维生素E对胃癌细胞系AGS环氧合酶-2转录和活性的影响  

Effect of Vitamin E on Transcription and Activity or Cyclooxygenase-2 in Gastric Cancer Cell Line AGS

作　　者：刘华[1,2] 李青芳[1,2] 刘文忠[1,2] 李恩灵[1,2] 

机构地区：[1]上海交通大学医学院附属仁济医院 [2]上海市消化疾病研究所,200001

出　　处：《胃肠病学》2005年第6期343-347,共5页Chinese Journal of Gastroenterology

摘　　要：背景:胃癌是人类的主要肿瘤死因之一。环氧合酶(COX)-2是催化前列腺素合成的关键酶,与胃癌的发生、发展密切相关、目的:探讨维生素E对胃癌细胞系AGS COX-2转录和活性的影响。方法:以选择性COX-2抑制剂尼美舒利作为阳性对照,应用不同浓度的3种维生素E(α-生育酚、α-生育酚醋酸盐和γ-生育酚)分别对AGS细胞进行干预,作用16h和24h后,以逆转录聚合酶链反应(RT-PCR)检测COX-2 mRNA和COX-1 mRNA的表达,以COX活性检测试剂盒检测COX-2和COX-1活性。结果:与空白对照组相比,3种维生素E对AGS细胞COX-2 mRNA、COX-1 mRNA的表达和COX-1活性均无显著影响。α-生育酚和γ-生育酚对AGS细胞的COX-2活性具有抑制作用,且这种抑制作用呈剂量和时间依赖性,其中γ-生育酚的抑制作用更为明显;α-生育酚醋酸盐对COX-2活性无明显抑制作用。α-生育酚或γ-生育酚与尼美舒利联用对COX-2活性的抑制作用具有协同性。结论:维生素E对胃癌细胞的COX-2活性具有抑制作用,与选择性COX-2抑制剂尼美舒利联用时两者的抑制作用具有协同性,这为维生素E或维生素E联合选择性COX-2抑制剂在胃癌化学预防中的应用提供了新的理论依据。Background： Gastric carcinoma is one of the most common causes of cancer death in human being. Cyclooxygenase （COX）-2 is the key enzyme which catalyses the synthesis of prostaglandins, and is considered to be involved in the tumorigenesis of gastric cancer. Aims： To investigate the effect of vitamin E on transcription and activity of COX-2 in gastric cancer cell line AGS. Methods： The AGS cells were treated with three types of vitamin E （α-tocopherol, α-tocopherol acetate, γ-tocopherol） at various concentrations respectively, and nimesulide, a selective COX-2 inhibitor, served as positive control. The expression of COX-2 mRNA and COX-1 mRNA was detected by reverse transcriptase polymerase chain reaction （RT-PCR）, and the activity of COX-2 and COX-1 by COX activity kit after 16 and 24 hours treatment. Results： As compared with blank control, all three types of vitamin E had no effect on COX-2 mRNA, COX-1 mRNA expression and COX-1 activity in AGS cells, α-tocopherol and γ-tocopherol showed a dose- and time-dependent inhibitory effect on COX- 2 activity in AGS cells, the effect of γ--tocopherol was stronger, while α-tocopherol acetate had no such effect. Combined treatment of α-tocopherol or γ--tocopherol with nimesulide had a synergistic role in inhibiting COX-2 activity. Conclusions： Vitamin E has inhibitory effect on COX-2 activity in gastric cancer cells, and this effect can be strengthened when combined with a selective COX-2 inhibitor nimesulide, which may provide a new theoretical basis for their use in chemoprevention of gastric cancer.

关 键 词：胃肿瘤 维生素E 环氧合酶 

分 类 号：R735.2[医药卫生—肿瘤]