摘要：目的探讨二十二碳六烯酸（DHA）对食管腺癌（EAC）和食管鳞癌（ESCC）细胞增殖调节过程中脂质过氧化反应（LPO）的影响。方法 DHA分别以100，50，1μmol/L干预Eca-109细胞（ESCC）及OE-19细胞（EAC）24h，设溶质对照组（0.1%乙醇）和空白对照组。四唑单钠盐（CCK-8）法检测各组细胞增殖情况；WST-1法检测细胞内总超氧化物歧化酶（SOD）活性、TBA法检测总丙二醛（MDA）含量及硝酸还原酶法检测一氧化氮（NO）水平。结果 DHA引起OE-19浓度依赖性细胞增殖抑制（P<0.05），仅高浓度（100μmol/L）时抑制Eca-109增殖（P<0.05）；干预24h后，MDA含量和NO水平在Eca-109及OE-19各组细胞均出现DHA浓度依赖性上升（P<0.05）；SOD活性在中低浓度DHA干预的Eca-109细胞无明显变化，但在高浓度组显著下降（P<0.05）；OE-19细胞的SOD活性在中低浓度DHA干预后明显下调，而在高浓度组显著上升（P<0.05）。结论 DHA可稳定抑制EAC细胞而非ESCC细胞增殖。DHA干预后，无论是EAC还是ESCC均发生显著的LPO，其与抗氧化物质SOD表达之间的相对平衡可能是影响肿瘤细胞增殖的重要因素。

Abstract：Objective To investigate the effects of docosahexaenoic acid (DHA) on proliferation and lipid peroxidation (LPO) of esophageal adenocarcinoma cells (EAC) and esophageal squamous carcinoma cells (ESCC) . Methods The Eca-109 (ESCC) and OE-19 (EAC) cells were treated with DHA in three different concentrations (100, 50, 1μmol/L) for 24 h. Cell proliferation was assessed by Cell Counting Kit-8 assay. The concentrations of superoxide dismutase (SOD), malonaldehyde (MDA) and nitric oxide (NO) were determined by WST-1, TBA and nitrate reductase method, respectively. Results Cell growth of OE-19 was inhibited by DHA in a concentration-dependent manner (P<0.05), while suppression of Eca-109 was only found in high concentration (100μmol/L) (P<0.05). In both groups, the levels of MDA and NO were increased in a concentration-dependent manner after DHA treatment (P<0.05). For Eca-109 cells, the inhibition of SOD activities were merely found in 100 μmol/L group (P<0.05), while the SOD levels in OE-19 cells showed a down-regulation after treatment of DHA in 1 and 50 μmol/L, but were sharply increased in 100 μmol/L treated group(P<0.05). Conclusions DHA treatment results in a steady growth inhibition in EAC cells, but not in ESCC cells. Activation of LPO is found in both Eca-109 cells and OE-19 cells after DHA treatment. Balance between LPO and SOD in EAC and ESCC may play a key role in the DHA induced cell growth inhibition.