Guo Yue-hui, Gao Feng-hou, Shi Jing, Yuan Hai-hua, Jiang Bin
Department of Oncology, No. 3 People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201900, China.
Zhonghua Zhong Liu Za Zhi. 2013 Mar;35(3):187-92. doi: 10.3760/cma.j.issn.0253-3766.2013.03.006.
To investigate the relationship between EGFR activation and down-regulation of miRNA-145 in lung cancer.
Normal human lung epithelia cell line (BEAS-2B), human lung adenocarcinoma cell lines with wild-type EGFR (A549 and H292) and human lung adenocarcinoma cell lines with EGFR mutation (H1975 and H1650) were chosen in this study. The levels of miRNA-145 and p-EGFR were determined by quantitative real-time PCR (qRT-PCR) and Western blotting, respectively, and the relationship between p-EGFR and miRNA-145 levels was analyzed. The miRNA-145 levels were determined by qRT-PCR after activating EGFR with EGF or blocking EGFR signal pathway with AG1478. In addition, ERK1/2 inhibitor U0126 was used to inhibit ERK1/2 activation and then the expression of miRNA-145 was detected.
The miRNA-145 levels were closely negatively related with p-EGFR in lung cancer cells (r = -0.926, P = 0.024). EGF down-regulated miRNA-145 expression, particularly in BEAS-2B cells (53.0%; t = 30.993, P = 0.001) and A549 cells (42.6%; t = 14.326, P = 0.005).The miRNA-145 was up-regulated after inhibiting p-EGFR with AG1478, and significantly enhanced by 67.5% in H1975 cells when treated with AG1478 (t = 8.269, P = 0.014). The ERK1/2 signal pathway was activated by p-EGFR. U0126 restored the miRNA-145 down-regulation induced by EGFR-activation in lung cancer cells.
The activation of EGFR down-regulates miRNA-145 expression through ERK1/2 in lung cancer cells.
探讨肺癌中表皮生长因子受体（EGFR）激活与微小RNA-145（miRNA-145）下调之间的关系。
本研究选用正常人肺上皮细胞系（BEAS-2B）、具有野生型EGFR的人肺腺癌细胞系（A549和H292）以及具有EGFR突变的人肺腺癌细胞系（H1975和H1650）。分别采用定量实时聚合酶链反应（qRT-PCR）和蛋白质免疫印迹法检测miRNA-145和磷酸化EGFR（p-EGFR）的水平，并分析p-EGFR与miRNA-145水平之间的关系。在用表皮生长因子（EGF）激活EGFR或用AG1478阻断EGFR信号通路后，通过qRT-PCR检测miRNA-145水平。此外，使用细胞外信号调节激酶1/2（ERK1/2）抑制剂U0126抑制ERK1/2激活，然后检测miRNA-145的表达。
肺癌细胞中miRNA-145水平与p-EGFR密切负相关（r = -0.926，P = 0.024）。EGF下调miRNA-145表达，尤其在BEAS-2B细胞中（53.0%；t = 30.993，P = 0.001）和A549细胞中（42.6%；t = 14.326，P = 0.005）。用AG1478抑制p-EGFR后，miRNA-145上调，在H1975细胞中用AG1478处理后显著增强67.5%（t = 8.269，P = 0.014）。ERK1/2信号通路被p-EGFR激活。U0126恢复了EGFR激活诱导的肺癌细胞中miRNA-145下调。
在肺癌细胞中，EGFR激活通过ERK1/2下调miRNA-145表达。
