,13,16,19-docosahexaenoic acid levels, whereas it decreased C20:4 level and the mRNA expressions of fatty acid synthase, Cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) in mammary tissues (P < 0.05). These results suggest that 1:1 n-6/n-3 in the diet is effective in the prevention of mammary tumor development by increasing the n-3 PUFA content and reducing the expression of lipid metabolic-related genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonate 5-Lipoxygenase / genetics
  • Arachidonic Acid / metabolism
  • Cyclooxygenase 2 / genetics
  • Dietary Fats / administration & dosage*
  • Fatty Acid Synthases / genetics
  • Fatty Acids / analysis*
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-6 / administration & dosage
  • Female
  • Mammary Glands, Animal / chemistry
  • Mammary Neoplasms, Experimental / chemistry
  • Mammary Neoplasms, Experimental / metabolism
  • Mammary Neoplasms, Experimental / prevention & control*
  • Rats
  • Rats, Sprague-Dawley
  • Weight Gain


  • Dietary Fats
  • Fatty Acids
  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Arachidonic Acid
  • Arachidonate 5-Lipoxygenase
  • Cyclooxygenase 2
  • Fatty Acid Synthases