Colocalization of β-catenin with Notch intracellular domain in colon cancer: a possible role of Notch1 signaling in activation of CyclinD1-mediated cell proliferation
Colocalization of β-catenin with Notch intracellular domain in colon cancer: a possible role of Notch1 signaling in activation of CyclinD1-mediated cell proliferation
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DOI：
10.1007/s11010-014-2163-7
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发表时间：
2014-11-01
影响因子：
4.3
通讯作者：
Devaraj, Halagowder
中科院分区：
文献类型：
--
作者：
Gopalakrishnan, Natarajan;Saravanakumar, Marimuthu;Devaraj, Halagowder
Wnt和Notch 1信号通路在肠道发育和肿瘤发生中起重要作用。β-连环蛋白的亚细胞定位与结直肠癌的发生有关。然而，必须解决β-连环蛋白和Notch胞内结构域（NICD）的相互作用。在结直肠组织和HT 29细胞系中分析β-连环蛋白、NICD的免疫组织化学以及β-连环蛋白和NICD的双重免疫荧光。此外，在经N-[N-（3，5-二氟苯乙酰基）-1-丙氨酰基]-S-苯基甘氨酸叔丁酯（DAPT）处理的HT 29细胞中进行CyclinD 1、Hes 1和MUC 2的实时PCR分析。双重染色强调β-catenin和NICD在腺瘤和腺癌中比在正常组织中更强的相互作用。在12.5和25 μ M DAPT处理的HT 29细胞中，Hes 1转录水平降低了1.5和7.1倍。在12.5和25 μ M DAPT处理的HT 29细胞中，CyclinD 1转录水平降低1.2和1.6倍，MUC 2转录水平增加4.3和7.5倍。本研究的结果表明，β-连环蛋白的亚细胞定位与NICD通过激活CyclinD 1和Hes 1诱导增殖收敛。此外，通过DAPT抑制Notch 1信号传导导致细胞增殖停滞并诱导细胞凋亡，从而导致分泌细胞谱系标志物MUC 2的上调。
The Wnt and Notch1 signaling pathways play major roles in intestinal development and tumorigenesis. Sub-cellular localization of beta-catenin has been implicated in colorectal carcinogenesis. However, the beta-catenin and Notch intracellular domain (NICD) interaction has to be addressed. Immunohistochemistries of beta-catenin, NICD, and dual immunofluorescence of beta-catenin and NICD were analyzed in colorectal tissues and HT29 cell line. Moreover, real-time PCR analysis of CyclinD1, Hes1 and MUC2 was done in HT29 cells upon N-[N-(3, 5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) treatment. Dual staining emphasized the strong interaction of beta-catenin and NICD in adenoma and adenocarcinoma than in normal tissues. Hes1 transcript levels were decreased 1.5- and 7.1-fold in 12.5 and 25 A mu M DAPT-treated HT29 cells. CyclinD1 transcript levels decreased 1.2- and 1.6-fold, and MUC2 transcript level increased 4.3- and 7.5-fold in 12.5 and 25 A mu M DAPT-treated HT29 cells. The results of this study showed that the sub-cellular localization of beta-catenin converges with NICD inducing proliferation through the activation of CyclinD1 and Hes1. Moreover, the inhibition of Notch1 signaling by DAPT leads to the arrest of cell proliferation and induces apoptosis leading to the upregulation of MUC2, a secretory cell lineage marker.