Inhibition of mTORC1 induces loss of E-cadherin through AKT/GSK-3β signaling-mediated upregulation of E-cadherin repressor complexes in non-small cell lung cancer cells.
Inhibition of mTORC1 induces loss of E-cadherin through AKT/GSK-3β signaling-mediated upregulation of E-cadherin repressor complexes in non-small cell lung cancer cells.
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DOI：
10.1186/1465-9921-15-26
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发表时间：
2014-02-26
影响因子：
5.8
通讯作者：
Chang YS
中科院分区：
文献类型：
--
作者：
Kim EY;Kim A;Kim SK;Kim HJ;Chang J;Ahn CM;Chang YS
mTOR 可根据其结合伙伴形成 mTOR 复合物 1 (mTORC1) 或 mTOR 复合物 2 (mTORC2)，在接受 rapalogs 治疗的患者的肺部肿瘤疾病和间质性肺疾病中经常失调。在这项研究中，我们通过剖析 mTOR 通路来研究 mTOR 信号传导与上皮间质转化 (EMT) 之间的关系。在一组非小细胞肺癌细胞系中，mTOR 信号通路的成分被 shRNA 沉默，并通过免疫印迹和免疫细胞化学评估上皮和间质标记物的蛋白表达。通过 qRT-PCR 评估 E-钙粘蛋白阻遏物复合物的 mRNA 水平。 IGF-1 治疗降低了 E-钙粘蛋白的表达，而雷帕霉素增加了其表达，表明 mTOR 信号传导的过度激活与 E-钙粘蛋白的丢失有关。 mTOR 的雷帕霉素不敏感伴侣 (Rictor)（mTORC2 的一个组成部分）的基因消除不会影响 E-钙粘蛋白的表达，而 mTOR (Raptor)（mTORC1 的一个组成部分）的调节相关蛋白的基因消除会导致 mRNA 水平的 E-钙粘蛋白表达降低。在 Raptor 沉默的 NSCLC 细胞中观察到 AKT Ser473 和 GSK-3β Ser9 磷酸化增加。在测试的 E-钙粘蛋白阻遏蛋白复合物中，Snail、Zeb2 和 Twist1 mRNA 在 raptor 沉默的 A549 细胞中升高，Zeb2 和 Twist1 mRNA 在 Raptor 沉默的 H2009 细胞中升高。通过使用 GSK-3β 抑制剂 LiCl 进行治疗，重现了这些发现。 Raptor 敲低 A549 细胞显示 N-钙粘蛋白和波形蛋白表达增加，并伴有间充质表型变化。总之，选择性抑制 mTORC1 会导致 AKT/GSK-3β 通路过度激活，从而诱导 E-钙粘蛋白阻遏复合物和 EMT。这些发现意味着 mTORC1 对 mTORC2 的反馈抑制环的存在，在 E-钙粘蛋白表达和 EMT 的稳态中发挥作用，因此在临床使用 rapalog 和选择性 mTORC1 抑制剂时需要谨慎。
mTOR, which can form mTOR Complex 1 (mTORC1) or mTOR Complex 2 (mTORC2) depending on its binding partners, is frequently deregulated in the pulmonary neoplastic conditions and interstitial lung diseases of the patients treated with rapalogs. In this study, we investigated the relationship between mTOR signaling and epithelial mesenchymal transition (EMT) by dissecting mTOR pathways. Components of mTOR signaling pathway were silenced by shRNA in a panel of non-small cell lung cancer cell lines and protein expression of epithelial and mesenchymal markers were evaluated by immunoblotting and immunocytochemistry. mRNA level of the E-cadherin repressor complexes were evaluated by qRT-PCR. IGF-1 treatment decreased expression of the E-cadherin and rapamycin increased its expression, suggesting hyperactivation of mTOR signaling relates to the loss of E-cadherin. Genetic ablation of rapamycin-insensitive companion of mTOR (Rictor), a component of mTORC2, did not influence E-cadherin expression, whereas genetic ablation of regulatory-associated protein of mTOR (Raptor), a component of mTORC1, led to a decrease in E-cadherin expression at the mRNA level. Increased phosphorylation of AKT at Ser473 and GSK-3β at Ser9 were observed in the Raptor-silenced NSCLC cells. Of the E-cadherin repressor complexes tested, Snail, Zeb2, and Twist1 mRNAs were elevated in raptor-silenced A549 cells, and Zeb2 and Twist1 mRNAs were elevated in Raptor-silenced H2009 cells. These findings were recapitulated by treatment with the GSK-3β inhibitor, LiCl. Raptor knockdown A549 cells showed increased expression of N-cadherin and vimentin with mesenchymal phenotypic changes. In conclusion, selective inhibition of mTORC1 leads to hyperactivation of the AKT/GSK-3β pathway, inducing E-cadherin repressor complexes and EMT. These findings imply the existence of a feedback inhibition loop of mTORC1 onto mTORC2 that plays a role in the homeostasis of E-cadherin expression and EMT, requiring caution in the clinical use of rapalog and selective mTORC1 inhibitors.
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DOI：
10.1345/aph.1q623
发表时间：
2012-03-01
期刊：
The Annals of pharmacotherapy
影响因子：
--
作者：
Depuydt, Pieter;Nollet, Joke;Caes, Frank
通讯作者：
Caes, Frank
DOI：
10.1083/jcb.200403069
发表时间：
2004-07-19
期刊：
The Journal of cell biology
影响因子：
--
作者：
Harrington LS;Findlay GM;Gray A;Tolkacheva T;Wigfield S;Rebholz H;Barnett J;Leslie NR;Cheng S;Shepherd PR;Gout I;Downes CP;Lamb RF
通讯作者：
Lamb RF
影响因子：
6.2
作者：
Morelon, E;Stern, M;Kreis, H
通讯作者：
Kreis, H
影响因子：
64.5
作者：
Peterson TR;Laplante M;Thoreen CC;Sancak Y;Kang SA;Kuehl WM;Gray NS;Sabatini DM
通讯作者：
Sabatini DM
影响因子：
29
作者：
Bjedov I;Toivonen JM;Kerr F;Slack C;Jacobson J;Foley A;Partridge L
通讯作者：
Partridge L