NGX6对Wnt/β-catenin通路β-catenin/TCF/LEF转录活化的影响  

Effects of NGX6 on the transcriptional activation of β-catenin/TCF/LEF in Wnt/β-catenin signal pathway

作　　者：刘芬[1] 沈守荣[1] 李宏韬[1] 王晓艳[1] 彭娅[1] 廖曼甜[1] 郭勤[1] 

机构地区：[1]中南大学湘雅三医院消化内科,长沙410013

出　　处：《中南大学学报（医学版）》2007年第6期985-991,共7页Journal of Central South University ：Medical Science

基　　金：国家"973"重大科技计划项目子课题(2006CB910503);国家自然科学基金项目(30500238;30770972);湖南省自然科学基金(06JJ20068;04JJ3109);中南大学研究生学位论文创新工程(234075245);中南大学湘雅三医院博士化基金~~

摘　　要：目的:探讨NGX6基因对结肠癌Wnt信号转导通路β-catenin/TCF/LEF转录活化的影响,明确NGX6在Wnt/β-catenin信号转导通路中的作用机制。方法:(1)构建β-catenin野生型真核表达载体pcDNA3.1(+)-β-catenin(WT),(2)转染外源性pcDNA3.1(+)-β-catenin(WT)及pCMV-myc-NGX6于COS-7细胞,TCF-4荧光素酶报告质粒检测转染NGX6前后TCF-4的转录活性。(3)无外源性β-cate-nin,pCMV-myc-NGX6单独转染COS-7细胞及结肠癌SW620细胞,TCF-4荧光素酶报告质粒检测TCF-4的转录活性,并采用Western blot的方法检测两组细胞核内β-catenin及TCF-4的表达。结果:(1)成功构建真核表达载体pcDNA3.1(+)-β-catenin(WT);(2)pcDNA3.1(+)-β-catenin(WT)与pCMV-myc-NGX6共转染COS-7细胞较pcDNA3.1(+)-β-catenin(WT)单独转染时TCF-4荧光素酶活性明显下降(P<0.05);(3)无外源性β-catenin,pCMV-myc-NGX6转染COS-7及SW620细胞后TCF-4荧光素酶活性较空白质粒转染组下降(P<0.05);(4)NGX6转染COS-7及SW620后核内β-catenin及TCF-4的表达下降。结论:NGX6对结肠癌中Wnt/β-catenin通路的β-catenin/TCF/LEF转录活化具有负性调节作用,其作用机制可能与NGX6抑制β-catenin的核转位有关。Objective To explore the effects of NGX6 on the transcriptional activation of β-catenin/TCF/LEF in Wnt/β-catenin signal pathway,and to identify the role of NGX6 in Wnt signal pathway.Methods The eukaryotic expression vector pcDNA3.1（＋）-β-catenin（WT）was constructed.pcDNA3.1（＋）-β-catenin（WT）and pCMV-myc-NGX6 were contransfected to COS-7 and the transcriptional activity of TCF/LEF was detected by TCF-4 luciferase report system.Without extrogenous β-catenin,pCMV-myc-NGX6 was transfected alone to COS-7 and colon cancer cell line SW620,and the transcriptional activity of TCF/LEF was detected by TCF-4 luciferase report system,and then the expression of nucleus β-catenin and TCF-4 was detected by Western blot.Results The eukaryotic expression vector pcDNA3.1（＋）-β-catenin（WT）was successfully constructed.The activation of TCF-4 luciferase report gene in the contransfection group in COS-7 was less than that in NGX6 alone transfection group（P〈0.05）.The activation of TCF-4 luciferase report gene in NGX6 alone tansfection group without extrogenous β-catenin was less than that in pCMV-myc transfection group in COS-7 and SW620.The expression of β-catenin and TCF-4 was decreased after the NGX6 transfection in COS-7 and SW620 cells.Conclusion NGX6 can inhibit the transcriptional activation of β-catenin/TCF/LEF in Wnt signal pathway by its negative regulation in the nuclear translocation of β-catenin.

关 键 词：NGX6基因 结肠癌 信号转导 WNT/Β-CATENIN TCF/LEF 

分 类 号：R735.35[医药卫生—肿瘤]