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线粒体复合物在维生素E琥珀酸酯诱导人胃癌细胞凋亡中的作用

张志宏/黄晓莉/贾 莉/张旭光/王晓琳/吴 坤*   

  1. 哈尔滨医科大学公共卫生学院营养与食品卫生学教研室,黑龙江 哈尔滨  150081
  • 收稿日期:2012-03-13 修回日期:2012-09-12 出版日期:2011-11-30 发布日期:2011-11-30
  • 通讯作者: 吴坤,E-mail:wukun_15000@126.com
  • 作者简介:张志宏(1982- ),男,黑龙江省哈尔滨市人,博士研究生。研究方向:肿瘤的化学预防。
  • 基金资助:

    国家自然科学基金资助项目(30972477)

The effects of four mitochondrial  complexes in vitamin E succinate-induced apoptosis  of human gastric cancer cells

ZHANG Zhi-hong,HUANG Xiao-li,JIA Li,ZHANG Xu-guang,WANG Xiao-lin,WU Kun*   

  1. Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin 150081, Heilongjiang, China
  • Received:2012-03-13 Revised:2012-09-12 Online:2011-11-30 Published:2011-11-30
  • Contact: WU Kun,E-mail:wukun_15000@126.com
  • About author:张志宏(1982- ),男,黑龙江省哈尔滨市人,博士研究生。研究方向:肿瘤的化学预防。
  • Supported by:

    国家自然科学基金资助项目(30972477)

摘要:

目的: 探讨维生素E琥珀酸酯(vitamin E succinate,VES)诱导人胃癌细胞凋亡过程中线粒体4种复合物的作用,并寻找对肿瘤细胞有抑制作用的关键酶。方法:体外常规培养SGC-7901细胞,分别加入线粒体复合物Ⅰ、Ⅱ、Ⅲ和Ⅳ (complexⅠ~Ⅳ, CⅠ~Ⅳ)的抑制剂鱼藤酮(rotenone,ROT)、噻吩甲酰三氟丙酮 (thenoyltri?uoroacetone,TTFA)、抗霉素A (antimycin A,AA)和叠氮钠 (sodium azide,SA)2 h后以20 μg/ml VES诱导处理,并设阴性对照组(含0.1%乙醇的培养液),20  μg/ml VES单独处理组;MTT法测定细胞增殖情况,共聚焦显微镜观察活性氧(reactive oxygen species,ROS)水平,流式细胞术检测细胞凋亡情况,Western blot法检测细胞中细胞色素C和Caspase-3表达情况。结果:与VES对照组比较,在VES诱导SGC-7901细胞凋亡的过程中,添加5 μg/ml TTFA抑制线粒体复合物Ⅱ酶活性后,细胞增殖抑制率水平显著降低 (P<0.05)。4个线粒体复合物抑制剂处理组ROS水平均显著降低 (P<0.05),而细胞凋亡率显著升高 (P<0.05);但5 μg/ml TTFA处理组ROS及凋亡率的升高均显著低于其他3个处理组 (P均<0.05)。分别抑制CⅠ~Ⅳ酶活后,VES上调细胞中细胞色素C和Caspase-3的能力均受到抑制,其中VES+TTFA组抑制程度明显高于另外3组 (P均<0.05)。结论:VES处理SGC-7901细胞,可影响线粒体复合物Ⅱ中琥珀酸脱氢酶活性,致使线粒体中ROS堆积,这可能是VES诱导人胃癌细胞凋亡的机制之一。

关键词: 维生素E琥珀酸酯, 线粒体复合物, 活性氧, 细胞凋亡

Abstract:

OBJECTIVE:  To study four key enzyme complexes in the mitochondria that contribute to vitamin E succinate (VES)-inhibited cell growth in human gastric cancer cells SGC-7901. METHODS:Gastric cancer cells SGC-7901 were grown in vitro. Cells were treated with rotenone(ROT),thenoyltri?uoroacetone(TTFA),antimycin A(AA) or sodium azide(SA) alone before treatment with VES for 2 h. Then cells were treated with VES at 20 μg/ml. MTT assay was used to evaluate cell growth. ROS was detected by confocal microscope. FITC/Annexin V was used to assess apoptosis. RESULTS:Cell growth inhibition induced by VES were obviously down-regulated after complex Ⅱ was inhibited by TTFA (5 μg/ml) (P<0.05). ROS induced by VES was all down-regulated after four complexes were inhibited respectively. Percentage of apoptosis induced by VES was all up-regulated after four complexes were inhibited respectively (P<0.05). However,levels of ROS and apoptosis were obviously lower than other three groups after complex Ⅱ was inhibited by TTFA (5 μg/ml) (all P<0.05). Cytochrome C and caspase-3 induced by VES were all down-regulated after cells treated with ROT,TTFA,AA or SA,respectively (P<0.05). Cytochrome C and caspase-3 were obviously down-regulated compared with other three groups (P<0.05). CONCLUSION:Key enzyme of complex Ⅱ (succinate dehydrogenase,SDH) was affected by VES. SDH induced ROS retention in cells. This may be the mechanism that VES contributes to vitamin E succinate-induced apoptosis in human gastric cancer cells.

Key words: vitamin E succinate, complex, ROS, apoptosis