Zic2 synergistically enhances Hedgehog signalling through nuclear retention of Gli1 in cervical cancer cells
Zic2 synergistically enhances Hedgehog signalling through nuclear retention of Gli1 in cervical cancer cells
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DOI：
10.1002/path.2901
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发表时间：
2011-12-01
影响因子：
7.3
通讯作者：
Ngan, Hextan Y. S.
中科院分区：
文献类型：
--
作者：
Chan, David W.;Liu, Vincent W. S.;Ngan, Hextan Y. S.
Hedgehog (Hh) 信号传导的异常激活与人类癌症的发病机制有关。然而，导致这种失调途径的同源分子机制尚不完全清楚。在这项研究中，我们通过免疫组织化学和定量 RT-PCR 分析表明，Zic2 经常过度表达，并与高级别宫颈癌 (p = 0.032)、高水平的 Gli1 (p < 0.001) 和 CyclinD1 (p < 0.001) 相关。使用荧光素酶报告基因、免疫共沉淀、亚细胞分级分离和免疫荧光分析的进一步生化研究表明，Zic2 可以与 Gli1 物理相互作用并将其保留在细胞核中，从而增加 Gli 介导的转录活性。 Zic2 的功能获得和丧失分析表明，Zic2 可以增加宫颈癌细胞中的 Hh 信号活性、细胞增殖和贴壁依赖性生长能力。相反，Zic2 C 末端锌指结构域的缺失显着消除了其与 Gli1 的相互作用、Gli1 在细胞核中的保留、对 Hh 信号活性和宫颈癌细胞致癌特性的影响。我们的研究结果表明，Zic2 是一种正调节剂，通过将 Gli1 保留在宫颈癌细胞的细胞核中来增加 Gli1 转录和致癌活性。版权所有 (C) 2011 大不列颠及爱尔兰病理学会。由约翰·威利父子有限公司出版
Aberrant activation of Hedgehog (Hh) signalling has been implicated in the pathogenesis of human cancers. However, the cognate molecular mechanisms contributing to this disregulated pathway are incompletely understood. In this study, we showed that Zic2 was frequently over-expressed and associated with high-grade cervical cancer (p = 0.032), high levels of Gli1 (p < 0.001) and CyclinD1 (p < 0.001) by immunohistochemical and quantitative RT-PCR analyses. Further biochemical studies using luciferase reporter, co-immunoprecipitation, subcellular fractionation and immunofluorescence analyses demonstrated that Zic2 can physically interact with Gli1 and retain it in the nucleus, which in turn increases Gli-mediated transcriptional activity. Gain- and loss-of-function analyses of Zic2 showed that Zic2 could increase Hh signalling activity, cell proliferation and anchorage-independent growth ability in cervical cancer cells. Conversely, deletion of the zinc finger domain at C-terminus of Zic2 significantly abrogated its interaction with Gli1, the retention of Gli1 in the nucleus, effects on Hh signalling activity and oncogenic properties in cervical cancer cells. Our findings suggest that Zic2 is a positive modulator increasing Gli1 transcriptional and oncogenic activity by retaining Gli1 in the nucleus of cervical cancer cells. Copyright (C) 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.