Global changes of mRNA expression reveals an increased activity of the interferon-induced signal transducer and activator of transcription (STAT) pathway by repression of miR-221/222 in glioblastoma U251 cells
Global changes of mRNA expression reveals an increased activity of the interferon-induced signal transducer and activator of transcription (STAT) pathway by repression of miR-221/222 in glioblastoma U251 cells
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mRNA 表达的整体变化揭示了胶质母细胞瘤 U251 细胞中通过抑制 miR-221/222 来增加干扰素诱导的信号转导和转录激活因子 (STAT) 通路的活性。
DOI：
10.3892/ijo_00000637
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发表时间：
2010-06-01
影响因子：
5.2
通讯作者：
Kang, Chunsheng
中科院分区：
文献类型：
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作者：
Zhang, Chunzhi;Han, Lei;Kang, Chunsheng
MicroRNA(MiR)-221和miR-222在包括胶质母细胞瘤在内的多种人类恶性肿瘤中频繁上调。以前的研究已经确定了miR-221和miR-222的一些靶点，如p27和p57。MiR-221和miR-222的表达与整体mRNA表达之间的相互关系仍然难以捉摸。在此，我们下调了miR-221和miR-222的表达，并通过微阵列分析发现了U251胶质瘤细胞中存在2倍变化的158个差异表达基因。利用KEGG通路数据库和BioCarta，我们发现干扰素-α信号通路是受差异表达基因调控的最重要的通路。STAT1和STAT2是干扰素-α信号通路的核心蛋白。通过Western blotting和免疫荧光检测发现，经miR-221/222基因敲除后，U251细胞中STAT1和STAT2的表达和磷酸化水平均上调。此外，在抑制U251细胞miR-221/222的表达后，STAT1和STAT2的酪氨酸磷酸化存在于细胞核中。这些数据首次表明，在U251胶质瘤细胞中，miR-221/222簇被敲除后，在INF-α信号转录控制下STAT1/2上调的机制。
MicroRNA (miR)-221 and miR-222 are frequently upregulated in various types of human malignancy including glioblastoma. Previous studies have identified some targets of miR-221 and miR-222, such as p27 and p57. Inter-relationship between miR-221 and miR-222 expression and global mRNA expression remains elusive. Here we knocked down miR-221 and miR-222 expression and found 158 differentially expressed genes with 2-fold changes in U251 glioma cells by microarray analysis. Using the KEGG pathway databases and BioCarta, we found that the IFN-alpha signaling pathway was the most significant pathway modulated by differentially expressed genes. STAT1 and STAT2 are core proteins in the IFN-alpha signaling pathway. By Western blotting and immunofluorescence, we found that STAT1 and STAT2 expression and phosphorylation were upregulated in U251 cells with knocked-down miR-221/222. Furthermore, tyrosine phosphorylation of STAT1 and STAT2 was present in the nucleus after repression of miR-221/222 expression in U251 cells. These data indicate for the first time a mechanism involving STAT1/2 upregulation under the transcriptional control of INF-alpha signaling after knockdown of miR-221/222 cluster in U251 glioma cells.