Mizutani Hideaki, Okano Tetsuya, Minegishi Yuji, Matsuda Kuniko, Sudoh Junko, Kitamura Kazuhiro, Noro Rintaro, Soeno Chie, Yoshimura Akinobu, Seike Masahiro, Gemma Akihiko
Department of Internal Medicine, Division of Pulmonary Medicine/Infection and Oncology, Nippon Medical School, Tokyo 113-8603, Japan.
Oncol Lett. 2010 Nov;1(6):1011-1016. doi: 10.3892/ol.2010.190. Epub 2010 Sep 23.
Epithelial to mesenchymal transition (EMT) is induced by transforming growth factor-β1 (TGF-β1) and is a crucial event for cancer cells to acquire invasive and metastatic phenotypes. However, the signals that induce EMT in cancer cells have yet to be adequately defined. In this study, a proteomic investigation was performed to understand the signaling pathway of the EMT of lung cancer using two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry. The protein expression profiles of A549 were compared to those of A549 cells treated with TGF-β1. Of more than 2,000 protein spots shown by 2D-DIGE, 53 were found to be up- or down-regulated upon induction with TGF-β1. In the 53 protein spots, the protein level of heat shock protein (HSP) 27 was found to increase significantly. HSP27 protein was higher in two different lung cancer cell lines, demonstrating the EMT phenomenon with TGF-β1. Notably, the silencing of HSP27 enhanced spindle integration, resulting in an additive effect with TGF-β1-induced EMT. Furthermore, the TGF-β1-induced HSP27 increase was not affected by the suppression of Smad2 and Smad3 in A549 cells. These results suggest that HSP27 was involved in TGF-β1-induced EMT in a Smad-independent manner in lung cancer cells and may provide an effective clinical strategy in lung cancer patients whose tumors are dependent on TGF-β1-induced EMT.
上皮-间质转化（EMT）由转化生长因子-β1（TGF-β1）诱导，是癌细胞获得侵袭和转移表型的关键事件。然而，诱导癌细胞发生EMT的信号尚未得到充分明确。在本研究中，利用二维差异凝胶电泳（2D-DIGE）和质谱技术进行了蛋白质组学研究，以了解肺癌EMT的信号通路。将A549细胞的蛋白质表达谱与经TGF-β1处理的A549细胞的蛋白质表达谱进行比较。在2D-DIGE显示的2000多个蛋白质斑点中，发现53个在TGF-β1诱导后上调或下调。在这53个蛋白质斑点中，发现热休克蛋白（HSP）27的蛋白质水平显著增加。HSP27蛋白在两种不同的肺癌细胞系中更高，表明存在TGF-β1诱导的EMT现象。值得注意的是，HSP27的沉默增强了纺锤体整合，导致与TGF-β1诱导的EMT产生累加效应。此外，A549细胞中Smad2和Smad3的抑制并不影响TGF-β1诱导的HSP27增加。这些结果表明，HSP27以Smad非依赖的方式参与肺癌细胞中TGF-β1诱导的EMT，并且可能为肿瘤依赖于TGF-β1诱导的EMT的肺癌患者提供一种有效的临床策略。
