title: Systemic treatment with n-6 polyunsaturated fatty acids attenuates EL4 thymoma growth and metastasis through enhancing specific and non-specific anti-tumor cytolytic activities and production of TH1 cytokines.
abstract: Recently, there has been a great interest in the effects of different types of n-6 polyunsaturated acids (n-6 PUFAs) upon the immune system and cancer development. However, the effects of n-6 PUFAs are still controversial and as yet undefined. The present study aimed to investigate the anti-tumor effects of n-6 PUFAs against EL4 thymoma and the associated immune mechanisms. To this, sesame oil, a vegetable oil enriched with n-6 PUFAs, or free linoleic acid (LA) were administered intraperitoneally into C57BL/6 mice before and after challenge with EL4 lymphoma cells. Treatment with either sesame oil or LA attenuated the growth and metastasis of EL4 lymphoma. The anti-tumor effect of LA was superior to that of sesame oil, and associated with an increase in the survival rate of the tumor-bearing mice. In addition, both sesame oil and LA showed dose-dependent anti-lymphoma growth in vitro. Treatment with LA generated significant increases in the anti-lymphoma cytolytic and cytostatic activities of T cells and macrophages, respectively, and enhanced production of IL-2 and IFN-gamma while decreased production of IL-4, IL-6 and IL-10. In summation, the results suggest that n-6 PUFAs, represented by LA, can attenuate EL4 lymphoma growth and metastasis through enhancing the specific and non-specific anti-tumor cytolytic activities and production of TH1 cytokines. These findings might be of great importance for a proper design of systemic nourishment with PUFAs emulsions for cancer patients.
authors.affiliation: Department of Surgery, Section of Surgical Oncology, Holling Cancer Center R313, Medical University of South Carolina, Charleston, SC 29425, USA. salemm@musc.edu
authors.forename: Mohamed Labib
authors.initials: ML
authors.lastname: Salem
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D019787:Linoleic Acid / Q000494:pharmacology; D008113:Liver Neoplasms / Q000517:prevention & control / Q000556:secondary; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000517:prevention & control; D012715:Sesame Oil / Q000494:pharmacology; D013154:Spleen / Q000166:cytology; D013268:Stimulation, Chemical; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology; D018417:Th1 Cells / Q000187:drug effects / Q000378:metabolism*; D013945:Thymoma / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D013953:Thymus Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D016207:Cytokines; D005231:Fatty Acids, Unsaturated; D012715:Sesame Oil; D019787:Linoleic Acid