Ablation of Dicer leads to widespread perturbation of signaling pathways.
Ablation of Dicer leads to widespread perturbation of signaling pathways.
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DOI：
10.1016/j.bbrc.2015.05.077
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发表时间：
2015-07-31
影响因子：
3.1
通讯作者：
Pandey A
中科院分区：
文献类型：
--
作者：
Sahasrabuddhe NA;Huang TC;Kumar P;Yang Y;Ghosh B;Leach SD;Chaerkady R;Pandey A
Dicer是参与mirna生物发生的重要核糖核酸酶。先前的研究报道了包括肝细胞癌在内的多种癌症中Dicer的下调。为了确定Dicer缺失后改变的信号通路，我们对Dicer基因敲除小鼠的肝组织进行了定量磷酸酪氨酸分析。我们采用基于抗体的磷酸化酪氨酸肽富集与SILAC尖峰法相结合进行定量。基于高分辨率质谱的分析鉴定出349个磷酸酪氨酸肽对应306个独特的磷酸化位点，其中75个被过度磷酸化，78个被低磷酸化。几种受体酪氨酸激酶，包括MET、PDGF受体α、胰岛素样生长因子1和胰岛素受体，以及非受体酪氨酸激酶，如Src家族激酶，在Dicer耗尽时被发现过度磷酸化。此外，IRS-2和STAT3等信号分子被过度磷酸化。这些信号通路的激活先前已被认为与各种类型的癌症有关。有趣的是，我们观察到包括黏附激酶和帕罗西林在内的分子的低磷酸化。我们的研究描述了受干扰的信号通路，以响应由Dicer耗竭引起的mirna失调。我们的发现为进一步研究Dicer下调在癌症中的致癌作用提供了依据。
Dicer is an essential ribonuclease involved in the biogenesis of miRNAs. Previous studies have reported downregulation of Dicer in multiple cancers including hepatocellular carcinoma. To identify signaling pathways that are altered upon Dicer depletion, we carried out quantitative phosphotyrosine profiling of liver tissue from Dicer knockout mice. We employed antibody-based enrichment of phosphotyrosine containing peptides coupled with SILAC spike-in approach for quantitation. High resolution mass spectrometry-based analysis identified 349 phosphotyrosine peptides corresponding to 306 unique phosphosites of which 75 were hyperphosphorylated and 78 were hypophosphorylated. Several receptor tyrosine kinases including MET, PDGF receptor alpha, Insulin-like growth factor 1 and Insulin receptor as well as non-receptor tyrosine kinases such as Src family kinases were found to be hyperphosphorylated upon depletion of Dicer. In addition, signaling molecules such as IRS-2 and STAT3 were hyperphosphorylated. Activation of these signaling pathways has been implicated previously in various types of cancers. Interestingly, we observed hypophosphorylation of molecules including focal adhesion kinase and paxillin. Our study profiles the perturbed signaling pathways in response to dysregulated miRNAs resulting from depletion of Dicer. Our findings warrant further studies to investigate oncogenic effects of downregulation of Dicer in cancers.