Liu Fen, Sheng Shourong, Wang Xiaoyan, Peng Ya, Guo Qin, Xiao Zhiming, Liu Jie
Department of Digestion Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2011 Mar;36(3):235-42. doi: 10.3969/j.issn.1672-7347.2011.03.008.
To explore the role of nasopharyngeal carinoma associated gene 6 (NGX6) in Wnt/β-catenin signaling pathway and to identify whether there is feedback regulation between NGX6 and Wnt signal pathway once the Wnt signal is blocked.
pCMV-myc-NGX6 and pCMV-myc were transfected to colon cancer cell line SW62O and the expression of downstream target molecules of Wnt/β-catenin signaling pathway such as c-myc, cyclinD1, and c-jun were detected by Western blot. The eukaryotic expression vector pcDNA3.1 (+)-LEF1(DN) (without N-terminal β-catenin binding domain) was constructed to inhibit Wnt signaling pathway, and the effect was confirmed by Western blot and TCF-4 luciferase report system. The mRNA expression of NGX6 in SW620 was detected by RT-PCR after pcDNA3.1(+)-LEF1(DN) transient transfection.
The expression of above molecules were obviously down-regulated by NGX6 transient transfection in SW620. The eukaryotic expression vector pcDNA3.1(+)-LEF1(DN) showed an inhibitory effect on Wnt/β-catenin signaling pathway. The mRNA expression of NGX6 in SW620 was up-regulated after pcDNA3.1(+)-LEF1(DN) transient transfection.
NGX6 could inhibit the expression of Wnt signaling downstream target genes, which maybe related to the potential feedback regulation between NGX6 and Wnt signal pathway.
探讨鼻咽癌相关基因6(NGX6)在Wnt/β-连环蛋白信号通路中的作用,并确定一旦Wnt信号被阻断,NGX6与Wnt信号通路之间是否存在反馈调节。
将pCMV-myc-NGX6和pCMV-myc转染至结肠癌细胞系SW62O,通过蛋白质免疫印迹法检测Wnt/β-连环蛋白信号通路下游靶分子如c-myc、细胞周期蛋白D1和c-jun的表达。构建真核表达载体pcDNA3.1(+)-LEF1(DN)(无N端β-连环蛋白结合结构域)以抑制Wnt信号通路,并通过蛋白质免疫印迹法和TCF-4荧光素酶报告系统进行验证。pcDNA3.1(+)-LEF1(DN)瞬时转染后,采用逆转录-聚合酶链反应(RT-PCR)检测SW620中NGX6的mRNA表达。
NGX6瞬时转染SW620后,上述分子的表达明显下调。真核表达载体pcDNA3.1(+)-LEF1(DN)对Wnt/β-连环蛋白信号通路具有抑制作用。pcDNA3.1(+)-LEF1(DN)瞬时转染后,SW620中NGX6的mRNA表达上调。
NGX6可抑制Wnt信号下游靶基因的表达,这可能与NGX6和Wnt信号通路之间潜在的反馈调节有关。