Four and a half LIM protein 2 (FHL2) negatively regulates the transcription of E-cadherin through interaction with Snail1
Four and a half LIM protein 2 (FHL2) negatively regulates the transcription of E-cadherin through interaction with Snail1
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四个半 LIM 蛋白 2 (FHL2) 通过与 Snail1 相互作用负向调节 E-钙粘蛋白的转录
DOI：
10.1016/j.ejca.2010.07.045
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发表时间：
2011-01-01
影响因子：
8.4
通讯作者：
Wong, Benjamin C. Y.
中科院分区：
文献类型：
--
作者：
Zhang, Wenjing;Wang, Jide;Wong, Benjamin C. Y.
E-钙粘蛋白是上皮-间质转化（EMT）的标志，在癌症转移中发挥着至关重要的作用。我们之前证明了四个半 LIM 蛋白 2 (FHL2) 抑制 E-钙粘蛋白表达并促进结肠癌的侵袭潜力和 EMT。在这里，我们的目标是进一步明确 FHL2 在结肠癌中抑制 E-钙粘蛋白的机制。首先通过Western blot、免疫荧光和免疫组化观察FHL2和Snail1的表达谱。我们发现Snail1在结肠癌中的蛋白水平和细胞定位与FHL2非常相似；免疫共沉淀实验表明FHL2能够结合Snail1并且需要其完整的结构。 FHL2的表达与Snail1呈正相关，与E-cadherin和磷酸化Snail1呈负相关。 FHL2 过表达诱导 Snail1 在细胞核中积累。此外，双荧光素酶测定显示，FHL2 过表达减少，而 FHL2 siRNA 增加了两个含有 E-box 位点（Snail1 结合元件）的 E-钙粘蛋白启动子构建体的转录活性。 E-box突变增加了转录活性，FHL2表达参与了突变的功能。这些结果表明 FHL2 通过与 Snail1 相互作用负向调节 E-钙粘蛋白转录活性。我们的研究建立了 FHL2 的新型调节功能，并揭示了促进 EMT 过程的潜在机制。 (C) 2010 Elsevier Ltd. 保留所有权利。
E-cadherin is a hallmark of epithelial-mesenchymal transition (EMT), which plays a crucial role in cancer metastasis. We previously demonstrated that four and a half LIM protein 2 (FHL2) inhibited E-cadherin expression and promoted invasive potential and EMT in colon cancer. Here, we aim to further define the mechanism underlying the inhibition of E-cadherin by FHL2 in colon cancer. The expression profiles of FHL2 and Snail1 were first observed by Western blot, immunofluorescence and immunohistochemistry. We found that both the protein level and the cellular localisation of Snail1 were quite similar to FHL2 in colon cancer; reciprocal co-immunoprecipitation assay showed that FHL2 was able to bind Snail1 and its intact structure was required. The expression of FHL2 was positively correlated to Snail1 while negatively to E-cadherin and phospho-Snail1. FHL2 over-expression induced the accumulation of Snail1 in the nucleus. Moreover, dual luciferase assay revealed that FHL2 over-expression decreased while FHL2 siRNA increased the transcriptional activities of two E-cadherin promoter constructs which contained E-box sites (Snail1-binding elements). Mutation of E-boxes increased the transcriptional activities and FHL2 expression was involved in the function of mutation. These results suggested that FHL2 negatively regulated E-cadherin transcriptional activity through interaction with Snail1. Our study established a novel regulatory function of FHL2 and revealed a potential mechanism on promoting the process of EMT. (C) 2010 Elsevier Ltd. All rights reserved.