分化抑制因子1在环氧合酶2介导的胃癌血管生成中的作用及机制研究  

The potential role of Idl in COX-2 mediated angiogenesis in gastric cancer

作　　者：雷婷[1] 韩霜[2] 郭雪艳[2] 丁锐[2] 李颖[2] 谢华红[2] 白飞虎[2] 吴开春[2] 丁杰[2] 

机构地区：[1]兰州军区乌鲁木齐总医院消化内科,830002 [2]第四军医大学西京医院全军消化病研究所肿瘤生物学国家重点实验室

出　　处：《中华医学杂志》2007年第22期1570-1575,共6页National Medical Journal of China

摘　　要：目的验证分化抑制因子1(Id-1)在环氧合酶2(COX-2)介导的胃癌血管生成中的作用及机制。方法建立高表达 COX-2和表达 COX-2特异性 siRNA 的胃癌 SGC7901细胞,通过Western 印迹和逆转录 PCR 方法检测两种亚细胞系中 Id1的表达,ELISA 方法分析两种细胞上清中血管内皮生长因子(VEGF)的表达差异。通过四唑盐比色(MTY)实验分析两种细胞亚系的上清对体外脐静脉内皮细胞(HU-LT)增殖的影响,并在 SGC7901/COX-2中抑制 Id1后观察培养上清中 VEGF 的变化以及对脐静脉内皮细胞(HU-LT)增殖的影响。裸鼠成瘤实验观察转染细胞的成瘤性及肿瘤新生微血管密度(MVD)。结果成功建立高表达 COX-2以及表达特异性 COX-2小干扰 RNA(siRNA)的稳定克隆,并鉴定了不同克隆的转染效率。高表达 COX-2的胃癌 SGC7901细胞中 Id1的蛋白及mRNA 表达水平增高,而转染 COX-2-siRNA 的 SGC7901细胞中 Id1的表达则均低于对照组。COX-2高表达的 SGC7901/COX-2细胞上清中 VEGF 的蛋白含量高于对照组(2060±42 vs 1248±28,P=0.000),而 SGC7901/COX-2-siRNA 细胞上清中 VEGF 的蛋白含量低于对照组(1024±20,2033±27 vsP=0.000)。在 SGC7901/COX-2细胞条件培养基中,HU-LT 细胞生长较对照组快;在 SGC7901/COX-2-SiRNA 细胞条件培养基中,HU-LT 细胞生长较对照组缓。在 SGC7901/COX-2中抑制 Id1后,培养上清中 VEGF 的含量增加以及对 HU-LT 促进增殖的作用均被逆转。裸鼠成瘤试验显示抑制 Id1后SGC7901/COX-2细胞成瘤性降低[(353±12)mg vs(1020±91)mg,P=0.038],MVD 降低(8.8±1.6vs 20±1.7,P=0.001)。结论 COX-2可以上调 SGC7901细胞中 Id1的表达,并通过此途径影响内皮细胞的体外增殖能力。因此在胃癌发生发展中 Id1参与了 COX-2所介导的促血管生成过程,有可能成为胃癌抗血管治疗的新靶标。Objective To investigate the potential role of inhibitor of DNA binding/differentiation 1 （Id1） in eyeleoxygenase-2 （COX-2） mediated angiogenesis in gastric cancer. Methods Two human gastric cancer sub-cell lines （SGC7901/COX-2 and SGC7901/COX-2RNAi） highly expressing COX-2 and COX-2 RNAi respectively were established. Western blotting and RT-PCR were performed to detect the protein and mRNA expression levels of Id1 in these transfectants. ELISA was performed to detect the levels of VEGF protein in the supernatants of these cells. Humane umbilical vein endothelial cells of the line HU- LT were cultured in condition medium, supernatant of SGC7901/COX2 cells transfected with COX-2 sense strand, COX-2 SiRNA and Id1. MTF assay was used to examine the proliferation ability of these cells. Suspensions of SGC7901/COX-2 and SGC7901/COX-2RNAi cells were injected subcutaneously to nude mice respectively. Eight weeks later the mice were killed and the tumors were taken out to undergo immunohistochemistry and detection of mcrovessel density （MVD）. Results Western blotting and RT-PCR showed that the expression levels of COX-2 protein and mRNA, as well as those of Id1 in the SGC7901/ COX-2 cells were high, and the expression level of Id1 was down-regulated in the SGC7901/COX-2RNAi cells transfected with Id1 RNAi. The VEGF level of the SGC7901/COX-2 cells was 2060 ± 42, significantly higher than that of the control SGC7901/PC cells （ 1248 ± 28, P = 0. 000）and VEGF level of the supernatant of then SGC7901/COX-2 RNAi cells was 1024 ± 20, significantly lower than that of the SGC7901/COX-2/ PC cells （2033 ± 27, P =0. 000）. The proliferation rate of the HU-LT cells cultured in SGC7901/COX-2 condition medium was higher than that of the HU-LT cells cultured in SGC7901/COX-2RNAi condition medium. The increase of VEGF in the SGC7901/COX-2 and the effect of contribution to the proliferation of HU-LT were both abrogated when Id1 was knocked out in the SGC7901/COX-2. The tumor weight of the COX-2 RNAi group was

关 键 词：胃肿瘤 环氧化合物 血管生成 

分 类 号：R735.2[医药卫生—肿瘤]