Effect of Postoperativeω-3 Fatty Acid Immunonutritional Therapy on NK Cell Gene Methylation in Elderly Patients with Gastric Cancer

Objective This study aims to investigate the effect ofω-3 fatty acid immunonutritional therapy on natural killer(NK)cell gene methylation and function in elderly patients with gastric cancer.Methods A total of 70 cases of elderly patients with gastric cancer were randomized into theω-3 fatty acid group and placebo group,according to the type of nutritional support administered.The methylation status of the tumor necrosis factor(TNF)-αgene promoter in peripheral NK cells was detected by methylation specific polymerase chain reaction,and the TNF-αlevel in peripheral NK cells was detected by enzyme-linked immunosorbent assay.Results After 14 days of immunonutritional therapy withω-3 fatty acid or placebo,patients in theω-3 group had significantly higher average NK cell activity(0.27 vs.0.24,P=0.013)and lower percentages of TNF-αgene promoter methylation(25.7%vs.60%,P<0.05)than the placebo group.However,there were no significant differences in the concentration of albumin,prealbumin and TNF-αin serum,and the NK cell count between theω-3 group and placebo group.Conclusion The postoperative application ofω-3 fatty acid may improve the activity of NK cells,which is correlated to the methylation status of the TNF-αgene promoter.