State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
Phytother Res. 2018 Oct;32(10):2009-2020. doi: 10.1002/ptr.6132. Epub 2018 Jun 28.
Epithelial-mesenchymal transition (EMT) plays important roles in the metastasis of solid tumors. In this study, the effect of toosendanin (TSN), a natural insecticide extracted from Melia toosendan Sieb et Zucc, on transforming growth factor-β1 (TGF-β1)-induced EMT was investigated. EMT was induced by TGF-β1 in A549 and H1975 lung cancer cells. The morphological alterations were observed with a microscopy. The protein expression and localization of EMT biomarkers were determined by Western blotting and immunofluorescence. The migration, invasion, and adhesion were determined by wound-healing, transwell, and adhesion assays. TGF-β1 treatment induced spindle-shaped alterations of cells, upregulation of N-cadherin, Vimentin, p-ERK1/2, and downregulation of E-cadherin. The abilities of migration, invasion, and adhesion were also enhanced. These effects were significantly reversed by TSN at very low concentration (<10 nM). Furthermore, silence Snail significantly reversed TGF-β1-induced EMT biomarkers. In addition, TGF-β1-induced phosphorylation of ERK1/2 without affecting p38 mitogen-activated protein kinases and Jun N-terminal kinase. PD98059 and U0126, inhibitors of ERK1/2, showed similar inhibitory effect to that of TSN. In summary, TSN significantly inhibited TGF-β1-induced EMT and migration, invasion, and adhesion through ERK/Snail pathway in lung cancer cells. This study provides novel anticancer effects and molecular mechanisms for TSN.
上皮-间充质转化 (EMT) 在实体瘤的转移中起着重要作用。在这项研究中，研究了从楝科植物苦楝中提取的天然杀虫剂川楝素 (TSN) 对转化生长因子-β1 (TGF-β1) 诱导的 EMT 的影响。TGF-β1 在 A549 和 H1975 肺癌细胞中诱导 EMT。用显微镜观察形态学改变。通过 Western blot 和免疫荧光法测定 EMT 标志物的蛋白表达和定位。通过划痕愈合、Transwell 和黏附测定测定迁移、侵袭和黏附。TGF-β1 处理诱导细胞纺锤形改变，上调 N-钙黏蛋白、波形蛋白、p-ERK1/2，下调 E-钙黏蛋白。迁移、侵袭和黏附的能力也得到增强。TSN 在非常低的浓度（<10 nM）下显著逆转了这些作用。此外，沉默 Snail 显著逆转了 TGF-β1 诱导的 EMT 标志物。此外，TGF-β1 诱导 ERK1/2 的磷酸化而不影响 p38 丝裂原活化蛋白激酶和 Jun N 末端激酶。ERK1/2 的抑制剂 PD98059 和 U0126 表现出与 TSN 相似的抑制作用。总之，TSN 通过 ERK/Snail 通路显著抑制 TGF-β1 诱导的 EMT 以及肺癌细胞的迁移、侵袭和黏附。这项研究为 TSN 提供了新的抗癌作用和分子机制。
