NOTCH1 activates the Wnt/β-catenin signaling pathway in colon cancer.
NOTCH1 activates the Wnt/β-catenin signaling pathway in colon cancer.
复制标题
DOI：
10.18632/oncotarget.19534
复制
发表时间：
2017-09-01
期刊：
影响因子：
--
通讯作者：
Takiguchi S
中科院分区：
文献类型：
--
作者：
Ishiguro H;Okubo T;Kuwabara Y;Kimura M;Mitsui A;Sugito N;Ogawa R;Katada T;Tanaka T;Shiozaki M;Mizoguchi K;Samoto Y;Matsuo Y;Takahashi H;Takiguchi S
β-catenin/CTNNB1移位到细胞核可激活Wnt信号转导和细胞增殖，但其确切机制尚不清楚。以前的报道已经提供了NOTCH1参与Wnt信号通路的证据。因此，我们试图确定NOTCH1影响Wnt/β-Catenin途径的机制。我们构建了NOTCH1胞内结构域(NICD1)的表达载体，并将其导入低表达的HCT116细胞中。此外，通过siNICD1或伽马分泌酶抑制剂DAPT的处理，抑制了大量表达NICD1的SW480细胞的Notch信号通路。此外，我们还检测了NICD_1和β-catenin在结肠癌细胞系和结肠癌组织中的定位，并分析了NICD_1的核定位与结肠癌患者临床病理特征的关系。免疫组织化学分析表明，NICD1和β-catenin在结肠癌组织中的定位模式相似。此外，我们还发现NICD_1诱导β-连环蛋白转位到胞核，并且NICD_1和β-连环蛋白共同定位于胞核。过表达NICD1可增强Wnt信号通路的荧光素酶活性。另一方面，NICD1的降低降低了Wnt信号通路的荧光素酶活性。在分析的189例结肠癌病例中，多因素COX回归分析显示NICD1核定位对预后的独立影响(p=0.0376)。NOTCH1在Wnt途径中起关键作用，NOTCH1的激活与β-连环蛋白的核内移位有关。
The translocation of β-catenin/CTNNB1 to the nucleus activates Wnt signaling and cell proliferation; however, the precise mechanism underlying this phenomenon remains unknown. Previous reports have provided evidence that NOTCH1 is involved in the Wnt signaling pathway. Therefore, we sought to determine the mechanism by which NOTCH1 influences the Wnt/β-catenin pathway. We constructed a vector expressing the NOTCH1 intracellular domain (NICD1) and transfected the vector into HCT116 which has low expression of NICD1. Furthermore, inhibition of NOTCH signal pathway in SW480 which has abundant NICD1 expression, was performed by transfection of siNICD1 or DAPT, gamma secretase inhibitor, treatment. In addition, we evaluated NICD1 and β-catenin localization in colon cancer cell lines and in 189 colon cancer tissue samples and analyzed the correlation between the nuclear localization of NICD1 and the clinicopathological features of colon cancer patients. Immunohistochemical assays demonstrated that NICD1 and β-catenin exhibited a similar localization pattern in colon cancer tissues. In addition, we found that NICD1 induced the translocation of β-catenin to the nucleus and that NICD1 and β-catenin co-localized in the nucleus. Overexpression of NICD1 increased luciferase activity of Wnt signal pathway. On the other hand, reduction of NICD1 reduced luciferase activity of Wnt signaling pathway. In the 189 analyzed colon cancer cases, multivariate COX regression analysis demonstrated the independent prognostic impact of nuclear localization of NICD1(p=0.0376). NOTCH1 plays a key role in the Wnt pathway and activation of NOTCH1 is associated with the translocation of β-catenin to the nucleus.