Wang Jing-Ming, Huang Fong-Chun, Kuo Margaret Hsin-Jui, Wang Zi-Fu, Tseng Ting-Yuan, Chang Lien-Cheng, Yen Shao-Jung, Chang Ta-Chau, Lin Jing-Jer
From the Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan.
Institute of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, Taipei 100, Taiwan.
J Biol Chem. 2014 May 23;289(21):14612-23. doi: 10.1074/jbc.M114.548230. Epub 2014 Apr 8.
WNT1 encodes a multifunctional signaling glycoprotein that is highly expressed in several malignant tumors. Patients with Wnt1-positive cancer are usually related to advanced metastasis. Here, we found that a stretch of G-rich sequences located at the WNT1 promoter region is capable of forming G-quadruplex structures. The addition of G-quadruplex structure stabilizers, BMVC and BMVC4, raises the melting temperature of the oligonucleotide formed by the WNT1 promoter G-rich sequences. Significantly, the expression of WNT1 was repressed by BMVC or BMVC4 in a G-quadruplex-dependent manner, suggesting that they can be used to modulate WNT1 expression. The role of G-quadruplex stabilizers on Wnt1-mediated cancer migration and invasion was further analyzed. The protein levels of β-catenin, a mediator of the Wnt-mediated signaling pathway, and the downstream targets MMP7 and survivin were down-regulated upon BMVC or BMVC4 treatments. Moreover, the migration and invasion activities of cancer cells were inhibited by BMVC and BMVC4, and the inhibitory effects can be reversed by WNT1-overexpression. Thus the Wnt1 expression and its downstream signaling pathways can be regulated through the G-quadruplex sequences located at its promoter region. These findings provide a novel approach for future drug development to inhibit migration and invasion of cancer cells.
WNT1编码一种多功能信号糖蛋白，在多种恶性肿瘤中高表达。Wnt1阳性癌症患者通常与晚期转移有关。在此，我们发现位于WNT1启动子区域的一段富含G的序列能够形成G-四链体结构。添加G-四链体结构稳定剂BMVC和BMVC4可提高由WNT1启动子富含G的序列形成的寡核苷酸的解链温度。值得注意的是，BMVC或BMVC4以G-四链体依赖的方式抑制WNT1的表达，表明它们可用于调节WNT1的表达。进一步分析了G-四链体稳定剂对Wnt1介导的癌症迁移和侵袭的作用。在BMVC或BMVC4处理后，Wnt介导的信号通路的介质β-连环蛋白以及下游靶点MMP7和survivin的蛋白水平下调。此外，BMVC和BMVC4抑制癌细胞的迁移和侵袭活性，并且WNT1过表达可逆转这种抑制作用。因此，Wnt1的表达及其下游信号通路可通过位于其启动子区域的G-四链体序列进行调节。这些发现为未来开发抑制癌细胞迁移和侵袭的药物提供了一种新方法。
