Ets1 was significantly activated by ERK1/2 in mutant K-ras stably transfected human adrenocortical cells
Ets1 was significantly activated by ERK1/2 in mutant K-ras stably transfected human adrenocortical cells
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DOI：
10.1089/dna.2005.24.126
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发表时间：
2005-02-01
影响因子：
3.1
通讯作者：
Lin, SR
中科院分区：
文献类型：
--
作者：
Chen, YF;Shin, SJ;Lin, SR
在我们先前关于人类功能性肾上腺肿瘤发生机制的研究中，我们观察到临床肾上腺肿瘤中K-ras基因点突变的频率很高。因此，我们利用DNA微阵列技术分析了突变K-ras基因在肾上腺皮质细胞中的表达谱，以确定与细胞周期、信号转导、细胞凋亡、肿瘤发生、类固醇生成等相关基因的表达模式。然后，我们用生物信息学工具“Matchminer”和“Gominer”分析了所有有意义的差异表达基因。结果表明，IPTG诱导突变型K-ras基因表达上调Ets1，这主要与细胞增殖有关。经软件“David”和“Pathart”仔细分析后，发现Ets1被ERK1/2在酪氨酸38处磷酸化激活，进而调节以下基因：uPA、MMP-3和催乳素(Ling等人，2003；Duffy和Daggan，2004；Maupas-Schwalm等人，2004；van Themsche等人，2004)。Western blotting分析结果证实，突变型K-ras被激活后，Ets1确实发生了磷酸化。另一方面，膜印迹分析表明，稳定转染突变K-ras基因的人肾上腺皮质细胞uPA、MMP3和PRL的表达水平显著高于正常对照细胞。与对照细胞相比，转基因细胞催乳素水平提高1.4倍，基质金属蛋白酶-3水平提高1.8倍，uPA水平提高2.1倍。根据这项研究的结果，我们提出了Ets1在表达突变K-ras基因的人肾上腺皮质细胞中的作用机制。
In our previous study on the tumorigenesis of human functional adrenal tumors, we observed a high frequency of point mutation in the K-ras gene in clinical adrenal tumors. Therefore, we analyzed gene profiles of mutant K-ras transfected adrenocortical cells by DNA microarray to determine the expression pattern of genes related to cell cycle, signal transduction, apoptosis, tumorigenesis, steroidogenesis, and other expressed sequence tags (ESTs). Then we analyzed all of the significant differentially expressed genes by bioinformatics tools, "Matchminer" and "Gominer." The results revealed that expression of mutant K-ras gene induced by IPTG upregulated Ets1, which was mainly related to cell proliferation. After carefully being analyzed by software "DAVID" and "Pathart," Ets1 was found to be activated by being phosphorylated at theronine 38 by ERK1/2, and in turn, to regulate the following genes: uPA, MMP-3, and prolactin (Ling et al., 2003; Duffy and Daggan, 2004; Maupas-Schwalm et al., 2004; van Themsche et al., 2004). The result of Western blotting analysis confirmed that Ets1 was really phosphorylated when mutant K-ras was activated. On the other hand, the membrane blotting analyses indicated that the expression levels of uPA, MMP-3, and prolactin in human adrenocortical cells stably transfected with the mutant K-ras gene were significantly higher than those in normal control cells. Compared to control cells, the level of prolactin raised 1.4-fold, the level of MMP-3 raised 1.8-fold, and the level of uPA raised 2.1-fold in the transfected cells. From the results of this study, we proposed a mechanism of Ets1 in human adrenocortical cells expressing a mutated K-ras gene.