【作者】 范立侨； 李勇； 巩涛； 王力利； 张志栋； 王冬； 焦志凯； 刘羽； 赵雪峰；

【Author】 Fan Li-Qiao Li Yong Gong tao et al. The Third Department of Surgery, The Forth Hospital of Hebei Medical University, Shijiazhuang 050011, China

【机构】 河北医科大学第四医院暨河北省肿瘤医院外科；

【摘要】 目的: 目前普遍认为,外界信号可通过G蛋白介导的信号传导途径将细胞膜外信息传递至细胞膜内效应器。近年来研究表明ω-3多不饱和脂肪酸可抑制肿瘤细胞的生长, 但其作用机制不甚明确。本研究通过观察二十碳五烯酸(cis- 5,8,11,14,17-eicosapentaenoic acid,EPA)和二十二碳六烯酸(cis-4,7,10,13,16,19-docosahexaenoic acid,DHA) 对人胃癌细胞BGC-823细胞bcl-2和G α q蛋白表达的影响,探讨ω-3脂肪酸的抗癌机制。方法:将人胃癌BGC-823 细胞分对照组、EPA药物组和DHA药物组,EPA组和DHA 组按15 μg／ml、30 μg／ml、45 μg／ml加药,肿瘤细胞处理48小时后,用流式细胞仪测定胃癌细胞bcl-2(鼠抗人bcl- 2,1:50)和G α q(兔抗人G α q抗体,1:50)蛋白含量, 以荧光指数(Flurorescene Index,FI)表示蛋白相对含量: FI={样品蛋白表达的平均荧光强度／正常对照样品平均荧光强度}×100％。SP-9000免疫细胞化学检测胃癌细胞G α q 蛋白分布,一抗鼠抗人PKC βⅡ单克隆抗体1:100,DAB显色。用SPSS13统计软件的单因素方差分析。结果:45μg／ml 的EPA处理人胃癌BGC-823细胞后肿瘤细胞bcl-2基因蛋白荧光指数(1．53±0．08)与对照组人胃癌BGC-823细胞 bcl-2基因蛋白荧光指数(2．18±0．20)比较明显下降(p< 0．001),30 μg／ml和45 μg／ml的DHA处理人胃癌BGC- 823细胞后bcl-2基因蛋白荧光指数(分别为1．62±0．16和 1．47±0．13)与对照组人胃癌BGC-823细胞bcl-2基因蛋白荧光指数比较明显下降(p<0．001)。30 μg／ml和45 μg／ ml的EPA处理人胃癌BGC-823细胞后G α q基因蛋白荧光指数(分别为2．39±0．27、1．97±0．22),30 μg／ml和45 μg／ml的DHA处理人胃癌BGC-823细胞后G α q基因蛋白荧光指数(分别为2．35±0．25和1．85±0．19),它们与对照组人胃癌BGC-823细胞G α q基因蛋白荧光指数(2．95± 0．35)比较均明显下降(p<0．05),且45 μg／ml的EPA或 DHA组比30μg／ml组下降更明显(p<0．05),G αq在对照组人胃癌BGC-823细胞膜、浆中强染色,用药后G α q在细胞膜、浆中染色减弱。结论:本实验提示EPA或DHA可降低人胃癌BGC-823细胞G α q蛋白的表达,从而使G α q蛋白的下游信号PLC β、DAG、PKC等也进一步下调,进而导致bcl-2的下降,抑制人胃癌BGC-823细胞的生长。更多还原

【Abstract】 Objective: To discuss the effect and mechanism of EPA and DHA on expression of bcl-2 protein and G α q protein of gastric cancer cells. Methods: Human gastric BGC-823 cells were divided into three groups control group, EPA group and DHA group. The cells were treated with EPA or DHA for 48h, then techniques were used as follows bcl-2 and G α q prote by flow cytometry, G α q by immuno cytochemistry. Results: Bcl-2 protein expression ( FI) in groups of control group and 45 μ g/ml EPA group were 2.18 ± 0.20,1.53 ± 0.08 respectively. In groups of 30 μ g/ml and 45 μ g/ml were 1.62 ± 0.16 and 1.47 ± 0.13, respectively. Compared the above with control group, bcl-2 was decreased (p<0.001 ), respectively. G α q protein expression (FI) in groups of EPA 30 μ g/ml and 45 μ g/ml were 2.39 ± 0.27 and 1.97 ± 0.22, respectively. G α q protein expression in groups of DHA 30 μ g/ml and 45 μ g/ml were 2.35 ± 0.25 and 1.85 ± 0.19, respectively. Compared the above with control group( 2.95 ± 035 ), the G α q protein expression was decreased (p<0.001 and p<0.001, respectively ). Strong staining of G α q was located in cellular membrane and cytoplasm in control group by immuno cytochemistry. After treatment with EPA or DHA, staining of G α q and PKC β II were decreased. Conclusion: EPA and DHA can decrease protein expression of bcl-2 and G α q and inhibit the growth of the cultured cell.更多还原